METHOD OF MEASUREMENT OF EQUIVALENT NOISE TEMPERATURE OF INPUT OF AMPLIFIER Russian patent published in 1995 - IPC

FIELD: radio engineering. SUBSTANCE: method is intended for measurement of noise temperature of SHF amplifiers, wide-band or of frequency ranges not provided with reference sources of noise signal. Power level P₁ of noise signal is measured across output of measured amplifier matched by input in specified bandwidth, noise signal from output of reference amplifier matched by input and certified by equivalent noise temperature T_n and gain factor K_g is sent to input of mentioned measured amplifier. Power level P₂ of noise signal across output of measured amplifier is measured in mentioned specified bandwidth. Power level P₃ of noise signal across output of matched load is also measured in mentioned specified bandwidth at ambient temperature T_ams. After this ratio γ of difference of levels P₁-P₃ to difference of levels P₂-P₁ is found and noise temperature T_n of measured amplifier is determined from expression T_n=γ/α[(T-T_ams)]-T_ams+T_ams/K_g, where α is attenuation of noise signal from source with noise temperature T to input of measured amplifier on measurement frequency T_n rel. units; K_g is gain factor of measured amplifier on measurement frequency T_n, rel.units. EFFECT: enhanced precision of measurements. 1 dwg