Design of Compact and High Selective RF Front-end Module for Low-band 5G and IoT Applications

Radio receiver RF front-end as one of core components in cognitive radio communication system, which determines the complexity of the system, power consumption, performance and cost, performance parameters of each circuit module in the system needed to be coordinate for achieving the system overall index. Based on the cognitive radio communication system, this paper discusses in detail the index distribution of components in RF front-end of wireless receiver, mainly for microstrip dual-mode bandpass filter with image suppression characteristic. The RF front-end module of wireless receiver is designed at 694 MHz ~798 MHz frequency range. The error vector magnitude (EVM) test was also performed on the receiver front-end module under modulated signals. The measurement results show that for the 5Msps QPSK, 16-QAM, the RF front-end module achieves EVM arrange from 2.3% to 4.8% while the gain flatness is below 0.63 dB. The proposed RF front-end module exhibits advantages such as highly-selectivity, compact size, and easy integrated with other planar microwave circuit. This RF front-end module is promising as important roles in 5G low-bands transceiver wireless communications systems which helpfully support widespread coverage across urban, suburban, rural areas and as well as Internet of Things (IoT) services.