Question
I am trying to design a rectifying antenna for recceive only. I want to design it at 2.45 GHz. I am not an antenna expert. So, I would need a parts list description aand how to put it together,please.
Answer
What you are looking to build is often called a "rectenna", a combination of an antenna and a rectifier.<BR><BR>A simple antenna which will work for this frequency is a dipole. You could use two stiff pieces of wire, about 3cm long, but if you make the halves of the dipole triangular, you'll have better bandwidth. To a first order, the overall length should be 1/2 wavelength, or about 6.125 cm. That is, you'd have two isoceles triangles, with height about 3cm, and base perhaps 1 cm, with the two sharp ends facing each other. The "feedpoint" of the antenna You could use something like copper sheet to make the antenna.<BR><BR>Then, you need some sort of rectifier at the feedpoint to turn the RF into DC. Ideally, you'd like something with a very low forward voltage, so a germanium or Schottky diode would be best, but it also needs to work at 2.5 GHz. GaAs diodes would be a good choice.<BR><BR>You can hook multiple antennas in parallel in an array.<BR><BR>If you search the web for "rectenna", and particularly "William Brown" you'll turn up a lot of examples of rectennas at various frequencies and power levels. You may want to try and find the following report:<BR>Brown, W., "Rectenna Technology Program:<FONT size=2>Ultralight 2.45 Ghz rectenna and 20 GHz rectenna," NASA Contractor Report CR 179558, Contract NAS3-22764, NASA LeRC, Mar. 1987. Likewise, searching for papers by William C. Brown (who basically invented the rectenna) will be quite productive.</FONT><BR>
rectenna<BR>wireless power transmission<BR>microwave power transmission
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