Click here to go to our main page on waveguide
Click here to go to our main page on attenuators
New for October 2012! Thanks to Name Withheld, we have a new portmanteau, which refers to a circular waveguide attenuator where the resistive element is constructed out of a carrot...
Thought you might be able to use these photos of a 13 GHz attenuator that I made recently.
The required attenuation was about 40 dB for circular waveguide, had to be cross polar and also bidirectional. The VSWR is unknown but all the other performance indicators such as signal quality and equalizers point to quite a reasonable result - considering it started life a carrot.
The end product was about half the length pictured on the lower left.
The attenuation decreased quite quickly at first, as the carrot dried out.
Fresh carrots are about 90% water. Determining the dielectric properties of vegetables has been of interest since the first microwave ovens were introduced in the 1959s. Here's one paper on the topic.
This reminds us of the story of Mike Yurosek, a Bakersfield farmer who came up with Bunny Luv baby carrots in the 1980s...
And it further reminds us of Cousin RayMar, who once sang a song about acorns. We can only remember that first soulful line, maybe someone else will finish the song now that Ray resides in a heart-shaped box.
Oh, acorn that I tried to cut square, don't you fret, don't you cry...