Wideband SPDT Switch With TTL Control

Abstract

this paper mainly introduces a wideband SPDT switch with TTL control. Firstly, everypossible configuration is contrasted, the theories of basic GaAs switch configurations arementioned. Secondly, the theories of basic GaAs switch configurations are mentioned.Subsequently, appropriate topology is selected for this SPDT switch. This switch has been realizedby 0.5µm GaAs pHEMT process. this switch exhibits high performance: over DC~4GHz, insertionloss is lower than 1dB; The isolation is lower than 50dB; the ripple variation of insertion loss is lessthan ±0.15dB; input return loss is lower than 14dB; on state, output return loss is lower than 16dB;off state, over 0.2GHz-4GHz, output return loss is lower than 12dB; on and off time are less than55ns. The layout of the switch with a chip size is 0.81 mm×1.22mm.