一种0.5～5GHz改进型折叠混频器

An Improved 0.5～5GHz Folded Mixer

采用SMIC 0.18μm CMOS工艺,设计了一种基于双平衡Gilbert单元的宽带低噪声亚阈值混频器。采用折叠型结构,在跨导级添加LC并联谐振电路,控制开关管工作在亚阈值区,以提高增益、降低噪声,同时降低本振功率。与传统的折叠混频器相比,该电路的增益达到9.5~18.4dB,噪声仅为6.1~7.2dB,在1.8V电压下功耗为18.18mW。

A broadband low noise sub-threshold mixer based on double balanced Gilbert ceil was designed in the SMIC 0.18 μm CMOS process. Based on folded structures, a parallel LC resonating network circuit was inserted between the trans-conductance stages, and the switching transistors were biased in sub-threshold region. So the gain was increased, the noise was suppressed, and the local oscillating power was reduced. The simulation results showed that the conversion gain was 9.5-18.4 dB, the noise figure was 6.1-7.2 dB. The mixer consumed 18.18 mW at a 1.8 V power supply.