I need to build a 2.4GHz field strength meter for cheap. (It's for a project) It should either use a row of LEDs or a TI-83 calculator for a display. Exact accuracy is not important. It should be able to pick up the signal from an 802.11b/g router at least 100 feet away. It doesn't need to tell the difference between WiFi, Bluetooth, and other 2.4GHz signals, but it would be really nice if it can. It should be about as big as a bar of soap (smaller would be better). What would you suggest to build this with?
On another board that I read, they make microwave cannons, and a simple dectector they use is a RF diode in antiparallel with a LED. Nothing fancy. I would imagine if you could get a fast enough op-amp or something, you could get something with a variable output strong enought to send a signal to an LM3914 or 3915.
Easyest way would be to get an antenna designed for 2.4Ghz then use a very good highspeed linear amplifyer. If you then measure the peak output from that it will give you an idea of field strength. To determine which device is transmitting is going to be harder. You will require so signal processing to determine what modulation is being used and hence work out what device it is.
