Nonlinear Embedding of FET Devices for High Efficiency Power Amplifier Design

Abstract

The nonlinear parasitic components of high-power FET devices require tremendous amount of device characterization efforts. The recent nonlinear embedding technique can significantly expedite the design process by removing the time-consuming source/loadpull measurements. This technique is demonstrated using the Angelov model for a 15 W peak power gallium nitride device. The power amplifier design starts from the intrinsic conceptual design and then the external conditions to maintain the intended operation are directly calculated using the nonlinear embedding. This technique is applied to a 9.54 dB back-off asymmetric Doherty power amplifier. 71 % drain efficiency at the peak power of 41.8 dBm and 62.7 % at 32.8 dBm (9 dB back-off) were measured. This technique is further investigated for the linear broadband design space identification. The linearization of the nonlinear intrinsic current source is proposed for the nonlinear embedding. The two dimensional design space is identified by applying the nonlinear embedding to the load modulated continuous-classF3 mode waveforms. The identified design space is applied to the manufacturer model and then the intrinsic waveforms are observed for the intended operation verification.