應(yīng)用于5.8ghz電子不停車收費系統(tǒng)的閱讀器中的混頻器設(shè)

1、南昌大學(xué)碩士學(xué)位論文應(yīng)用于5.8GHz電子不停車收費系統(tǒng)的閱讀器中的混頻器設(shè)姓名：譚泉海申請學(xué)位級別：碩士專業(yè)：通信與信息系統(tǒng)指導(dǎo)教師：劉曄20091225Abstract II ABSTRACT Mixer is an absolutely necessary key component in modern communication system. Based on the technical requirement for the

2、 physical layer of part 1 of GB/T20851-2007 “Electronic Toll Collection-Dedicated Short Range Communication”, a kind of image injection mixer, which is applied in the reader of 5.8GHz system of ETC, is designed in t

3、his paper. This kind of mixer can effectively inhibit signal at the image frequency, which comes from the external of the receiver and being generated itself by mixing, enhancing the capability of anti-jamming. The main

4、structure of the mixer adopts two symmetrical single-balanced mixers, with phase-shifting of the up and down path signals to eliminate the image frequency. During designing the single-balanced mixer, this paper introduce

5、s two methods to match the diode circuit and compares the advantage and disadvantage of both two kinds of circuits. Furthermore, we improve the VSWR by matching the input port. The final results of simulation show that t

6、he VSWR of input port at 5.79 to 5.8GHz achieve good effect, however, the bandwidth of less than 1.5 is narrow, so the versatility is limited; the isolation of LO-RF at 5.79 to 5.8GHz can reach-30dB; when the power of lo

7、cal oscillator is 11 to 13 dBm, conversion loss of the mixer is 10dB，noise figure is 8 to 10dB, and the minimum of noise figure is 8.8dB when the power of local oscillator is 13dBm. And more, the mixer provides with imag