Research And Implementation Of Concurrent Dual-band RF Transceiver With One Frequency Divided Local Oscillator

With the continuous development of wireless communication technology in recent years,the RF transceiver system has gradually developed with multi-band and multi-mode.Among them,concurrent dual-band transceiver,as a solution that can simultaneously transmit and receive RF signals of two different frequencies and different communication standards,becomes a very valuable research direction in the research of RF transceiver.With the efforts of scientific researchers,concurrent dual-band devices such as dual-band power amplifier,dual-band filter,dual-band low noise amplifier have been theoretically verified and hardware implementation.This paper proposed a single channel concurrent dual-band mixing architecture with one frequency divided local oscillator.Based on the proposed architecture,a concurrent dual band transceiver is designed and realized.The main research contents include:(1)A mixing architecture with one frequency-divided local oscillator is proposed.In order to downconvert the dual-band input signal to IF,a frequency-divided local oscillator which consists of a two-output local oscillator and a frequency-divide circuit is employed to generate LO signals.Comparing with previous mixing method,the proposed architecture miniaturizes receiver architecture and has a better performance in filtering interfere signals.In this paper,the output signal of the proposed method is theoretically deduced,the formula of local oscillator frequency selection is obtained,and the applicable range of this method is given.Finally,the conclusions are demonstrated by experimental results.The EVM of the output signal is less than 5%,and the performance of the output signal meets the requirement of communication transmission.(2)Based on the proposed mixing architecture,a concurrent dual-band transceiver with the proposed architecture is designed and implemented.The proposed transceiver works in the frequency bands of 2010MHz?2025MHz and 2570MHz?2620MHz.The simulation and test results show that the maximum output power of the transmitter can reach 20dBm,the dynamic range is 60dB,the output signal ACPR is better than-45dBc,and the EVM is lower than 5%.The receiver sensitivity can reach-75dBm,the dynamic range is 60dB,the demodulation signal E VM is lower than 5%,and the flatness of the signal is less than 3dB.