Distributed amplifiers as duplexer/circulator components at S-band

The signal flow characteristics of distributed amplifiers are studied, and it is found that such modules can be designed to suit certain solid-state duplexer/circulator or bi-directional amplifier applications. A module with a measured S₃₁ (transmit to receive) isolation of typically 10 dB is described, and found to have a gain of about 6.0 dB in the S₃₄ direction and 7.5 dB in the S₂₁ direction. A major motivation of this research is to seek all solid-state design solutions for low power FMCW radar and duplex communications equipment; thereby obviating the use of ferrite circulator components