Experimental characteristics of GaAs read-type reflection amplifiers at X-band

The paper examines the performance of Read impatt devices when they are operated as stable reflection amplifiers. In particular, the small- and large-signal amplifier behaviours are related to the different r.f. modes of the device (i.e. small-signal, intermediate and high-efficiency regimes) that are characterised by the signal dependence of the d.c.-bias operating point. The outcome of a device-characterisation procedure has enabled a stable reflection amplifier to be realised which can deliver a continuous output power of 2.8 W from a single diode, at a saturated gain of ~6dB, with a power-added efficiency of 21% at a frequency of ~8 GHz, when operating with certain bias constraints.