Research And Design Of Ultra-Wideband Receive Radio Frequency Front-End

With the rapid development of wireless communication,the application scenarios of wireless communication are increasing,and the demand for related communication equipment is also growing.The market is increasingly expecting wireless communication equipment with high performance and multiple communication bands.Facing the current multifield application and multi-band usage of wireless communication and the trend that future communication may continue to increase,ultra-wideband receiving front-end have obvious advantages because they can meet the application of various communication scenarios and work on multiple communication frequency bands,will better meet the needs of the communication market for receiver equipment.This thesis conducts corresponding research on traditional active and passive architecture receiving front-end so that they can meet broadband communication needs.The primary research and work done in this thesis are as follows:1.The existing common receiving front-end architectures are described in detail,the advantages and disadvantages of the different frontend architecture are analyzed,and the key performance indexes of radio frequency receiver and their influence on communication quality are expounded in detail.Aiming at the problem of image interference in superheterodyne receiving front-end,this thesis designs an image suppression architecture,which also suppresses the image signal in the process of normal signal mixing without limiting the working bandwidth of the receiving front-end.To make the receiving front-end broadband,this thesis constructs a multi-channel receiving architecture through radio frequency switches,and different receiving channels correspond to different working frequency bands.2.Based on the traditional superheterodyne architecture,an ultrawideband superheterodyne receiving front-end with image rejection capability is designed using the image rejection architecture and the multichannel receiving front-end architecture.After the final design and processing,the working bandwidth of the receiving front-end finally completed in this thesis is 2.5 GHz to 12 GHz,and its ultra-wide working frequency band has a gain of at least 17 dBm and an input compression point of more than-5 dB.The designed image suppression architecture has a suppression capability of 29 dB for image signals higher than local oscillator signals.When the receiving front-end r receives QAM signals with different rates,the error vector magnitude is kept below 1.90%.3.Aiming at the defects of the traditional demodulation method of the six-port receiving front-end,this thesis proposes a calibration algorithm,which makes up for the error factor of the six-port front-end and makes the receiving front-end meet broadband communication.In this thesis,the calibration algorithm is based on the generalized memory polynomial model and Wiener model.The least square method combined with Newton method is used to update the parameters.When calibrating a six-port receiving front-end with a working frequency band from 2 GHz to 8 GHz,the error vector magnitude of QAM signals with different frequency bands and bandwidths are below 1.70%,and the iteration times of algorithm model parameters are all within 7 times.