PYROELECTRIC RADIOMETER Russian patent published in 1997 - IPC

FIELD: radio-measuring technology. SUBSTANCE: adaptation capabilities of instrument are improved due to introduction of adaptation unit which includes frequency-dependent stage, mode of operation change-over unit and controlled phase shifter. Provision is made in pyroelectric radiometer for modulation frequency variation in direct proportion to output signal level. Signal level variation in signal channel is maintained within small range by means of frequency-dependent stage. At the same time phase shift between signal and reference inputs of synchronous detector caused by pyrodetector reaction to modulation frequency variation is compensated by controlled phase shifter. Angle of phase turn of phase shifter is also determined by modulation frequency. EFFECT: higher adaptation capabilities. 3 dwg