Experimental investigation of TRAPATT diode trigger conditions

Experimental studies have been carried out to determine the mechanisms by which the TRAPATT mode can be triggered into operation in the S-band frequency range. These investigations indicate that the TRAPATT mode can be triggered either by VHF oscillations or by IMPATT oscillations. The various frequencies interact to control the turn-on time and the current required to trigger the diode into oscillation. The interactions between the frequencies is controlled by the microwave and bias circuits. Changing the bias circuit alters the interaction thus causing the turn-on time and trigger current to be different. From this information the necessary bias conditions can be given to reduce the turn-on time and trigger current. With appropriate circuit elements the VHF have been observed to trigger the TRAPATT mode into operation in 5 ns. The IMPATT mode of triggering, however, results in a 20 to 25 ns delay before the TRAPATT signal appears.