带有低噪声单端转差分电路的射频增益可控放大器

为了改进传统电路中单端转差分电路的噪声性能,提高传统射频可变增益放大器的覆盖范围和步进精度,该文设计了一种带有低噪声单端转差分电路的射频增益可控放大器。该文利用噪声抵消技术降低了噪声系数,利用电容交叉耦合技术展宽电路带宽,利用输出源级跟随器的增益可调功能实现更高的步进精度。电路采用0.18 mm CMOS工艺,1.8 V供电电源,在170-870 MHz频率信号输入下,可以实现最低3.8 dB的噪声系数,55 dB的动态范围,步进精度0.8 dB,消耗14.76 mW的功耗,面积800 mm×600 mm。测试结果表明在覆盖更宽的频段范围下,该文设计的射频可变增益放大器在消耗相同功率条件下与传统的单端转差分电路相比可以达到更低的噪声系数,同时整个可变增益放大器可以提供更高的步进精度。

RF Programmable Amplifier with Low Noise Single-ended Differential Circuit

To reduce the noise figure in the tradition low noise amplifier,extend the bandwidth and achieve more precise step accuracy,a RF programmable amplifier with low noise single-ended differential circuit is proposed.The single-ended differential circuit uses the noise cancellation method to reduce the noise figure and uses the capacitance cross technique to extend the bandwidth.The improved source-level follower structure can achieve more precise step accuracy.The circuit is fabricated in 0.18 mm CMOS process.Under 1.8 V power supply and 170-870 MHz frequency signal input,the circuit achieves a 3.8 dB noise figure.The circuit shows a 55 dB gain control range by 0.8 dB each step.The overall power consumption is less than 14.76 mW,and the die area is 800 m m ×600 m m.The test result shows that the circuit can provide lower noise figure and cover wider bandwidth while consumes the same current comparing with the tradition structure and the circuit can provide more precise step accuracy.