Scattering parameter determination of nonlinear HF power amplifier - determining forward and backward wave components of wavelength-selective directional coupler at output of tested circuit

摘要

The circuit under test (MO) is driven by a generator (G) via an adjustable attenuator (DG2) and a two-way directional coupler (K3). To simulate variable loading, part of the generator output is taken from a power divider (LT) through an adjustable phase shifter (PS), attenuator (DG1), amplifier (V) and wavelength-selective coupler (K1) to the output of the circuit under test. The couplers are connected to e.g. a vector network analyser (AE1). ADVANTAGE - S-parameters are measured reliably with electronically controllable device which can be coupled to high-power load impedance and requires no mechanical parts susceptible to wear.