A 10 Watt S-Band MMIC Power Amplifier With Integrated 100 MHz Switch-Mode Power Supply and Control Circuitry for Active Electronically Scanned Arrays

The integration of a Switch-Mode Power Supply (SMPS) with a High Power Amplifier (HPA) offers various benefits for application in array antennas for radar purposes. Among the most distinct advantages are removal of a single point of failure from the antenna system, individual bias control for local efficiency optimization, the high switching frequency which separates the spurious contributions from the carrier and the improved control of the HPA supply voltage rise- and fall times. The latter provides the possibility to control the RF pulse shapes thereby reducing the temporal side lobes and enhancing the output signal spectrum. An S-band HPA with integrated SMPS is designed, fabricated and tested. The SMPS includes the control circuitry for the switches. The SMPS is optimized to operate at a switching frequency of 100 MHz. The MMIC delivers an output power of 10 W with an HPA efficiency of more than 40% and an SMPS efficiency of more than 75%. This paper presents an overview of the design aspects and the obtained results.