X-Band 25 W High PAE Power Amplifier MMIC with Second Harmonic Suppression for Radar Network Application

This letter introduces a high-power-added efficiency (PAE) and high second harmonic suppression (SHS) power amplifier monolithic microwave integrated circuit (MMIC) designed for operation in the frequency range from 8.5 GHz to 10.5 GHz. The design is based on a 0.25 µm gallium nitride (GaN) high electron mobility transistor (HEMT) process. To achieve high power gain, a three-stage amplifier structure is employed. Additionally, a SHS topology is incorporated in the output matching network to enhance harmonic suppression while maintaining high efficiency. The measurement results showed that the output power is around 45 dBm, the PAE ranges from 41.0% to 51.7%, the SHS exceeds 54 dBc from 8.5 GHz to 10.5 GHz. Furthermore, the size of the PA is 3.5 × 3.2 mm
²
. Compared to other reported MMICs with similar size, this design exhibits significantly higher PAE and higher SHS.