Stabilisation mechanism for ´supercritical´ transferred-electron amplifiers

It is shown that a supercritical GaAs c.w. Gunn diode with a cathode doping notch and doping profile sloping upwards from the cathode to anode may act as a stabilised amplifier at high bias voltage. This profile is similar to that in many present-day devices, and may provide a more practical way of increasing the field uniformity so that the noise figure may be reduced, as described by Thim. It is suggested that this mode of operation may be more relevant to the operation of supercritical amplifiers than other stabilisation mechanisms involving large anode fields.