Homepage Archive (current)

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. See current page or previous page of the homepage archives.

Friday 23

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Tuesday 20

Microwave Power Diodes

Microwave Power Diodes, July 1969 Electronics World - RF CafeEveryone who is interested enough in microwave diodes to read this article surely knows* what IMPATT, GUNN, and PIN diodes are, but have you heard of Read-effect, TRAPATT, LSA, or QMD diodes? If not, it is likely because you entered the microwaves field long after 1969 when this edition of Electronics World was mailed to subscribers. Device improvement and obsolescence accounts for familiarity with the former and unfamiliarity with the latter, respectively. The article below by two Sylvania Electronic Products engineers describes the properties of various up-and- ...

Webinar: Introduction to Radar

Introduction to Radar Webinar - RF CafeMicrowave Journal is conducting along with National Instruments and Wolfspeed a webinar titled, "Introduction to Radar," on Wednesday, March 28, 2018, at 11:00 AM. Mr. Scott Bullock presents on the topics of radar detection and ranging, pulse vs. CW, radar modulation, radar path budget, basic radar equation, radar range equation, range ambiguity and mitigation, maximum and minimum detectable range, and more ...

Receiving Antennas for the Radio Amateur

Receiving Antennas for the Radio Amateur - RF CafeHere is a brand new book being offered by the ARRL: Receiving Antennas for the Radio Amateur, by Eric P Nichols (KL7AJ). "Although the fundamental characteristics of antennas apply to both transmission and reception, the requirements and priorities of receiving antennas can be vastly different from those of transmitting antennas. Receiving Antennas for the Radio Amateur focuses entirely on active and passive receiving antennas and their associated circuits. There are relatively few cases where a radio amateur ..."

5G to Alter RF Front-End Landscape

5G to Alter RF Front-End Landscape - RF Cafe"While the mobile industry is done with its annual Mobile World lovefest - held last month in Barcelona - tech suppliers, system OEMs, and mobile operators now face a host of 5G obstacles not yet overcome. In fact, they’re just getting started. The technical issues of 5G are manifold. Among them, smart antennas and RF front ends for 5G mmWave - typically expected to operate at frequencies such as 28 GHz, 39 GHz, or 60 GHz - could seriously affect the performance of yet-to-emerge 5G mmWave mobile phones ..."

Monday 19

What Is the Role of Satellite Communications in 5G?

What Is the Role of Satellite Communications in 5G? - RF Cafe"Satellite communications have been in use for decades now, providing connectivity to remote areas, acting as backup in disaster relief situations, and being a major access mechanism for TV in certain parts of the world. Satellite use has been vital for government, military, and remote operations, while geostationary orbit (GEO) satellites are providing global coverage for voice, TV, and, in some cases, broadband Internet services. The telco industry is now working toward the standardization and commercialization of the next generation of cellular standards ..."

High Exposure Advertising Plan Now Includes a 728x90-px Banner

High Exposure Advertising Plan Now Includes a 728x90-px Banner - RF CafeIn an ongoing effort to provide the best return on investment to RF Cafe website sponsors (aka advertisers), I have decided to allocate the 728x90-pixel banner ad slot at the bottom of all web pages to companies who participate in the High Exposure plan. That is in addition to the other features that have always been included. The cost is still only $150 per month; i.e., no price increase. A full list of advertising options is available on the Sponsorship Rates page, but just the features which are part of the High Exposure plan are highlighted in the screen capture ...

Electrochemistry Quiz

Electrochemistry Quiz, March 1966 Popular Electronics - RF CafeA lot of RF Cafe visitors might not be familiar with some of the electronic devices presented in this Electrochemistry Quiz by Popular Electronics' resident quizmaster, Robert Balin (a big list of his other quizzes is at the bottom of the page). I offer my assistance. A is a photocell, B is an early type of rectifier, C is a varistor, D is a cathode ray tube (CRT), E is an electrolytic capacitor, F is a heated cathode in a vacuum tube, G is a flashlight battery, H is an early receiver crystal detector, I is a magnetic audio recording tape, and J is phonograph cartridge. I scored ...

Codan Radio Communications in the Arctic

Codan Radio Communications in the Arctic - RF Cafe"During Exercise Northern Warrior 2018, 35 Canadian Brigade Group (35 CBG) Communications Detachment did an impressive job of testing and solving problems. The detachment's two objectives were to provide high-quality communications to the Arctic Response Company Group (ACG) personnel and test new equipment in an arctic environment. 'The arid and austere environment of the Canadian Arctic requires effective communications. The work done by the G6 35 GBC team has undoubtedly demonstrated the relevance of the HF communications that are essential to operate effectively in this hostile climate ..."

3-D Measurements Improve Understanding of Geomagnetic Storms

3-D Measurements Improve Understanding of Geomagnetic Storm Hazards - RF Cafe"Measurements of the three-dimensional structure of the earth, as opposed to the one-dimensional models typically used, can help scientists more accurately determine which areas of the United States are most vulnerable to blackouts during hazardous geomagnetic storms. Space weather events such as geomagnetic storms can disturb the earth's magnetic field, interfering with electric power grids, radio communication, GPS systems, satellite operations, oil and gas drilling and air travel. Scientists use models of the earth's structure and measurements of Earth's ..."

Sunday 18

** New E-Mail Address for RF Cafe **

New E-Mail Address for RF CafeEarthlink no longer provides Internet service in the Erie area, and they want to charge a monthly fee to retain the current e-mail address, which is not worth the expense. Accordingly, please note that effective immediately RF Cafe's primary e-mail address will be rfcafe@yahoo.com. The Earthlink e-mail will be kept for a month or two so as not to miss any useful message, but please begin using the Yahoo e-mail now. I apologize for any inconvenience.

RF Cafe Engineering & Science Crossword Puzzle for March 18

RF Cafe Engineering & Science Crossword Puzzle March 18, 2018For the sake of all the avid cruciverbalists amongst us, each week I create a new technology-themed crossword puzzle using only words from my custom-created lexicon related to engineering, science, mathematics, chemistry, physics, astronomy, etc. You will never find among the words names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort. You might, however, see someone or something in the exclusion list who or that is directly related to this puzzle's theme, such as Hedy Lamar or the Bikini Atoll, respectively. Enjoy! ...

Friday 16

Methods of Suppressing PIM in Multicarrier Systems

Methods of Suppressing PIM in Multicarrier Systems - RF CafeSteve Ellis, product manager at Pasternack, wrote an article titled, "Methods of Suppressing PIM in Multicarrier Systems," that appeared in the February 2018 issue of Microwaves & RF magazine. "Passive intermodulation distortion (PIM) - the nonlinear effects that are observed from the passive components (i.e. antennas, cables, connectors, power dividers, and mixers) of a system at high signal levels - is a phenomena of particular relevance in wireless infrastructures dedicated to the propagation of vast amounts of traffic. Cellular and ...

Comics with an Electronics Theme, March 1967 Popular Electronics

Comics with an Electronics Theme, March 1967 Popular Electronics - RF CafeHere are a couple more electronics-themed comics from the March 1967 issue of Popular Electronics magazine for your TGIF enjoyment. The comic on page 100 especially appeals to me since I am finishing the installation of a Channel Master CM-5020 antenna. It has been a long time since I installed a traditional style TV antenna - about 40 years ago when I put a Radio Shack antenna on the roof of my mother's house. The entire 109" long by 100" wide antenna, including mounting hardware, weighs only 11.5 pounds and presents a wind resistance of 30 pounds. This is Channel Master's best antenna ...

Existence of New Form of Electronic Matter Demonstrated

Existence of New Form of Electronic Matter Demonstrated - RF Cafe"Researchers have produced a 'human scale' demonstration of a new phase of matter called quadrupole topological insulators that was recently predicted using theoretical physics. These are the first experimental findings to validate this theory. The researchers report their findings in the journal Nature. The team's work with QTIs was born out of the decade-old understanding of the properties of a class of materials called topological insulators. 'TIs are electrical insulators on the inside and ..."

8th RF & Microwave Paris Exposé

8th RF & Microwave Paris Exposé - RF Cafe
The 8th RF & Microwave Paris Exposé will be held March 21 & 22, 2018, at Porte de Versailles, Paris, France. Vendors will have products on exhibit, and conferences include EMC and RF simulation, IoT and Radio, Reliability of Components and Electronic Systems, GaN for Microwave Applications , Antennas Made by 3D Printing, GaN for Microwave Applications, Evolution ...

Arecibo Radio Observatory Saved from Closure

Arecibo Radio Observatory Saved from Closure - RF Cafe"The Arecibo Observatory in Puerto Rico has been saved following an agreement signed by a consortium led by the University of Central Florida (UCF) in Orlando. The announcement was made on 22 February by the National Science Foundation (NSF), which has been looking for an alternative sponsor for the iconic, 305 m-diameter radio telescope since 2006. The NSF currently spends around $8M a year to keep Arecibo operating. The final impetus for the NSF to find new funding sources came in September 2017 when the telescope was damaged by Hurricane Maria ..."


















Group Delay Measurements with Signal and Spectrum Analyzers

Group Delay Measurements with Signal and Spectrum Analyzers - RF CafeThe available bandwidth of RF channels are often limited by the bandpass characteristic of filters, amplifiers and mixers. Detecting amplitude flatness and phase distortion is crucial in characterizing the quality of a transmission channel. The amplitude flatness within the used bandwidth may have an influence on the signal quality. Knowledge about phase distortion is essential to maintain low bit error rates in data transmissions and VNAs commonly perform amplitude flatness and phase distortion measurements ...







Amprobe Clamp-on Ammeter

Amprobe Clamp-on Ammeter - RF CafeCool Products images folder



MEMS Technology Shrinks Loudspeakers

MEMS Technology Shrinks Loudspeakers  - RF Cafe"Miniature MEMS-based speakers could revolutionize speech and music reproduction in mobile communication devices. They combine the advantages of a large frequency bandwidth and high acoustic quality with the ability to generate very high sound levels. Nevertheless, they are so tiny that they can be integrated into headphones. Such micro-loudspeakers were developed by the Fraunhofer Institutes for Digital Media Technology (IDMT) and Silicon Technology (ISIT). MEMS technology stands for microelectromechanical systems and combines classical ..."

Analysts Predict >500 Million NB-IoT Connected Devices by 2025

Analysts Predict Over 500 Million NB-IoT Connected Devices in Use by 2025 - RF Cafe"Narrowband Internet of Things (NB-IoT) has reached critical mass as network operators all over the world have announced their deployment plans. Last year, the NB-IoT market was driven by a handful of operators, primarily in Asia and Europe. U.S. operators Verizon, Sprint and T-Mobile have started to fast track their NB-IoT development. By the end of 2018, most of the U.S., Europe and Asia Pacific will be covered by at least one NB-IoT network. Despite the early lead by unlicensed Low Power Wide Area ..."

A New Way to Gauge Growth of Nanowires

A New Way to Gauge Growth of Nanowires - RF Cafe"In a new study, researchers from the U.S. Department of Energy's (DOE) Argonne and Brookhaven National Laboratories observed the formation of two kinds of defects in individual nanowires, which are smaller in diameter than a human hair. These nanowires, made of indium gallium arsenide, could be useful for a wide range of applications in a field scientists have termed optoelectronics, which encompasses devices that work by converting light energy into electrical impulses. Fiber optic relays are a good example ..."

Spark Kicks off 5G Era in New Zealand with Live Trial

Spark Kicks off 5G Era in New Zealand with Live Trial - RF Cafe"New Zealand telecom operator Spark announced what it claims to be the country's first live 5G mobile test site in Wellington. The 5G trial used equipment and technical support from Chinese vendor Huawei. It will test speeds, coverage and the parameters of the spectrum in a real-world environment, and run throughout March connecting equipment in a specialized vehicle drive-testing the streets of Wellington. 'We intend to be at the forefront of deploying this technology in New Zealand once ..."

mm-Wave Far More Resilient Than Expected

mm-Wave Far More Resilient Than Expected - RF Cafe"Millimeter wave signals were more found to be more robust than expected and provided high speeds - although not gigabit speeds - at distances of several thousand feet from a node, Signals Research Group found in recent testing of Verizon's 28 GHz fixed wireless access network in Houston. 'Millimeter wave signals are far more resilient than we expected, even at distances exceeding several thousand feet. Tree foliage, passing school buses, buildings, glass ..."

Mystifying Physics of Paint-on Semiconductors

Mystifying Physics of Paint-on Semiconductors - RF Cafe"It defies conventional wisdom about semiconductors. It's baffling that it even works. It eludes physics models that try to explain it. This newly tested class of light-emitting semiconductors is so easy to produce from solution that it could be painted onto surfaces to light up our future in myriad colors shining from affordable lasers, LEDs, and even window glass. These materials are very radiant. The nagging question of whether hybrid organic-inorganic perovskites (HOIPs) could really work just ..."