A novel technique based on power combining mechanism that yields HPA arrays with high power efficiency

This paper proposes a new concept utilizing a novel technique to reduce the intermodulation distortion products (IMD) allowing the efficiency of a high-power amplifier (HPA) array to be increased by operating the array in the saturation region. Since we use even-order distortion implemented intermodulation distortion controllers (EODIC), IM is controlled independently of the carriers and thus IM power is reduced while maintaining carrier power. This improves the carrier power to intermodulation power ratio (CIMR) of the HPA array in the saturation region. The improvement in CIMR is 10logN dB where N is the number of HPA. The effect is demonstrated experimentally by using a 4-parallel HPA array. The measured CIMR improvement, 6 (10log4) dB, confirms the feasibility of the proposed technique and the feasibility of highly efficient active phased array operation in the saturation region with large N