A class-E RF power amplifier with a novel matching network for high-efficiency dynamic load modulation

We present in this paper a proposed high-efficiency Class-E power amplifier (PA) for RF Polar transmitters. The PA embodies a proposed novel matching network (MN) with three salient features. First, it is digitally-controlled, and can directly receive the digital Amplitude Modulation (AM) input data to the PA without the need for a conventional supply modulator. Second, the MN performs high-efficiency dynamic load modulation, where load impedance seen by the PA is varied by the MN according to the AM data, and simultaneously, this load impedance is also ensured by the MN to satisfy the zero-voltage-switching condition at the PA to result in high-efficiency operation. Third, it has a novel architectural design that can employ on-, or off-chip inductors, or both inductor types; high quality-factor bond-wires can therefore be used as the inductors to improve the efficiency. The proposed PA with the MN is designed using a 40 nm CMOS technology. Simulation results at 2.4 GHz and 1.1 V supply show that the PA achieves a high power efficiency (drain efficiency) of 48% at peak output power of 17 dBm.