Travelling-wave microwave device

摘要

A travelling-wave transistor structure (50) with the input and output transmission lines (54,58) terminated with unmatched impedances (70,72,74;80,82,84) to improve high-frequency response by reflection and phase shift to provide constructive interference is disclosed. Preferred embodiments include a pi -gate (52,56) MESFET structure travelling-wave transistor with many periodically spaced gate feeding fingers (56) connecting gate (52) to gate transmission line (54) which parallels gate (52). This provides a compact structure and has large advantages at millimeter wave frequencies. Source (60) may be grounded by vias (61) or may pass over gate transmission line (54) by air bridges to a ground on the same surface as the MESFET.