A High Power Density Ku‐Band <scp>GaN</scp> Power Amplifier Based on Device‐Level Thermal Analysis

ABSTRACT This paper introduces a new design method for a high‐power density GaN MMIC amplifier operating in the Ku‐band. A thermal model to investigate the thermal distribution of power amplifiers is proposed to achieve optimal performance in terms of power density, chip size, and channel temperature. The thermal distribution and channel temperature of a single device, an eight‐way parallel device combination, and the entire PA layout are obtained by finite element simulation. The thermal coupling effects of high‐power MMICs are analyzed in detail. The thermal resistances are extracted from the simulation to design a Ku‐band amplifier. Measurement results demonstrate that the designed amplifier achieves 43.0–44.2 dBm output power and 22.7%–34.5% PAE at 28 V drain voltage with a 100 μs pulse width and 10% duty cycle within 12–18 GHz. The proposed design method enables the amplifier to have a compact layout of 10.88 mm 2 and a power density between 1.84 and 2.42 W/mm. This design method can offer valuable insights for future development of high‐power MMIC amplifiers.