The Analysis And Design Of The RF Receiver For Wireless Communications

Radio frequency transceiver circuits have a very broad range of applications. As a result, RF front-end circuits have become one of the most active research areas in wireless communications. This paper mainly focuses on the issues of RF receiver.Firstly, the Antenna and Antenna Switch which are presently used in Cell Station are introduced, and the design procedure of the RF Switch is given in detail.Secondly, a method which can prejudge the gain and noise figure of the low noise amplifier(LNA) is put forward. With this method, we can prejudge the feasibility of LNA design once the S-parameter and noise parameter of the device are gained. The design process is considerably simplified compared with traditional methods. Meanwhile, CMOS technology, due to its mature application in base band uses, draws more and more attentions in RF area. In this paper, the traditional cascode structure of CMOS LNA is considered as a two-stage amplifier and inter-stage matching network is introduced accordingly. Deduction shows that a series inductor can be applied as the inter-stage matching network between the two stages. A 2GHz CMOS LNA is designed as an example. Simulation results show that the noise and gain performance is improved evidently after the introduction of the series on-chip inductor.The commonly used passive mixer is also discussed and a single balanced mixer is designed. Then the theory of image rejection mixer and factors that affect its performance are presented. For the application of Direct Broadcast Satellite (DBS), a Ku-band high image rejection broadband mixer is designed using ADS. It appears predominant performances when compared with common single balanced mixer.Finally, a Ku-band receiver combined with LNA, mixer and filter is designed, and a complete flow chart for the design process of the front-end circuit is given. In the end, some RF transceiver examples such as Microwave Power Transfer System, Satellite Communication Receiver System and PHS Cell Station System are introduced and analyzed.