Three-terminal GaAs switches

A new three-terminal GaAs device has been developed and its switching characteristics investigated. The third ohmic contact of the device is located on a side surface near the cathode of a conventional two-terminal long n-type GaAs oscillator. High-speed switching of oscillation, with turn-on and turnoff times of one nanosecond, has been successfully obtained by applying single short triggering pulses or combined positive and negative pulses between the third contact and the cathode, using a fixed bias voltage between the cathode and the anode. The triggered oscillation can be sustained after the triggering pulse is removed if the bias voltage is above the minimum sustaining voltage of oscillation, which is about 80 to 90 percent of the threshold value. This paper will briefly review the triggering conditions of the two-terminal oscillator devices and present various current waveforms of triggered oscillations obtained with the three-terminal devices. Some correlations between the sustaining voltage of oscillation and the triggering voltage will be discussed. This device could be used as high-speed switching and memory elements in logic circuits.