You can make these, easy!
By soldering a bunch of "low forward voltage" diodes in series (the leads act as antennas) you can make large flat arrays of high gain? energy collectors that collect Microwave/RF/DTV/Radio signals and whatever else hits it!!! (cb radio blasts, wifi, cosmic rays, cme's, tesla coil emmissions etc..) These couldnt be easier to make! (This is a crude version that works OK!? (make one and tell me!!!).. to increase the sensitivity even more, you need waveguides and to tune it right..Maybe we could call it the poor mans rectenna hehe:) )
Detailed instructions on how to make this:
Step 1: Connect a bunch of diodes (try and get 1N34 germanium, or shotky ) together in series (arrange them like an antenna)..
Step 2: BAM! RECTENNA!
Step 3: YEAHHHHHH!!!!!!!!!!!!!!!!!!! (optional step)
Notes: The lower forward switching voltage the diodes are, the more sensitive your Rectenna will be: Germanium or Shotkey types should work best. Could also try low voltage bridge rectifiers used in WIFI equipment (and loop antennas or dipole... )// Works best closest to radio sources like radio towers, wifi/cell tranmitters etc.. experiment! The larger the array the more energy will be collected! You can make an 8.5X11 inch array that could fit in your backpack to charge your phone if your in the city :D maybe make fractal patterns golden ratio fibianaci sequence for the antenna configuration...
I made a diagram on my google plus thing.. https://plus.google.com/107797881587621987231/posts/jFa9URbo3HY
Music: Q Project - Champion Sound http://www.youtube.com/watch?v=eeD530GlgaY