Adaptive Impedance Matching Networks for Power Amplifiers

This chapter presents the applications of adaptive impedance matching networks, including passive controlled adaptive impedance and active adaptive impedance networks for power amplifiers. The thyristor-controlled impedance matching network (TCIMN) is first used to realize adaptive broadband impedance matching for a wide range of load impedances. To achieve long range detection and good matching performance, a shunt adaptive broadband active impedance matching network (SAIMN) is proposed by injecting a capacitive reactive current into the system, which can reduce the current stress of the power amplifier switching devices while supplying the same active power to the load. Then, a series active adaptive broadband full-bridge converter impedance matching network (FCIMN) and its segmented PR controller are proposed to operate at a wide frequency range to realize broadband impedance matching in a wide frequency range. Furthermore, a hybrid impedance matching network (HIMN) and its two-step model predictive control (MPC) method are proposed to realize broadband impedance matching and reduce the delay of matching value calculation.