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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Here is page 1 of the August 2014 homepage archive
This week's crossword puzzle, like last week's crossword puzzle, and all the weeks before that, was custom made by me and contains only words and clues pertaining to science and engineering. Print it out and take it to your next diversity in the workplace meeting so you can honestly say you got some mental stimulation out of it. Enjoy!
It wasn't all that long ago that deadlines for magazine printing cycles were measured in months - unlike today where electronics on-demand printing has cut lead times to weeks and even days. Accordingly, this National Schools advertisement pitching 'after the war' training in electronics servicing that appeared in the September 1945 edition of Radio Craft was likely designed and submitted two or three months ahead of the publication month (e.g., in June or July). How could they be so sure that their scarce advertising dollars wouldn't be wasted? Simple. By that time, the entire country seemed to have a sense that World War II would come to an end soon since Hitler's, Mussolini's, Tojo's...
After you've turned off all the lab equipment and are sitting around waiting for the 3-day Labor Day weekend to start, kill some time with a couple of these new articles.
- Precision Validation
System Performance in the
Field, W. Yu
- Why Are Oscilloscope Probe
Amps at the Tip?, A. Pini
& L. Jacobs
- Selecting an RF Power Meter
or Sensor (p.54), LadyBug
- Match Impedances When
- On-Site Testing of Lightning
Protection Devices, K. Rand
- Next Generation
Communications for Next
- Analyzing Active
X. Sheng & X. Yuanming
Sure, you do it all the time, but at some point either someone suggested and/or showed you how to clip substitute components into a circuit in place of a suspected bad component while troubleshooting or maybe during the design or tuning process. Miniature circuits of today pretty much rule out using alligator clips to patch in a part, but sometimes it is possible to use miniature J clip leads or even pin probes to make the connection long enough to take a measurement. Since I do a fair amount of circuit work on other-than-RF applications, I often find myself using short insulated, stranded wires with mini alligator clips on each end to make connections.
Anatech Electronics designs and manufactures the industry's widest range of RF and microwave filters at frequencies up to 40 GHz, as well as power dividers, directional couplers, and many other product types. We specialize in standard and custom designs for commercial wireless, public safety, satcom, and defense applications, and we can meet stringent military environmental specifications.
Delta's 4.1 / 9.5 Mini DIN series of coaxial connectors are designed to meet the growing demands of today’s high performance mobile communications systems. Mechanically similar to the 7/16 series, the 4.1/9.5 Mini DIN's 30% smaller size and reduced weight, allow increased package density and flexibility in system design. Delta offers a wide range of standard 4.1 / 9.5 Mini DIN configurations including: male and female
Audio crossover networks have the same fundamental mission as RF multiplexer filters in radio systems, which is to separate and steer specific bands of frequencies into two or more signal paths. While simple in concept, implementation in hardware can be a major challenge depending on requirements for channel separation, feedthrough, phase and group delay, amplitude equalization, distortion, and other factors. This article discusses some of the decisions used by crossover network designers when considering where to make band breaks, while leaving actual circuit design rules to other authors. I built a set of custom speakers many moons ago and went through the frustrating process...
Planar Monolithics Industries, Inc. (PMI) announced that they have received their ISO 9001:2008 certification for their Quality Management System. With the recent successful completion of the audit at the El Dorado Hills, CA facility, now all three PMI facilities, including both facilities located in Frederick, MD, are ISO certified. ISO 9001:2008 certification is a prestigious certification requiring companies to meet the complex and demanding documentation, quality system and continuous process improvement requirements.
You can still buy from Moog today the same sort of Theremin that was described in this 1961 Carl & Jerry episode. Ever the early adopters of breaking technology, the teenagers exploit the motion-sensitive feature of the Theremin in hopes of improving Carl's basketball game. As usual the boys, in mock dialog, describe the Theremin's operational theory for the benefit of readers not familiar with the musical instrument. They do not, however, mention that the device is named after its Russian inventor, Léon Theremin, who patented the device in 1928. Read on to discover how a Theremin strapped to Jerry's back...
Test Equipment Connection Corporation is your single source test & measurement solution. We offer over 300 test equipment manufacturers including Agilent, Tektronix, Anritsu, Rohde & Schwarz, Advantest and Fluke, plus thousands of New, Used, Second Hand, and Refurbished test equipment products. We buy and sell bench top, general-purpose test and measurement equipment. $2M is budgeted each month for the purchase of surplus equipment.
Envelope Tracking Power Amplifiers for Wireless Communications, by Zhancang Wang. Envelope tracking technology is seen as the most promising efficiency enhancement technology for RF PA for 4G and beyond wireless communications. More and more organizations are investing and researching on this topic with huge potential academic and commercial values. This is the first book on the market to give complete introduction, theory, and design considerations on envelope tracking for wireless communications...
These days, I'm always a bit hesitant to publish or do Internet research on items mentioning chemical compounds any more toxic than rubbing alcohol. This article reports on early plans of the Vanguard satellite launch platform for America's first orbiting satellites. Although the main focus is on the electronic steering and stabilization systems, it mentions the fuel composition of nitric acid and unsymmetrical dimethylhydrazine. That's probably enough to cause a federal agent to come knocking on my door... or at least put me on some sort of surveillance list. Less exotic fuels like LOX (not to be confused with the fish used on bagels), kerosene...
"He no sooner gets alone with a sweater girl than he's trying to pull the wool over her eyes." That's a really old joke that only old guys remember. 'Sweater girl' was a term used to describe... how do I properly put it?... Dolly Parton types (you know, having a good singing voice ). Anyway, I thought you might need to be apprised of the origin of the term to appreciate the title of this article from a 1944 edition of Radio Craft. You're welcome.
NI (formerly AWR Corporation) awarded the first-, second- and third-place winning teams of the IMS2014 Student Design Contest for High-efficiency Power Amplifier and High-sensitivity Radar complementary one-year licenses of NI AWR Design Environment™ software.
"It is apparent to me that the possibilities of the aeroplane, which two or threes years ago was thought to hold the solution to the [flying machine] problem, have been exhausted, and that we must turn elsewhere." - Thomas A. Edison, New York World, November 17, 1895. This, from the man who reportedly tried more than 1,000 different materials for his incandescent light bulb before arriving at a coil of carbon filament.
Here is a little more tech comic artistry from Bill Hutchinson. Bill created a lot of work for Popular Electronics over the years in addition to his semi-regular Hobnobbing with Harbaugh series. One of the comics mentions an operator being referred to as a 'lid.' In Hamdom, the term means a person who is incompetent or stupid. The history of 'lid' is apparently uncertain (as is 'Ham') per many sources I checked, but two explanations seem the most feasible to me. The first is that in the olden days of land telegraphy, less skilled Morse code operators supposedly placed the lid of a tobacco...
This first of a two-part "Radar Principles" article by British engineer and researcher Dr. R.L. Smith-Rose. Dr. Smith-Rose explains the basics of radio detection and ranging using simple illustrations and calculation examples. When these articles were written, radar had recently been credited with playing a major role in helping the Allies successfully wage war against aggressive Axis powers that were ravaging London and other European cities with air attacks comprised of both manned and unmanned vehicles. While the principles of radar were somewhat familiar to people...
RFMW, Ltd. announces design and sales support for four new high-linearity, low noise gain blocks from TriQuint. Offered as DIE, they target hybrid assembly designs requiring the highest level of performance unencumbered by package parasitics. All devices cover applications from 0.05 to 4 GHz such as commercial and military radar receivers, EW, communication LNA designs and general purpose LNA designs needing highly linear amplifiers
Parsec specializes in embedded passive and active antenna modules for GPS, GNSS, M2M, IoT (Internet-of-Things) and LTE. Parsec also has a full line of high performance, LNA ICs for wireless and mobile markets. Parsec's offerings significantly improve system performance and signal integrity with high efficiency embedded antennas using smaller ground planes, higher gain, and higher IP3 performance while insuring low noise and excellent Rx abilities.
LinkedIn's CEO Jeff Weiner hit a home run with his recent post titled The 3 Qualities of People I Most Enjoy Working With. The article's content is undeniably interesting, but I guarantee the fame factor is based on the Venn diagram that he created. It's simple and sure to get a chuckle out of you. Here are a few more useful articles:
— Running an
— 5 Ways New Grads Can
Get a Boost up the
— Fired at 50? Now What?
— How to Answer the 'Tell Me
About Yourself' Interview
This week's science and engineering-themed crossword puzzle, like last week's crossword puzzle, and all the weeks before that, was custom made by me and contains only words and clues pertaining to science and engineering. Print it out and take it to your next diversity in the workplace meeting so you can honestly say you got some mental stimulation out of it. Enjoy!
This second part of the "Radar Principles" article by British engineer and researcher Dr. R.L. Smith-Rose provides a historical perspective of the very beginnings of radar systems. Although alluded to by technical visionaries like Hugo Gernsback, George Orwell, Jules Verne, H.G. Wells, et al, for use in target detection and ranging (but rarely speed, oddly enough). According to Dr. Smith-Rose, the first use of radio waves for detection and distance measurement was in atmospheric studies to characterize the ionosphere, in a bistatic configuration. It is an interesting and quick read, and you might even be introduced to the concept of a "squegging" (self-quenching)...
Thanks to our 50 years of industry experience, Aviat Networks knows microwave transmission better than anyone, and now we are delivering the next generation of LTE proven microwave networking solutions that bring together high performance radio transmission and smart network evolution to all-IP. Aviat has an opening for a Systems & Services Networks Director, responsible for developing and executing a services strategy that supports the existing customer business and the sector's growth strategy. Please see description for details if interested
QRM and QRN (manmade and natural interference, respectively) has been a problem to be dealt with since the beginning of radio communications. Amplitude modulation (AM) was and is still the most vulnerable because there are so many sources of electrical and electromagnetism generation - both intentional and unintentional. Filters can take care of out-of-band noise, but inband noise needs to be dealt with differently. Some inband interference can be reduced in effectiveness with circuits using specific time constants that address specific noise types. One of the most successful methods for mitigating generic noise is to limit the opportunity for noise signals to enter the system by employing directional antennas...
Signal multiplexing was originally performed using a rotating mechanical device with commutator contacts. Such a contraption suffered from a number of limitations including contact wear, noise, speed, size and weight. Probably the most limiting were contact wear and switching speed. Bulk could be accommodated because back then everything was bulky. Standard vacuum tube switches were eventually used to build multiple (n) input / multiple (m) output switching circuits, but the space needed to contain them grew exponentially with the...
Innovative Power Products has more than 30 years of experience designing and manufacturing RF passive components. Our couplers, combiners, baluns, resistors, and terminations incorporate the latest technology in materials available, which equates to unrivaled product performance.
NI (formerly AWR Corporation) has added three locations in India during the first week of September to its 2014 AWR Design Forum (ADF) tour. The event agenda has been set and registration is now open. Agenda highlights include: New Innovations and Technologies in the NI AWR Design Environment™ Microwave Cavity Filter Design Transceiver Module and Multi-Element Phased Array Design Cree GaN Models and Process Design Kit for First Pass MMIC Designs RFIC Design 3D EM Simulators for PCB Design
Frontiers in Antennas: Next Generation Design & Engineering, by Frank Gross. Edited by one of the world's foremost authorities on smart antennas and featuring contributions from global experts, Frontiers in Antennas discusses the latest advances in antenna design and engineering. This pioneering guide deals primarily with frontier antenna designs and frontier numerical methods. Many of the concepts presented have emerged within the last few years and are still in a rapid state of development. Each chapter provides in-depth details on a unique and modern antenna technology.
Anyone who has done a lot of electronics troubleshooting - especially on a wide variety of hardware - knows that proficiency depends on acquiring a 'feel' for how things ought to be. An oft-given example is that bank tellers and store clerks are taught to spot counterfeit bills not by showing them what all the different phony currency looks like, but what real money looks like. That way, anything that does not look familiar is readily apparent. The same philosophy has served technicians and engineers well since the beginning of electrical and electronic circuits. The more senses that can be drawn upon to facilitate troubleshooting, the more quickly you are likely to pinpoint the problem. Depending on the symptoms of the failure, sniffing the assembly for toasted or...
Pasternack Enterprises, an industry-leading manufacturer and supplier of RF, microwave and millimeter wave products, debuts an entirely new family of high isolation PIN diode switches consisting of three low insertion loss, high isolation and high speed modules, covering a frequency range of 1 to 12 GHz. When signal integrity and performance are a critical component of system functionality, the higher the isolation figure, the better the overall performance will be
Specialising in the design and development of high gain, printed circuit arrays, ultra wide-band directional antennas, multi-octave bicones and high gain collinear omni-directional antennas. Large catalogue of antenna designs. Specialist development projects from 250 MHz to 40 GHz. Communication industry awareness and expertise in antenna physics ensure customer satisfaction.
Radio Craft magazine ran a monthly series of short articles paying tribute to some of shakers and movers in the field of science - this time it was Sir Oliver Lodge. "While Hertz was discovering radio waves in air, Lodge was determining the laws of the corresponding activity which takes place in electrical conductors. It was Lodge who demonstrated the possibility of radio communication, experimentally, as Marconi did its commercial value - just as Henry created the telegraph and Morse made it of practical utility."
...well, a human handful with a complete compliment of four fingers and a thumb. I have no idea who first thought of these jokes, but thanks to whoever did. I especially like the iPod joke!
Once mobile and other high-vibration and impact operational environments became the norm for communications, it became necessary to design hardware so that electronic components would not work themselves loose and cause intermittent or total failure. With vacuum tubes, placing locking shields over them did the job, but that caused other issues such as increased cost, poor cooling, and increased chassis size and weight. Some circuits with high power and/or frequency benefited from shields, but most did not need them. Sylvania introduced a scheme called "Lock-In" (trademark name of "Loktal")where the center pin incorporated a circumferential groove that latched into a capturing mechanism. It was strong enough...
Werbel Microwave is developing a standard line of narrowband 180-degree hybrids. A signal applied to the sum port produces two outputs of equal amplitude and phase, while a signal applied to the delta port produces output signals of equal amplitude but opposite phase. The model 2Q11 was designed to fulfill a custom requirement from 2.2-2.3 GHz. Measured return loss was 1.2:1 or better, 25 dB isolation and 0.3 dB insertion loss. Phase balance was within ±5 degrees
"Stationary waves in the earth mean something more than mere telegraphy without wires to any distance. They will enable us to attain many important specific results impossible otherwise. For instance, by their use we may produce at will, from a sending-station, an electrical effect in any particular region of the globe; we may determine the relative position or course of a moving object, such as a vessel at sea, the distance traversed by the same, or its speed; or we may send over the earth a wave of electricity traveling at any rate we desire... " - Nikola Tesla describing a future technology called radar. "The Problem of Increasing Human Energy," The Century, 1900.
Anatech Electronics, a manufacturer of RF and microwave filters, has published its August 2014 newsletter. As always, it includes both company news and some tidbits about relevant industry events. This month, Sam Benzacar offers his views on the subjects of Fiber: Too Slow for Wall Street, NASA Examines Microwave Propulsion, Report: Northeast Has "Fastest" Broadband. It also pays tribute to Dr. Norman Abramson, founder of ALOHAnet as part of his theme on "Wi-Fi's Changing the Wireless Playbook."
For over 40 years KR Electronics has designed and manufactured high quality RF & microwave filters for the commercial and military markets. KR Electronics manufactures all filter types and individually synthesizes filters for special applications. State of the art computer synthesis, analysis and test methods are used to meet the most challenging specifications.
Success won in the realm of space-based communications has been fraught with many failures. As with most endeavors, it is thanks to the relative few who have sacrificed and endured against overwhelming odds to bring significant technological advances in communications to the many. Space presents a particularly difficult venue because of the harsh deployment and operational environment, and inaccessibility after deployment. Personal sacrifice has taken the form of depression, financial ruin, lost opportunity for other endeavors, broken families, sickness, substance abuse, and other maladies...
Lester William Polsfuss is credited with being a major player in the pioneering of electric guitars with his solid-body (no acoustic resonance chamber) model... but you probably knew that. As if being a popular musician and, along with wife Mary Ford, selling millions of records wasn't enough, Les Paul was an experimenter and inventor in the electronic music realm. Here is what was at the time a contemporary look inside his home-workshop-studio. Mr. Polsfuss designed and built the record cutter that he used in his early days out of scrounged automobile...
RIGOL Technologies is an emerging T&M leader and a technology innovator in electronic measurement. RIGOL's line of products including: Digital o-scopes, RF spectrum analyzers, DMMs, programmable power supplies, signal generators, and waveform generators. The DSA800 Spectrum Analyzer redefines the product category by setting new standards for performance and price.
Well, almost free. The price paid is providing your email address so they can be sent to you. In >5 years of recommending these books and white papers, I have never had anyone complain about spam after requesting them. I make a few ¢ on each, so please help yourself to any or all of these offered by TradePub.
You - According to Them: Uncovering blind spots that impact your reputation and your career
Find - and Get - The Job You Want: 12 Steps to Job Search Success
Every Sunday I create an engineering-themed crossword puzzle using a word list that I personally created and added to during over a decade of making puzzles. All of the words are related to engineering, science, mathematics, chemistry, astronomy, etc. There are no numbnut clues about movie stars or clothing designers. Enjoy.