Split gate line distributed power amplifier using tapered drain line approach and active broadband input power divider

In this contribution the analysis, design and results of a distributed power amplifier for ultra wideband operation are presented. The tapered drain line, capacitive coupling and split gate line techniques have been simultaneously applied to obtain a high-performance MMIC design. The power amplifier exhibits a P.A.E. higher than 27% and a constant output power in the region of 36 dBm at 3 dB gain compression. The small signal gain is 21dB; all values are considered over the 2-8 GHz bandwidth. The drain line impedance tapering technique is shown to significantly increase the efficiency and output power of a distributed amplifier while the capacitive coupling and split gate line technique are applied to obtain constant electrical performance over the requested frequency bandwidth. Finally the choice of selecting an active power divider, acting as a first stage gain section, greatly improves the overall MMIC´s gain behaviour.