Triggered Operation of Tunnel Diode Oscillators and Pulse Generators

This paper describes a method of designing the optimum monostable tunnel diode switch: optimum in the sense that it permits the highest switching rate for the minimum expense of the output pulse height for a given tunnel diode. The selection criteria of the tunnel diode for high speed switching applications are also given. The method is based on a unified theory of operation of the tunnel diode oscillator and pulse generator by means of a graphical analysis, taking the nonlinear nature of the diode into consideration. The theory explains the phase-gated microwave oscillation; an experimental 9-GHz oscillator generated a very short carrier pulse consisting of any controlled number of oscillation cycles, even of one cycle, thus reducing itself to a monostable pulse generator. 4-GHz oscillators of the optimum design using 20-mA, GaAs tunnel diodes have been demonstrated to be capable of operating as the monostable switch at 2-GHz repetition rate. This is an improvement of the speed capability of the device which has been limited below one GHz.