Temperature dependence of millimetre-wave MMICs

The authors report the on-chip measured and modelled temperature dependence of the performance of GaAs MMIC components for 60-70 GHz mobile broadband communication systems, namely two amplifiers and a down converter. A new model has been developed, which uses the cut-off frequency of the active device for predicting the drop in gain with temperature, thereby circumventing the need for complex temperature dependent device models. Amplifier gain was measured and predicted to decrease from 4 dB at 273 K to 2.9 dB at 413 K for a single stage amplifier, from 8.5 dB at 273 K to 6.7 dB at 413 K for a dual stage amplifier, while mixer conversion loss was measured and predicted to increase by ~3 dB from 1 to 4 dB over the same temperature range