A 10-to-650MHz 1.35W class-AB power amplifier with instantaneous supply-switching efficiency enhancement

A broadband PA is presented, combining a Class AB core with instantaneous supply-switching (ISS). High-ft NPN cascodes switch the amplifier signal current to high or low supply rails depending on instantaneous amplitude. Current-mode switching at GHz rates enhances efficiency for bandwidths well beyond existing envelope trackers. 1.35W peak power and efficiency=13.6% @11dB PAPR are observed. The combination of Pout, large fractional bandwidth and high-PAPR efficiency exceeds prior art.