Comparison of a small parabolic reflector for use with an acoustic and a radar microphone

The gain, beamwidth and frequency response of a small, portable parabolic reflector used in an acoustic microphone and in a radar microphone are compared. These microphones are intended for remotely monitoring the 170-250 Hz buzz of honey bees. The RF microphone is based on a Doppler radar operating in the 5.8 GHz ISM band. It detects mechanical vibrations rather than sound. The gain and beamwidth of a reflector with an audio microphone is very good at high audio frequencies, however it is very poor at low frequencies. By contrast, when properly tuned, the performance of the same parabolic reflector with a radar microphone excels at a 200 Hz audio frequency.