An X‐Band 35‐dB Gain 3.4‐dB Noise Figure and 42‐dBm Output Power GaN HEMT MMIC FEM With Harmonic‐Trapping Matching

This paper presents the design and measurement results of a high‐gain high‐output power 0.25‐m gallium nitride (GaN) on SiC monolithic microwave integrated circuit (MMIC) front‐end module (FEM) for high‐power X‐band radars. The FEM integrates a three‐stage power amplifier, a three‐stage low‐noise amplifier, and an SPDT T/R switch to provide more than 40‐dBm output power with a small‐signal gain of more than 35 dB and 40% power‐added efficiency for the transmitter and 16‐dBm output power with a small‐signal gain of 22.5 dB and a noise figure of 3.4 dB for the receiver in the 9‐ to 10‐GHz portion of the X‐band. The peak power is 16 W with 43% efficiency at 9.5 GHz. Efficiency is enhanced using a harmonic‐trapping network. Low‐noise amplifier (LNA) design is realized with the minimum supply voltage possible for the required gain. Isolation is improved with resonant switch high‐electron mobility transistors (HEMTs) in the series‐shunt switch. The transmitter draws 1‐A peak and 250‐mA quiescent current from a 28‐V supply for 10‐W output power, while the receiver consumes 63‐mA quiescent current from a 7‐V supply for maximum gain. The total die area is 4.2 mm 5.7 mm.