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Homepage Archive - January 2019 (page 1)

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. About RF Cafe.

Homepage Archive Pages

2019:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2018:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2017:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2016:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2015:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec


See Page 1 | 2 | 3 | 4 | 5 of the January 2019 homepage archives.

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Friday 4

A Look at the PC Market

A Look at the PC Market, January 1972 Popular Electronics - RF CafeWhen I first read the title for this article, "A Look at the PC Market," I was thinking personal computers, not printed circuits. It being from a 1972 issue of Popular Electronics, my assumption was that the photos of circuit boards were from early kit format computers, but then it finally dawned on me that there were no personal computers in 1972 - not even in kit form. Actually, that is not entirely true since there were advertisements for hokey contraptions called "computers" that combined some switches, logic gates, and LEDs for implementing simple multiple choice true/false testing boxes or rudimentary (with emphasis on "rud[e]") calculators. Getting to the real story, though, the 1970s was the decade where printed circuit boards (PCBs) were replacing point-to-point wiring wherever possible. If you opened a radio or television ...

Electromagnetism - What It Is

Electricity - Basic Navy Training Courses, NAVPERS 10622, Chapter 12 - Electromagnetism - RF CafeChapter 12 of the U.S. Navy's basic electronics training course discusses electromagnetism. It follows on the heels of the sections introducing magnetism and electrical currents. The Navy (and the Air Force, I must add) is renowned for its high quality training and for turning out graduates that perform highly in both their service duties and in private industry after separation. It describes the electromagnet as being like a natural or artificial magnet in its attractive force, is tremendous and can hold tons of iron. Because this magnet is powered by an electric current, the magnetism can be turned on and off with the flick of a switch. Electrically-powered magnets are called electromagnets. Electromagnets come in all sizes and shapes ...

Technical Support Representative Wanted by Infinite Electronics

Technical Support Representative Wanted by Infinite Electronics - RF CafeInfinite Electronics, a global supplier of RF and Microwave components and assemblies, is looking for a Technical Support Representative. We have an exciting opportunity for a technically savvy individual with proven customer facing and team skills to round out our Sales and Tech Support team. Job Summary: The Technical Support Representative's duties and responsibilities include, but are not limited to: (80%) Resolving customer technical questions directly through telephone, email, chat or other methods of communication, or via the Sales and Service Representative. The TSR will identify customer needs and resolve routine customer technical questions by identifying the appropriate RF/Microwave part, recommending additional or alternative ...

E-Skin Turns a Person into a Compass

E-Skin Turns a Person into a Compass - RF Cafe"A new electronic skin with magnet-sensitive capabilities developed by researchers in Germany can turn someone into a human compass, providing opportunities for navigation as well as virtual-reality and other applications. Researchers at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) developed the e-skin, which can detect and digitize body motion as it corresponds to the Earth's magnetic field, they said in an HZDR news release. An ultra-thin golden foil on the middle finger is all that’s needed to control a virtual panda with the help of the Earth's magnetic field, thanks to new research to develop an electronic skin by researchers in Germany. The e-skin is extremely thin and malleable, which means ..."

KR Electronics: RF & Microwave Filters

KR ElectronicsKR Electronics designs and manufactures high quality filters for both the commercial and military markets. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop and individually synthesized filters for special applications - both commercial and military. State of the art computer synthesis, analysis and test methods are used to meet the most challenging specifications. All common connector types and package form factors are available. Please visit their website today to see how they might be of assistance ... 

Thursday 3

Variable-Voltage Tuning: How It Works

Variable-Voltage Tuning, April 1969 Radio-Electronics - RF CafeHave you ever used any of these voltage-variable capacitor (VVC) types: varicaps, epicaps, minicaps, voltacaps, capistors and varactrons? If you answered "no, but I have used varactor diodes," then the more correct answer would have "yes, I have, but by a different name." Construction was similar for all variations. This article from a 1969 issue of Radio-Electronics magazine reports on some of the earliest forms of diodes specifically designed to use a reverse bias on the PN junction to control the effective capacitance of the device for use in frequency tuning circuits. The first uses were for electronically tuning local oscillators in mixing stages, and then for making tunable filters. Capacitance ratios greater than 10:1 with some VVCs allowed tuning over a very wide range. At the time the article was written, there was not universally agreed upon schematic symbol for the VVC, as illustrated in Figure 2. Varactor-tuned television channel selectors ...

How to Use Filter Equations in Software and Spreadsheets

How to Use Filter Equations in a Spreadsheet - RF CafeDo a WWW search for filter equations and you will find thousands of pages, including a few here on RF Cafe. However, if you want an example of how to implement the transfer functions in a spreadsheet or software, examples of actual code are elusive (other than maybe a Matlab or MathCAD worksheet). As one who has incorporated equations for Butterworth, Chebyshev Type 1, Chebyshev Type 2, and other filter functions in many spreadsheets and software over the past few decades, I figured it might be useful to post snippets of my code so that someone else can copy and paste it directly into other work. BTW, I do not consider myself to be a filter expert by any means and there is no ground-breaking knowledge here; it's just hopefully easier to find. Writing a macro to use in a spreadsheet is the preferred ...

FCC Certification for Part 15C Wireless Transmitters

FCC Certification for Part 15C Wireless Transmitters - RF CafeElite Electronic Engineering, of Downers Grove, Illinois, if offering as a free download this whitepaper titled, "Guide to FCC Certification for Part 15C Wireless Transmitters." Elite is a recognized Telecommunication Certification Body (TCB) for the FCC, Foreign Certification Body (FCB) for Canada, and Notified Body (NB) for the European Union under the Radio Equipment Directive. These credentials assure the speedy and convenient processing of your approval. FCC Certification Elite is designated by the United States government as an accredited Telecommunication Certification Body (TCB). We provide FCC compliance testing services to manufacturers of radio-frequency transmitting devices ...

Triad RF Systems Intros 30 - 2700 MHz, 8 W Bi-Directional Amplifier

Triad RF Systems Intros a 30 to 2700 MHz, 8 W Bi-Directional Amplifier - RF CafeTriad RF Systems, a top-tier designer and manufacturer of RF and microwave amplifiers, announces the introduction of their TTRM1210 bi-directional amplifier, a wideband GaN Bi-Directional Amplifier (BDA) that operates from 30 MHz to 2700 MHz and produces over 8 W of transmit power. The receive side has over 20 dB of gain to overcome losses between the antenna and the radio. The noise figure is 2 dB which makes the BDA practically invisible to the system. Switching between transmit and receive can be done either automatically when RF is sensed at the radio port, or manually switched by the radio or user. One of the smallest BDAs in the industry measuring only 3.25 x 2.12 x 0.53 inches, this feature rich BDA is also one of the most efficient. While producing 8 W of RF power ...

'Magic-Angle Graphene' Behaves Like High-Temperature Superconductor

'Magic-Angle Graphene' Behaves Like High-Temperature Superconductor - RF Cafe"The Physics World 2018 Breakthrough of the Year goes to Pablo Jarillo-Herrero of the Massachusetts Institute of Technology (MIT) in the US and colleagues for making the discovery that led to the development of 'twistronics,' which is a new and very promising technique for adjusting the electronic properties of graphene by rotating adjacent layers of the material. The technique was first used by the team to create 'magic-angle graphene,' which behaves like a high-temperature superconductor. Nine other achievements are highly commended in the Top Ten Breakthroughs of 2018 and cover topics ranging from the first full body PET/CT scan to a zero-carbon aeroplane propelled by a jet of ions. Graphene is a layer of carbon just one atom thick that has a honeycomb lattice. Bilayer graphene ..."

Innovative Power Products: RF & Microwave Passive Components

Innovative Power ProductsInnovative Power Products (IPP) has over 30 years of experience designing & manufacturing RF & microwave passive components. Their high power, broadband couplers, combiners, resistors, baluns, terminations and attenuators are fabricated using the latest materials and design tools available, resulting in unrivaled product performance. Applications in military, medical, industrial and commercial markets. Take a couple minutes to visit their website and see how IPP can help you today ...

Wednesday 2

Thanks to Copper Mountain Technologies for Continued Support

Copper Mountain TechnologiesCopper Mountain Technologies develops innovative and robust RF test and measurement solutions for engineers all over the world. Copper Mountain's extensive line of unique form factor Vector Network Analyzers include an RF measurement module and a software application which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware via USB interface. The result is a lower cost, faster, more effective test process that fits into the modern workspace in lab, production, field and secure testing environments ...

RF Cascade Workbook 2018

RF Cascade Workbook 2018 Is Available Now! - RF CafeRF Cascade Workbook 2018 is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features ... 

Magnetism - Its History

Electricity - Basic Navy Training Courses, NAVPERS 10622, Chapter 11 - Magnetism - RF CafeAn ancient legend tells us that nearly 5,000 years ago an Emperor of China had a small statue of a man mounted on his chariot. This statue was pivoted at the base and one outstretched arm always pointed to the south. In those ancient times, this action must have seemed truly miraculous - probably the Emperor used his statue more to impress his subjects than he did to find his way. This legend is the first report of man's use of a black or lead-colored stone called magnetite. About the time of Christ, magnetite was rediscovered by a Grecian shepherd. He noticed that the iron of his staff was attracted to certain stones. But for nearly another 1,000 years, no particular use was made of this discovery ...

3D-Printed Antennas

Antenna Test Lab Co  - RF CafeA while back I mentioned that Mr. Glen Robb, owner of Antenna Test Lab, had an article in the October 2018 issue of Microwaves & RF magazine titled, "Assemble Antennas with 3D Printing." He told me a future issue of the ARRL's QST magazine would also be running an article on his 3D antenna printing project. It just showed up in the January 2019 edition. Unfortunately, QST does not have a publically accessible version of the magazine, but for ARRL members you can find the article under the title of , "3D-Printed Antennas," on page 67. It is featured in Paul Wade's monthly "Microwavelengths" column. "3D printers have become quite inexpensive, and many hams have acquired one. Printing hard-to-machine horn and antenna feeds is a natural task for 3d printers ..."

RF Cafe Poll: Do You Plan to Change Jobs in 2019?

RF Cafe Poll: Do You Plan to Change Jobs in 2019?The first RF Cafe Poll for the new year asks, "Do you Plan to Change Jobs in 2019?" Voting is totally anonymous and does not require registration. I also will not hit you with a full-page advertisement, require you to submit an e-mail to view the poll results, or set a cookie with the poll code. My cardinal rule on RF Cafe is to never subject visitors to any form of treatment I despise when going to a website. Thanks for your participation ...

Topological LC Circuits Transport EM Waves Without Backscattering

Topological LC Circuits Transport EM Waves Without Backscattering - RF Cafe"Engineers have succeeded in fabricating topological LC circuits arranged in a honeycomb pattern where electromagnetic (EM) waves can propagate without backscattering even when pathways turn sharply. These circuits may be suitable for use as high-frequency electromagnetic waveguides, which would allow miniaturization and high integration in various electronics devices, such as mobile phones. NIMS succeeded in fabricating topological LC circuits arranged in a honeycomb pattern where electromagnetic (EM) waves can propagate without backscattering even when pathways turn sharply. These circuits may be suitable for use as high-frequency EM waveguides, which would allow miniaturization and high integration in various electronics devices, such as mobile phones ..."

Bittele Electronics: PCB Fabrication & Assembly

Bittele Electronics PCB Fabrication - RF CafeSince 2003, Bittele Electronics has consistently provided low-volume, electronic contract manufacturing (ECM) and turnkey PCB assembly services. It specializes in board level turnkey PCB assembly for design engineers needing low volume or prototype multi-layer printed circuit boards. Free Passive Components: Bittele Electronics is taking one further step in its commitment of offering the best service to clients of its PCB assembly business. Bittele is now offering common passive components to its clients FREE of Charge ...

Tuesday 1

Citizen Band Radios

CB Radios, May 1967 Popular Electronics - RF CafeAlthough "Citizens Band" (CB) is the common reference to these unlicensed two-way radio service transceivers, the official name for the spectrum allocated by the FCC to their operation is "Citizens Band Radio Service" (CBRS). It was originally called just "Citizens Radio Service," but the popular use of "Band" caused the FCC to incorporate the additional term later on. Early Part 95 Class D citizens band radios offered up to 23 channels in the 11-meter band from 26.965 MHz through 27.255 MHz. CB radio channels increased to 40 in 1977 due to the immense popularity at the time (long before cellphones) - recall the "Convoy" song. The 11−meter band was re−allocated from the amateur radio spectrum in 1958 (to the great dismay of Hams). CB radios are still used heavily by truckers who don't like the idea of "Big Brother" listening to and recording conversations ...

Must-See Stargazing Events for 2019

Telescopic Watch Infographic 2019 - RF CafeNot everyone is an ardent observer of astronomical events, but most people are still as awestruck as were primitive peoples when a lunar eclipse or solar eclipse occurs, or when a massive meteor shower happens. Centuries ago most of those phenomena were not predicted because the mathematics and mechanics of gravity were not known. The kings' best astronomers and astrologers leveraged ignorance to influence ruling policy similar to how politicians and activists do today. The folks at the Telescopic Watch website created this infographic titled "Must-See Stargazing Events for 2019" which highlights the 10 most significant astronomical events of the new year. First up is a total lunar eclipse on January 21st ...

Manhole Cover Antenna Propagation Strategy for 5G

Manhole Cover Antenna Propagation Strategy for 5G - RF Cafe"The inconvenient truth of future 5G networks is that their increased high-speed bandwidth, and the use of the millimeter wave spectrum (the radio spectrum above 30 GHz) to achieve it, comes at a price: Those radio signals barely propagate around the corners of buildings. To overcome this issue, the strategy has been a combination of small cells with massive multiple-input multiple-output (MIMO) antennas to increase coverage. Small cell deployment will be so extensive that the Small Cell Forum predicts 5G small cell will overtake 4G small cells by 2024. The total installed base of 5G or multimode small cells will reach 13.1 million by 2025, constituting more than one-third of the total small cells ..."

Windfreak Technologies: USB-Powered RF Synthesizers, Mixers

Windfreak TechnologiesWindfreak Technologies designs, manufactures, tests and sells high value USB powered and controlled radio frequency products such as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters. Since the conception of WFT, we have introduced products that have been purchased by a wide range of customers, from hobbyists to education facilities to government agencies. Worldwide customers include Europe, Australia, and Asia. Please contact Windfreak today to learn how they might help you with your current project ...

 
   
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About RF Cafe
Kirt Blattenberger - RF Cafe Webmaster
Copyright: 1996 - 2024
Webmaster:
    Kirt Blattenberger,
    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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