Analysis of nonlinear distortion in phased array transmitters

This paper investigates nonlinear distortion effects in active antenna phased array transmitters. Using a nonlinear modeling technique, the joint interactions between power amplifiers and antennas are investigated in detail. Numerical simulations based on a 28 GHz GaN MMIC PA and a 64-element antenna array are used to exemplify the use of the proposed technique in a typical 5G application. The results show that the antenna mutual coupling will cause the individual PA compression characteristics and hence the far field distortion to depend significantly on beam steer angle.