Nonlinear Embedding Model-Based Continuous Class E/F Power Amplifier

This letter presents the design of a continuous class E/F power amplifier (PA) using model-based nonlinear embedding. The theoretically calculated continuous class E/F loads defined at the current source reference plane (CRP) may not guarantee feasible loads at the extrinsic package reference plane (ERP) due to nonlinear parasitic. Hence, a design space is analyzed to map the correct mode of the class E/F continuum over broadband to obtain feasible loads. A scheme is presented to assign fundamental current component (φ) to various frequencies over the band to obtain a tradeoff between best bandwidth and feasibility of a passive matching network. A nonlinear embedding model is used to project the loads from CRP to ERP. As a proof of concept, a continuous class E/F PA is designed using CGH27015F. The prototype developed has measured a drain efficiency of 60.2%-76.5% from 1.5 to 2.9 GHz which corresponds to 63.6% fractional bandwidth.