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 ...
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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.
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Please click here to view June 2014 homepage archive page 2.
Assuming that a couple creative teenage boys could get away today with electrifying weapons to dramatize a mock sword fight during a high school production of a Roman battle, you can be sure the suit of armor required by safety monitors would consist not of coats of mail, but coats of rubber and fire retardant material, fully sealing OSHA-approved goggles for eye protection, ear plugs, and electrical lineman's gloves. Offstage would be certified fire fighting professionals (formerly called firemen) and an emergency response crew specially trained in high voltage electrical contact with a hospital-style emerge...
NuWaves Engineering, an international RF and Microwave solutions provider, announced today that the company has been awarded a Phase I SBIR contract from NASA to research and develop a linear C-band PA for unmanned aircraft systems (UAS). NuWaves, in collaboration with Auriga Microwave, proposed an innovative method to reduce the size, weight and power (SWaP) of a linear C-band power amplifier for non-payload command and control systems on UAVs by leveraging advanced MMIC technology and linearization techniques. The team's PA solution is expected to help overcome operational range limitations
The new R&S CMA180 radio test set uses state of the art digital measurement technology for testing analog radios. Rohde & Schwarz designed the CMA180 radio test set especially for analog radio production and maintenance. Equipped with a touchscreen for easy operation, the new tester can generate any test signal of up to 20 MHz bandwidth and process high input power levels of up to 150 W. It offers all of the functions of a high end device at an attractive price.
"A record 'Moocher' is one of the lowest forms of human life. He has no particular habitat but can be found wherever there is a record owner." Anyone who grew up in the record player era, or for that matter the 8-track tape or cassette tape era has known (or has been) such a moocher. This is the person who was always asking to borrow your music media either for listening to on his personal equipment or copying onto his own tape (cassette or reel-to-reel). He rarely ever bought any of his own music, but was more than happy to generously re-lend his copies to fellow Moochers, and of course he never had anything you might want. The modern-day equivalent is...
This has been a big engineer and technician job posting week on RF Cafe. Check the Jobs page and/or look around the homepage for what you might have missed. Here is my weekly collection of relevant items found on the WWW:
The Jobs Recovery Remains
¤ Is It Your Age or Your
¤ College Grads: Here's the
Secret to Getting a Hiring
Manager to Notice You
¤ 5 Ways to Put Spring into
Your Job Hunt
¤ The Right Keywords Are
Essential When Applying for
¤ 7 Legitimate Reasons You
Might Not Get the Job
The Windfreak Technologies AmpNV is a 50 MHz to 6 GHz RF Power Amplifier capable of supplying up to 1 Watt of RF power. Gain is adjustable across a 31.5 dB range in 1/2 dB steps for up to 35 dB of total gain with pushbuttons on the device or with the included open source LabView software. Device settings can be remembered during power down for stand-alone operation. The amplifier runs off of DC power in the range of 15 - 28 V and draws around 5 watts. Dimensions are 2.75" wide x 2.15" deep x 1.95" tall (7.0 x 5.46 x 4.95 cm) not including mounting tabs and connectors.
Linx Technologies' RF modules, remote controls, evaluation kits and master development systems feature straightforward hardware configuration and clear documentation, making it simple for engineers and hobbyists to integrate wireless features without the hassle and expense of engineering RF functionality from scratch. Design services including board layout assistance, programming, certification advice and packaging design.
everythingRF wishes to thank everyone who stopped by their booth at the IMS2014 trade show in Tampa. These newsletters highlight some of the products, white papers, etc., that were featured at the show.
16-year-old David Hamilton won 2nd place in the Math-O-Vision contest held by Dartmouth College's computer science and math departments. David uses the recently popular stop-motion cinematography method for rapid hand-drawn illustrations that are accompanied by narration on how the GPS system works. His 7-year-old sister, Lizzie, provides the voice-over and dramatic hand/arm gesticulation during personal shots. 1st place was a video titled "How I Met Your Mather," by Tim Schauer. It was humorous, but I like David's video better since it actually demonstrates a math application for a familiar topic. Besides, the Hamiltons live just a few miles from me, so plugging local talent is an expected courtesy.
We are passionate about developing products that work better, and we have been delivering on that passion for 25+ years, helping dozens of companies bring innovative wireless products to market in a variety of markets. We design and develop products that analyze, measure, control, and communicate. Our in-house developed customizable, modular wireless platform, RFOS™ , allows us to do this better, faster and with less NRE cost.
You and I know them as 'varactor diodes,' but originally the semiconductor junctions whose reverse bias determines its capacitance was called the 'Varicap.' The new and wondrous semiconductor craze was in full swing by 1958. Scientists, engineers, and hobbyists were burning the midnight oil (to use a popular phrase of the day) performing experiments and designing circuits to replace vacuum tubes and manual controls with transistors and other electrically variable semiconductors. The Varicap had the ability to tune receiver and transmitter oscillators and filters without the need for high tube bias voltages and large mechanically variable...
For the first time, according to Bloomberg Businessweek's demographic data assimilated from 2008 to 2012, Asian Americans became the majority tech workforce constituents in California's Silicon Valley: 50.1% vs. 40.7% for Whites. The map to the left shows where The Valley's immigrant (foreign and domestic) workforce comes from. Circle size indicates the relative number of people and distance from the center indicates how far they have traveled to get there. The standout circle represents immigrants from Mexico, which is interesting since this map purportedly reports on "Tech Immigrants: A Map of Silicon Valley's Imported Talent." I could be wrong, but I seriously doubt that all - or even the majority...
Stimson's Introduction to Airborne Radar, by Hugh D. Griffiths, Christopher Baker, and David Adamy. Has any technical book, radar or otherwise, presented the fundamentals and applications of a topic with such clarity and interest as George Stimson’s masterpiece has? Over 50,000 happy Stimson owners would say, "Not likely!" Now a skilled and respected team of radar and EW engineers, working closely with a community of radar advisors and the publisher’s editors, have fully modernized coverage and maintained the unique Stimson look and feel. Even the "timeless principles" and core fundamentals of general radar have been updated...
Antenna Factor is a world leader in cost-effective antennas. Standard and custom products are available to support a wide variety of OEM applications. Our monopole, dipole, embeddable, GPS, fixed-point, and many other varieties of antennas are designed to offer maximum performance at a cost-effective price.
NuWaves Engineering currently has need of an RF Design Engineer to design and develop RF circuits, components, and systems, create documentation, and support customer needs. Experience with amplifiers and frequency synthesizers is required. An RF Engineering Technician is also needed to support design and production efforts using a variety of solder and rework tools, test equipment, and laboratory organizational skills. An Engineering Manager is sought to write proposals, direct engineering and manufacturing activities, set and analyze financial goals, oversee staffing, and perform RF design as required.
Asian Circuits, with its HQ in Toronto, Canada, and production facilities in China, has emerged as a well known turn-key PCB assembly service provider. Asian Circuits is known for providing electronic manufacturing services, including PCB fabrication, components sourcing, and complete electronic assembly. We cater to customers primarily located in the U.S. and Canada.
"Bill Gates is a very rich man today... and do you want to know why? The answer
is one word: Versions."
- Dave Barry, humorist.
Advancing the Wireless Revolution®. The wireless revolution that brought smart phones and wifi-enabled everything to you, is largely thanks to AWR. Our software is what microwave and RF engineers use to design wireless products... from base stations to cellphones to satellite communications. We accelerate the design and product development cycle of high-frequency ICs and systems found within the aerospace/defense, semiconductor, computer, consumer electronics, and telecommunications markets.
Earlier this year, two analog and microwave component corporate giants, RF Micro Devices (RFMD) and TriQuint, announced a merger that took the industry by surprise. Yesterday, we were knocked back on our heels again by a headline telling of plans for Analog Devices and Hittite Microwave to merge into a single company for a paltry $2.45B. Not being a business or finance guru, I don't know whether to interpret the actions as a sign of a booming economy or a desperate attempt to keep making a profit in bad times. Regardless of the motive, I wish the companies and, most importantly, their employees well...
Do a Google search on "variable inductance servo" or "inductive feedback servo" and you will not find anything useful. That alone these days is sufficient to prove that the concept never caught on in popularity. I don't think it is because the configuration is not good, it is just that the problems associated with early potentiometer feedback elements were solved long ago. Prima facie evidence of that is seen in the millions upon millions of servos sold yearly for model airplanes, helicopters, cars, boats, and drones. They all use servos with potentiometers mechanically coupled to the rotating output shaft. That said, this article is an excellent example of research and development...
Anatech Electronics has released new designs for a 2033.5 MHz cavity bandpass filter, a 2077 MHz surface mount SAW bandpass filter, and a 2002.5 MHz surface mount ceramic bandpass filter. All can be ordered directly through their AMCrf web store.
It wasn't until I moved to Vermont in the mid 1980s that I first heard about cow tipping (which is mostly just legend). Now there is a high tech version of cow tipping known as Smart Car tipping, and it is definitely NOT legend. 'Smart' began as an adjective that referred to a class of hybrid cars whose small, lightweight form factor resulted in high fuel efficiency, but 'Smart' became a noun when Mercedes-Benz capitalized on the nomenclature to name its car that. Hopefully, only the all-electric Smart Cars are being tipped or the eco-warriors...
NoiseWave Corporation is an international supplier of noise sources and test equipment. At NoiseWave, we have one goal: to give you the most reliable, the most advanced and the most cost effective Noise products, while providing unmatched, superior service. NoiseWave was founded by microwave and RF engineers with many decades of design experience in noise theory and noise fundamentals! Only experts with hands-on experience in AWGN could deliver such a high quality product and the personal service.
With the addition of the new R&S SGU100A RF upconverter, Rohde & Schwarz expands its tried and tested R&S SGS100A vector signal generator to cover microwave applications. The combination of the two instruments yields the most compact vector signal source on the market with up to 20 GHz. The R&S SGU100A is available as a pure CW upconverter or as an upconverter for I/Q-modulated signals
Just before Christmas in 1947, Bell Labs' John Bardeen, Walter Brattain, and William Shockley announced their invention of the first semiconductor device capable of producing positive signal amplification. They dubbed it the 'transistor' because it was a transconductance amplifier. In very short order, the laboratory experiment consisting of a metallic point contact (a piece of gold foil) interfaced with a slab of purified and doped germanium became commercially available at a price that easily competed with a vacuum tube...
That Hugo Gernsback was a profound and prolific visionary is obvious by anybody's estimation. Throughout the early and middle 20th century, the man both predicted and participated in as many technical creations as any of his contemporaries. Being a publisher of both science fiction and science fact books and magazines, Gernsback wrote of fantastic inventions ranging from weapons to medical equipment to space travel (and the vehicles that would shuttle mankind about his quests). Just as Arthur C. Clarke's talents extended beyond sci-fi adventures to include devising a scheme for geosynchronous orbit...
Amplical was founded by Engineers for Engineers. Amplical is determined to be a leading supplier of quality RF microwave components. Utilizing the latest in RF Microwave technology, Amplical focuses on premium quality amplifiers and attenuators at affordable prices. Amplifiers are tuned for exceptional amplitude flatness and our attenuators are designed for precision and the utmost in accuracy. Our products are typically available from stock.
Take a break and let this week's physics and engineering-themed crossword puzzle be a Father's Day present to yourself. All the words are pulled from a hand-built list of terms, names, and abbreviations that have only to do with science, mathematics, and engineering. If you want a crossword with names of movie stars and obscure countries, try the local newspaper.
On June 6, 1944, the Associated Press' (AP) Wes Gallagher filed the first news report from the beachhead at Normandy. The code name was "D-Day" (see today's RF Cafe logo). It has now been 70 years since the day "American, British and Canadian forces landed by daylight in massive strength on the Normandy coast of France today and sped inland from quickly-established beachheads. Gen. Dewight[sic] D. Eisenhower told his troops this grand assault was a crusade which must bring 'nothing less than full victory.'" The animation below shows day-by-day progression of WWII in all theaters of operation - sobering to see how bad things got before the U.S. entered the war.
KEYW is a specialized provider of cybersecurity and geospatial intelligence solutions to commercial enterprises and Government defense, intelligence, and homeland security agencies. They are looking for an innovative RF engineer and technical leader who likes unconventional design work at the component level. This position affords an opportunity to work with a team to design systems that solve complex and unique mission and operational requirements. Most projects involve the entire gamut of engineering: concept, design, development, test
Over the last couple weeks, lots of tassels were shifted from one side to the other and mortarboards tossed into the air at graduation ceremonies. Accordingly, this week's job hunting and career tips lean more heavily toward new college graduates than to the general population.
Finding, Landing and Loving
a Hard-to-Fill Job
- 10 Easy Tips to Take You
from College to Success in
Jobs, Love and Life
- The Top 5 Job-Hunting Tips
for 2014 Grads
- How to Evaluate a Job Offer
to Job Searching
- 10 Career Tips For a
-Making the Most of an
- Career Tips from the World's
Skyworks Solutions today unveiled a suite of new, ultra-low noise amplifiers (LNAs) for cellular infrastructure, wireless connectivity and broadcast communication applications. The new LNAs provide best-in-class noise figure as well as high gain and linearity, improving receiver sensitivity and dynamic range. Receiver sensitivity is a key specification of any radio used in wireless communications given its important role in detecting and separating signals, as well ensuring effective operations. "Skyworks' new ultra-low noise amplifiers offer unprecedented performance levels for 4G wireless
Honestly, I don't remember why I scanned this advertisement for Sarkes Tarzian recorder tape that appeared in a 1962 edition of Popular Electronics. Maybe it was to illustrate how far personal recording technology has come in the half century since the ad ran. Today's recorders are in the form of a very small digital device the size of a pack of gum, and not only is the miniature recorder capable of storing longer sessions, but the quality of the recording is probably better. The cost of a digital recorder is about the same...
BOSH specializes in unmanned systems-related operations and technology services (sUAS). They are currently looking for an engineer with extensive knowledge and experience in RF communication for line-of-sight and beyond line-of-sight technologies. Knowledge and experience with military (e.g., UHF, C-band, S-band) and commercial (e.g., GSM, W-CDMA, LTE) radio systems, and leadership experience on technical projects is required. Design, test and implementation of RF systems delivering real-time video and other data for military aerial platforms (aka drones - a great opportunity for sport aeromodelers).
These days, not being on the right side of a government enforcement agency can cost your your life, liberty, and/or pursuit of happiness - just ask about it from politically antipolar citizens who have been descended upon physically by armed commando teams or financially crippled by the IRS or EPA. The meaning of law is nowadays declared to be whatever the bureaucrat involved thinks it should be, and nobody dares to challenge it. Amateur radio operator Daniel G. Churovich, N9RSY, of Ripley, Tennessee, recently learned how failing to comply with one FCC lawyer's interpretation of Section 97.111(a)(1) - see letter below - can result in a scary contact...
Wireless Hall of Fame
Inductees for 2014
Do you know there is a Wireless History Foundation, whose charter it is, "to preserve and promote the history of the wireless industry?" Bill Carlson, Rob Conway, Sam Ginn, and Dr. Jan Uddenfeldt certainly do since they are the 2014 inductees into the Wireless Hall of Fame. "The selection committee easily recognized that these inductees have all made unique, personal and important contributions in selecting them for the Wireless Hall of Fame...
Carl & Jerry
Ultrasonic Sound Waves
Aside from the storyline, one notable aspect of this installment of Carl & Jerry is one of the illustrations used in it. Jeff Duntemann (K7JPD), himself a sci-fi and technical book author, wrote a piece on the evolution of John T. Frye's Carl & Jerry series in Popular Electronics, and in it he commented on the changes in drawing styles and character appearances over the many years that Frye inked his illustrations. I read Duntemann's article a while ago, but remembered the picture of Norma and Carl's dog Roscoe when I saw it again just now. The format obviously departs from the vast majority of Frye's typical works due to its distinctly cartoonish look. As for the plot of the story...
Vector Circuit Matching Quiz
This vector circuit matching quiz will hurt the brain a little more than most of the ones that were printed in Popular Electronics. In order to score well, it helps to visualize the circuits relative to where they would appear on a Smith Chart. Capacitive impedances lie in the bottom half and have negative phases (-s, -jω). Inductance lie in the upper half and have positive phases (s, jω). The familiar 'ELI the ICE man' mnemonic helps, too. Be sure to pay attention to the color of the vector arrow heads. Example: In a purely inductive circuit like #4, voltage leads current by 90°. Since phase rotation...
Skyworks Cedar Rapids Team
Seeking RF Design Talent
If you enjoy working in a highly collaborative, fast paced environment designing RF products in today's wireless technology, then this is the opportunity for you! In this role you will be part of a product development team composed of other design engineers, technicians, and layout designers effectively planning and executing RF/analog IC and printed circuit board designs to meet critical deadlines within cost and performance criteria provided by customers and marketing. You will face challenging performance parameters in the design of power amplifiers
R&S Upgrades SMW200A
Vector Signal Generator 20 GHz
Rohde & Schwarz has expanded the frequency range of its R&S SMW200A high-end vector signal generator to 20 GHz. The R&S SMW200A is the only instrument on the market to combine a baseband generator, RF generator and fading simulator in a single box. In addition, the R&S SMW200A can be equipped with a second 20 GHz path, making it possible to simultaneously generate up to two wideband microwave signals with any type of modulation. For these types of complex setups, other solutions require at least three devices - and considerably more
Vacuum Tube Amplifier Basics
Tubes and Circuits, by Bruce Rozenblit. The most up to date vacuum tube design book currently available. Packed with information...Loaded with projects...Nothing like it anywhere! Join Transcendent Sound's Bruce Rozenblit as he takes you on a journey from the basics of tube circuitry, through advanced designs. Tubes and Circuits is a condensed engineering manual that teaches the theory and operation of vacuum tubes—as well as circuit design. In addition, five projects are included that you can build that provide step-by-step design procedures...
GemTune GS-02 KT88
Vacuum Tube Audio Amplifier
Audiophiles rejoice: What's old is new again! If you have been longing for the fabled tones that, according to the Apollonic faithful, only a vacuum tube amplifier can produce, then the GemTune GS-02 might be what you have been seeking. Of course you could buy a vintage tube amp off of eBay or at a Hamfest, but maybe you don't have time or knowledge or desire to recondition it. One nice feature of the GemTune GS-02 is that the five vacuum tubes it uses, one (1) each 5Z3PA and two (2) each KT88 (matched pair) and 12AX7, are readily available, whereas you could have trouble...
Sr. RF Engineer Position
with Applied Instruments
Applied Instruments has a position available for a Sr. RF Engineer. The senior RF engineer is responsible for the design of RF circuits and circuit boards for use in test instrument products. Products range in frequency from 5 MHz to 3 GHz. All RF aspects of product development are included: feasibility analysis, component selection, schematic creation, board layout, prototyping, and testing. Projects include signal generators, tuners, receivers, demodulators, filters and amplifiers. Preference will be given to experience with modern digital tuner design. Familiarity with various RF signal formats (QAM, QPSK, 8VSB, NTSC) required
WWV Offers Additional Services
WWV is the oldest continuously-operating radio station in the U.S. since first going on the air from Washington, D.C. in May 1920. It moved around an area near D.C. for a few years before being relocated to its current location in Boulder, Colorado, in 1966. WWVB, another time standard transmitter, had already been established in Boulder a few years earlier. Sister station WWVH is located in Hawaii. The National Bureau of Standards (NBS) was renamed National Institute of Standards and Technology (NIST) in 1988, nearly a century after its inception in 1890. Having grown up not too far from...
AWR and ANSYS Partner
to Bring HFSS into MWO
AWR Corporation, the innovation leader in high-frequency EDA software, and ANSYS, Inc., a global leader and innovator of engineering simulation software, announced today that they have integrated ANSYS HFSS into AWR’s Microwave Office™ high frequency circuit design software. This integration unites the industry standard for full-wave EM field simulation and NI AWR Design Environment / Microwave Office to quickly and accurately simulate microwave circuits. With this design flow
"Since many years scientific men engaged in the study of physics and electrical research have taken it for granted that certain quantities, entering continuously in their estimates and calculations, are fixed and unalterable. ...some of the quantities referred to are variable and that, owing to this, a large portion of the technical literature is defective." - Nikola Tesla, New York Sun, January 30, 1901
Congrats to Chris M. for
Winning the May Drawing!
Chris M., of Durham, NC, is the May 2014 book drawing winner. Chris opted for Antennas and Site Engineering for Mobile Radio Networks, by Bruno Delorme. Each month I randomly select a name from the people who order one of my software items and offer them a free book; I even pay shipping. Graciously provided by Artech House
"What are these devices?" "How do they work?" "What are their characteristics?" "How are they used?" Those are the kinds of questions about semiconductor diodes posed - and answered - in this article in a 1961 issue of Popular Electronics. Author Jim Kyle runs through a short history of he diode and then delves with more detail into physical construction, I-V curves, power handling, junctions capacitance, resistance, etc. An interesting point mentioned is that while a semiconductor diode will conduct some finite amount of current when biased in the reverse direction (sometimes a desired characteristic), a vacuum tube diode will not conduct at all when reverse biased...
KR Electronics part number 3154 is a 1325 MHz bandpass filter. The filter has a minimum 2 dB bandwidth of 750 MHz. An Elliptic type filter is used for high selectivity. Typical insertion loss is <1 dB. The filter is supplied in a small surface mount package measuring .88" x 0.38" x 0.235". Other frequencies and bandwidths are available.
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.
EDN, Microwave Product Digest (MPD) have published another find batch of articles. This is a sampling of ones that interested me most, but your needs might be different, so be sure to check out everything offered.
Δ Ultra Low Noise Amplifiers,
(I know Jody - good guy!)
Δ How Much Return Loss is
Too Much?, E. Bogatin
Δ Reduce Defense Products
Cost, Lead Time with Highly
Δ Troubleshooting EMI on
Your Bench Top, K. Wyatt
Δ GaN Solutions for Next
Δ Measure Throughput of
Cellular and WiFi MIMO
Radios, F. Mlinarsky