Integrated Design Method for Doherty Power Amplifier and Antenna Based on Lossy Equivalent Two-Port Network

This paper presents an integrated design method for Doherty power amplifier (DPA) and antenna based on lossy equivalent two-port network. The load modulation network in a traditional DPA and antenna is represented as a lossy two-port network. The input impedances of this network are adjusted to match the optimal impedances of both the carrier and auxiliary power amplifiers. By eliminating the separate matching network and the 50-ohm transmission line between the Doherty power amplifier and the antenna, this approach reduces the transmission loss and circuit size. The lossy two-port network is implemented by using a four-segment transmission line in combination with the antenna. The simulations show a saturation output power of 42.2 dBm, a saturation efficiency of 65%, and a 6 dB back-off efficiency of 51%. Additionally, it provides a small-signal gain of 12.3 dB with a gain compression of 0.7 dB at saturation.