Study Of Dual-Band Six-Port Direct Conversion Receiver Technology

In recent years,with the development of technologies such as the Internet of Things and autonomous driving,the demand for wireless communication rates has been increasing,and the number of wireless devices has also risen sharply.Therefore,multi-band,high-throughput and low-cost wireless communication technologies have been the focus of research.Different from the traditional receiver architectures,the six-port direct conversion receiver is mainly based on six-port correlators and detectors to realize signal demodulation.It has drawn much attention with the advantages of simple structure,high bandwidth,low cost and low power consumption.This thesis focuses on the research of dual-band six-port direct conversion receiver technology.Based on the theoretical analysis and key components design of six-port receiver,the system implementation and theory verification of dual-band six-port direct conversion receiver is completed.The main work includes:1.Based on the modeling analysis of the six-port correlator,the demodulation principle of the six-port direct conversion receiver is proved by theoretical derivation;2.A novel filtering coupler with filtering integration and DC-block function is proposed to achieve arbitrary coupling levels and phase differences.The theoretical verification is completed by example design and experimental measurements;3.The design and implementation of a new dual-frequency impedance transformer is completed.All the zeros and poles can be resolved through theoretical derivation,which makes excellent frequency selectivity.It also achieves arbitrary frequency ratio,arbitrary impedance ratio and DC-block function.4.A novel wideband filtering six-port correlator with 47.6%fractional bandwidth is proposed.Excellent amplitude-frequency and phase-frequency characteristics are obtained in the whole operating band,and the filtering integration and DC-block function are realized.5.The design and implementation of the dual-band six-port receiver is completed.The demodulation of the modulated signal is realized with the manufactured dual-band six-port receiver measurement setup.