Uniphase Unidirectional Microphones
Benjamin B. Bauer · The Journal of the Acoustical Society of America · 1941
The unidirectional microphone is treated as a generalized transducer and network which are subjected to sound waves at two points in space. Network relationships are derived to produce unidirectional operation. These relationships are fulfilled in the “uniphase” structure which has a single transducer and a phase-shifting network instead of the two transducers normally used in unidirectional microphones. Acoustical phase-shifting networks applied to a diaphragm-type piezoelectric microphone and to a moving coil dynamic microphone producing a cardioid-type polar pattern are described.