An RF Direct Sampling Hardware Platform and Broadband Digital Predistortion

In this paper, we introduce an RF direct sampling hardware platform, including an RF receive and transmitter board and an FPGA development board (VCU118). Based on this platform, a digital predistortion (DPD) experiment was performed when an RF PA was excited by the 5G NR signals with a center frequency of 3.5 GHz and a bandwidth of 200 MHz. The platform not only supports high data rates, but also has a 4T4R configuration capability to transmit and receive signals simultaneously. The experimental results show that the ACPR of the 200 MHz signal can be successfully reduced to below −45 dBc after DPD processing. This result validates the powerful functionality and flexibility of the hardware platform, and also explores the DPD technology of broadband signals.