| WPT(Wireless Power Transmission) technology as a form of energy transmission and attracted more and more attention of researchers. MPT technology is a kind of WPT technology. MPT transmit power through microwave. Through the efforts of researchers, the microwave power transmission technology has been widely used in various fields, such as RFID, pipeline robot, etc. In the MPT system, rectifying antenna located in the receiver. The function of rectifying antenna is the conversion of the RF – DC. In this thesis, the research contents as follows.Firstly, the characteristics of the rectifying diode in the rectenna are analyzed in detail. The closed formulas of rectifying diode’s rectifier efficiency and input impedance are derived in analytical method. The equivalent circuits of rectifying diode are studied by the software of(ADS).Secondly, in order to harmonic suppression, the low-pass filter using the defected ground structure(DGS) of double U-shaped and nested ring shape is proposed. The measured 3d B cutoff frequency of double U-shaped defected ground structure low-pass filter is 3.26 GHz with 0.4d B ripple level. The rejection bandwidth of the insertion loss more than 20 d B is 5.2GHz. The measured 3d B cutoff frequency of nested ring shape defected ground structure low-pass filter is 8.0 GHz with 0.3d B ripple level. The rejection bandwidth of the insertion loss more than 20 d B is 12.4 GHz.Thirdly, due to its advantages of slight, high gain, the design of microstrip slot antenna is studied in this thesis. The traditional T shaped microstrip line fed slot antenna is analyzed by Ansoft HFSS. Based on the traditional T shaped microstrip line fed slot antenna, the compact T shaped microstrip line fed slot antenna is designed and fabricated in this thesis. The impacts of slot antenna structure on antenna characteristics are analyzed by Ansoft HFSS. It is measured that the antenna’s working at 5.8GHz and the bandwidth of S11 less than 10 d B reaches to 700 MHz.Finally, the rectifying antenna system is analyzed in the overall. The model of rectifying antenna system, working at 5.8GHz, is built by the software of Advanced Designed System(ADS). The good match of rectenna system through the method of microstrip stub. Due to the limitation of laboratory conditions, the low-pass filter-rectifier circuit is fabricated, but this thesis does not complete the test of rectifying antenna system. In order to testing low pass filter- rectifier circuit, the microwave signal source equivalent into receiving antenna. The RF-DC conversion reaches 54%. |
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