Characterisation of PHEMT intermodulation behaviour for highly linear MMIC power amplifier design

In this paper the intermodulation distortion (IMD) behaviour of a 0.25 power PHEMT is investigated under several device operating conditions. An extensive experimental device characterisation, together with numerical simulations using suitable non-linear transistor models is carried out. Experimental data were compared with different transistor models in order to understand the effect of the various cell parameters on the device IMD3 response. The data collected were applied in the design of a highly linear power amplifier family, covering different frequency ranges.