Resonant-Tunneling Transmission-Line Relaxation Oscillator

A new type of resonant-tunneling oscillator is analyzed that does not require dc bias stability in the negative-differential-resistance region. The oscillator consists of a resonant-tunneling diode coupled to a transmission line in such a way that repetitive switching of the diode occurs across the negativeresistance region. The output waveform consists of a sequence of pulses having a repetition rate determined by the electrical delay of the transmission line and a pulse width determined by the switching time of the diode. When the electrical delay is comparable to the switching time, the output is quasisinusoidal. Numerical simulations with a prototype resonant-tunneling diode yield a maximum repetition rate of 192 GHz and a pulse width of 2 ps.