| 摘要 |
Radio-heat thermometer has antenna, balance mixer, low frequency generator, connected in sequence sampling low frequency amplifier, synchronous detector control input of which is connected to output of low frequency generator, integrator and digital voltmeter, SHF transformer coaxial line, SHF switch, two broadband SHF amplifiers and low frequency filter. Potential output of antenna is connected through coaxial line to one end of primary winding of SHF transformer second end of which is earthed. Potential ends of secondary winding of SHF transformer with earthed middle point are connected to inputs of SHF switch output of which through first broadband SHF amplifier is connected to one input of balance mixer the other input of which through second broadband SHF amplifier is connected directly to one of potential ends of secondary winding of SHF transformer. Input of balance mixer through low frequency filter is connected to input of sampling low frequency amplifier. Control input of SHF switch is connected to input of low frequency generator. |
