The effects of nonlinear high power amplifiers on space based phased array antenna patterns

This paper investigates the effects of intermodulation distortion (IMD) produced by the nonlinear high power amplifiers (HPA) of the space based phased array antenna. Several HPA models are investigated, which include the TWTA, SSPA, an “ideal” HPA which is perfectly linear up to saturation, and a “perfect” HPA which is perfectly linear and experiences no saturation. This paper demonstrates that to achieve the optimal EIRP for a given system, there is a tradeoff between the main beam power loss at a low input backoff (IBO) due to IMD and the power loss at a high IBO due to decreased input power