Abstract

Novel types of predistortion MMICs for the linearisation of short and standard length travelling wave tubes were developed. We measured single setting optimum performance over a wider a bandwidth than any previously reported. The two designed chip sets operated correctly at the specified 10.7 to 12.7GHz and 18.5 to 20.2GHz bands, however, there is no limitation to the wider bandwidth operation of the circuits. By utilising a transmission line simulating network of series inductors and shunt Schottky-diodes we designed these MMICs on a commercially available 0.25um PHEMT process. The chip set includes separate AM/AM and AMIPM circuits for accurate and separate linearisation adjustment of the TWT.