1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.
My Hobby Website:
These archive pages are provided in order to make it easier for you to find items that you remember seeing on the RF Cafe homepage. Of course probably the easiest way to find anything on the website is to use the "Search RF Cafe" box at the top of every page.
Homepage Archive Pages
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USAF Radar Tech
Greg Bucchieri Checks In
Fellow USAF radar tech Greg Bucchieri just checked in with his service information. Greg worked on the one-of-a-kind MPN-17 radar that operated simultaneously on two separate S-band search frequencies in order to reduce ground clutter in the display. Like the MPN-13/14 that I worked on, it had a vacuum-tube-based transmitter and receiver.
Thanks Much to PMI
for Renewing Their Support
Planar Monolithics Industries' organization has been setup to design, develop, manufacture, test, and market complex state-of-the-art hybrid RF MIC and MMIC components, supercomponents, and subsystems. Unique products for applications in space, military, commercial, telecommunications, and consumer electronics systems in the DC- 40 GHz range are their specialty.
PMI Intros 2 to 18 GHz
Low Noise Amplifier
PMI Model No. PE2-30-218-4R0-20-12-SFF-BT is a 2.0 to 18.0 GHz Low Noise Amplifier that has an integrated bias-tee network on the output port. This amplifier provides 30 dB of gain while maintaining a maximum gain flatness of ±2.0 dB max over the operating frequency. The noise figure is less than 4dB and offers an OP1dB of +20 dBm minimum and an OIP3 of +30 dBm typical. The amplifier requires +12 to +15 VDC and the current draw is less than 350 mA.
How to Hire
the Perfect Employee
A picture of human brains is not the way I normally prefer to illustrate a concept, but in this case it works pretty well. Inc magazine columnist Phil Libin, who is a co-founder of Evernote, wrote about a common lament of not just entrepreneurs like himself, but also of big corporation managers - a tendency to micromanage underlings. The article is only one page long so I won't regurgitate everything he wrote other than to say that in the end, the solution is to always hire people that can do the required job better than you can do it yourself. That way you are not always disappointed at performance because you believe you could do the job better yourself if only you had the time. That's great advice. Look at the full-size picture he uses.
February MPD Articles Online
Microwave Product Digest has become my favorite trade magazine because at least for my level of involvement, it seems to have a more consistent selection of practical application articles. That's not to take away from the others; it's just a personal choice. Barry Manz's Military Microwave Digest, also the best in class for its specialty, is an occasional supplement to the monthly mailing of MPD.
Time for an iPad Ban?
It was only a matter of time before someone became a victim of an iPad assault. A story hit the wires this morning about a firefighter in NYC beating his wife in the head with an iPad. "When she tried to escape, he grabbed her by the hair, threw her onto a patio floor and locked the door, according to published reports." So, we have a hostage taken and extreme physical violence, all caused by easy access to a personal electronics device. No doubt the domestic terrorist had large capacity RAM modules installed. Does anyone really need more than 16 GBytes of RAM for sport computing? Only someone with an intent on doing personal harm would need the newest large capacity 128 GByte model. Do iPads imbue owners with a sense of superiority and invincibility who feel powerful when in possession of one? What about iPhones, which are easier to conceal? Why do citizens even need iPads when the Constitution was written and shared with pen and paper? Lawmakers should immediately introduce legislation to ban RAM modules of more than 16 GBytes for iPads and iPhones. Only law enforcement and the military need more.
McWatts Comic Strip
McWatts was an electronics-themed comic that appeared in Popular Electronics back in the late 1957s. Artist Carl Kohler's main character is a stereotypical Joe Sixpack electronics hobbyist who always dreams up unique way to deal with situations. This edition shows McWatts' way of keeping the kids from using his prized tools as toys. I was always leaving my poor father's tools laying around the house and too often in the yard where they would get rained on and start to rust. If I were him, I would have been harder on me for repeat offenses.
Antenna Tuning Solutions
Skyworks Solutions is ramping several antenna tuning products with leading smartphone manufacturers. Skyworks’ devices are meeting the market demand for tunable antennas which dramatically improve performance by increasing data throughput, reducing dropped calls and minimizing the antenna footprint needed for today’s multiband LTE smartphones. Antenna tuning and antenna diversity are both key elements to solving these challenges. Antenna tuning enhances cellular operators’ available spectrum while antenna diversity is an effective means for improving RF transmission performance.
Thanks to Innovative Power
Products (IPP) for Support!
IPP has been designing and manufacturing RF passive components for more than 25 years for all aspects of commercial and military applications. Their couplers, combiners, RF resistors, and terminations incorporate the latest technology in materials available, which equates to unrivaled product performance. An ISO-registered quality system assures customers of a reliable supply of components for their applications. Contact a design engineer today for special requirements.
Why Key Clicks?
Waveform shaping is essential in today's crowded communications spectrum. Spectral masks are precisely defined in order to prevent "spreading" beyond the allocated frequency ranges at defined power levels. Whenever anything other than a continuous sinewave is being broadcast, there is spectral content generated in addition to the fundamental frequency. A Fourier transform of the waveform reveals which frequencies at what power levels comprise the waveform. The CW (continuous wave) signal used by Morse code operators is a pure sinewave (or nearly so), but there is a spectral problem with it every time the signal turns on or off because of the square-ish edges involved during switching. RC networks are used in the transmitter circuits to tame the edges so that they do not turn on and off so quickly and in doing so reduce the extraneous frequency content. Author George Grammer argues that even though the signal could theoretically be made 'clickless' (aka "chirpless'), there is an auditory benefit to the clicks or chirps that aids operators listening to high speed code transmissions.
AWR Sponsors and Exhibits
at EDICON 2013 - Many Papers
AWR is a gold sponsor at the Electronic Design Innovations Conference ( EDICON) 2013, which runs from March 12 -14 in Beijing, China. Together with parent company National Instruments, AWR will be showcasing at Booth #255 joint hardware/software solutions, as well as the first update in 2013 of the AWR Design Environment™, inclusive of Microwave Office®/Analog Office® circuit design software, Visual System Simulator™ (VSS) system design software, as well as AXIEM® 3D planar electromagnetic (EM) software and Analyst™ 3D finite element method (FEM) EM software.
Skyworks Captures Initial
SkyOne™ Design Wins
Skyworks Solutions today announced that several leading OEMs and smartphone providers are leveraging the company’s highly customizable, fully optimized SkyOne™ front-end solution. The SkyOne™ platform, which integrates all RF and analog content between the transceiver and antenna, reduces complexity, size and time-to-market for customers with demanding architectures for advanced mobile applications. Utilizing Skyworks’ full technology portfolio and advanced multichip module capabilities including proprietary shielding and packaging, SkyOne™ is the world’s first semiconductor device to condense multiband power amplifiers and high throw switches along with all associated filtering, duplexing and control functionality into a single, ultra-compact package.
A Passive Audio Amplifier
for Your iPhone or iPad
Christopher Locke has taken a low tech approach to making amplifiers for your iPhone and iPad. Rather than build an electronic contraption out of electrical components and speakers that requires a power source, he 'repurposes' discarded brass musical instruments for the task - ingenuous, I must say. Valves and levers are removed and a fancy metal cradle is attached to the reed port in a manner that positions the mobile device's speaker directly over the instrument's air intake. Videos are provided demonstrating the significant amplification afforded by the arrangement. It's hard to tell whether the full audio range is amplified sufficiently or if only those frequencies within the normal playing range are affected. Regardless, these functional sculptures would make a great conversation piece or even a gift for a musician friend.
Foil Those Tube Forgers
Gray market electronic components are not just a recent problem. Long before IC foundries were set up in China, Indonesia, Vietnam, etc., to produce counterfeit semiconductor components, there were unscrupulous manufacturers turning out bogus components of all sorts. Marking unauthorized microprocessor and amplifier packages with an industry-leading brand name and part number is a real problem, but such practices extend back to the vacuum tube era. This story from a 1957 edition of Popular Electronics tells the story of how companies like General Electric and Sylvania dealt with the situation.
A Review of Transmission
Lines as Circuit Elements
Mr. Wilfred Jensby wrote an incredibly detailed article for the November 1966 edition of QST that delves deeply into the subject of using transmission lines as distributed circuit elements. I did a search on his name, figuring that he likely had other publications of like sort, but nothing was found. Information contained herein is similar to what you would expect to find in a Master's level engineering course textbook or in a $100+ technical book from Artech House, Cambridge University Press, John Wiley & Sons, etc. The brain-zapping equations are omitted with only a great, layman-level discussion of the concepts and some really nice illustrations and graphs. This is definitely an article you will want to check out and pass on to colleagues.
The Global Innovation
INSEAD, "The Business School for the World," located in France, has just released its 5th annual publication of The Global Innovation Index 2012. The study analyzes a country's ability to foster invention and innovation. For the second year in a row, Switzerland lead in overall innovation performance. The U.S. squeaked into last place within the top 10, with even Ireland (no disrespect meant to the Emerald Isle) squarely whooping us. Canada came in at #12. Of EUR (European) countries Switzerland leads at #1, the U.S. leads NA (N. America - real difficult) at #10, Israel tops the NAWA (North Africa-West Asia) region at #17, Singapore (#3) leads SEAO (South East Asia Outlook), Chile (#39) tops the LCN (Latin America and the Caribbean) region, and India, #64, rules CSA (Central and Southern Asia). As usual, I blame the pathetic politicians for utterly destroying the country's ability to create and produce. Their overbearing regulations, obsession with 'diversity,' social engineering, national self-flagellation, and pandering to leeches is killing us.
RFMD Expands Leadership
in RF Power Management
RF Micro Devices today announced the addition of multiple new products to RFMD's industry-leading portfolio of envelope tracking (ET) power management and power amplifier (PA) solutions. RFMD's ET-based solutions leverage the Company's leadership in RF power management and cellular PAs to improve system-level efficiency in high-data rate applications. The new RF solutions — the RF7389, RF7390, RF7459, RF8081, and RF8085 — comprise ET PMICs, ET multimode multi-band (MMMB) PAs, and ET ultra-high efficiency PAs. RFMD's expanding ET product portfolio is compatible with the leading LTE chipsets and provides full ET compatible coverage of all FD-LTE and TD-LTE bands.
Analog Devices' ADSimRF v1.7
Analog Devices just announced the release of the latest version of their ADISimRF applet for calculating cascaded RF component parameters. It takes typical input values for up to 15 stages and returns typical cascaded values at the output. As I do with any such program, I compared its results with those of my RF Cascade Workbook (RFCW) spreadsheet. The numbers agree as expected since both use pretty much the same set of well-established textbook formulas. One difference in the two programs is that ADISimRF appears to use the standard IP3 (3rd-order intercept point) cascade formula for calculating P1dB (1 dB compression point), whereas RFCW uses Psat (saturated power) instead since the P1dB formula is only an approximation of widely varying nonlinear response and might lead to a false sense of security. RFCW's Psat calculated values simply test what the output power level for a device would be
Amateur Radio Quiz: Book ’Em!
Ham or not, this amateur radio quiz will provide a nice break from the workaday routine and might even challenge you a bit. Sez the ARRL: "The great tradition of self-learning and mutual education is alive and well at the outset of Amateur Radio’s second century. The success of that tradition leans heavily on the books -- and now websites -- of amateurs willing to share their radio know-how with others. This month’s quiz touches on publications from yesterday and today, in honor of the many authors from whom we learn."
E- Discovery: 10 Strategic
Steps for Defensible Search
Every once in a while I receive an e-mail from someone wanting advice on how to conduct a patent search to determine whether his idea has already been registered. Many people are sorely disappointed to learn after putting a lot of work into what is truly an original idea for them only to discover later that a patent has already been issued for the concept. The U.S. Patent and Trademark Office (USPTO) has some pretty good tools for research (see "How to Conduct a Preliminary U.S. Patent Search"), but in order to be successful you really need to have a proven, methodical strategy for using those tools. Simply entering a few keywords rarely - if ever- results in a sufficient effort. Mr. Tino Kyprianou, guest author for IMS ExpertServices, has written an article titled, "E- Discovery: 10 Strategic Steps for Defensible Search" that provides some advice on how to proceed.
February's RF Magazine
Articles Now Available
Most of February's magazine articles are now available online for the RF industry. Here are a few that look most interesting to me.
Please visit Dong Jin TI in Appreciation of Their Support
Dong Jin Technology Innovations is a premier manufacturer of RF Connectors, Cable Assemblies and Components. They are highly recognized as an RF industry leader in Korea. Dong Jin TI's premium products offer a competitive price, on-time delivery and best quality in the industry with No Minimum Order and One Day Delivery. Equivalent product suggestions with drawings and speciation available to replace existing items. VSWR reports available on request.
Science & Engineering
Crossword for Feb. 24, 2013
Every Sunday I create an engineering-themed crossword puzzle using a word list that I personally created and added to during over a decade of making puzzles. All of the words are related to engineering, science, mathematics, chemistry, astronomy, etc. There are no numbnut clues about movie stars or clothing designers. Enjoy.
Hi-Fi: The Guest
This series of comics describing the kinds of reactions you might expect to receive from various people who are visiting your crib and are introduced to your new stereo setup. Done in a 1959 edition of Popular Electronics, the scenarios still hold true today, only now you can extend the equipment type to include your gaming computer and wide screen television, and add to the distractions the guy who is dividing his attention between you and his smartphone. It's too bad you don't see this kind of stuff in newer publications.
Sherlock Ohms: Case of the
Sherlock Ohms is a regular feature of Design News that presents submissions from readers about troubleshooting challenges and how they were solved. This story titled "The Subcontractor Zapped the Network" addresses the dangers an unbalanced 3-phase load can cause when the neutral is improperly terminated. As an electrician many, many moons ago, I encountered this scenario a couple times during trouble calls to industrial locations. Also demonstrated is the all-too-common problem of having mindless drones on staff.
How the Slinky Buckles:
Mathematicians have a need to express every aspect of nature in terms of an equation. That's a good thing... if not a bit obsessive. The March 2013 edition of SciAm has an article about "overcurved rings" such as those in a flat spiral spring; e.g., a Slinky. If you cut a full rotation of a Slinky (360°) and join the ends, you find that it does not lay flat due to overcurvature, but instead it assumes a saddle shape. Another familiar example of an overcurved ring is found in a pop-up tent. Interestingly, the author describes a method for folding an overcurved ring into a set of three concentric rings that will lay flat. I immediately recognized it as the method used to package large bandsaw blades, fan belts, etc. It can take a bit of noodling to figure out how to get the ring into that configuration if you don't have instructions. The video below is one I made a while back demonstrating how to fold a bandsaw blade.
RF Microelectronics, 2nd Edition, by Behzad Razavi. Wireless communication has become almost as ubiquitous as electricity, but RF design continues to challenge engineers and researchers. In the 15 years since the first edition of this classic text, the demand for higher performance has led to an explosive growth of RF design techniques. In RF Microelectronics, 2nd Edition, Behzad Razavi systematically teaches the fundamentals as well as the state-of-the-art developments in the analysis and design of RF circuits and transceivers. The 2nd edition to reflects today’s RF microelectronics, covering key topics in far greater detail. At nearly 3x the length of the first edition, the 2nd edition is an indispensable tome for both students and practicing engineers.
Please Visit Baytems
in Appreciation of Support
Baytems designs and manufactures electronic instruments and systems geared to the specialized needs of electronics manufacturers for product testing, product development and research. Their product line includes ESD Simulator/Testers, Broadband Amplifiers, MIL-STD-1553 Interface Cards, and Line Impedance Stabilization Networks. Commercial, aerospace, defense industries served.
Popular Electronics Builds
a Vacuum-Tube Voltmeter
RF Cafe visitor Terry W. recently wrote to me about a topic that ended up mentioning RCA's vacuum tube voltmeter (VTVM) known as the VoltOhmyst. VTVMs were the era's high-input-impedance multimeter, before field effect transistors (FETs) came on the scene. The higher a meter's input impedance, the less it loads the circuit under test. Any meter connected across a circuit appears as a parallel load to the source, so the closer it is to an open circuit, the better. Terry mentioned how the VoltOhmyst was a key component on test benches of many professionals. You can still buy various models of the VoltOhmyst on eBay.
Inline Clock Uses
Here is a different type of digital clock that uses a single digit to read out the time serially; i.e., if it the new time is 3:51, the clock first displays a 3, then a second or so later displays a 5, then finally a 1. Obviously it cannot update the time every second, but that is not what this kind of timepiece is meant for. It is purely a conversation piece. What makes this clock, designed and built by David Christianson, is its electromechanical incandescent display. "The displays make use of a small piece of film and 12 lens systems to project whatever of 12 images you want to provide." Reportedly, this method was devised in the 1960s and was very expensive even back then - about $100 per digit. No info is provided about the exact display used, but it seems any 7-segment display type can be adapted, even a cheap LED.
Pasternack Intros Line of SMP
& SMPM Adapters up to 65 GHz
Pasternack Enterprises' SMP and Mini-SMP, also known as SMPM, are coaxial adapters capable of converting multiple connector types including SMP, Mini SMP, SMA, 2.92mm, 2.4mm, 3.5mm and 1.85mm connectors. Frequency ratings for these SMP and SMPM microwave adapters range from 18 GHz to 65 GHz depending on type and style. These new higher frequency SMP and Mini-SMP versions are compatible and fully mate-able with Corning Gilbert GPO™ and GPPO™ connectors. Pasternack’s new lines of SMP adapters and SMPM adapters utilize passivated stainless steel construction and Beryllium copper (BeCu) designs for the SMP female connectors.
IEEEIEEE JobSite Career Alerts
"Reasonable men adapt themselves to the world; unreasonable ones don't - therefore all progress comes from unreasonable men." – George Bernard Shaw as paraphrased by Eli Broad in Inc. BTW, GBS, a widely lauded author, also said, "Assassination is the extreme form of censorship," yet he was an extreme Fabian Socialist who condoned the extermination of what he considered useless humans "in a kindly manner" (video).
Engineer Needed by TRU
TRU Corporation has announced an opening for an RF/Interconnect Design Engineer. As directed by engineering management, this position is primarily responsible for product design and development for customer funded programs and new product research and development. In addition, provides direct support to business development functions as well as operations on existing products.
PMI Intros 4 to 8 GHz
Low Noise Amplifier
PMI Model No. PEC2-60-4G8G-1R75-14-12-SFF is a 4.0 GHz to 8.0 GHz low noise amplifier that typically provides 60 dB of gain. The gain flatness is ±1.25 dB maximum with a noise figure is 1.75 dB maximum. This amplifier provides a minimum OP1dB of +14 dBm. The VSWR is 2.0:1 maximum into 50 ohms impedance and operates on a single DC supply of +12 to +15 volts with 350 mA nominal current consumption. This unit is supplied with field removable SMA female connectors and in our standard PEC2 housing that measures 2.98" x 0.78" x 0.26".
AWR App Note for
A new application note, “Using Analyst™ To Quickly And Accurately Optimize A Chip-Module-Board Transition,” highlights the unique features of AWR’s 3D finite element method (FEM) EM simulator by demonstrating the optimization of the transition from a board-to-chip signal path. The example shows how the ability to access Analyst seamlessly from within the Microwave Ofﬁce® environment saves time by eliminating not only the need for the design to be drawn and/or redrawn, but also provide ready access to additional and powerful features of a circuit design tool such as tuning and optimization.
Your iPad is the App in This
Foosball Game Table
With this miniature foosball game, your iPad is the app relative to the physical table frame that it snaps into. Sensors built into the eight familiar control handles send position and rotation information to the iPad's interface connector, which the foosball software app running on the iPad uses to simulate action on a real table. Sensor technology has made major advances in the last decade. Buy Classic Match Foosball on Amazon for $99 w/free shipping. I used to think $99 was a lot to spend on frivolities, but last week commercials were running for $99 Valentine's Day teddy bears, so evidently my perceptions are outdated. The company also has a slot machine for plugging your iPod into.
Beware the Patent Trolls
Nonpracticing entities (NPEs), aka patent trolls, think they're getting a bum rap. Those companies that buy up patents and then search to the ends of the Earth for potential cases of infringement say they are only protecting the original inventors' right to an exclusive claim to innovation, even though the inventor is no longer involved. An article by Kris Frieswick in the February 2013 edition of Inc demonstrates otherwise. Frieswick takes the unusually brave step of naming names of the industry's most notorious abusers. According to his research the practice cost industry $29B in 2011. Typically, a troll serves the accused with a notice of infringement along with proposed settlement terms which could be a license fee or purchase of the patent. Neither comes cheap. Software, the biggest target, comprises 74% of all cases even though it represents only 12% of total patents. 90% of the abused surrender without a challenge and settle out of court. Trolls count on that. Rarely does anyone threaten to sue a troll, so the business is pretty lucrative with low risk. The best defense thus far has been to prove existence of "prior art" on file with the Patent Office that invalidates the troll's patent. They usually retreat back under the bridge upon presentation of that evidence. Here are some related patent articles on Inc.
Thanks, Applied Computational
Sciences, for Support
ACS designs, develops and sells Electronic Design Automation (EDA) software tools for RF and microwave engineering applications. ACS's main product is the LINC2 linear circuit simulator and RF Tools products. LINC2 runs on versions of MS Windows for the PC and compatibles, and is a lower cost alternative to the high-end design and simulation tools. Visual System Architect, Filter Pro, Amp Pro, Match, TLine, RF Calculato, and De-embed are among the available modules.
Electronic News Circa 1958
There was a time when "Pong" was a must-play breakthrough bit of futuristic technology with people waiting in line to give it a try, but now nobody would invest a quarter to play it in an arcade. Similarly, believe it or not, people were mesmerized when listening to the series of "beeps" coming from Sputnik I satellite during its short life circling the Earth. This item from a 1958 edition of Popular Electronics shows high school students listening intently to a tape of Sputnik's broadcast. The same "Electronic News" page reported on the availability of a special record with calibrated sounds for helping to calibrate and troubleshoot hi-fi systems, and also a new low-wattage public address speaker system installed at Yankee Stadium that needed only 6½ watts per speaker.
Please Welcome "Analyzer
Repair" as a New Sponsor
BRL Test, who has been an advertiser on RF Cafe since 2010, is now promoting separately their Analyzer Repair website. "We absolutely know analyzer repair." BRL Test's in-house Repair Engineering Group promises low pricing, experienced metrology technicians (15 years on average) that includes military PMEL graduates, and parts for repair in stock to guarantee fast turnaround. Popular spectrum and network analyzers from Agilent, R&S, Anritsu, HP, and Avantest are among their specialties.
to Nicolaus Copernicus
Google's homepage today has an animated tribute to Nicolaus Copernicus on this 540th anniversary of his birthday. Only the planets know to exist in Copernicus's day (out to Jupiter) are shown orbiting the sun, plus our moon is orbiting Earth. Galileo had not yet discovered the large large moons of Jupiter nor had Christiaan Huygens found Saturn's largest moon, Titan. Right-click in an empty place on the screen and select View Source to see the immense amount of code used to generate that animation (turn word wrap on).
UFO Landing Site Markers?
This evidently buzz-worthy item du jour hit the news wires in the last couple days. There are many people who's hobby is scanning every square inch of terra firma as imaged from space by Google Earth and Street View cameras. I could not find an official organization they can belong to, but most would not want to be identified anyway lest the black helicopters swoop in to snatch them in the middle of the night. Like the mysterious patterns that were spotted in the Gobi Desert last year, these black and white patterns show up at U.S. military installations and various other locations. Reportedly, they were constructed as long ago as the 1950s for calibrating cameras in high-altitude spy aircraft like the SR-71 Blackbird and the U-2 Dragon Lady (not Bono's group). The Center for Land Use Interpretation has a collection of aerial images of the bar codes and some from-the-ground images. For other interesting images, try the Google Earth Cool Places website, where people continuously upload new sightings.
AWR App Note for End-to-End
Design of X-band Analyzer
AWR has just published a new Microwave Office® software application note titled, “End-to-end Design and Realization of an X-band Transmission Analyzer Using AWR Circuit, System, and EM Software.” The note examines the complete flow and details the design of several critical design elements for this device, which integrates many RF components on a single printed circuit board (PCB). Design challenges include coupling issues between the RX and TX paths, as well as numerous distributed elements that required EM simulator-based tuning for optimal performance.
Grounding, Shielding, Guarding
in High-Impedance Applications
There is an article on the EDN website that does a quick review of "Understanding Grounding, Shielding, and Guarding in High-Impedance Applications," written by James Niemann. It covers topics like electrostatic coupling, RF coupling, shielding, safety grounding, and more.
Telemetering - Vital Link
to the Stars
Telemetering - the remote sensing and reporting of system parameters via radio link - was just coming of age in the late 1950s when this article appeared in Popular Electronics. It was the age of space payload rocket development (as opposed to artillery and fireworks rockets), high speed jet airliners, and the Pioneer 1 space probe. There was a great need to collect data during the developmental and operational engineering project stages in order to ascertain causes for failures when they occurred and to know what went right when success triumphed. A pinnacle of the newborn telemetering era was Pioneer 1, which carried an image scanning infrared television system to study the Moon's surface to a resolution of 0.5 degrees, an ionization chamber to measure radiation in space, a diaphragm/microphone assembly to detect micrometeorites, a spin-coil magnetometer to measure magnetic fields to...
10th Military Antennas Show
Be sure to sign up early and make your hotel registration now for Military Antennas West 2013, being held April 22 - 24, 2013 at the Hilton San Diego Resort & Spa, San Diego, California. Attendees of IDGA's Military Antennas (West) Summit will have the first look at up-and-coming technologies and programs, as well as revamped initiatives , including, but not limited to, electrically small antennas, conformal wideband antennas, RF distribution systems, integrated circuits, the Phoenix project, and much more.
Hittite Intros Groundbreaking
Hittite Microwave has introduced a complete Multi-GHz Quantizer chip set that enables quantization of ultra wideband signals from DC to 18 GHz with excellent linearity and low noise. This groundbreaking Multi-GHz Quantizer solution can facilitate unparalleled levels of performance in test and measurement systems, Bit Error Rate Testers (BERTs), and Pulse Detection Systems including Pulse Doppler Radars where wideband sampling capability is a necessity. This combination of ADC and T/H delivers high linearity of >50 dB SFDR up to 7 GHz and low noise of >40 dB SNR up to 9 GHz at 1 Vp-p full scale level.
Science & Engineering
Crossword for Feb. 17, 2013
Every Sunday I create a crossword puzzle using a word list that I personally created and added to during over a decade of making puzzles. All of the words are related to engineering, science, mathematics, chemistry, astronomy, etc. There are no numbnut clues about movie stars or clothing designers. Enjoy.
PMI Intros 500 MHz to 6 GHz
Low Noise Amplifier
PMI Model number PE2-30-0R56R0-5R0-22-12-SFF is a 500 MHz to 6.0 GHz low noise amplifier that typically provides 30 dB of gain. The gain flatness is ±1.0 dB maximum with a noise figure is 5.0 dB typical. This amplifier provides a minimum OP1dB of +21 dBm. The VSWR is 2.0:1 maximum into 50 ohms impedance and operates on a single DC supply of +12 to +15 volts with 325 mA nominal current consumption. This unit is supplied with field removable SMA female connectors and in our standard PE2 housing that measures 1.08" x 0.71" x 0.29".
Thanks to KR Electronics for
Their Long-Time Presence
For over 35 years KR Electronics has designed and manufactured high quality filters for the commercial and military markets. KR Electronics manufactures all filter types (LC, active, lowpass, highpass, bandpass, bandstop, etc.) and individually synthesizes filters for special applications. State of the art computer synthesis, analysis and test methods are used to meet the most challenging specifications.
IEEE-USA Job Resources
"IEEE-USA has been one of the loudest critics in Washington of the H-1B program for more than a decade... Companies have far more control over H-1B workers than they would over an American, creating a powerful economic incentive for companies to hire an H-1B worker instead of an American. This is legal under the H-1B program... The H-1B is tailor made for outsourcers because the visas are totally controlled by companies and H-1B workers can't easily quit... In 2011, over 50% of all authorized H-1Bs in several states went to outsourcing companies."
Silicon-Based RF Front-Ends for Ultra Wideband Radios, by Aminghasem Safarian and Payam Heydari, comprehensively studies silicon-based distributed architectures in wideband circuits. The book begins with an introduction of several transceiver architectures for UWB. The discussion then focuses on RF front-end of the UWB radio. First, the design and analysis of a performance-optimized CMOS distributed LNA is presented. This is followed by design of novel distributed RF front-ends for UWB IF-receivers (UWB-DRF). The book continues with the introduction of a novel distributed direct conversion RF front-end (DDC-RF).
60 GHz Transceiver Products
Hittite Microwave has launched a new, highly integrated HMC6000LP711E / HMC6001LP711E Antenna-in-Package (AiP) Silicon Transceiver Chipset Solution, which is fabricated with silicon germanium (SiGe) BiCMOS semiconductor process technology and targets 60 GHz applications such as short range Gbps data links, wireless sensors and test applications. The HMC6000LP711E AiP solution combines a 60 GHz antenna with the HMC6000 transmitter IC while the HMC6001LP711E AiP solution combines a 60 GHz antenna with the HMC6001 receiver IC. Both transceivers are available in 7 x 11 mm QFN plastic packages which support low cost surface mount PCB assembly and require no experience in handling millimeterwave devices.
500 Injured in Meteor Strike
An epic event occurred in Russia last night. A huge meteor passed through the atmosphere over the Russian city of Chelyabinsk, setting off a shock wave with a force great enough to shatter windows and injure nearly 500 people. Any living Siberian that might remember the Tunguska event over Siberia in 1908 must have had a wicked flashback. There is a good possibility it was a chunk of space rock associated with asteroid 2012 DA14, due to fly by today this afternoon. There could be more to come. Earth is a hard hat area today.
Please Visit Amplifier Solutions
in Appreciation of Support
Amplifier Solutions Corporation (ASC) is a designer and manufacturer of RF & Microwave hybrid amplifiers for the military and commercial markets. ASC's thick film hybrids utilize GaAs FET, silicon bipolar transistor and MMIC technologies to achieve low to medium power output in the 300 kHz to 6 GHz frequency band. Their amplifier specialties include Low Noise, Wideband, High Power, Low Distortion, General Purpose, CATV (50 & 75 Ω versions), and GaN.
The 'Almighty' Federal Circuit?
Patent Policy & Jurisprudence
Expert witnesses play a big role in most of the court cases that get reported here. IMS ExpertServices is a law firm specializing in expert witnesses. Every month or so they send me an article about specific court cases that could be of interest to RF Cafe visitors. This article is entitled The 'Almighty' Federal Circuit? Evolving Patent Policy & Jurisprudence, and asks, in only a slightly rhetorically manner, the question: "Has the importance of the patent system on the U.S. economy propelled the Federal Circuit to be, de facto, the most powerful court of the land?" Author Maggie Tamburro, JD, points out that the U.S. Court of Appeals for the Federal Circuit was established in 1982 under Article III of the U.S. Constitution (which, perhaps not coincidently, also addresses acts of treason). Reportedly, a whopping 34% of the 2010 GDP derived from IP-related industries. That's an amazing statistic. You will find a lot of interesting tidbits like this in the article.
AWR Whitepaper on RF System
Software for Wireless RF Links
Understanding and correctly predicting cellular, radar, or satellite RF link performance early in the design cycle has become a key element in product success. The requirements of today’s complex, high performance wireless devices are driving designers to assess critical measurements long before manufacturing begins. A new white paper from AWR, "Understanding and Correctly Predicting Critical Metrics for Wireless RF Links," highlights the advantages of using Visual System Simulator™ (VSS) RF system simulation software for detailed insight into the full performance of an RF link in next- generation wireless products.
"You know what they say: Applied physicists are from Venus; Theoretical physicists wonder why it spins in the other direction." - Dr. Larry Fleinhardt, from NUMB3RS "Sacrifice" episode
RF Cafe Makes the Top 100
Engineering Websites List
RF Cafe is in the news again. This note was received yesterday: "I'm contacting you because RF Cafe is featured on the list of 100 Top Resources for Electrical Engineers that we published today on ElectricalEngineeringSchools.org Our readership is mostly composed of aspiring students of electrical engineering. We compiled this list to show them the best in projects, companies, and general engineering advice. Your site has great articles for someone whose goal is to study electrical engineering!" Look waaaaaay down near the bottom at #33 (out of 34) in the "Engineering" section to find RF Cafe. Evidently, I have a lot of work to do ;-)
The concept of a field effect transistor (FET) has been around in theory for a long time*, but manufacturable devices arrived in designers' labs not until the early 1960s. This article from the October 1966 edition of QST magazine gives a good introduction to the physics of a basic FET as well as the junction FET (JFET) and the insulated gate FET (IGFET), all of which are still in widespread use today. What you learn about them here is applicable today. In fact, I swear some of the drawings are the same ones that appeared in my college semiconductor physics text books (admittedly from the late 1980s, so not too much of a surprise).
Yagi vs. Quad
Here is a story of one Ham's experience in determining how the performance of his Yagi antenna compared to his identically configured (number of elements, height off of the ground, etc.) cubical quad antenna. His location was a farm field in Tennessee, back in the mid 1960s, so there was really not much in the way of obstacles to perturb signals arriving at one antenna versus the other, except of course when the direction of operation happened to have the antennas in line with each other. Both antennas were tuned for optimal performance at 14.22 MHz, which is in the high frequency (HF) band.
Replaces Holtek® Products
The new DS Series Encoder/Decoder IC from Linx makes it simple to add a robust serial protocol with the ease of DIP switch addressing. The DS lets users set up to 1,022 unique addresses for reliable communication between devices, similar to older Holtek® products, but with a stable serial protocol. Testing shows greater than 2x range increase in reliable, stable communication over the Holtek® protocol, with the DS Series device in serial protocol mode. The market exit by Holtek® from the DIP switch device market has left many customers in a lurch – Linx is here to help you out.
VE2EK-9Q1EK Ham Shack
A Homebrewer's Paradise
Georges Schleger, United Nations Director of Snr Broadcast Technologies in 9Q (Democratic Republic of Congo), has quite an impressive homebrew setup that you will want to see. His equipment assemblies remind me a lot of the many prototype builds I've done over the years for various systems for radars, satellite earth stations, and land radio systems. If you're a builder at heart, you will appreciate Georges' handiwork. Few things beat the satisfaction of connecting a bunch of filters, amplifiers, attenuators, couplers, and cables together and then making measurements to test your predictions.
RF CAD Drafter Needed
by SEA COM CORP
SEA COM CORP, a manufacturer of marine and land mobile communications equipment, has an opening for an RF CAD drafter on a contract basis. PADS and Altium experience required. RF experience necessary. Request occasional visits to the factory. Immediate work available for long term projects. Self-employed Contractor desired.
Thanks for Putting RF Cafe
in LinkedIn's Top 10%
This notice from LinkedIn came in my e-mail this morning. According to it, RF Cafe's LinkedIn profile is in the top 10% viewed in2012. Thanks to everyone who has viewed it. It's nice to be up that high in the ranking, but being in the top 10% of 200 million members means being in the company of 20 million others. The U.S. Census Bureau estimates there are 7.1 billion people in the world today (includes every man, woman, and child), so that works out to 1 of every 350 people in the world being in LinkedIn's top 10%. While not particularly impressive from that perspective, as compared to my home state of Pennsylvania's population of 13 million, it makes RF Cafe unique! This is a good illustration of how statistics can be manipulated to draw false conclusions.
Hittite PLL with Integrated
VCO for MIMO Architectures
Hittite Microwave has launched the HMC835LP6GE, a wideband fractional-N PLL with integrated VCO that generates continuous fractional frequencies between 33 MHz and 4100 MHz. Targeted at the cellular infrastructure market, the HMC835LP6GE features industry leading PLL & VCO phase noise performance with a PLL figure of merit of -230 dBc/Hz in integer mode, and -227 dBc/Hz in fractional mode, and typical VCO phase noise of -134 dBc/Hz at 4 GHz output frequency and 1 MHz offset. Along with industry leading phase noise performance, the HMC835LP6GE includes advanced features demanded by modern LTE MIMO radio architectures.
An Amateur Application
of Modern Filter Design
The term "modern" in the title of any book or article never has set right with me because it is utterly ambiguous about the era to which "modern" refers. Sure, it sounds good at the time, but when applied to this 1966 QST article, "modern" should be replaced with "four-decade-old." However, in this case the content is still relevant even thought it was written so long ago (or else I would not be reproducing it here). It may well have been most people's first exposure to elliptical (Cauer) filters. As you might expect, the rigorous, headache-inducing mathematics is omitted, but the article does give an example of implementing an audio frequency bandpass filter by cascading a lowpass filter and a highpass filter. If you are familiar with filter design, you know that because of phasing and inband impedance mismatch issues you cannot simply butt the two together to yield an equivalent bandpass filter. In fact, the author found it necessary to insert a 13 dB attenuator between them in order to get acceptable performance.
Tutorial for Conducting
a Patent Search
While conducting a patent application search for the nCap Technology product which was posted just a few moments ago, it occurred to me that a lot of people have never searched for a patent. If you have an idea you believe needs to be protected by a patent, one of the first things you need to do is determine whether your invention has already been claimed. Another scenario that necessitates a patent search is when designing a new product to make sure a patent holder cannot file a n infringement claim against you, and then sue to either prevent its use altogether or to require a royalty payment (you have no control over the $$$ amount). I know an engineer whose company is essentially being held hostage to the tune of several hundreds of dollars per unit shipped because of just such an infringement claim. The USPTO has a well-done video tutorial for first-time patent investigators.. You could potentially save yourself a lot of grief by learning to do patent searches.
PMI Intros 700 to 1300 MHz
Successive Detection LVA
Model SDLVA-0R71R3-75-CD-1 is a Successive Detection Log Video Amplifier that operates over the 700 to 1300 MHz frequency range. This model has a Dynamic Range of 75 dB, a log slope of 40 mV/dB and a nominal video bandwidth of 20 MHz. The log linearity is ±1.2 dB typical from -65 to +5 dBm input power levels and a typical TSS of -70 dBm. The limited IF Output is +5 dBm typical. This model offers very fast rise times of 9nsec and fall times of 25 nsec typically. Other frequency ranges available.
Spray WiFi Hot Spots
Let me check the calendar. Nope, it's not April 1st. This item on Wired magazine's website reports a spray-on antenna product that, according to inventor Chamtech Enterprises, works near miracles on almost any antenna within its operational frequency (no details at this point). Tests have been conducted at 50 MHz (underwater communications) 100 MHz (aircraft VHF), 2 GHz (iPhone), and 2-5 GHz (microwave RFID tag). What is so magic about the spray? Per a recent press release, "Chamtech's patented nCap Technology is a breakthrough in antenna technology, replacing or enhancing traditional antennas to improve signal range, data rate, and battery life of devices relying upon antenna technology." This appears to be the patent application: Techniques for Conductive Particle Based Material Used for at Least One of Propagation, Emission and Absorption of Electromagnetic Radiation, 20120146855.
Nortec RF Launches RF/μwave
Line for Wireless and Military
Nortec RF has launched its new RF and Microwave line of products serving the wireless and military needs. Some of the newly introduced products are the high power, broadband 0.7-2.7 GHz, and 0.8-2.2 GHz, 75 W mismatch tolerant power combiners. These combiners can withstand 180 degree phase mismatch and 0 to full power mismatch at the input ports. Nortec also introduced the newly designed high power bandpass filter, 0.8-2.2 GHz, with maximum insertion loss of 1.0 dB in the pass band and at least 20 dB rejection up to 11 GHz. Other new products developed by Nortec are 8W, general purpose amplifiers spanning 60-500 MHz and directional and hybrid couplers up to 3 GHz and up to 200 W power handling capability.
Hittite's Low Power 8-Bit
450/900 MSPS ADC's Best SNR
Hittite Microwave has introduced the HMCAD1512, a 2/1 channel 8-bit ADC sampling at 450/900 MSPS. The HMCAD1512 is ideal for point-to-point microwave links and digital oscilloscopes. The HMCAD1512 contains two ADCs that can be interleaved by the user to act as a single channel or two channels. At full speed operation, the HMCAD1512 delivers an SNR of 49 dBFS when applied with an input signal of 170 MHz. Total power dissipation at full speed operation is only 650 mW, including I/O. This performance to power ratio makes the part a perfect choice for low power high performance devices, including handheld and portable test equipment.
PMI Intros 20 to 40 GHz
Low Noise Amplifier
PMI Model No. PE2-28-20R040R0-5R5-18-12-SFF is a 20 GHz to 40 GHz low noise amplifier that typically provides 28dB of gain. The gain flatness is ±2.5 dB maximum and ±1.5 dB typical with a noise figure is 5.5 dB typical. This amplifier provides a minimum OP1dB of +15 dBm minimum. The VSWR is 2.3:1 into 50 ohms impedance and operates on a single DC supply of +12 to +15 volts with 350 mA nominal current consumption.
Thanks to MECA Electronics
for Their Long-Time Support!
Since 1961, MECA has designed and manufactured an extensive line of RF/Microwave components with industry leading performance including Fixed Attenuators, Directional & Hybrid Couplers, Isolators/Circulators, Power Divider/Combiners, RF Loads, DC Blocks, Bias Tees and Adapters & Cables. MECA serves all areas of the RF and Microwave industries including world class network providers and supporting supply chain infrastructure, and has long been the “backbone” of high performance wired and air-interfaced networks such as in-building applications, satellite communications, radar, radio communications, telemetry applications, mobile radio, aviation & air traffic communications.
QSL from Sputnik
Securing confirmation of having made a contact (QSL in ham-speak) with a radio operator behind the communist Iron Curtain was a real achievement during most of the 20th century. Russian and Chinese citizens were routinely imprisoned for such activity, and if you did manage to elicit a response to your CQ (request for contact), there was a good chance it was with a government propagandist posing as a civilian. When Sputnik 1 was put in orbit on October 4, 1957, a whole new realm of DXing (long distance communication) opened up by providing satellite relay paths. Sputnik 1, the world's first artificial satellite, broadcast a series of pulses at 20.005 and 40.002 MHz that were tracked and reported by both professional and amateur radio operators. Vital data was learned based on the time and strength of signals that allowed scientists to ascertain the physics of upper atmosphere characteristics. Not wanting to give the impression that the assistance of the rest of the world's capitalist pigs was needed or wanted (although it definitely was), virtually no acknowledgement was forthcoming from Radio Moscow...
Webinar: Technology Trends
for Radar Systems
Caution! A video ad that has nothing to do with the webinar will start
playing automatically. This is the last webinar I will post from MWJ because of the ongoing obnoxious practice.
Is Friday's Asteroid Approach
One Possible Future?
Y'all know there's a 150-foot-wide meteor due to scream by within 17,200 miles of the Earth on Friday, February 15, that will pass inside the orbits of many communications satellites, right? Well, maybe this is the "possible future" that Griffin envisions at the very end of Men in Black 3 (MIB3) for the scenario where Agent K forgets to leave a tip. I'm just say'n it's possible.
Watch this media moron ask Bill Nye the Science Guy if the meteor is due to global warming - pathetic!
Electrical Engineering Crossword - February 10, 2013
For the sake of avid cruciverbalists, each week I create a new crossword puzzle that has a theme related to engineering, mathematics, chemistry, physics, and other technical words. You will never be asked the name of a movie star unless he/she was involved in a technical endeavor (e.g., Hedy Lamar). This particular puzzle has lots of abbreviations and acronyms.
Micro 3-D Printer Makes
Dust Mite Size Spacehip
As with most things, once a physical entity or concept has been produced there is always the 'need' to build one on the macro scale and on the micro scale. Here we have a 150-mm-long spaceship that was built by German's Nanoscribe GmbH using a 3-D laser photolithography printer. A scanning electron micrograph was needed to capture a picture of the model due to its smallness. It took about 50 seconds to create the model out of a photosensitive powder (a video captures the process). Of course the purpose of the exercise is not to be able to create spaceships the size of a dust mite, but to demonstrate the capability using an object that the public will be familiar with and impressed by. A micro-size 3-D model of a fountain pen just wouldn't cut it.
Good Magazine Articles
from February Issues
Here are a few articles that should be of interest. I try to avoid including articles that are mainly advertisements for a company's product.
Microwaves & RF:
* White-Space Comms Will
Kickstart the "Internet of
Things", by Paul Whytock
* Low-Power Receiver Serves
Multiple Wireless Standards,
by K. Fu, X. Guo, C. Wang,
Y. Tu, C. Liu, J. McGeehan
* Metamaterials Form Mini
Bandstop Filters, by
N. Benmostefa, M. Meliani,
H. Ouslimani, M. Feham
Top 10 Companies College
Grads Want to Work For
Yet another survey is out of the most desirable companies to work for according to college types. This one is from AfterCollege.com, "the Leading Career Network for College Students and Grads." They all claim that. Here are the results:
My personal #1 would be NASA, then NSA at #2.
Microwave Engineering Handbook Vol 2: Microwave Circuits, Antennas and Propagation, by B. Smith and M.H. Carpentier. The Microwave Engineering Handbook provides the only complete reference available on microwave engineering. All entries in the handbook are written by experts in the area, bringing together an unrivalled collection of expertise on microwave technology. It covers all of the major circuit types used in microwave systems and also covers antennas and propagation, an area vital to microwave systems. The emphasis is on fundamental principles and practical hardware, providing a wealth of information for engineers and system designers.
Here are a few more electronics conundrums with which to exercise the old noodle. These are puzzlers from a 1959 Popular Electronics magazine, but at least one of them (#4) will likely prove to be a real stickler unless you have seen a similar resistor mesh problem before. There are no tube circuits to use as an excuse for not getting them - just resistors, batteries, switches, meters, a motor, and a couple light bulbs. All four would be fair game to present to an interviewee to see where he/she stands on basic circuit analysis.
Iran Airs Flight Footage of
Captured Stealth U.S. Drone
With all the fundamental changing going on in the country, it's easy to forget about any one particular significant event. Iran just sent a reminder about their commandeering of our most advanced RQ-170 Sentinel stealth technology drone in December of 2011. Revolutionary Guard controllers were able to simply usurp control and guide the craft to a perfect landing on their airstrip. Evidently just as with the highly classified stealth helicopter than went down during the Bin Laden assassination mission and ended up in a Chinese military hangar for dissection, the drone capture is no big deal either. I wait with bated breath to see what we yield to next.
IEEE JobSite Career Alerts
How to Find a Job When
Employers Who Haven't
¤ Dream Jobs 2013
¤ Why You Should Go out of
Your Way to Find an
Awesome Peer Mentor
¤ 5 Ways You Can Improve
Your Image to Impress,
Attract Success and Attain
Professor Venus Flytrap
Teaches the Bohr Atom Model
Does anyone out there other than me remember watching WKRP in Cincinnati? Here is a video clip of DJ Venus Flytrap teaching a lesson on the atomic model to a street thug in a way he can understand. Unfortunately, he's using the outdated Bohr model with electrons orbiting the nucleus, but hey, Bohr's work got chemistry through the middle of the 20th century. With the extreme level of science ignorance these days in the general public, maybe PBS should broadcast an entire series on science and mathematics using Venus' method. Maybe they could call it "Essential Science and Math for Dummies - and Yes, We're Talking About You."
NMIC Ships 10,000th Aluminum
Diamond Heat Spreader for GaN
Nano Materials International Corp. (NMIC) today announced that it has shipped its 10,000th aluminum diamond metal matrix composite heat spreader for use in GaN RF power transistors and MMICs. The achievement is a significant milestone for acceptance of NMIC’s aluminum diamond MMCs and for manufacturers of defense and commercial RF power amplifiers who must dissipate the heat generated by high-power-density GaN devices. Orders for NMIC’s aluminum diamond MMCs have continuously increased as tests by GaN device, power amplifier, and system manufacturers have validated the benefits of the technology and as NMIC has optimized its processes so that it adds minimally to the cost of each device.
College Fund vs. KickStarter
I like reading comic strips just for the fun of it. Many of the newer ones are too political or have nasty characters, but some do a pretty good job of addressing today's societal concerns in a humorously clever way without insulting the audience. Moderately Confused™, by Jeff Stahler, is one of them. In this one from February 5, the son is asking his parents if they would prefer to invest in his Kickstarter project rather than in a college fund. In an age where less than half of college graduates are getting jobs in their chosen fields of study, and where payback on exorbitantly high college costs could take a lifetime, rethinking the direction Junior should take might be a worthwhile exercise. A lot of people end up much happier in life pursuing a dream/idea early on rather than starting out with four years of college then being at the mercy of the corporate world. Not everyone would succeed in a start-up venture while going to the School of Hard Knocks rather than to a university, but then most aren't succeeding after graduating nowadays, either. Our daughter Sally, a straight-A student in college, elected to get Associates' degrees in business and logistics, then start a horse riding school instead of pursuing Bachelor's degree. She has never regretted the decision.
Thanks to JQL Electronics
for Long-Time Support
JQL Electronics is a leading manufacturer of microwave ferrite isolators & circulators, directional couplers, power divider/combiners, ceramic filters, power transformers, waveguide to coax adapters, and power supplies. In addition to their design capability, JQL has strong production capability to deliver its products. Lead time is among the shortest in the industry.
Pasternack Releases Line of
Medium Power Attenuators
Pasternack Enterprises introduces their new line of 50 Watt medium power attenuators. This innovative line of medium power attenuators offers one of the most comprehensive selections of RF connector combinations available, thus eliminating the need for coaxial adapters or custom cable jumpers to change connector types. The new medium power 50 Watt attenuators from Pasternack Enterprises can be ordered with any combination of passivated stainless steel SMA, TNC and N connectors as well as silver plated brass 7/16 DIN connectors. Pasternack medium power RF attenuators operate from DC to 18 GHz depending on connector configuration.
Antenna Design Automation
Parameterized EM Analysis
Antenna Design Automation with Scripting and Parameterized EM Analysis, by MWJ and Agilent, February 7, 1:00 PM ET. Full-wave 3D EM software is an indispensable tool for designing RF antenna structures. However, complex array-based antennas can be cumbersome to set up and analyze in traditional EM software tools. Agilent EMPro has integrated Python based scripting that provides the user the ability to automate geometry creation, simulation and data analysis. This, combined with parameterization of key design variables can greatly accelerate the development process. This webcast will illustrate the advantages of scripting and parameterization by considering the example of an MxN element Microstrip Phased Array patch antenna.
YL New & Views
"YL" in amateur-ese stands for "young lady." It refers to any ham operator of the female gender regardless of age. I don't know how many women were Hams in 1966 when this article appeared in QST, but according to Communities of the Air: Introducing Radio to the World, author Susan M. Squier, by 2003 women made up 40% of new amateur radio license applicants. Judging by amateur radio club rosters and field day events, YLs don't make up anywhere near 40% of the Ham population, but maybe they just tend to shun the public light. A 2008 presentation on the YL Radio Website estimated 15% in 2000. I searched around the Young Ladies Radio League (YLRL), American Radio Relay League (ARRL) and the Federal Communications Commission (FCC) websites for current statistics but could not find anything specifically about the percentage split between males and women...
NuWaves Selected to Provide
RF Subsystems for ViaSat
NuWaves Engineering announced today that two of its module-level RF products, the Multi-Octave RF Upconverter (MORF™) and the ConvertaWave2™ Downconverter, have been selected by ViaSat Inc. to be embedded in the company’s VRG-1000 RF Signal Environment Generator product line. NuWaves’ MORF accepts a range of intermediate frequency (IF) signals and delivers a user selectable RF output between 2 and 3000 MHz for RF transmission. On the RF receiver side, NuWaves’ ConvertaWave2 accepts an RF signal from 200 to 2500 MHz and delivers a bandwidth-filtered IF of 70 MHz, ready for baseband processing. Both modules are compact, offer highly precise tuning resolution, and provide superior out-of-band interference rejection. “We are very proud that ViaSat selected these commercial-off-the-shelf products to serve as key RF subsystems in their RF signal environment generator products,” said Jeff Wells, President and CEO of NuWaves Engineering.
SynRF for Matlab Circuit
Analysis Software - Free!
Heuermann HF-Technik GmbH is offering their Matlab-based circuit analysis tools as a free download. From their website; "SynRF allows you to perform the synthesis of RF circuits in seconds.SynRF calculates the element values and illustrates the transfer function over frequency. This gives you the information of the bandwidth of the circuits." SynRF supports the calculation of more than 50 circuit types including various attenuators, impedance transformers from lumped and distributed elements, phase shifters, resistive and reactive power dividers, couplers, transmission lines, transmission-line-based inductors and capacitors, even and odd mode blockers, baluns, lumped and distributed resonators, band pass filters, and a diplex filter. The price is definitely right.
Webinar: The Effects of
Jamming on GPS/GNSS Signals
GPS Interference & Spoofing: Origins, Effects and Mitigations for the Military and Civil Communities, by MWJ and Rohde & Schwarz, February 6, 2013, 1:00 PM ET. Overview: After a review of GPS signal structures and current satellite constellation status, this webinar provides a tutorial examination of how interference affects GPS signal reception. In particular, interrelations between jammer spectrum and GPS signal spectrum are explored. The Betz equation for computing cross coupling between an interference source and a spread spectrum signal is introduced in the context of GPS signals and the role of signal and jammer RF propagation is considered. CAUTION: A video ad will probably start playing - tell MWJ to stop this annoying practice!
2850 to 3050 MHz S-Band VCO
Z-Comm announces a new RoHS compliant VCO model in the S-band. The SMV2950A-LF operates at 2850 to 3050 MHz with a tuning voltage range of 0 to 2.5 Vdc. This compact VCO features phase noise of -85 dBc/Hz @10 kHz offset while operating off a 3.0 Vdc supply and typically drawing 15 mA of current. The SMV2950A-LF provides the end user typical output power of 3±3 dBm into a 50 Ω load while operating over the industrial temperature range of -40 to 85 ºC. This robust VCO suppresses the second harmonic to better than -15 dBc and covers the frequency range with a tuning linearity of better than 1.1:1.
It is good practice to occasionally rehash old topics for two reasons. One is that there are always new people coming to the website and have not seen the information before (at least not here). The second is because most people, especially RF Cafe visitors, experience information overload just about every day so a lot of unused data gets pushed off the bottom of the memory stack. Although admittedly a bit self-serving, I want to remind you - or inform you for the first time as the case may be - about the really useful WayBack Machine (borrowed from Mr. Peabody's WABAC machine) at archive.org. There, you have a good chance of finding long-gone web pages. Paul van Oorschot, of ResistorGuide.com, just found the long ago disappearing article titled Near Field vs. Far Field from the equally mysteriously disappearing Conformity magazine website.
Are You a Skeuomorphist?
(skeuomorpher in today's vernacular)
Scientific American's David Pogue wrote an article titled "Out with the Real*," which laments the continued widespread use of skeuomorphs in software. According to Dictionary.com a skeuomorph is "an ornament or design on an object copied from a form of the object when made from another material or by other techniques." Familiar examples include animated book pages on e-readers that appear to be turning like a physical book, the desktop wastebasket icon, and clickable buttons for options. He argues that such an attachment to the past holds back progression toward the future. In a sense he's correct insofar as a new generation of people who do not really need to transition from a non-computer world to a computer-centric world - the technology is now introduced almost at birth these days. Entirely new software interface strategies can be designed that more effectively assist the user with operations if the old crutches are abandoned. Human evolution is spinning its wheels, so to speak (dang, I just skeuomorped). Of course if that new software paradigm is taken too far, we will need to start applying skeuomorphisms to physical objects to make them simpler to use for the person who has lived his life on a computer since the time mom and dad gave him an iPhone-shaped pacifier to teethe on. *SciAm stupidly uses different titles for print vs. online articles.
PMI Intros 900 to 930 MHz,
6-Bit Phase Shifter
PMI Model No. PS-360-900M930M-6-SFF is a 900 MHz to 930 MHz, 6-BIT digitally controlled phase shifter having a LSB of 5.6 degrees. The insertion loss is 7 dB typical, 7.5 dB maximum with a typical VSWR of 2.0:1. This is a high speed phase shifter that can switch from one phase state to the next in typically 250 nsec. This model will operate at input power levels up to +14 dBm CW and operates on a DC power supply of ±15 VDC. The housing measures 2.0" x 2.1" x 0.5" and is painted gray. Other frequency ranges are available.
Please Visit Coaxial Dynamics
in Appreciation of Support
Coaxial Dynamics has been a leading manufacturer of precision equipment for the measurement and termination of RF power for over 30 years. Their equipment is used by engineers and technicians in a wide variety of applications throughout the world, and they have sales offices all over the world to serve your needs. Coaxial Dynamics' dual-directional wattmeters appear in the ARRL's monthly QST magazine.
Response Microwave has been added to the RF Cafe vendor listings. They are a manufacturer of drop-in and connectorized hybrids & couplers, combiners & dividers, filters & diplexers, isolators & circulators, coaxial & optical attenuators & adaptors, terminations, surge protection, delay lines, connectors, cable & cable assemblies, laser diodes, and custom assemblies. 978-772-3767 | Devens, MA
Everything You Ever Wanted
to Know About Resistors!
After spending a while perusing Paul van Oorschot's ResistorGuide.com website, I can say with a high degree of confidence that if there is anything you need to know about resistors, you will find the answer there. If it is the fundamentals you're after like power dissipation, resistance tolerance, stray inductance and capacitance, and how Ohm's law applies, Paul's got you covered. How about package configurations, color codes and alphanumeric markings? Yep, that's on the website as well. So also is info on resistor compositions (metal film, metal oxide, carbon, et al), resistor physical configurations (fixed, variable, thermistor, magneto resistor, others), and applications (heating, current limiting, voltage division), and even schematic symbols for each. Oh, and did I mention all of the instructional videos? It is probably no exaggeration to say that if you cannot find the information you need about resistors here, you're not going to find it anywhere.
Nitronex Has a Senior Product
Senior Product Engineer (ENG13001), Location: Durham, NC, Department: Engineering. Basic Function: Senior level experienced engineer to assist in the development and design of MMIC RF and Microwave products. This position will drive MMICs and discrete devices from design engineering to production release. This includes product characterization, datasheet creation, application board development, automated test development, statistical analysis and specification definition. Experience: 5 to 10 years RF product development experience with at least four years in product engineering, applications or design field developing RF semiconductor products.
"In every direction around him, he will rely on other people's knowledge. The bad news is that this engineer will never know all of engineering; the good news is that he doesn't have to. The world doesn't work that way anymore." – Robert Lucky, January 2013 Spectrum
Many Thanks to RF Dude
Consulting for Support
Lance is always the first person I refer people to when I get a call looking for an RF/microwave circuit and system designer. Says Lance, "When you hire RFdude.com for a project you receive design and analysis services in the realm of applied research and development. We appreciate the big picture and choose to operate where we can do our best work for you. Our operation has extremely low overhead which allows us to be very responsive and efficient. Experience is in medium volume production where 'design for manufacturing,' 'design for test,' and overall solution cost have been very important." Please see Lance's resume page for more details.
Patent Term Calculator
Compliments of the USPTO
The United States Patent and Trademark Office does not calculate expiration dates for patents. In response to patent owner and public inquiry, the USPTO is providing a downloadable patent term calculator in Excel format as a resource to help the public estimate the expiration date of a patent. The calculator can be used to estimate the expiration dates of utility, plant, or design patents. The calculator contains prompts to enter specific information related to the patent in order to help in estimating expiration dates.
Wireless Crossword Puzzle
February 3, 2013
Work this Wireless Engineering-themed crossword puzzle in the bathroom at your own risk; it's going to take a while. The words are not real hard, but there are 413 of them. It has been a while since I made one this large. If you insist on indulging your habit against my admonishment, you'd better have some Prep H on-hand (truly bathroom humor).
You're Not Very Smart After All
2001: A Space Odyssey, released in 1968 and based at least in part on Arthur C. Clarke's 1948 novel The Sentinel, was more than just a science fiction movie. It was a reflection on the public's and even some of the scientific community's trepidation over the potential power of run-amok computers to be used for or even themselves commit evil (e.g, HAL 9000). Fear of the unknown is nothing new. Noted mathematicians and computer scientists quoted in this 1950 article from The Saturday Evening Post worry about robots (aka computers) "going insane" or being used by the likes of Hitler and Stalin to dominate the world with totalitarian rule. Others, however, have a more optimistic outlook: "The men who build the robots do not share these terrors. Far from destroying jobs, they testify, they will create new ones by the hundreds of thousands, just as the industrial revolution eventually did. Moreover, most of the robot builders would make book that in time 'thinking machinery' will bring about a happier, healthier civilization than any known heretofore. What the odds on Utopia...
Skyworks Does TI Reference
Design for Smart Energy Apps
Skyworks Solutions has secured a reference design with Texas Instruments Incorporated (TI) for smart energy, industrial and networking applications including electric/gas/water meters, street lighting, telematic and tracking systems. Skyworks' highly integrated, power efficient front-end solutions are in volume production and compatible with single-chip transceivers for wireless systems requiring high performance at low power and voltage. "TI is delighted to be collaborating with Skyworks to develop a new reference design using TI's sub-1 GHz RF performance line transceiver and Skyworks' front-end solutions," said Terje Lassen of TI.
January 2013 Book Drawing
Spread Spectrum Comms
by Another Name
RACEP (Random Access and Correlation for Extended Performance), was an early form of frequency hopping spread spectrum (HFSS) devised by the Martin Company (now Lockheed-Martin). It was used for secure voice communications and worked by sampling speech in small 'slices' and then transmitting each slice modulated onto a carrier whose frequency was determined by a predetermined sequence of center frequencies. A receiver with a matching sequence key would then decode the speech and, with appropriate filtering, reassemble it into its original content. President John F. Kennedy had such systems at his disposal whether on the road or in the Oval Office. General Electric (GE) had a different idea it dubbed 'Phantom' that spread the signal over a very wide bandwidth. Today, we refer to it as Direct Sequence Spread Spectrum (DSSS). Not to be outdone, Hughes Aircraft...
Please Visit DCH Systems in Appreciation of Their Support
DCH Systems designs and manufactures high power military wireless networking amplifiers and RF systems. Their products provide range extension, higher data rates, and increased performance in both legacy and next-generation commercial and military UAV data/video links and also networks based on 802.11, WiMAX, LTE, and proprietary standards. See their line of Mil-Spec RF products: Military WLAN Amplifiers, Military / Commercial, WiMAX & WLAN TMAs, Bi-Directional Up/Down, Converters & Amplifiers, 19” Rack Mount Systems
Modern Antennas, by S. Drabowitch, A. Papiernik, Hugh Griffiths, J. Encinas, and B.L. Smith. A complete and rigorous treatment of design principles for modern antennas, including chapters on signal theory and signal processing antennas, radar and polarimetry. Contains significant new material on antennas for mobile communications to supply a complete picture of antennas for modern radio communications applications. Says a reviewer, "This is an excellent book both technically and because it gives a 'fresh' European perspective on modern antenna engineering written by practicing antenna designers."
vida RF Magazine Ad
Even in hard economic time like the entire world is experiencing now, it is necessary to continue advertising campaigns in order to capture as large a piece of the consumer pie as possible. I offer my advertisers an opportunity to have their magazine ads posted here since they are able to present more information than can be accommodated on one of the many Product Vendor pages on RF Cafe. The newest addition was supplied by vida RF, a manufacturer of RF cables, and many types of RF / microwave components like coupler, attenuators, and baluns.