X-Band Semiconductor Switching and Limiting Using Waveguide Series Tees

摘要

The purpose was to describe a technique for achieving series mode switching and limiting at X-band, using semiconductor diodes in a waveguide structure. Switching was achieved by the application of forward and reverse bias potentials to the diode terminals. When operated as a switch, the three-element configuration provided high isolation and low insertion loss, using either silver-bonded germanium varactors or silicon junction varactors. The better switching performance, i.e., higher isolation and lower insertion loss over wider bandwidths was obtained using the silver-bonded germanium diodes. The threeelement series configuration has also functioned passively as a microwave power limiter. Good limiting action was attained only when silver-bonded germanium units were used. One of the principal disadvantages of this series mode of operation is power absorption. Most of the incident microwave power is absorbed within the diodes. This investigation determined the feasibility of further engineering effort and together with techniques incorporated in the diode series limiter made possible the successful development of semiconductor receiver protectors and duplexers, thereby increasing the capability and reliability of military radars.