A compact DGS load-network for highly efficient class-E power amplifier

A 20 W class-E power amplifier (PA) with compact defected ground structure (DGS) load-network is presented for WCDMA base-station application. From the experiments, the proposed class-E PA achieves maximum power added efficiency (PAE) of 70.2% at the output power of 43.05 dBm with the saturation gain of 12.7 dB. Harmonics are well below -46 dBc for 2nd harmonic and -52 dBc for 3rd, 4th, and 5th harmonics through the 8 dB output dynamic range. Comparing the complexity and the size, the proposed DGS load-network is much simpler and smaller than the conventional load-network with a number of open stubs, ensuring comparable harmonic load impedance and amplifier performance.