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About RF Cafe

Kirt Blattenberger - RF Cafe WebmasterCopyright
1996 - 2016
Kirt Blattenberger,

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.

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Homepage Archive May 2013

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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2013:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

Please click
here for 5/1/2013 through 5/15/2013

Many Thanks for Windfreak
Tech's Continued Underwriting

Windfreak TechnologiesWindfreak Tech designs, manufactures, tests and sells high value radio frequency products such as RF Signal Generators, RF Synthesizers, RF Power Detectors, RF Mixers, RF Upconverters and RF downconverters. They develop high quality, reliable, low cost products to make your life easier. Windfreak Tech is developing high quality, low cost products to make life easier for RF Engineers and hobbyist. Future products will be more synthesizers, transmitters, receivers and test equipment. All at low cost. Please note that Windfreak Tech has relocated to Florida.

Empower's Live Demo
of 20-1000 MHz, 1 kW PA

Empower's Live Demo of 20 to 1000 MHz, 1 kW PA Highlights Unrivaled Size and Power Advantages - RF CafeContinuing to build momentum and recognition for their "Size Matters" HPA platforms, Empower RF Systems is hosting live demonstrations of their 1 kW, 20 to 1000 MHz, 5U chassis design (model 2162) at IMS 2013, Booth 1827. Packaged in a 5U, air cooled chassis and delivering over 1 kW of output power, three specific models are released (in the frequency ranges of 20 to 500 MHz, 500 to 1000 MHz, and 20 to 1000 MHz), and more on the way based on an amplifier architecture that offers unrivaled size / power advantages. Specs are guaranteed across full bandwidth and over temperature. Embedded controls and user access are standard.

Heathkit Resurrection
in the Works - Again?

Heathkit Resurrection in the Works, Again? - RF CafeI saw a headline on EDN about Heathkit being back - again. They reappeared a couple years ago with a few small build-it-yourself electronics kits, but that quickly died out. I immediately went to the Heathkit website and saw its sole content, the U.S. postage stamp with Mark Twain (Samuel Clemens) speaking his famous quote, "Just say the report of my death has been grossly exaggerated." Pretty clever. There are no hyperlinks, just the stamp, copyright info, and the Heathkit logo. The EDN article had a link to an online survey asking people what they want to see in the way of kits. In case you don't know the origin of the Twain quote, here is Bartleby's attribution: "In 1897, Twain was living in London where a cousin, Dr. Jim Clemens, fell ill. The newspapers, believing Twain was near death, sent reporters to investigate. Twain made his remark when the correspondent for the Evening Sun told him his death had been reported in New York, and asked what he should cable in reply." (Bartleby, of "I would prefer not to." fame, was the scrivener in Melville's eponymous story)

Thanks to Venture
Technologies for Support!

Venture TechnologiesVenture Technologies Designs and develops innovative wireless products. They design and develop products that analyze, measure, control, and communicate. In-house developed customizable, modular wireless platform, RFOS™ , allows them to do this better, faster and with less NRE cost. Venture wraps their core embedded wireless capability in full service "spec to production" product development.

Tales from the Cube:
Resistor Turned Strain Gauge

Tales from the Cube: Resistor Turned Strain Gauge - RF CafeTales from the Cube is an occasional feature published by EDN. It is akin to Sherlock Ohms in that readers submit stories of personal experiences. This is an interesting account of troubleshooting a circuit under extremely pressing conditions - it might determine whether the maiden flight of the F-117A Nighthawk would happen on schedule. Author Edward Nauman worked at Lockheed Skunk Works. Commercial-off-the-shelf (COTS) usage was an unknown entity in the day for such projects, so when a specially selected and vetted part ended up having an inherent design shortcoming, it could really spell disaster for the end user design team. Interestingly, the ensuing discussion by readers ends up debating the spelling of 'gauge' vs. 'gage.'

Getting to Know the UJT

Getting to Know the UJT, April 1970 Popular Electronics - RFCafeThe unijunction transistor (UJT) was originally known as a 'double-base diode' and explains why to this day the terminals are labeled 'E,' 'B1,' and B2.' It is commonly modeled as a diode connected between two resistors, with one resistor being variable. As the name implies, unlike a bipolar junction transistor (BJT) that is more familiar to most people and has two semiconductor junctions connected to the base, a UJT has just one junction. As is explained in detail in the article, the net effect of the UJT's arrangement is a region of negative resistance which makes it good for use as an oscillator. In fact, the relaxation oscillator was one of the most popular uses of the UJT.

Frequency Modulation

Frenquency Modulation Fundamentals, August 1939 QST - RFCafeFrequency modulation (FM) was, is, and shall always be: x(t) = Xc·cos [Ωct + β·sin (Ωmt)], where the carrier is xc(t) = Xc·cos (Ωct), and the modulating signal is xm(t) = β·sin (Ωmt). Yea verily, thus sayeth Edwin H. Armstrong. Amen. The methods for generating and degenerating[sic] FM might vary, but the fundamentals do not vary. Mr. Armstrong developed and patented his system of frequency modulation in the late 1920s and early 1930s, so when this article appeared in QST in 1939, FM was still fairly new - or even unknown - to most people. Household radio dials still had only markings for the commercial AM band (520 - 1720 kHz) and, in a few cases, a couple shortwave bands (also AM). The information presented here is suitable for study by anyone at any time.

Asteroid QE2 Close Pass
to Earth on Friday

Frank & Ernest Asteroid Comic, May 13, 2013 - Airplanes and RocketsYou have probably seen the news about asteroid "QE2" (1.5 miles wide, like the one which eradicated the dinosaurs) that will pass within 3.6 million miles of the Earth on May 31. That might seem like far, but it is only 15x the distance between Earth and the moon. Anyway, this Frank and Ernest comic strip appeared on May 13th and I cut it out to remind me to post it today, on the eve of QE2. QE2, BTW, is a nerd pun on the potential destruction to Earth that the government's Quantitative Easing policy might cause.

Featured Book
Please Support RF Cafe

Featured Book: Digital Front-End in Wireless Communications and Broadcasting (Cambridge University Press) - RF CafeDigital Front-End in Wireless Communications and Broadcasting: Circuits and Signal Processing, by Fa-Long Luo. Covering everything from signal processing algorithms to integrated circuit design, this complete guide to digital front-end is invaluable for professional engineers and researchers in the fields of signal processing, wireless communication and circuit design. Showing how theory is translated into practical technology, it covers all the relevant standards and gives readers the ideal design methodology to manage a rapidly increasing range of applications. Step-by-step information for designing practical systems is provided, with a systematic presentation of theory, principles, algorithms, standards and implementation.

Z-Communications Intros
390 to 440 MHz VCO

 The CRO0419A-LF is designed to operate between at 390 and 440 MHz within a tuning voltage range of 0.5 to 5 Vdc.Z-Comm announces a new RoHS compliant VCO model CRO0419A-LF for P25 mobile radios and basestation equipment. The CRO0419A-LF is designed to operate between at 390 and 440 MHz within a tuning voltage range of 0.5 to 5 Vdc. This VCO features phase noise of -117 dBc/Hz @ 10 kHz offset and a typical tuning sensitivity of 17 MHz/V. The robust CRO0419A-LF provides the end user typical output power of -4.0 dBm into a 50 Ω load while operating off a 5 Vdc supply and drawing 40 mA.

Entertaining Uncle Oscar

Entertaining Uncle Oscar, August 1939 QST - RFCafePopular comic strips (aka 'funnies') in the 1930s and 1940s featured numbskulls, ne'er-do-wells, and simpletons. There was usually one character in the strip's cast that was smart - at least in a relative way if not absolute. Being familiar with some of the old comics like Blondie, Barney Google, Krazy Kat, Beetle Bailey, Gasoline Alley, etc., I can see a definite relationship between the story line of "Entertaining Uncle Oscar" and the comics of the era in this short piece that appeared in a 1939 edition of the ARRL's QST magazine. As you might guess, the feller named 'Ham' is the smart one. 

NuWaves Engineering's
May 2013 Newsletter

NuWavesNuWaves has published its MayNuWaves has published its May 2013 newsletter. They invite you to meet them at the MTT-S show in Seattle, introduce a new bi-directional RF amplifier for the L and S bands, and tell a little of what they've been up to.

American Standard Circuits
Continues Sponsorship

American Standard CircuitsRF Cafe depends on the generosity of advertisers to provide me with enough income to subsist on. American Standard Circuits has been doing so for many years. Please visit their website to see whether they offer anything you can use. The ASC staff is made up of world class, highly experienced Ph.D. materials scientists, engineers, Six Sigma black belts, and several Six Sigma green belt candidates undergoing training. ASC has state-of-the-art process control systems.

Anatech Electronics Offers
Free MTT-S  IMS2013 Passes

IMS2013 Admission PassesAnatech Electronics, Inc. has free passes for the 2013 MTT-S IMS show in Seattle Washington. These passes allow complimentary access to the IMS exhibition floor. We are offering passes on a first come first serve basis. If you are planning to attend and would like to obtain these passes please contact us as soon as possible. It happens next week!

Printed Circuits

Printed Circuits, January 1950 Radio & Television News - RF CafeWhen you think of printed circuits, probably what comes to mind is what is really a photo-etched circuit board. In the early days of printed circuits a lot of the circuits actually were 'printed' on a  substrate of some sort. A silkscreen process was often used for low resistance interconnects and printed inductors, as well as for printed resistors on materials like fiber, plastic, phenolic, and even (yikes) asbestos board. There is still what is called a thick film screen printing process used today primarily in military systems, but overwhelmingly the photo etching process is used to generate circuit boards. In the era of vacuum tubes, it was not uncommon to have grid biasing circuits printed directly on the glass enclosure using a resistive paint and then trimming for the target resistance by removing excess material. This article shows an example of a circuit printed on a 6J6 twin-triode tube.

Technical Aspects of
Naval Communications

Technical Aspects of Naval Communications, December 1950 Radio & Television News - RF CafeThe December 1950 issue of Radio & Television News ran a series of articles on Navy communications. This was a mere four years after the end of World War II and right at the beginning days of the Korean War. Communist and fascist regimes never give the world a moment's rest (some - not me - think just being nice to them will cause them to be nice in return). Discussed here are issues still relevant to modern outfitting of naval assets with new or updated communications equipment. Unlike land-based systems, naval environments impose increased requirements for ruggedness due to harsh vibration, impact, and corrosion issues. Weight added above the waterline needs to be offset with weight below the water line to preserve stability. Reliability and personnel training also need to be increased because being at sea means access to replacement parts, operators, and service technicians are harder to accommodate. The military people (officer and enlisted) who do the work do so out of dedication and a sense...

Thanks to Vector Telecom
for Long-Time Support!

Vector TelecomPlease take a moment to visit Vector Telecom to see whether they have products useful to you. Vector Telecom has fully instrumented microwave, millimeterwave, & antenna laboratories and production facilities. Their professional engineers have backgrounds from telecommunications, electronics, space and aviation industries, with frequencies up to 50 GHz and at globally competitive prices.

Effective Tax Rates of
U.S. Corporations

Across U.S. Companies, Tax Rates Vary Greatly - RF CafePerhaps the most interesting aspect of this chart is the animated way in which it changes shape when you click the "Show Industries" button. As technology and human capability increases over time, our expectations increase for more sophisticated and entertaining presentations be they business reports or movie scenes. This Javascript-enabled chart plots U.S. corporation effective tax rates. Those to the left of the mean line paid the least. Circle size indicates total earnings. So, a big circle to the left indicates big revenue and low taxes paid. Apple is one of the largest circles with $135B earnings and a 14% tax rate. Amazon, at $5.5B, paid 6%. Google paid 17% on $56B. Warren Buffet's company paid 23% on $96B. On the other side of the line lies Exxon Mobile at 37% on $395B earnings. Pharma giant Pfizer paid 43% on $63B, Chevron paid 39% on $220B. As a group, Utilities and IT companies paid the least while energy and insurance paid the most. In the light of the current IRS scandal, an interesting dimension to add to the chart would be donations by corporate chieftains to political parties. BTW, my effective tax rate for 2012 was 37% (Fed alone was 26%).

Microwaves for the "Ham"

Microwaves for the "Ham", August 1952 Radio & Television News - RF CafeWhile this article is directed at amateur radio operators who want to explore working in the microwave bands, it is good fodder for anyone who wants a fundamental introduction to waveguides, resonant cavities, distributed elements, and atmospheric propagation. If that describes you, and particularly if you have formulaphobia, then start reading. Even though the article appeared in a 1952 issue of Radio & Television News, the list of frequency band allocations are not much different than today so the information is useful.

New "Pay-As-You-Watch"
Television System

New "Pay-As-You-Watch" System, August 1953 Radio & Television News - RF CafeOn-demand television is a concept that has existed about since the time commercial broadcast TV first came on the scene. Known as "Boxoffice Television," it used a "Picture-caster" to scramble the picture so that a subscriber needed a rented descrambler in order to view the program. A rented key (physical, not digital) was used to turn the box on and off. The signal went out over a standard local broadcast tower or even over coaxial line. Channels 2 through 13 were it for the day.

Linx Technologies' CEO Gets
Service Member Patriot Award

Linx Technologies' CEO Tolga Latif Receives Service Member Patriot Award - RF CafeTolga Latif, CEO of Linx Technologies, has received the Service Member Patriot Award sponsored by the Employer Support of the Guard and Reserve (ESGR). This award recognizes supervisors and bosses nominated by an employee serving in the National Guard or Reserve for support provided directly to the nominating Service Member. The Patriot Award reflects the efforts made to support the ‘Citizen Warriors’ through a wide-range of measures including flexible schedules, time off prior to and after deployment, caring for families and granting leaves of absence if needed.

As True Today as in 1863

Memorial Day - RF Cafe"Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal. Now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and so dedicated, can long endure. We are met on a great battle-field of that war. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live. It is altogether fitting and proper that we should do this. But, in a larger sense, we can not dedicate - we can not consecrate - we can not hallow - this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great task remaining before us -- that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion - that we here highly resolve that these dead shall not have died in vain - that this nation, under God, shall have a new birth of freedom -- and that government of the people, by the people, for the people, shall not perish from the earth." - President Abraham Lincoln

Notable Quote

Notable Quote: "Luck is what happens when preparation meets opportunity" - RF Cafe"Luck is what happens when preparation meets opportunity." - Lucius Annaeus Seneca, 4 BC - A.D. 65 (thanks to Ted B.)

Wireless Crossword Puzzle
for May 26, 2013

Wireless Crossword Puzzle for May 26, 2013 (Memorial Day) - RF CafeEvery 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. This is a special puzzle in honor of Memorial Day (originally Decoration Day) in the USA.

Isolink Intros Dual Channel,
Radiation-Tolerant Optocoupler

Isolink Intros Dual Channel, Radiation-Tolerant Phototransistor Optocoupler - RF CafeIsolink, a subsidiary of Skyworks Solutions, is pleased to offer a new dual channel, radiation-tolerant, hermetic surface mounted phototransistor optocoupler that is designed for high-reliability military and medical applications requiring optical isolation in gamma, neutron and proton radiation environments with high current transfer ratio and low saturation Vce. Each optocoupler channel consists of a light emitting diode and NPN silicon phototransistor that is electrically isolated but optically coupled inside a hermetic 8-pin leadless chip carrier package. 

Printed Circuits (c.1949)

Printed Circuits, December 1949 Radio & Television News - RF CafeMost people today under 30 years old have probably never seen the mechanics or electronics inside their many personal devices. Everything is so miniaturized and optimized that if something does go wrong, there is little chance of the owner repairing it. Instead, the phone, television, stereo, microwave oven, whatever, gets thrown away and a relatively cheap (compared to paying for a repair) replacement is purchased (or stolen). Besides, if the item was more than two years old, it was on the verge of obsolescence anyway. Up until around the early to mid 1980s you had a fair chance of being able to repair an electronic circuit if trouble arose because at least with commercial products printed circuit boards were usually 1- or 2-sided and the components still had leads protruding from the sides of the packages. A $10 Radio Shack soldering iron and some solder wick was sufficient...

Sales Engineer Needed
by Trak Microwave

Trak Microwave Sales Engineer Job May 25, 2013 - RF CafeTrak Microwave, a division of Smiths Interconnect, has an opening for a Sales Engineer. The Sales Engineer provides sales management and technical support in pursuit and capture of new product development and recurring business opportunities. For over 50 years, Trak Microwave has delivered reliability and performance to every mission. Trak Microwave designs and manufactures a diverse range of RF and microwave integrated assemblies, subsystems, components and time and frequency systems for defense, space and commercial applications worldwide.

Z-Communications Intros
1250 to 1400 MHz VCO

Z-Comm Intros 1250 to 1400 MHz VCO - RF CafeZ-Comm announces a new RoHS compliant VCO model USSP1325-LF in the L-band. The USSP1325-LF operates at 1250 to 1400 MHz with a tuning voltage range of 0.5 to 4.5 Vdc. This miniaturized VCO features phase noise of -100 dBc/Hz @ 10 kHz offset while operating off a 5 Vdc supply and typically drawing only 25 mA of current. The USSP1325-LF provides the end user an output power of 3±3 dBm into a 50 Ω load while operating over the industrial temperature range of -40 to 85 º C. 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.

R&S FSW50 Signal and SA
for WB Signals up to 50 GHz

The R&S FSW50 Signal and Spectrum Analyzer Characterizes Wideband Signals Continuously up to 50 GHz - RF CafeRohde & Schwarz has increased the frequency range of its high-end R&S FSW signal and spectrum analyzer to 50 GHz. In conjunction with analysis bandwidths of up to 320 MHz, the new microwave model is perfect for sophisticated R&D measurements and for radar and satellite applications. The new high-end R&S FSW50 signal and spectrum analyzer is ideal in the development, testing, verification and production of transmitters and components such as those used in radar applications and satellite and military communications systems. The analyzer covers the frequency range from 2 Hz through 50 GHz.

Anatech Introduces 4 Filters,
Power Divider, Coupler

Anatech Electronics Introduces New Products, 5-22-2013 - RF CafeThis new product announcement month highlights a 913 MHz outdoor cavity BPF, a 2440 MHz cavity BPF, a water-resistant 5350 MHz cavity BPF, a 380 to 2500 MHz 2-way power divider, a 800 to 2500 MHz 8-dB directional coupler, and a 800 MHz LPF. Anatech Electronics' Sam Benzacar invites you to visit them in booth #2710 at the IMS 2013 trade show in Seattle, Washington.

Symmetricom Looking for an
R&D Hardware Engineer

Symmetricom Looking for an R&D Hardware Engineer - RF CafeSymmetricom is a world leader in precise time solutions. The company generates, distributes and applies precise time for the communications, aerospace/defense, IT infrastructure and metrology industries. As an R&D Hardware Engineer, you will be designing and developing leading edge timing solutions, and supporting production for a variety of precision frequency source applications in the space, defense, and avionics industries. In particular, you will be the responsible Project Engineer for various precision Rubidium and crystal oscillator projects at the component and sub-system level involving synthesized reference sources. The detailed responsibilities include

RF Cafe Quiz: High-Frequency
Integrated Circuits

RF Cafe Quiz #49: High-Frequency Integrated Circuits - RF CafeThis quiz is based on the information presented in High-Frequency Integrated Circuits, by Rosin Voinigescu (printed by Cambridge University Press). The book is an incredible repository of information that would be an immensely valuable resource for any circuit designer whether dealing with discrete components or laying out an integrated circuit substrate.

Revolutionary New

Revolutionary New Oscillator-Amplifier, June 1955 Radio Electronics - RF CafeWhen I read about Du Mont's Iconumerator, the first thing that came to mind was the video of the Rockwell Retro Encabulator and General Electric's Turboencabulator. As it turns out, the Du Mont device is real. This article from a 1955 issue of Radio Electronics discusses a new type of oscillator-amplifier that works on the principle of microwave amplification by stimulated emission of radiation (maser). It used ammonia as a masing medium. Masers were quickly applied to commercial broadcast systems, to military communications systems, and in laboratories. The state of the art has of course advanced far beyond the relatively crude apparatus shown here, but it is always good to have a working knowledge of the technology's history.

RF Cafe Poll
Started  May 22, 2013

Engineering Poll beginning 5/15/2013 "Will you attend IMS2013 in Seattle?" - RF CafePlease take a moment and vote in this poll. No sign-in-required. Results are displayed automatically. Thanks! See current.

10 Tips for a Successful
Engineering Resume

10 Tips for a Successful Engineering Resume - RF CafeYep, this is another Top 10 list for you. I am surprised to see that a 1-page resume still tops these resume writing tip lists, but evidently it is what busy (or not so busy) hiring managers want to see. Most of the bullet points are things like... using bullet points to organize and focus related topics, not mixing font types, etc. One interesting piece of advice is if you are a new grad and do not have intern experience to list DIY projects (related to your field of study, of course).

A couple other resources:

Job Hunting After 50
Top Talent Leaving China
   for Clearer Skies
Attracting Recruiters to
   Your LinkedIn Profile

Featured Book
Please Support RF Cafe

Featured Book: Handbook of RF and Microwave Power Amplifiers (Artech House) - RF CafeHandbook of RF and Microwave Power Amplifiers, by John L. B. Walker. Whether you are an RF transistor designer, an amplifier designer or a system designer, this is your one-stop guide to RF and microwave transistor power amplifiers. A team of expert authors brings you up to speed on every topic, including: devices (Si LDMOS and VDMOS, GaAs FETs, GaN HEMTs), circuit and amplifier design (discrete, hybrid and monolithic), CAD, thermal design, reliability, and system applications / requirements for RF and microwave transistor amplifiers. Covering state-of-the-art developments and emphasizing practical communications applications, this is the complete professional reference on the subject.

AWR Announces Agenda
of Activities for IMS 2013

AWR Announces Agenda of Activities for IMS 2013 - RF CafeAWR Corporation is a gold sponsor and will offer a full agenda of activities at the International Microwave Symposium (IMS) 2013 that inform and educate attendees about new ways to use RF/microwave software for circuit and system design. IMS 2013 takes place from June 4 to 7 in Seattle, Washington. In its Booth #330, AWR will showcase software demonstrations of key features in its current product release, v10, as well as a sneak-peek preview of features within its pending v11 release.

Acoustical Tile - A New
Hi-Fi Component

Acoustical Tile - A New Hi-Fi Component, October 1959 Popular Electronics - RFCafeWhile acoustical tiles are not exactly the stuff of RF engineering, their properties and their effects on sound waves are analogous to RF absorbers and their effects on electromagnetic waves. Reflections that cause multipath reception of signals that contain the same information but are out of phase and unequal in amplitude to the primary (direct) path seldom combine to enhance the overall signal-to-noise ratio, so placing absorbent material in the surrounding environment is necessary to improve signal quality. This article from Popular Electronics goes through the process of outfitting an area with acoustical tiles and give some empirical test data from before and after. 

PMI Intros 26.5 to 40 GHz
High Power Limiter

PMI Intros 26.5 to 40 GHz High Power Limiter - RF CafeModel LM-26G40G-14-20W-292MM is a high power limiter capable of withstanding an input power level of 20 Watts, 440 to 670 nsec Pulse Width, PRF 600 to 900 kHz, 40% Duty Cycle. This model operates in the 26.5 GHz to 40 GHz frequency range. The insertion loss is 4.0 dB maximum, VSWR of 2.0:1 and 250 nsec response time and a typical leakage of +14 dBm. This limiter is packaged in a small 0.50 X 0.50 X 0.22 housing and is supplied with 2.92mm male connectors.

Become a Patent Agent

Become a Patent Agent - RF CafeAn article on the IEEE website pitches a career as a patent research agent, which might be a particularly attractive notion in this lousy engineering job environment we now experience. A law degree is not required for many positions. The average salary range for a patent agent is between $52k and $143k, with a median of almost $90k. One of the first steps in exploring the possibility is to download the United States Patent and Trademark Office's (USPTO) Manual of Patent Examining Procedure (MPEP). Once you are prepared, you pay the required fee and take the exam. I did not see anything that addresses what your chances of being hired are if you pass, or whether you would need to reside in Washington, D.C.

Ham Etiquette (or lack thereof)

Ham Etiquette (or lack thereof) - RF CafeOften in the letters to the editor section of ARRL's QST magazine there are lamentations about an overwhelming lack of technical knowledge and/or proper etiquette and manners amongst fellow Hams. One contributor commented, "Today, it's hard to distinguish a radio amateur from a CB operator." DX operation (long distance) seems to be the most affected aspect, although the problem is fairly widespread. Most writers blame the problem on the ease with which a license may be obtained these days. Ever since a requirement to demonstrate proficiency in Morse code was removed, ostensibly, the quality of operators has plummeted (my license was earned in the sans code test era). That may be so, but I propose the problem is much deeper - it is societal. Every generation whines...

Made by Monkeys:
The Messed-Up RF Generator

Made by Monkeys: The Messed-Up RF Generator - RF CafeMade by Monkeys is a regular feature of Design News. Readers submit stories of instances of what they consider to be terrible product design. Some of the stories are good, but generally I like Sherlock Ohms and Tales from the Cube articles better because they concentrate on troubleshooting rather than complaining. This particular episode belongs in the Sherlock or Tales category rather than Monkeys. In fact, "The Messed-Up RF Generator" experience is just the opposite in nature of something made by monkeys. Read it and see what I mean.

R&S SMW200A High-End
Complex Multichannel VSG

Flexible R&S SMW200A High-End Vector Signal Generator Creates Complex Multichannel Scenarios for Highest Demands - RF CafeThe new R&S SMW200A high-end vector signal generator from Rohde & Schwarz combines maximum flexibility, outstanding performance and intuitive operation to outperform all comparable solutions available on the market. It is the perfect tool for generating complex, digitally modulated signals of high quality. Thanks to versatile configuration options, its range of applications extends from single-path vector signal generator to multichannel MIMO receiver tester.

Please Welcome Supporter
Rohde & Schwarz

Rohde & SchwarzRohde & Schwarz is one of the world's leading manufacturers of test & measurement, communications and broadcasting equipment. They have just joined with my other highly appreciated advertisers to help deliver RF Cafe content to you. Vector network analyzers (VNA), communications and spectrum analyzers, signal generators, and o-scopes (DSO), power supplies are among their offerings. Please visit them today.

Quick and Easy "Lawrence"
Slide Rule Instruction Book

The Quick and Easy "Lawrence" Slide Rule Instruction Book - RF CafeSlide rules were an enigma and a thing to be feared to most people even in the days when handheld digital calculators had not entered the scene. The rows of numbers generally look nothing like a simple, familiar ruler, and the sliding window thingy with the thin line sent kids and adults alike running for the tall grass for cover. As with most things not too complicated, learning to use the slide rule can be mastered with a little instruction. You don't necessarily need to understand logarithms and trigonometry functions, but it certainly helps if you also want to understand how the device works. It is the same thing as not needing to know how your Casio digital calculator works in order for it to be useful. If you do an Internet search for instructions on slide rule usage, there is no shortage of documents. This one from Lawrence I believe does a particularly good job because it is filled with examples of the most common types of mathematical operations, including powers and roots...

Notable Quote

Notable Quote: "The world is run by 'C' students" - RF Cafe"The world is run by 'C' students." - Anon. Bush and Clinton were both 'C' students. We have no idea what Obama's GPA was because his records are sealed, but we're assured by the media he is an absolute genius.

When Spectrum Auctions Fail

When Spectrum Auctions Fail (IEEE Spectrum) - RF CafeIf you have been a bit fuzzy on how spectrum auctions work (or don't work, per author Mitchell Lazarus), then this article might be worth perusing. A brief history on the pre-auction days and how the system worked then, versus the government-manipulated environment now in effect. In its ever-increasing mission to extract money from productive enterprises, the FCC has caused an enormous waste of available spectrum. Rather than creating an electromagnetic platonic utopia, it has largely mucked up the works. The same type of bureaucrats will soon be running our health care.

Microwave Engineering
Crossword Puzzle

Microwave Engineering Crossword Puzzle for May 19, 2013 - RF CafeEvery 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.

Anatech electronics' May 2013
Newsletter Now Available

Anatech Electronics has published its May 2013 newsletter. As always, it includes both company news and some tidbits about relevant industry events, regulations, and standards. Anatech Electronics' Sam Benzacar invites you to visit them in booth #2710 at the IMS 2013 trade show in Seattle, Washington.

Google's White Spaces
Spectrum Database

Google's Spectrum Database - RF Cafe SmorgasbordThere are not many technical realms where Google engineers have not either entered or created. Wireless connectivity is key to their continued dominance in the information domain, so they understandably have a vested interest in the "white space" spectrum debate. White space comprises portions of the electromagnetic spectrum where bands are either unlicensed or where licensed bands are or will be up for grabs. An example of the former is the 2.4 GHz Wi-Fi band, and an example of the latter is some parts of the broadcast television band that is being vacated in areas. Google is working with the FCC to build a real-time database of what they term "dynamic spectrum" in order to provide useful information to both users and providers. A separate database is available for fixed and mobile spectrum. Enter your location of interest and the map zooms into that region. For instance, in my town of Erie, Pennsylvania, there are 21 channels available as of January...

Please Thank IPP for Their
Long-Time Support

Innovative Power ProductsInnovative Power Products has 25 years of experience designing & manufacturing RF passive components. Our couplers, combiners, resistors, and terminations incorporate the latest technology in materials available, which equates to unrivaled product performance. We're proud that our RF resistors, terminations and 90 degree hybrid drop-in couplers are RoHS compliant

Are You a Startup
Looking for Funding?

How We Got Funded: Qualtrics - RF CafeThis is a different kind of venture capital story. Tables are turned in this story where, rather than the company founders desperately chasing after investors with deep pockets, the investors pursue a highly successful startup. Qualtrics is a data collection and analytics company that grew from a father and son basement operation in 2002 to $48M in sales in 2012. They boast such clients as Barnes & Noble and Zappos. Ryan Smith, the son, decided in 2009 to chum the investment waters and was overwhelmed with responses (I'm not going to call the VCs sharks... not here, anyway). This short article in Inc. magazine recounts his selection process. The old adage about everyone loving a winner rings true here.

Electronics Crossword
Sept. 1957 Popular Electronics

Crossword Puzzle, September 1957 Popular Electronics - RF CafeHere is a 1950s vintage electronics crossword puzzle by Arthur L. Branch. Unlike the weekly crosswords from RF Cafe that uses only relevant technical words, this one fills in with common words when necessary. It's still a good puzzle, though.

A Few Good White Papers...

Here are a few white papers that might interest you if you are a circuit or system designer. Some require you to fill in a form for access.

- Determination of Capacitor
  Life as a Function of
  Operating Voltage & Temp

- Weight Reduction and Space
  Savings in Wire and Cable
  Design and Their
  Contribution to Aerospace
  Design and Efficiency

- What They Didn't Teach You
  in Engineering School About
  Heat Transfer

- Techniques for Precise
  Measurement Calibrations
  in the Field

- Techniques for Precise Cable
  and Antenna Measurements
  in the Field

Sherlock Ohms: Case of the
Nonstandard Time Standard

Sherlock Ohms: The Case of the Nonstandard Time Standard - RF CafeThe latest entry in the case journal of the renowned Sherlock Ohms is titled "What's the Time?" It is indicative of what happens when the government decides to try an experiment without letting the entities that rely on them know what is going on.

Spectrum Allocations Poster
from Rohde & Schwarz

Free Rohde & Schwarz Spectrum Allocation Poster - RF CafeThe national and international spectrum usage has continued to undergo a constant cadence of change. These changes necessitate the need to continue to evolve your awareness of valuable spectrum allocation information. As evidenced recently in the U.S.: Analog TV has mostly gone quiet and been replaced with Digital TV; the LORAN-C navigation system has been shut down; new GPS satellites and frequencies provide coverage to Smartphones; and the National Wireless Initiative is looking to actively refarm and commercialize over 500 MHz of spectrum for commercial high-speed wireless services. Please click to get the latest Spectrum Allocations Poster from Rohde & Schwarz.

Prismark's "Electronics
Industry Report 2012"

Prismark Electronics Industry Report 2012 - RF CafeDuring my many years as an RF applications engineer with a well-known RFIC manufacturer, I did a lot of competitive analysis work that involved doing teardowns on products like cellphone PAs, Wi-Fi transceivers, FEMs, SAW filters, and even entire commercial products like cellphones and Bluetooth devices. During the process, I learned a lot about how to identify components with no external markings and how to check for copyright infringements. Most of the work I did myself, but occasionally outside assistance was required to do x-rays, decapping of ICs, etc. One company that we solicited to provide overall industry state of the art info was Prismark. Their reports were always excellent and full of data that is nearly impossible to obtain otherwise. Their annual reports are something you or your marketing and engineering managers would be interested in seeing. The reports are not cheap, but could pay for themselves many time over. (No, I do not receive any compensation for my endorsement)

Skyworks Antenna Switches
for Carrier Aggregation

Skyworks Launches Family of Antenna Switches Supporting Carrier Aggregation - RF CafeSkyworks Solutions introduced groundbreaking RF switching technology that is enabling early adopters to implement carrier aggregation solutions. Carrier aggregation allows mobile service providers to combine spectrum and increase data rate throughput by utilizing two or more bands simultaneously instead of the single band method used currently, thereby giving consumers an enriched data experience regardless of location. Skyworks' devices support standardized inputs to popular industry chipsets (MIPI RFFE compatible) and address both transmit and receive switching paths. "Skyworks' carrier aggregation switching solutions, which are compliant to tier-one, carrier-driven specifications, offer dedicated receive diversity functionality to accompany the primary antenna-switch path."