High Power X-Band Monolithic GaAs p-i-n Balanced Limiter

In this article, a 40-W X -band monolithic GaAs balanced limiter with a size of 2.5 mm × 2.0 mm is fabricated by GaAs p-i-n technology. To improve the power-handling capability of the limiter, a rounded rectangular p-i-n diode with a process-determined maximum circumference, a Lange coupler with widened crossover wires, an I-layer with a reasonable thickness, and an optimized isolated terminal resistance are used in the limiter. The experimental results show that in the operating frequency band of 8–12 GHz, the limiter has an insertion loss of less than 1.2 dB, and input and output return losses of less than –20 dB, indicating that the limiter has good small-signal performance. Notably, the balance limiter has a maximum power handling capacity of more than 40 W, which is higher than the existing balanced limiters. Meanwhile, the output power of the limiter is less than 20 dBm, which indicates that the back-end circuit will not be damaged when the limiter resists high input power. Therefore, the balanced limiter has a great application prospect in high-power X -band communication system.