3．1～10．6GHz超宽带低噪声放大器的设计

基于SIMC0．18μmRFCMOS工艺技术，设计了可用于3．1—10．6GHzMB—OFDM超宽带接收机射频前端的CMOS低噪声放大器（LNA）。该LNA采用三级结构：第一级是共栅放大器，主要用来进行输入端的匹配；第二级是共源共栅放大器，用来在低频段提供较高的增益；第三级依然为共源共栅结构，用来在高频段提供较高的增益，从而补偿整个频带的增益使得增益平坦度更好。仿真结果表明：在电源电压为1．8v的条件下，所设计的LNA在3．1～10．6GHz的频带范围内增益（521）为20dB左右，具有很好的增益平坦性f±0．4dB），回波损耗S11、S22均小于-10dB，噪声系数为4．5dB左右，IIP3为-5dBm，PIdB为0dBm。

Design of Low Noise Amplifier for 3.1 - 10.6GHz UWB Receiver

A CMOS low noise amplifier （LNA） for RF front-end of 3.1 - 10.6GHz MB-OFDM ultra wide- band （UWB） receiver was designed.The LNA consists of three stage amplifiers.The first stage is a common-gate amplifier which is used to get the wideband input matching and lower the noise.A cascode amplifier as the second stage achieves high gain at the low frequency.A cascode amplifier as the third stage achieves high gain at the high frequency.Designed in SMIC 0.18p m RFCMOS technology,this proposed UWB LNA achieves the power gain （$21） is about 20dB from 3.1 - 10.6GHz and input/output reflection coefficient （$11,$22） of less than -10dB,the noise figure is about 4.5dB,IIP3 is about -5dBm and PldB is about 0dBm.