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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The inventions and products featured on these pages were chosen either for their uniqueness in the RF engineering realm, or are simply awesome (or ridiculous) enough to warrant an appearance.
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RF design includes fitting your circuit into a sometime barely big enough package. I have worked on more than
one project in the defense electronics realm where a prototype enclosure did not allow enough room for cable
routing, hardware, access for assembly, etc., even after careful planning. Tools like modern 3-D "printers,"
that can build solid prototypes of complex structures, can help reduce or eliminate such schedule and budget
busting demons. Dimension 3D Printing is one
company that offers the capability for a little as $15k - about the price of a medium grade o-scope.
This might be the world's smallest spectrum analyzer. Wi-Spy plugs into a USB port and displays the local spectrum in the 2.4 GHz ISM band. There is a version for the 5.1 GHz band as well. Included software paints the picture. WiFi, cordless phones, ZigBee, Bluetooth, even R/C airplanes and cars occupy the bands. At $200, this is a very affordable tool for inspecting the environment. Ubiquiti Networks has similar AirView units at 900 MHz ($95) & 2.4 GHz ($70).
Here is an innovation that is long overdue: 135° connectors and adapters. This configuration will make cable routing a lot easier in certain situations, like when you have a dense connector panel behind an equipment rack door. The VSWR is probably a little better than a 90° version to boot. Spectrum Elektrotechnik is the manufacturer.
This is really a sign of the times in which we live. If you like engaging in self-flagellation, add to your widget list this new Layoff Tracker from the sadistic folks at Telonu. Counting began in October of 2008. Let's see... 2,000 at Micron; 1,000 at Nokia; 1,500 at GE; 15,000 at Panasonic... Maybe they can compliment this with a DOW Plunge widget in the same time period.
stacking to conserve PCB real estate is nothing new. Stacks as high as 3 or 4 have been successfully mass
produced for memories. Typically, die-to-die interconnections are made using gold bondwire or sometimes copper
pillars that are ultrasonically welded. Vertical Circuits has formulated a new silver epoxy that allows a
further reduction in stack height by as much as 1.6 mm per tier. It not only saves process cost, but can make
room for an additional die.
Here is the GM car of the future - no kidding. In a joint venture with Segway the PUMA (Personal Urban Mobility and Accessibility) will be hitting the streets of a city near you. Wow, how great will that be?! Chrysler might be merging with Fiat, but GM is merging with a U.S. Government fiat. Bureaucrats and activists will be designing cars of the future. Oh, it doesn't really come with the target painted on the side, but it might as well. Would you ride one of these in New York City?
Long ago and far away, there was a time in this country when even engineers were permitted to express their unique nerd humor in stealthy ways. Chip art is one well-known method. Watkins Johnson pulled off a great ruse in their 1989 catalog. If you never saw it, you have to see it. If you remember it, you will be glad to see it again.
Astronaut Donald Pettit conceived of this On-Orbit Coffee Cup while drinking his cup o' joe from a tinfoil packet in orbit aboard Space Shuttle mission STS-126, far from the nearest Starbucks. Once safely back on terra firma, he solicited the help of designer Travis Baldwin. The unique shape exploits the properties of surface tension to hold the coffee near the sides of the vessel. This problem had been solved 30 years ago by the chow hall where I was stationed at Robins AFB. The coffee there stuck equally well to the sides a regular cup.
has a handy translator for converting SMS-based Teen-Talk texting into understandable dialog. There has been a
lot of news lately about teen texting, including some of the dangerous practices easily overlooked by parents
who don't speak the language. DTXTR (Dee-Text-Er) will help solve the problem.
NetLingo has a manual list. A bit of trivia
about LG: Their current ads use "Life's Good" in conjunction with the LG letters, but LG really stands for "Lucky
GoldStar." No kidding.
Cisco Field will become the Oakland A's new baseball stadium in 2012. Cisco Systems, plans to outfit all 35,000 seats with wireless interactive touch screens. Fans will be able to look up stats, keep score, and even order a beer or hot dog. There's also a promise of a "virtual autograph session" whereby fans will be able to talk with their with favorite players through teleconferencing. As shown, they do not appear to be nearly rugged enough to survive more than a few games.
Analog Devices is offering a free system simulator download titled ADIsimSRD Design Studio. Yes, it is tailored to the products they sell - which are very good - but it is also a very useful tool for investigating how system parameters affect the modulated spectrum, phase noise, etc.
If you thought the display used by Tom Cruise on Minority Report was cool, you will appreciate Sixth Sense. Graduate student Pranav Mistry developed a version that takes cues from the thumb and forefingers of both hands to manipulate a display projected by a wearable device. He demonstrates dialing your cellphone on the palm of your hand, fetching and projecting user reviews onto a book or product, and projecting a Yahoo map while in a car. Sixth Sense should hit the store shelves within a couple years.
its part to bolster the notion that there is practically no household item which cannot benefit from a
wireless interface, Radio Thermostat
Company of America offers a line of thermostats, in-home displays, and load shed devices specifically for
energy management and home automation applications. Plug-in radio modules support ZigBee, Z-Wave, 6LOWPAN, and
a number of proprietary solutions for applications like AMR/AMI and Home Automation.
The latest RF Cafe Poll asks about visitor experience with electronic kits. It appears many have built at least one kit. Maybe it has been a while since you picked up a soldering iron. There are many sources for kits if you do a Google search. One fun project would be the circuit shown above is an ultrasonic parking radar (a misnomer, of course). Need more of a challenge? Try this handheld o-scope kit (I once built a 10 MHz o-scope and a DMM from kits). Heathkit color TV kits are long gone, but there is still a plethora of cool gadgets available.
I am not an avid cyclist, but do have an appreciation for high tech replacements for the status quo. That is why this Dura-Ace Di2 Electronic Shifter system from Shimano is worthy of note. Powered by a 7.4 V Li-Ion battery, the CPU controls the servo motor for the derailleur while monitoring tension and alignment to keep the gear train in perfect order. It can be yours for a mere $5,555.
Speaking of serendipity... British researchers were mixing orange marmalade in the lab for lunch, when a jokester poured in the entire can of powder. The result was a thick gel that instantly transforms into a rigid, impact resistant solid when struck, then returns to its gooey state. This mucilaginous concoction can even stop a bullet or knife. Now, the MoD wants it for flexible body armor and helmets. Oddly, the company that makes it is Blue Divine - maybe the owner is color blind.