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 ...
All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.
My Hobby Website:
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.
All Featured Product Archive Pages:
Here is a real "thinking outside the box," or in this case, thinking inside the tower,
proposal that addresses many concerns about wind power generation. The "Wind-It" generator would be constructed within the confines of high
voltage transmission towers, thereby eliminating the need for additional real estate, unsightly massive wind farms
(I think they look cool), reducing bird strikes, distributing generation points to reduce vulnerability,
and simplifying maintenance among other things.
This is a carpet made of looms from conductive thread. By standing on it, your body acts as an antenna. The carpet picks up the radio waves, which your body receives and makes them hearable. When walking on the carpet you can tune it to a certain frequency, like the tuner of a radio. It is made of loops from conductive thread. I hope those incredibly red feet on the model are not from RF burns!
Vaunix Technology has a line of products called "Lab Bricks" that, as the name implies, are reminiscent of red building bricks. Programmable signal generators (50 MHz to 6 GHz @ +10 dBm) and digital attenuators (100 kHz to 6 GHz, up to 63 dB) are available, and they all have a standard USB interface. USB lab instruments have become very popular as low-cost options. Interface software is included. MPD did a nice write-up here.
Other than maybe checking e-mail or surfing the Web, a standard size screen is simply not convenient these days. Working with a spreadsheet or simulation program is always much easier if you have a second screen for displaying utility stuff rather than having it hidden behind the main program display. With a desktop setup it's easy, but not on the go with a notebook... until now. gScreen hopes to have this on sale by Christmas.
Inventor James Dyson refers to his breakthrough Air Multiplier™ cooling device as a bladeless fan... but that is not completely accurate. It does have blades, but they are contained within the base. The breakthrough feature is that the primary "fan" has no moving parts. A proprietary 15x "air multiplier" effect is created by the computer optimized venturi shape and air feed holes in the ring. The resulting airflow is smooth rather than turbulent. Cool, literally.
TEMs are very handy devices for making RF measurements. A minor inconvenience is the enclosed, sealed chamber where the DUT sits for testing - necessary both to shield from ambient signals and to focus DUT signals on the detector. APELC produces what I have dubbed a "phantom" TEM-type enclosure constructed of a portable, open tubular structure. Although intended for RS-105 (EMI/RFI/EMP) testing per MIL-STD 461E/F, it should be adaptable to other uses.
MATLAB is very popular software used by engineers of all sorts. MATLAB is also expensive. This open source equivalent is called FreeMat, and is available for download at no charge. Just as Open Office has given Microsoft Office a run for its money (literally), FreeMat and other open source software is driving a lot of companies crazy, especially since most programs can import and export files with complete compatibility for the features a majority of people use.
A lot of people write to ask where to find a good point-to-point transmission path calculator. I usually provide the URL to my calculators page, which has a couple. The P2P Estimator, by AlphiMAX, is one of the best examples of a FREE calculator I have seen. The screen shot thumbnail is from RF Cafe to a spot in Lake Erie, about 2 miles away. Note the GPS database indicates the elevation transition to Lake Erie (571' ASL) profile correctly. Pros and hobbyists will love this.
While sitting at a lab bench with a circuit prototype, swapping out fly speck sized resistors, capacitors, and inductors, it is easy to lose track of which value is which. Let a test cable or your arm inadvertently swipe across your neatly arrange lineup of parts and all hope is lost. Unless you have an expensive LCR meter, you might as well throw them away. Not anymore. Now, for a tad more than $300, you can get a pair of Smart Tweezers that not only measures each speck, but can be used to place the part on the PCB. Sweet.
Start your Christmas shopping early this year with the perfect gift for that person who has everything… a $3.2 million solid gold iPhone. More than 200 flawless diamonds adorn the case, and the navigation button sports a 7.1 carat diamond. With the price of gold rising on a daily basis (almost at $1200/oz. now), you had better hurry.
You probably looked at this picture and said to yourself, "Self, that must be a speaker." No? Well, it is. This new invention called fleXpeaker is basically a sandwich of paper and metal filled with an electroactive polymer that contracts and expands with an audio signal's electric field. "Product customization can be done in diverse fields, such as art for public facilities, interior design, costume accessories, and others." Production could begin by 2010 which, amazingly, is almost here.
iPhonemania has resulted in millions of applets being written by aficionados of the device for just about every imaginable subject. Now, thanks to folks at Sanie Ventures, you can use iWafer calculate die size, utilization, I/O placement, die count per wafer, manufacturing yield, and typical die cost. $9.99 will get you a copy from the iPhone Store. Other apps like RFLinkCalc and iAttenuate and from Black Cat Systems are available for a couple bucks.