Temperature-dependent characteristics of InP-RTD-based microwave amplifier IC

Abstract

A reflection-type microwave amplifier using InP-based resonant tunnelling diodes (RTDs) has been designed and fabricated. The implemented amplifier shows a low dc-power consumption of 270 mu W with RF gains of more than 11 dB at 5.61 GHz. Temperature-dependent characteristics of the RTD amplifier have been investigated at a high temperature. With increasing temperature from 25 to 100 degrees C, the centre frequency shift was measured to be 60 MHz. The RF gains (S-21/S-12) and the return losses (S-11/S-22) of the amplifier decreased from 11.45/11.32 and -7.96/-8.11 dB at 25 degrees C to 7.06/6.91 and -11.36/-11.15 dB at 100 degrees C, respectively. The S-parameter degradation phenomena are shown to mainly arise from the temperature dependence of the negative differential resistance (R-D) characteristic for the fabricated RTD.