RF Cafe Software
About RF Cafe
1996 - 2022
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 ...
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Here is page 1 of the April 2014 homepage archive
New RF Cafe Quiz:
This 10-question quiz tests your knowledge about microwave circulator design. Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators.
Cover Sistemi Uses Microwave
Cover Sistemi, an Italian electronics developer, used AWR software to design a UWB receiver from concept to final production in a single pass. Specifications were for a complete design starting from the antenna through to the entire RF/baseband analog chain down to the AD converter. Cover Sistemi used Microwave Office® for the circuit design and AXIEM® for the EM simulation. The scope of work included all design phases, from high-level simulation to circuit-level design and final verification of pre-layout and post-layout.
An Interesting Experiment
"We might say almost, that all modern scientific investigation in the basic sciences, and a good deal of all practical developments, are connected in some way or other with the electron." So writes Dr. Irving J. Sax in 1932 regarding the incentive for determining as precisely as possible the mass and electrical charge of an electron. The Bohr atomic model had just been introduced two decades earlier, so the entire concept of particle physics was still in its infancy. As with most areas of physics, experiments are conducted with particular biases and expectations such that often the results are manipulated as needed to conform to preconceptions. Look no further than the complex retrograde motion planetary models devised and perfected by early astronomers...
Many Thanks to ISOTEC
Since our inception in 1996, ISOTEC has been a leading manufacturer of RF and microwave connectors such as SMA, MCX, SSMB, Low PIM, N, 7/16 type, and RF components such as attenuators, terminations, power dividers and more, for wireless service providers, and other RF systems designers. We provide recognized and trusted products and service to our customers in more than 60 countries worldwide. ISOTEC offers also an extensive product mix with RF Filters and Multiplexers and others.
What to Do with a Tape
Remember tape recorders? They began going the way of the typewriter about two decades ago when solid state voice recorders hit the market, but now smartphones with sound recording have made even those devices seem outdated. In fact, when my daughter's house burned down a few weeks ago, all of the on-site conversations with the insurance adjuster, fire marshal, and housing contractors were recorded to ensure an accurate account of what was said by all parties. Even though I was 800 miles away at the time, I was still able to listen to the dialog. In North Carolina, law does not require you to apprise other parties...
Anatech Intros Cavity BPF,
Anatech Electronics has released new designs for a 2,533 MHz cavity bandpass filter, a 749 MHz ceramic bandpass filter, and an 800-2,500 MHz 13 dB directional coupler. All can be ordered directly through their AMCrf web store.
New Dilbert Book: I Sense
You can't go wrong with a good Dilbert book like I Sense a Coldness to Your Mentoring, by Scott Adams. Dilbert is the most photocopied, pinned-up, downloaded, faxed, and e-mailed comic strip in the world. Dubbed "the cartoon hero of the workplace" by the San Francisco Examiner, Dilbert has been syndicated since 1989 and now appears in 2,000 newspapers in 65 countries and 25 languages.
Please Visit Orbel in
Orbel is the leading designer and manufacturer of RF Shielding and EMI/RFI Isolation Products for printed circuit boards and electronic enclosures. Board level shielding, EMI contact strips and rings, BeCu finger-stock and metalized fabric gaskets, connector gaskets. Orbel also specializes in thin gauge Photo Etched Metal Parts and Precision Metal Stampings made from a wide variety of material options.
A New Round of RF
House Bill S.2206
Question: What do Google, LinkedIn, Apple, Twitter, Facebook, Yahoo, Bing, Verizon, Microsoft, Sprint, etc., etc., etc., all have in common? Answer: They all willingly participate with the NSA, FBI, CIA, DHS, ATF, etc., etc., etc., in collecting as much data as possible about you and me. You might say the former group has become an unofficial branch of the later group. Well, it is about to become official based on House Bill S.2206 - Let Me Google That for You. It is just as well since the Google twins (not really twins) already get discount military jet fuel purchases and, along with other American royalty like Mr. Gates and Jeff Bezos, have open doors to the White House any time they demand it. The Act is ostensibly a cost-cutting measure and effectively...
A Nostalgic Adventure: Midland
Thanks to Internet, there has never been a better opportunity to be able to step back in time and reclaim some of your past indulgences. A lot of guys are using resources like eBay and specialty website forums to search for items remembered from days of yore. Although I can't imagine how it can be so based on my slacker personal habits as a teenager, there are still available a fairly large number of hobby type items that I recall owning - many in like-new condition and some even in their original, unopened packages. If you are about my age or even older, chances are you have either done some of the same, or have considered doing so. Bob Davis, an RF systems and circuits designer of many years, has submitted accounts of a couple radio restoration projects he...
Test your diode switch analysis skills here with six circuits designed by Mr. Robert P. Balin in the July 1961 issue of Popular Electronics. When evaluating the equivalent circuits with the diodes biased on or off, don't make the job more difficult for yourself by considering whether there is enough voltage or current to turn a particular diode on or not, just whether the diode is forward or reverse biased. Doing so reduces everything to simple series and parallel combinations. Redrawing each circuit either with a short for a forward biased diode and an open for a reverse biased diode makes the task easier.
Radar & Radio Crossword
Take a break from the drudgery by trying your hand at some of these goodies. Every word in the RF Cafe crossword puzzles is specifically related to engineering, mathematics, and science. There are no generic backfill words like many other puzzles give you, so you'll never see a clue asking for the name of a movie star or a mountain on the Russia-China border.
I will be travelling and have limited access to RF Cafe for the next couple days. Please forgive any delay in response.
Z-Comm Intros Ultra
Z-Communications announces a new RoHS compliant VCO model USSP1570-LF in the L-band. The USSP1570-LF operates from 1540 to 1600 MHz with the narrow tuning voltage range of 0.5 to 2.5 Vdc. This miniaturized VCO features phase noise of -90 dBc/Hz @ 10 kHz offset while operating off a 2.7 Vdc supply and drawing a mere 6mA of current. The USSP1570-LF provides the end user an output power of -1±3 dBm into a 50 Ω load while operating over the industrial temperature range of -40 to 85º C
Out of Order:
This story, submitted by RF Cafe visitor Jerry L., of Cincinnati, OH, reminds me of a certain manager in a popular engineering comic strip. Jerry writes: I worked in the defense electronics industry for my entire career and it is hard to think of a project in more than four decades that was not made infinitely more difficult due to the 'helpful' input of project managers. One experience in particular comes to mind as a perfect topic for your Out of Order feature. In the mid 1970s I was a "fresh-out," as new engineering college graduates were called at the time. Newly minted as a Masters degreed electrical engineer, my aspirations were high and I was ready to set the mobile radio system world on fire...
Advanced Test Equipment
Advanced Test Equipment Rentals just issued their TEC Talk newsletter for April 2014. It includes hot topics in the tech news world, highlights of new or special function test equipment they have available, and some electronics industry news.
PMI Dielectrically Stabilized
PMI Model No. DRO-16D3G-CD-1 is a dielectrically stabilized GaAs FET oscillator with a center frequency of 16.3 GHz. This model provides minimum output power of +11 dBm with all spurs held to -55 dBc and harmonics held to -20dBc. The mechanical tuning frequency is ±25 MHz and the unit has a phase noise of -70 dBc/Hz. The unit requires +15 VDC and 150 mA and measures 1.06" x 1.63" x 0.98"
The Tube Family Tree (Part 3)
Magnetron, photomultiplier, traveling wave, compactron, klystron, backward wave, pencil, lighthouse, cathode ray, indicator, nuvistor, acorn, peanut, T-R, electrostatic, cat's-eye, orithon, and loctal, are just a few of the many types of vacuum tubes that have been and in some cases still are in use in various types of electronic equipment. Some you have heard of, others you probably have not. All are discussed in a series of three articles published in Popular Electronics. This is part 3, which includes operational descriptions of klystrons, magnetrons (in your microwave oven), and traveling wave tubes...
Carl & Jerry:
Carl and Jerry in handcuffs? Say it ain't so! Has the pair of good-natured, upstanding high-tech sleuths gone to the Dark Side (George Lucas 18 years old in 1962 when this was written)? Read the tale to see how they figure into a plot to kill a local judge, and why they decide to cannibalize a service station television set for parts. What has come over Carl and Jerry?
Tracking Signal Generator
DS Instruments offers the TG6000, a generic tracking signal generator that is compatible with new and legacy RF/microwave spectrum analyzers. The TG6000 can provide a TG signal from near DC to beyond 6 GHz enabling swept scalar type measurements with a Spectrum Analyzer. In addition a fully synthesized signal source is integrated into the TG6000 allowing its use as a standalone signal generator. The SG source has a frequency range from 25 MHz to 6 GHz. Typical dynamic range for swept response of a DUT is >80 dB.
Skyworks Intros Family of
Skyworks introduces a series of surface-mount, silicon, hyperabrupt junction tuning varactor diodes for automotive, consumer, defense and infrastructure markets. The SMV2026 Series provides high capacitance ratio and low-series resistance, suitable for use in low-phase noise, voltage-controlled oscillators, voltage-tuned phase shifters, bandpass filters and microwave tuners at frequencies up to and above 2.5 GHz. The Series is also ideal for wideband UHF and VHF applications.
Look How They're
In the early 1960s, nickel-cadmium (NiCad or NiCd) batteries were the way of the future due to a combination of high charge storage density and recharging ability. Carbon-zinc (C-Zn) cells were well established by then and had performed reliably during World War II and in Korea. Alkaline batteries were considered the de facto high standard for critical applications that required longer life and higher current than C-Zn could supply, but were (and still are) considerably more expensive. Mercury cells exhibited a fairly constant voltage level during useful life, which made them preferable for applications with a low voltage variance tolerance. Lithium-ion (Li-Ion) cells, those things...
What the #!$% Is Bitcoin?
Bitcoin has been in the headlines often for the last couple years. It was heralded in the media as "a new kind of money," a form of e-currency that was supposed to level the global financial playing field so that no one country would have a monopoly on the economy. Mt. Gox, a short form of "Magic: The Gathering Online Exchange," was smoking hot. Fantastic stories appeared almost daily of Bitcoin valuations rising at astronomical rates while making overnight millionaires of people who had "discovered" forgotten caches of bitcoins in their computer hard drives. For a while, it appeared the goal might be achieved, but then suddenly Bitcoin mania was stigmatized by word of scandal. Mt. Gox was shut down suddenly...
Many Thanks for AMC's
American Microwave Corporation (AMC) uses a state-of-the-art clean room to manufacture all of it's products, as well as a fully automated machine shop. AMC is a leader in the design and manufacturing of DC to 40 GHz solid state control components for commercial and military grades. PIN diode switches and attenuators, detector log video amplifiers, and power dividers and couplers are among their offerings.
Here is a humorous "kwiz" that appeared in the June 1970 issue of Popular Electronics magazine. Your answers to questions will determine whether you are a truly cool technophile, or you are just a maniacal misanthrope who happens to know something about radios and regulations. This would probably have been more aptly printed two issues earlier as an April Fools' joke.
Please Welcome Fast Circuits
Fast Circuits has been providing since 2009 high-quality PCB manufacturing and fabrication services to U.S. and Canadian clients. Our fabrication facilities give us the capability of producing PCBs such as FR4, high temp FR4, Rogers high frequency, heavy copper, and high density. We also have expertise at delivering impedance control, buried & blind vias, and multiple layered PCBs. Our assembly services in SMT and PTH capabilities are popular with overseas clients who seek a low cost, high quality and fast turnaround time.
Z-Comm Intros Low Phase
Z-Communications announces a new RoHS compliant Fixed Frequency Synthesizer model SFS11800C-LF in the X-band. The SFS11800C-LF is a single frequency synthesizer that operates at 11.8 GHz with a 10 MHz reference and features a typical phase noise of -90 dBc/Hz and -120 dBc/Hz at the 10 kHz and 100 kHz offsets, respectively. The SFS11800C-LF is designed to deliver a typical output power of 3 dBm with a VCO voltage supply of 5 Vdc while drawing 90 mA
Fundamentals of RF and Microwave Transistor Amplifiers, by Inder Bahl. A comprehensive and up-to-date treatment of RF and microwave transistor amplifiers. This book provides state-of-the-art coverage of RF and microwave transistor amplifiers, including low-noise, narrowband, broadband, linear, high-power, high-efficiency, and high-voltage. Topics covered include modeling, analysis, design, packaging, and thermal and fabrication considerations. Through a unique integration of theory and practice, readers will learn to solve amplifier-related design problems ranging from matching networks to biasing and stability.
National Radio News was published bi-monthly by the folks at the National Radio Institute (NRI). NRI used to be a major training center for electronics technicians beginning in the early part of the 20th century. This article was provided for them by the FCC as a synopsis of radio frequency spectrum allocations at the time. Compare a 1940 spectrum allocation chart (just a simple description here) to one for 2014 and you will see a remarkable difference in not just the number of bands, but in the extension of the frequency range...
A Yell from an XYL
Most amateur operators know that "YL" is Hamese for "young lady," meaning a female operator. Less well known these days is "XYL" which decades ago, referred to an ex-young lady, implying either an older woman or the wife of a Ham. According to online call sign lookup services, Popular Electronics' poet laureate K8AOU was in fact a YL; the call sign was later assigned to an OM ("old man;" i.e., male operator).
AWR Presents & Exhibits
AWR will be presenting and demonstrating its soon-to-be released V11 NI AWR Design Environment™ at EDICON 2014 in Beijing, China starting April 8 and running through April 10, 2014. V11, the first major software release in 2014, includes new features, functionality and enhancements to Microwave Office/Analog Office circuit design software, Visual System Simulator, AXIEM 3D EM, and Analyst™ 3D FEM EM software. Demonstrations within booth #301
"Conquer Radio Frequency"
RF and microwave engineering has been aptly described as a "black art." Even for those who have a deep understanding of the concepts, there is still an element of mystery involved, particularly when it comes to troubleshooting misbehaved circuits or systems. When frequencies are high and wavelengths are so short that everything conductive becomes an antenna absorbing and conducting or reflecting signals elsewhere, tracking down a source can be like feeling you way around a house of mirrors at an amusement park while looking for the exit. Fortunately, someone like Francesco Fornetti, at Explore RF, not only grasps the concepts but also has the ability to develop...
Many Thanks to Nortec RF
Nortec RF has more than 22 years of experience designing power combiners and dividers, directional couplers, hybrid couplers, and filters. Our research and development group and engineering team constantly introduces new, top of the line products into our product line. Custom designs on request.
Helleroy Needs an RF Engineer
Helleroy is a startup working on building high-quality waterproof audio systems for extreme watersports (e.g. surfing, kayaking or sailing). Currently, we're just 3 people - an award-winning industrial designer and graduates from Harvard and uPenn. Our mission is to enable people to have next-level experiences on the water through music. So far we've built and tested a series of prototypes and have build a large pre-sales list. As an RF Engineer, you will be involved in all stages of engineering from R&D to DFM. NOTE: The schedule begins in April, so do not delay if you are interested!
Notable Tech Quote
"Nothing spoils numbers faster than arithmetic!" - Peppermint Patty, from the Peanuts comic strip by Charles M. Schulz. The Peanuts comic strip has been a lifelong favorite of mine.
Your Dream Home
Are you looking for a quality starter home, retirement home, vacation home, or a home for a small family? This home has quality construction that includes a maintenance-free full brick facing from the ground up to the soffits, all the way around. Windows are double paned and airtight. R-45 insulation in the attic keeps heating bills at a minimum as does the metered gas supply for the furnace and water heater. That, and sitting on 1.28 flat acres with beautiful trees, on a private road 100' from the main highway, deeded access to a boat launching area on Long Lake, a large 2-story pole barn, with boat/camper storage, topped off by great neighbors, makes this estate an ideal choice for your lifestyle. Low taxes, very high speed cable Internet are a bonus to boot. SimpliSafe alarm installed.
I have no idea whether the engineering and science themed crossword puzzles I have created every Sunday for the last decade are worked by anyone. Occasionally, an editor from an engineering school newsletter will ask for permission to reprint one, or some company might ask to include one in a corporate email, but other than that, I usually do not receive any feedback. Please let me know if you have ever worked one of my custom-made crosswords. Thanks.
Hobnobbing with Harbaugh:
TGIF. To top off your good fortune, here is a little levity from the "Hobnobbing with Harbaugh" series of comics that appeared in Popular Electronics. Unfortunately, none of the "The 5 Most Wanted Household Inventions" have come to full fruition in the marketplace yet, although the Conversation Jammer can be found on the Internet in various unofficial forms. Personal computers were a pipe dream in 1963, but nowadays we do have software like TurboTax to take care of filing taxes, although you still can't simply dump all your receipts into a bin and have it work. Flat-fixing robots...
Free White Papers
TradePub is a service that offers free whitepapers and magazine subscriptions to qualifying engineers and technical professionals. I have downloaded many over the years and find them to usually be useful. A few turn out to not be what I wanted, but since they're free, all that was lost was a few moments spent filling out the form. Here are a few of the trending "hot" topics per TradePub that might be of interest. Many are geared more toward business and management, but even if you are 100% engineer, it never hurts to round out your knowledge base a bit and get an insight into how the company managers think...
As with just about every other type of hobby anymore, creativity and mechanical aptitude is not much of a necessity if you have money to spend. Heck with all the government handouts these days, all you need is other people's money. There is such a plethora of options available for every conceivable need to satisfy whatever degree of complexity you want your hobby to entail. The back 1/3 of every edition of the ARRL's QST magazine is loaded with advertisements offering antennas, radios, towers, test equipment, guy wires, insulators, cables, connectors, soldering stations, semiconductors, tubes, nuts and bolts. It is a wonderful world we live in if your desire is to engage...
Ribbon cable has been around and familiar to most of us for as long as we can remember. The advent of personal computers in the 1980s brought ribbon cable into the homes of millions of people in the form of the interface to disk drives. In 1957, however, when this news story appeared in Popular Electronics, ribbon cable, known initially as "tape cable." was just being introduced to industry. There was also a story on what might have been the first flat panel display screen, the "Sylvatron," developed by Sylvania. Finally, we have a report on bouncing radio signals...
Anatech Intros Cavity Duplexer
Anatech Electronics has released new designs for a 825-835 MHz, 870-880 MHz cavity duplexer, a 950 MHz cavity bandpass filter, and a 748 MHz surface-mount ceramic bandpass filter . All can be ordered directly through their AMCrf web store.
Press Release Archive
An archive of 2014 press releases has been created to help if you recall seeing something but do not remember exactly when or by whom. These press releases were either submitted by the manufacturers or I created them on request based on information on the companies' websites. If I create them, the format is my copyright and cannot be distributed to other media outlets. I strongly encourage you to write and submit your own press releases. Due to time availability, I am currently posting press releases only for advertisers, but occasionally I do so others as well, particularly for upstart companies.
Carl & Jerry: Slow Motion
Our two intrepid techno-sleuths are in college by now, but that does not keep them from applying their well-honed mystery solving skills to hometown situations while on spring break. The boys invoke the scientific method of Mr. R.R. Dibble, a New Zealand scientist, to help prove to county commissioners that a certain part of their critical infrastructure was in need of repair. An nth-generation farmer's observation was not proof enough, so indisputable empirical data would be needed. Real-life inventors and company's unique instruments are often incorporated into the Carl & Jerry series that ran for many years in Popular Electronics.
American Radio Supply Giving
This month, as an advertising promotion, American radio Supply is giving away an Alinco DR135T 2-meter mobile transceiver to a lucky ham radio operator. No purchased necessary; however, registration is required. At American Radio Supply we recognize the importance of amateur radio operators and the valuable service they render to the public. As a token of our appreciation we give away an amateur radio each month to a licensed amateur radio operator. To enter our random drawing
Congrats to March Book
Congratulations to Mr. David L., of High Point, NC, the latest RF Cafe Book Drawing winner for March 2014. David chose Digital Front-End in Wireless Communications and Broadcasting: Circuits and Signal Processing, by Fa-Long Luo. The book was graciously provided by Cambridge University Press.
Station Design for DX - Part III
Paul Rockwell wrote a 4-part series on station design for long distance (DX) communications that covered antenna selection and siting (Part I), economics and construction (Part II), station configuration and receiver topics (Part III), and propagation quirks and operating tips (Part IV). This is part III, and discusses topics such as Receiver preamplification, preselectivity and matching.
Z-Comm Intros Synthesizer w/Low Ø-Noise at 10.625 GHz
Z-Communications announces a new RoHS compliant fixed frequency synthesizer model SFS10625E-LF. The SFS10625E-LF is a single frequency PLL solution that is pre-programmed to operate at 10.625 GHz. This fixed frequency device utilizes ceramic resonator topology to achieve integrated RMS noise performance of better than 0.4° while consuming less than 500 mW of power. It is designed to operate over the temperature range of -30 to +70°C and delivers +3 dBm of output power into a 50 Ω load. Package measure 1.0 x 1.0 x 0.22 in.
Dilbert Versus Daubert
This article by Joshua Fruchter, writing for IMS ExpertServices, tells an interesting tale of what can happen when a powerful megacorporation, in this case Apple Computer, decides to match wits with a 10-year-old child prodigy who, by no coincidence, was named Dilbert by his adoring engineer father. The few minutes it will take you to read will leave you with a sense that yes, there is still a bit of sanity remaining in today's court system. Daubert, for the uninitiated, is a landmark legal decision regarding expert testimony in damage liability litigation.
PMI Intros 8-Bit Digital
PMI Model No. PS-360-DC-3 OPTION 618-15D is an 8-bit, digitally controlled phase shifter operating from the 6.0 to 18.0 GHz. frequency range. This unit has a typical insertion loss of 10 dB, accuracy of ±15°, switching speed of 500 ns maximum, and a VWSR of 2.0:1 maximum. It is supplied with removable SMA(F) connectors in a housing measuring 1.6" x 1.75" x 0.5".
How My Radio Helped Me Break
"Compactness distinguishes the Western Electric 8A airplane receiver." That statement describes a 160-pound system that included a wind-driven electricity generator for the equipment used by Captain Frank M. Hawks when setting coast-to-coast time records in the year 1929 using his Lockheed Air Express airplane, dubbed "Texaco 5." A simple 4-tube AM radio, its chassis measured a whopping 6" x 10" x 12". There were no radio direction finding stations enroute at the time, so the radio's usefulness was limited to being "comforting to listen in every half-hour and be advised of general conditions...
Free Engineering & Science
Today might be April 1st, but these giveaways are not a joke! Many of your favorite magazines offer free subscriptions to qualifying people. Qualifying usually means that you are currently employed in a field related to the primary theme of the magazine, and often you also need to be a decision maker for buying products represented within the pages. Technical magazines, like RF Cafe, get paid by advertisers and therefore need the public to support those companies by purchasing their products and/or services. If you believe you meet the standards and can use a subscription...
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