20 GHz gated tunnel diode based UWB pulse generator

We demonstrate a pulse generator based on a GaAs-AlGaAs gated resonant tunneling diode (RTD). This is realized by integrating a third terminal, the gate, into the current path of a RTD. The gate consists of a 200 A thick tungsten grating buried 300 A above the RTD. This implementation allows for control of the current through the RTD. By integrating this device in parallel with an on-chip inductance, a negative differential resistance (NDR) oscillator is formed. It is demonstrated that by using the gate to change the output conductance of the device, the oscillations may be switched on and off, creating short bursts of RF power. This technique allows for rapid quenching of the oscillator, and hence the ability to generate short pulses at high frequency, enabling impulse radio ultra-wideband communication implementations. The highest demonstrated oscillation frequency is 22 GHz with an output power of -4.1 dBm, and the shortest pulses generated are 1.3 ns. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim