Digital Predistortion of Phased Array Transmitters with Multi-Channel Time Delay

In this paper, a novel digital predistortion (DPD) technique is proposed to linearize a phased array transmitter with multi-channel time delay in the over-the-air (OTA) feedback loop-based structure. Compared to the conventional DPD concept, the proposed method treats the whole phased array transmitter as an integration, and thus transforms the multi-channel system to a one-to-one mapping system. The relationship between the input and output with multi-channel time delay and intrinsic nonlinear distortion can be effectively modeled by the proposed model, and then applied into the DPD technique. The excellent experiment results indicated that the proposed DPD technique can be adaptive to the OTA-feedback architecture, which is suitable for the applications in 5G systems.