Low cost microwave field strength meter
When operating, a waveguide directs energy onto a crystal detector. The diode shown is for X-band operation. The waveguide is a 1H inch piece of plastic tubing with the ends flared. The plastic is coated with an elec-troless copper solution to provide a conducting surface. The dimensions are not critical. For calibrated readings, the meter is placed in a known field or else compared to a calibrated meter
To operate the meter, point it away from the signal. Switch the meter to the desired range, and adjust the zero control for a 0 reading. Then point the waveguide at the signal, and read field strength directly.