FIELD: high-gain (20 to 60 dB and more), low-noise, broad-band microwave amplifiers. SUBSTANCE: gain linearity of high-gain broad-band, low-noise microwave amplifiers is measured within power range in which they are used in measuring equipment. To this end, noise signal is applied from reference noise source having noise temperature T1 to input of additional single-stage amplifier 2 whose noise temperature is similar to that of amplifier 5 under test; noise signal power level is measured across its output at noise temperature measurement frequency of amplifier 5 under test. Then similar noise signal is applied to input of amplifier 5 under check and noise signal power level across its output is varied until this level is obtained at noise temperature measurement frequency equal to that measured across output of additional amplifier 2. Then noise signal is applied to input of tested and additional amplifiers from reference noise source having noise temperature T2, noise signal power level is varied across output of tested or additional amplifier until similar power level of noise signal is attained across their outputs at noise temperature measurement frequency. EFFECT: enlarged functional capabilities. 1 dwg
