提高射频前端AMI前端系统的灵敏度

　　提高射频前端AMI前端系统的灵敏度

　　正在部署的基于RF的先进计量基础设施（AMI）系统的数量正在稳步增加。这种AMI系统的射频前端必须具有很好的灵敏度，同时证明它不受来自不同RF应用的干扰。这些干扰既不妨碍数据传输，也不可能接收测量数据。

　　图1显示了一个基于射频的AMI系统中典型的收发器设计。

　　The transmitter section of the AMI transceiver consists of a balun which transforms the differential signal coming from the RF output of the IC to a single ended signal. After passing through the SPDT switch and the PA， the RF modulated signal is filtered by a SAW filter. This SAW filter suppresses the harmonics as well as the spurious emission generated by the internal phase locked loop （PLL） of the Transceiver IC. The antenna then transmits the data to the meter.

　　The receiving path is where the trigger signal for data transmission is received. This consists of a SAW filter right after the antenna， a second SAW filter for increasing selectivity， and the balun which transforms the unbalanced signal into a balanced one.