Directional dual band distributed power amplifier with composite left/right-handed transmission lines

We present the design of a directional dual band six-cell distributed power amplifier (DPA) that can direct the amplified power to the output ports depending on the input RF frequency. Different from conventional DPA, the dual band DPA implements the composite right/left-handed (CRLH) transmission line (TL) structure in the artificial gate line but keeps the conventional transmission line (right-handed) in the drain line. The distributed power amplifier using CRLH TL can output 39 dBm maximum power to one port at 1.5 GHz with 27% PAE and the other at 2.9 GHz with 22% PAE. It acts like an active diplexer (power amplifier plus diplexer). It can potentially reduce the size and cost of the communication system.