The first chapter , introduce the rf receiver ’ s devolop and current situation . the second chapter , introduce the effect of the exterior environment to the rf receiver . the third chapter introduce some different structure and the design parameters of each structures . the parameters of the rf receiver are introduce in fourth chapter . the fifth chapter design a s band rf receiver . this s band rf receiver use a structure of superheterodyne module 第五章,介绍了一种s波段射频接收前端的设计,基于分析的结果对一种射频接收机的低噪放大、下变频、锁相环( pll )频率合成器、中频agc电路进行了设计,并在第六章完成了接收机各组件及总体的测试。
This paper introduce a design of the s band wireless rf receiver . which work at frequence 2 . 0ghz to 2 . 5ghz . this rf receiver has character of high sensitivity low noise 、 low power supply and if variable output . it also has compact structure , can great use in military application as well as civil 本文主要介绍一种工作在s波段频率为2ghz 2 . 5ghz的无线通信射频接收前端的设计。该射频接收前端具有高灵敏度、低噪声、低功耗、可变中频频率、稳定的中频输出的特点,结构紧凑,可以满足s波段射频无线接收在军事和民用方面的应用。
There are three power transistor which have been widely used in s band now : bipolar junction transistor ( bjt ) , gaas metal - oxide semiconductor field effect transistor ( gaas mosfet ) and lateral diffuse metal - oxide semiconductor field effect transistor ( ldmos fet ) . thanks to the advantages , such as , wide frequency , easy power supply , good stability , the ldmos fet has used in the motion telecommunication 目前在s波段人们常用的放大器有双极性晶体管( bjt ) 、砷化镓场效应晶体管( gaasmosfet ) 、边缘扩散场效应晶体管（ ldmosfet ）等，由于ldmosfet具有频带宽、供电方便、稳定可靠等优势，目前已经广泛用于移动通信3g的研究。
