1-D Reconfigurable Pseudo-Doherty Load Modulated Balanced Amplifier With Intrinsic VSWR Resilience Across Wide Bandwidth

This article presents the first-ever wideband pseudo-Doherty load-modulated balanced amplifier (PD-LMBA) with load-mismatch tolerance through 1 -D reconfiguration. It is theoretically unveiled that when the control amplifier (CA, as a carrier) in PD-LMBA is driven to its saturation, it is endowed with a duality between the current source (CS) and voltage source (VS), which makes the BA (as peaking) have complementary load-modulation trajectories for the two sub-amplifiers (BA1 and BA2) under load mismatch. As a result, the BA in PD-LMBA inherits the intrinsic load insensitivity from the generic quadrature-balanced amplifier. Meanwhile, the saturation power of CA can be maintained by only reconfiguring the dc bias voltage ( V_\mathrm{DD,CA} ) that solely depends on the real part of load impedance, real \mathrm(Z_\mathrm{L}) . As such, the degree of freedom for PA reconfiguration and load sensing (ideally) is minimized to 1 -D, and the entire PD-LMBA can maintain a nearly constant efficiency profile against arbitrary load mismatch. The theoretical analysis is well verified using emulated circuit model, and it is further experimentally validated by a prototype designed with GaN transistors and wideband quadrature hybrids. As a proof of concept, the fabricated PD-LMBA circuit achieves state-of-the-art performance in measurement at matched load with 1.7 - 2.9 GHz of bandwidth, 65\% - 77\% of drain efficiency at peak power of 39 - 43 dBm, and 55\% - 71\% of efficiency at 10 -dB output back-off (OBO). More importantly, the prototype also experimen