增益可调宽带CMOS低噪声放大器设计

设计了一种应用于超宽带系统中的可变增益宽带低噪声放大器。电路中采用了二阶巴特沃斯滤波器作为输入和输出匹配电路;采用了两级共源共栅结构实现电路的放大,并通过控制第二级的电流,实现了在宽频带范围内增益连续可调;采用了多栅管(MGTR),提高了电路的线性度;设计基于SMIC 0.18μm CMOS工艺。仿真结果显示,在频带3~5 GHz的范围内最高增益17 dB,增益波动小于1.8 dB,输入和输出端口反射系数分别小于-10 dB和-14 dB,噪声系数nf小于3.5 dB,当控制电压Vctrl=1.4 V时,IIP3约为2 dBm,电路功耗为16 mW。

Design of variable gain wideband CMOS LNA

A variable gain wideband LNA(VG-LNA) is designed for Ultra Wideband System application. The two-order Butterworth filter is adopted to achieve excellent input match and output match in the circuit. A continual tunable amplifier with two stages cascode is proposed by controlling the current of the second stage. The linearity of LNA is optimized by using multi-gated transistors. The design of LNA circuit is based on SMIC 0.18 um process. The simulated results show that the highest gain is 17dB, the gain fluctuation is less than 1.8 dB, S11 and S22 are less than -10dB and -14dB respectively, noise figure is less than 3.5dB, IIP3 is about 2 dBm at controlled-voltage Vctrl of 1.4V at the frequency from 3GHz to 5GHz. The power consumption is 16mW.