为满足3.5GHz单载波超宽带无线接收机的射频需求,设计了一种工作在3—4GHz的超宽带低噪声放大器。电路采用差分输入的CMOS共栅级结构,利用MOS管跨导实现宽带输入匹配,利用电容交叉耦合结构和噪声消除技术降低噪声系数,同时提高电压增益。分析了该电路的设计原理和噪声系数,并在基于SMIC0.18μm CMOS射频工艺进行了设计仿真。仿真结果表明:在3—4GHz频段内,S1和s22均小于-10dB,S21大于14dB,带内起伏小于0.5dB,噪声系数小于3dB;1.8V电源电压下,静态功耗7.8mW。满足超宽带无线接收机技术指标。
In order to satisfy the demands of wireless receiver of 3.5 GHz sole-carrier UWB communication system,an ultra-wideband 3 - 4 GHz low noise amplifier is presented. The circuit is implemented in CMOS common-gate differential structure, using capacitor cross-coupling structure and noise canceling technology to reduce the noise coefficient and boost its voltage gain. The design principle of the circuit as well as noise coefficient are analyzed. Design simulation in SMIC 0.18μm CMOS RF processis carried out S21 is more than 14 dB power gain and noise coefficient is less than 3 dB, with S11 and S22 less than -10 dB, while consuming 7.8 mW power under 1.8 V supply,which meets the requirements of UWB communication system.