Gas discharge switches for S and X-band

A broadband plasma waveguide switch has been developed which provides greater than 100 db isolation when active and less than 0.2 db insertion loss when passive. The cold loss is under 0.1 db over the mid 10% frequency band. The turn-on time is 100 nanoseconds and the turn-off time is 120 microseconds. The absorbed switch power (arc loss) was measured and found to be negligible under conditions of high ionizing beam strengths and moderate plasma densities. The operation of the switch is very similar to gas thyratrons except that the grid is replaced by a perforated waveguide with no internal resonant structures. Consequently, the device can be simultaneously used as a fail-safe receiver protector and switchtube in (magnetron source) radars; the hybrid nature provides receiver isolation (>100 db) during transmit time since the switchtube must be conducting in order for the magnetron to oscillate. Experiments have shown feasibility of this class of operation.