Up-converted dual-envelope injection enhanced digital predistortion for inverse class-E power amplifier linearization

A novel injection linearization technique called as up-converted dual-envelope injection (UCDEJ) is proposed in this paper, which combined with digital predistortion (DPD) can get better linearization performance. Starting with an investigation of traditional envelope injection (EJ) method, the UCDEJ technique with enhanced performances is deduced. The injected signal is composed of up-converted two tones of (ω₂-ω₁) and 2(ω₂-ω₁). Experimental results prove that its performances are far better than traditional envelope injection. The superiority of the linearization performance is verified by combining with DPD for a high efficiency GaN inverse class-E amplifier with strong nonlinearity. Thus performance of DPD is enhanced by UCDEJ.