LOW-NOISE SHF BALANCED AMPLIFIER Russian patent published in 2008 - IPC H03F3/00 

FIELD: physics, radio.

SUBSTANCE: low-noise SHF balanced amplifier includes two amplifiers connected between input and output 3 dB directional couplers connected in cascade on linked microstrip lines of Lange bridge-type interdigital structure. Central frequency of input directional coupler is higher than central operation frequency of balanced amplifier. Input directional coupler features link length L against central operation frequency of balanced amplifier, meeting the condition where λ is wavelength in microstrip line relating to central operation frequency of balanced amplifier, with absolute link factor for central frequency of input directional coupler is defined by formula

EFFECT: reduced self-noise level and dimensions of balanced amplifier.

2 dwg