Microwave amplification and phase shifting with impatt diodes

The gain-phase responses of × band amplifying impatt diode phase shifters have been experimentally investigated. The design procedure is described for a gallium arsenide diode for which 180° phase shifts were obtained with gains of 7.5 dB. The power handling capability of the phase shifter is limited by the incidence of parametric oscillation due to the non-linear inductance associated with the avalanching mechanism. Signalling speeds of 20 Mb/s were shown to have no deleterious effects and speeds of 4 or 5 Gb/s are theoretically possible.