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.
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These images have been chosen for their uniqueness. Subject matter ranges from historic events, to really cool phenomena in science and engineering, to relevant place, to ingenious contraptions, to interesting products (which now has its own dedicated Featured Product category).
Cool Pic Archive Pages
project sponsored by DARPA gives a whole new meaning to the electronic surveillance "bug." In this case it uses
a real bug. A wireless controller stimulates the giant flower beetle's optical and muscle signaling system to command
takeoff, landing and left / right turns. The only power needed is a small battery for the controller, and a little
pollen. Heat sensors, microphones, and cameras will eventually be added.
Here is an excellent photo of the Planck satellite's 0.35 mm to 1.0 cm antenna farm. How many hours of simulation went into designing the feed horns and array layout? Its mission is to study of the origin of the universe in the sub-mm domain by mapping the cosmic microwave background. The CMB was discovered serendipitously by Bell Labs scientists in 1962. More images of the installed configuration are on the CNES website.
Here is a new way of looking at 10,000 pennies. Well, not exactly pennies. This image of a $100 bill is composed of an effort by 10,000 people from 51 countries tasked with digitally rendering 1/10,000th of the picture - without knowing what the overall subject would create. Participants were found on Amazon's Mechanical Turk collaboration website (an interesting concept).
This photo is as hilarious as it is poignant. It was in a magazine article I was reading that invoked the famous Peter Principle. It made me laugh out loud. "The Peter Principle: Why Things Always Go Wrong" is as valid today as it was 40 years ago when Laurence Peter and Raymond Hull wrote it. Just read the headlines about the world's financial crisis brought on by government geniuses and you will see what I mean.
season is upon us again, so I thought it would be a good idea to remind everybody of the hazard it presents. A year
or so after leaving a company where I designed and built the RF & analog portion of an S-band surveillance radar
system, I received word that the phased array antenna and equipment rack had been torched by lightning. The site
maintenance guy had unhooked the lightning protection cable during the winter to facilitate snow plowing. He never
Here is an EM spectrum chart that you probably have not seen. It is one of many drawings, done by physicist Randall Munroe on xkcd. He creates "webcomic[s] of romance, sarcasm, math, and language." They are sort of like stick figure Dilbert comics. "Warning: this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors)." - Thanks to Ljube Babunski
Borrowing from laser research, scientists are now working on using "twisted beams" in an attempt to cram more data into the crowded frequency spectrum. Digital data is encoded based on the rate of twist. The downside is that a phased array is required on both the transmit and receive side of the system, so it will be a while before your cell phone is using the technology. However, fixed terrestrial and space communications can benefit mightily from it.
Popular Science is running a feature on the private labs and workshops of hobbyists. They encourage readers to submit photos of their workbenches. The electronics bench shown here appeared in the magazine, and something hanging on the pegboard wall immediately caught my eye - makes me wonder how old the owner of the bench is. Can you find what I refer to? BTW, send me a photo of your bench and I'll post it.
maps have a great feature built in that allows companies to electronically insert a map tack at their physical locations
so that viewers automatically get notified. You can even create specialty maps for your particular needs, like this
map of electronics research & development companies in the UK. Click on the blue teardrops for detail on the
companies. You can add your company to the map. It would be a good idea to add your company to Google's main map
database like I have done for
Few things are as awesome as peering through a large telescope and witnessing the Coma Custer of galaxies in the constellation of Coma Berenices (near Leo & Virgo). I had the opportunity to view it through a 14" Celestron. Although not quite as vivid as this photo, the style variation is clearly discernable - spiral, barred, elliptical, top-down, edge-on, the complete gamut. It seems as though you can reach out and touch them. Not until the early 20th century did we even realize what those fuzzy patches of light were.
As if it is not cool enough to inspect the insides of an old watch and be amazed at the precision of the hand-formed gears, springs, and escapements, this particular watch is especially incredible. On March 10, 2009, permission was granted to open the case of Abraham Lincoln's pocket watch to verify or discredit rumors of an inscription made by a repairman stating, "Fort Sumpter was attacked by the rebels..." Look at what was discovered.
Have you seen the map of the world's undersea and overland Internet backbone routing? It is amazing. This photo is of the Terremark headquarters in Miami, where undersea Internet cables emerge from the Atlantic and connect to the rest of the country. Click on the Proxy Trace option for any website on YouGetSignal.com site to see how a webpage gets to you - it's a mess... and a wonder.
the good old days, back when a 4-inch diameter cable with 1,500 twisted pair of wires (3,000 total) carried about
10% of the channels now handled by a single fiber optic cable. Those lightning-fast dial-up connections were really
great. Not. Have you ever seen the
termination panels for these monster cables? These old cables make for cool pictures, like old newsroom typewriters,
but give me modern equipment any day.
French amateur astronomer Thierry Legault snapped this image of the Space Shuttle Atlantis silhouetted against the sun using a five-inch telescope and a digital camera. The next day, he got the rendezvous with the Hubble Space Telescope. High quality equipment at reasonable prices are readily available to amateurs. Even hydrogen-alpha filters for directly observing sun spots and prominences fit the budget of many people - for as little as a kilobuck.
Taiwan's World Games Stadium can generate up to 1.14 GWh of energy using 8,844 solar panels, which cover the 14,155 m^2 (162 kft^2) roof. The US$150M structure will be used to host events in July 2009. When not powering the stadium, the panels pump energy back into the local grid, generating revenue. Construction photos showing the open structure are equally cool.
"The Observable Universe - from Top to Bottom." Here is a very clever graphic that shows relative distances on a log scale. It begins at ground level, works its way up past Mt. Everest, past the ISS, our Milky Way galaxy, and all the way to the edge of the observable universe. (large graphic - 662x2647 pixels).