射频微电子学概论-chapter4 Transceiver Architectures--gao.pdfVIP

Chapter 5 Transceiver Architectures 5.1 通常考虑 5.2 接收机体系结构 5.3 发射机体系结构 5.4 OOK 收发机 Gao Zhiqiang, RF Microelectronics. Prepared by HIT Chapter Outline Heterodyne Direct-Conversion Receivers Receivers  镜像问题  本振泄漏和失调  混频器杂散  偶数阶非线性  变化的中频接收机  正交失配 Image-Reject and Transmitter Low-IF Receivers Architecture  Hartley and Weaver Receivers  发射机基带信号处理  低中频接收机  直接上变换发射机  超外差and Sliding-IF TX General Considerations: 窄信道带宽  Narrow channel bandwidth impacts the RF design of the transceiver. 信道选择and 灵敏度  All of the stages in the receiver chain that precede channel-selection filtering must be sufficiently linear  Channel selection must be deferred to some other point where center frequency is lower and hence required Q is more reasonable  Most receiver front ends do incorporate a “band-select” filter 双工器特性  The front-end band-select filter suffers from a trade-off between its selectivity and its in-band loss because the edges of the band-pass frequency response can be sharpened only by increasing the order of the filter.  Front-end loss directly raises the NF of the entire receiver TX-RX Feedthrough  In full-duplex standards, the TX and the RX operate concurrently.  With a 1-W TX power, the leakage sensed by LNA can reach -20dBm, dictating a substantially higher