X-band pulsed measurement system of transmittance changes of power amplifiers

The paper presents a system designed for measurements of transmittance changes of amplifiers and other active N-ports. This system is especially developed for measuring the transmittance variation of X-band T/R modules used in Active Phased-Array Radars (APAR). The measurements are automatically performed with the controlled sampling period 0.2μs÷2μs for RF pulse of 5μs÷300μs duration and 20Hz÷2kHz repetition frequency over an 8.8GHz to 9.5GHz frequency range. The system is capable of achieving the transmittance changes with accuracy of 0.2^o for phase and 0.05dB for amplitude.