A nanosecond X-band switch

An experimental low-power nanoseceod X-band microwave switch and accompanying video driver circuit are described. The switch is used to modulate the output of a CW X-band source and provides pulses at a nominal 2-MHz repetition frequency for an experimental, coherent pulse Doppler radar application. Pulse lengths at the -3 dB and -40 dB points are 1 ns and 2 ns, respectively. Pulse shape is characterized by subnanosecond rise and fall times and the amplitude of the pulse time sidelobes is -35 dB or less. The switch provides an isolation of 50 dB or more in the off-state, and 6 dB or less ha the on-state. Maximum X-band input power capability is 10 mW at a frequency of 9.2 GHz.