Characterisation of GaAs pseudomorphic high electron mobility transistors for Volterra-series circuit analysis

Explicit extracting procedures for nonlinear transconductances and capacitances of GaAs pseudomorphic high electron mobility transistors are presented for Volterra-series circuit analysis. Nonlinear transconductances are acquired by low-frequency harmonic measurements with the associated phase polarities at various attenuations. Biased-dependent scattering parameter (S-parameter) measurements are utilised with curve-fitting processes to deduce the nonlinear capacitances. The extracted data up to third-order nonlinearities are validated by the two-tone signal tests in a bias range of 180-250-mA and a power sweep of -9.3-6.7-dBm, respectively. This device characterisation is quite useful for intermodulation reduction of power amplifier designs in modern digital wireless communications.