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Copyright 1999-2015

- RF Cafe Homepage -
"Those who cannot remember the past are condemned to repeat it." - Santayana

Today in History

Tech Headline News

- Archives -

U.S. Amateur Radio Numbers Reach an All-Time High

China and U.S. Clash over Software Backdoor Proposals

2D Material Beats Graphene (dethroned already?)

Intel and Qualcomm Want 60 GHz Spectrum for 3 Gbit/s Wi-Fi

Target Cutting Thousands of Jobs in U.S.

Facebook Explains When and Why It Peeps at Your Account (this might spook you a bit)

Connected Home Growth Hindered by Inaccessibility, Conflicting Standards

Smog Blankets China Once More (compliments of all your China-made stuff)

Outdated Encryption Keys Leave Phones Vulnerable to Hackers

First-Ever Quantum Device That Detects and Corrects Its Own Errors

Pennies Reveal New Insights on Nature of Randomness

Demand for Linux Skills Growing Faster Than Talent Pool

Prepare for 'The End of College' as You Know It

Blackberry Unveils 'Leap' with No Physical Keyboard

Supreme Court Backs Trade Group’s Challenge to Internet Sales Tax Law

WordPress to Remain Most Attacked Platform

Electronics-Themed Comics

October 1944 & May 1945 Radio-Craft - RF CafeIt's Friday again already (...finally). In that these comics from Radio-Craft magazine have an electronics theme, you can claim looking at them is work-related. You might consider using one of them for your next conference or project status presentation. There is a list of many more similar comics at the bottom of the page in case you haven't seen them yet. Enjoy.

Intermediate Engineer:
Embedded Hardware/Software
and Mixed Applications

Synergy Intermediate Engineer Job Opening:  Embedded Hardware/Software and Mixed Applications - RF CafeSynergy Microwave currently has an opening for an Intermediate Engineer: Embedded Hardware/Software and Mixed Applications. A very exciting opportunity to join a strong engineering team dedicated to developing radio frequency products for the microwave communication, microwave instrumentation, radar and defense applications. You will have extremely deep resources and guidance for modern radio product development using mixed signal and digital radio techniques. Qualifications include experience in radio frequency applications, modulation algorithms, signal detection, leveling and

See The Full-Page Splash Ad
You've Been Missing on RF Cafe

Website Entry Screen Splash Advertising - RF CafeAre you kidding me ?!?!?! Why in the world would you WANT to see a full-screen splash ad when you visit any website? I absolutely detest those things. When I visit a website, I want the first thing I am presented with to be the content of the site, NOT a full-page advertisement with some lame message like, "Please wait while your page is loading," or "Welcome Screen," or some other annoying and/or disingenuous text. Do the webmasters really think visitors are stupid enough to believe that the website's real content is loading behind the advertising screen, and that they are doing visitors a favor by providing

Author: Kirt Blattenberger on Google+ Author:
Kirt Blattenberger

Pilotless Plane Run by Radio

Pilotless Plane Run by Radio, May 1946 Radio News - RF CafeNews reports are full of features about the wave of radio controlled (R/C) 'drones' terrorizing citizens with their often inexperienced pilots navigating their camera-laden craft to peer into bedroom windows, obtain 'birds-eye' views of sporting events, and to be a general pain in the posterior to people trying to enjoy their right to privacy and safety (except, of course, unless it is the Government choosing to violate them). Incredible advances in radio, navigation, and sensor systems has facilitated a wide variety of very affordable multirotor (the correct term, not 'drone') aircraft that can literally fly themselves. For under $500 you can buy a GPS-guided multirotor that can be programmed to fly to one or more waypoints and return to the launch location, with range and flight duration limited

Vintage Amphenol
Coaxial Cable Advertisement

Amphenol Advertisement, October 1945 Radio News - RF CafeAmphenol has been around since 1932, when founder Arthur Schmitt offered sockets for vacuum tubes. Now headquartered in Wallingford, CT, the company began life in Chicago, Illinois. Amphenol was a major supplier of coaxial cable in the days when most of the cable Americans used was produced in the country. Alpha Wire, Amphenol, Carol Cable (now part of General Cable), and General Cable are the names that come to mind that were around in the 1970s when I entered the radio-electronics realm. The radar system I worked on in the USAF, and all of the defense electronics electronics systems I worked on as a technician and engineer, used those four brands. Today, of course, there is a seemingly unlimited number of coaxial cable

Training with Visual Aids

Training with Visual Aids, October 1945 Radio News - RF CafeLong before there was Power Point (OpenOffice's Impress is the free equivalent), presentations at training seminars were conducted using overhead projectors and larger-than-life props of the devices being taught. The U.S. Navy, during World War II, set up a special facility called the Visual Aid Model Shop located at Radio Chicago, Chicago, Illinois. Its charter was to design and build very large scale models of equipment and tools that service personnel used while performing their duties. It is kind of funny to look at the sizes of some of the items, like the 8x size radio chassis assembly shown in this article's main photograph. As a life-long model builder myself, I would have loved to work in a shop

NI AWR Design Environment
Application Note Now Available

NI/AWR "How to Improve Second-Harmonic Passband Rejection Microstrip Side-Coupled Filters" - RF CafeNI (formerly AWR Corporation) released a new NI AWR Design Environment application note, “Improving the Second-harmonic Pass Band Rejection of Microstrip Side-coupled Filters.” Because of their low cost and easy manufacturability, side-coupled filters constructed from printed-circuit board-based microstrip are widely used throughout the industry. One of the main drawbacks of the side-coupled filter is its limited rejection of the second harmonic. This application note demonstrates a solution that mitigates this problem through the introduction of notch-filter elements that improve the overall rejection of side-coupled filters at the second harmonic without significantly affecting the filter passband behavior

Using Simulation Tools to
Troubleshoot LC Filter Design

Using Simulation Tools to Troubleshoot an LC Filter Design (by Ed TRoy) - RF CafeEd Troy, owner of Aerospace Consulting, LLC, was kind enough to offer a few of his articles for posting on RF Cafe. With more than 30 years in the electronics communications design field, Ed has a lot of valuable knowledge to impart to us mortals ;-) This first paper discusses a method for accommodating real-world stray capacitances in the simulation model for helping to assure first-pass success on LC filter designs. He's a highly rated airplane pilot as well, which counts for something in my book. Stay tuned for others

Werbel Microwave Intros 4-Way
Splitter for 2-18 GHz

Werbel Microwave Intros 4-Way Splitter for 2-18 GHz - RF CafeWerbel Microwave expands its series of 2-18 GHz coverage with the new, model 4PA1000 four-way SMA splitter. Can be optimized using our trade techniques to meet strict amplitude and phase balance per customer requirements. High isolation, typically 22 dB or more between all branches. Great for lab test setups, made in USA.

Poll: Which OS Does
Your Phone Use?

Official RF Cafe Website Poll

RFMW SM Iso-Attenuator for
High Power Circuit Protection

RFMW Offers Surface Mount Iso-Attenuator for High Power Circuit Protection - RF CafeRFMW announces design and sales support for the Iso-Attenuator model RFSL2308-A30 from RF Circulator Isolator (RFCI). RFCI Iso-Attenuators combine protection for active components from distortion or potentially damaging reflected power with a convenient, attenuated port for monitoring RF power or providing a feedback loop. The RFSL2308-A30 is capable of handling 1000 W peak / 200 W average forward power and 100 W CW reverse power into the on-board, 30 dB attenuator. Spanning 2200 to 2400 MHz, the RFCI RFSL2308-A30 provides >25 dB typical port-to-port isolation

February 2015 Book Drawing
Winners Have New Selection

Thanks to Qorvo's Jeff Cameron, Sr. Manager, Product Marketing, Filter Solution, for providing this very high quality polo / golf shirt (made by the Pebble Beach brand) with a Qorvo company logo embroidered on the front. It is being offered as a prize selection in the monthly RF Cafe Book Drawing. I knew Jeff back in the early / mid 2000s when I worked for RF Micro Devices in Greensboro, NC. As you probably know, RFMD merged with TriQuint last year and became Qorvo. Both of February's winners have been notified, but I haven't heard back yet from either. The shirt might be gone before the March drawing occurs.

Radar Engineering Crossword
Puzzle for March 1, 2015 

Radar Engineering Crossword Puzzle for March 1, 2015 - RF CafeI stopped creating the RF Cafe engineering and science themed crossword puzzles at the end of January in order to test the interest in them. As of today, on March 1st, I will resume creating them every couple weeks. It takes up to an hour to make each crossword. Enjoy this radar engineering themed puzzle.

Carl & Jerry:
Extra Sensory Perception

Carl & Jerry: Extra Sensory Perception, December 1956 Popular Electronics - RF CafeCarl and Jerry were early adopters of the near field communications (NFC) craze that is going full-swing today. The often harmlessly mischievous teenage duo used their combined grasp of modern electronics to pull off gags on unsuspecting friends... and sometime adversaries. In this episode, a near-field transmitter and receiver pair is designed to help Carl bedazzle a scientist who was attempting to disprove the ability to use extrasensory perception (ESP) to determining what another person was thinking about. In this case it was detecting which playing card was being displayed on an overhead projector. Of course Carl didn't really have 'the gift,' but relied on his co-conspirator, Jerry

Frequency & Time Standards

Frequency & Time Standards, August 1964 Electronics World - RF CafeIt was not until 1963 that the International Committee of Weights and Measures (CIPM) adopted the cesium clock as the world scientific community's standard time reference. It boasted an accuracy that kept it within 1.1 parts in 100 billion, meaning it would not gain or lose more than a second in 3 thousand years. To show how far technology has advanced since 1963, in April of 2014 the National Institute of Standards and Technology (NIST) launched a new atomic clock called NIST-F2 (also cesium-based) to serve as a new U.S. civilian time and frequency standard. NIST-F2 would neither gain nor lose one second in about 300 million years - a factor of 10 thousand. According to the U.S. Navy's official Time.Gov website, the Internet time reported on my computer was 1 minute and

Terahertz Metrology

Terahertz Metrology - RF CafeTerahertz Metrology, by Mira Naftaly. "This new book describes modern terahertz systems and devices and presents practical techniques for accurate measurement with an emphasis on evaluating uncertainties and identifying sources of error. This is the first THz book on the market to address measurement methodologies and issues - perfect for practitioners and aspiring practitioners wishing to learn good measurement practice and avoid pitfalls. This book provides a brief review of different THz systems and devices, followed by chapters detailing the measurement issues encountered in using each of the main types of THz systems, and a guide to performing measurements rigorously. Particular attention is given to evaluating

Notable Tech Quote:
- Marshall McLuhana

Herbert Marshall McLuhan - RF Cafe"Xerography is bringing a reign of terror into the world of publishing, because it means that every reader can become both author and publisher." - Marshall McLuhana, 1966, from March 2005 Smithsonian magazine. An unregulated Internet provided the next step in that freedom. On February 26, 2015, the FCC adopted "Net Neutrality," giving the Federal government control over the Internet under the guise of protecting little 'ol you. Be sure to thank the people you know who voted for the people who passed this. If you think you're being spied on now, you ain't seen nothin' yet.

Your RF Cafe
Progenitor & Webmaster

Click here to read about RF CafeKirt Blattenberger… single-handedly redefining what an engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem!
(Seize the Day!)

5th MOB: My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website