Ultrahigh-Speed Diode Switch for 50 GHz Band Utilizing Avalanche Breakdown in Varactor Diodes

Ultrahigh-speed switches for the 50 GHz frequency range utilizing avalanche breakdown in varactor diodes have been developed as transmitter-modulators for millimeter-wave PCM communication systems. By switching the diode between forward conduction and avalanche breakdown, better performance was obtained than with standard switching conditions. A typical switch of transmission type with a silver-bonded Ge varactor, GSB3C for an input power of +17 dBm at 48 GHz, gave an insertion loss of 3.5 dB with a maximum attenuation of 31 dB. Some of the distinctive characteristics of diode switches utilizing avalanche break-down in varactor diodes are discussed.