Analysis And Design Of The Image Rejection Receiver For2.45GHz Semi-passive Tag

Radio frequency tag utilized wireless communication technology is applied inthe fields of data transmissions, personnel and stocks tracking,financial paymentetal. The thesis studies the receiving link of semi-active microwave tag basing onISO/IEC18000-4protocol that is suitable to wireless communication on2.45GHzISM band.The receiving link is low-IF topology which mostly reduces the off-chipcomponents. The chip comprises RF front,IF filter and IF amplifier. Imagingrejection is achieved by complex band pass filter.This paper introduces firstly the development of radio frequency and the tagsoperating on microwave is investigated. Link budget of RF system is analysed.Receiver topologies are classified and compared by the factors of current consuming,integrating level, sensitivity, noise factor and offset etal. Noises, distortions of lownoise amplifier and passive mixer are analysed and the optimal circuits are verified bysimulation. LNA achieve21dB voltage gain,1.5dB noise figure and3.77dBm IIP3by10mA current consuming with1.8V supply. The passive mixer achieve-4dB gain,11.5dB noise figure and7.9dBm IIP3.The problem of imaging signal is investigated.A6thorder butterworth imaging rejection filter is proposed. Noise, linearity andimaging rejection ratio of the filter is analysed. A novel limiting amplifier with goodPVT is proposed. The proposed limiting amplifiers are applied in the IF amplifier andRSSI circuit. The filter achieves-1dB bandwidth of1MHz,26dB adjacent channelattenuation and30dB IIR. The IF amplifier and RSSI achieve48dB dynamical.Layouts are given in the last. The chip is designed and layout by UMC0.18μmprocess. Some of the module had been tape out and tested to achieve the goal.