Microwave characterization of the contiguous domain oscillator

Summary form only given. The authors report the first observation of microwave oscillation in the contiguous domain oscillator (CDO). Computer simulations indicate that, if the channel field V_GG/L is in the regime of negative differential mobility for electrons in GaAs, a contiguous sequence of charge domains will form spontaneously along the entire length of the channel, continuously drifting into the drain. Experimental devices were fabricated using a standard ion-implanted MESFET process, modified to include a WSiN resistive gate. The gate resistivity is 30 k Omega /sq, channel doping is 1.2*10¹⁷ cm^-3, and channel thickness is 150 nm. Channel widths range from 200 to 400 mu m and lengths from 10 to 50 mu m. Devices were mounted in a waveguide insertion unit, and operation was characterized between 26 and 140 GHz using a Tektronix 2755P spectrum analyzer. Modulation of the oscillation frequency by the gate-to-source V_G1-s was observed, as predicted by the computer simulation.