宽带低附加相移可变增益放大器

A wideband low additional phase shift variable gain amplifier

基于130 nm BiCMOS(Bipolar Complementary Metal Oxide Semiconductor)工艺提出一款超宽带低附加相移可变增益放大器.该设计采用可变增益放大器和开关衰减器的组合结构,其中可变增益放大器在宽带、高效率的反馈式放大器的基础上通过改变偏置实现增益控制,而开关衰减器的应用在拓宽增益控制范围的同时减小了偏置变化范围,从而减小了不同增益状态下的附加相移.提取版图寄生参数后的仿真结果表明:在1.6 V供电电压下,该可变增益放大器在3.5~11 GHz范围内增益平坦度小于±0.75 dB,增益控制范围为-22~10 dB,增益步进值为0.5 dB,噪声系数小于6.5dB,不同增益状态下的附加相移小于±5°,电路输出1 dB压缩点大于12 dBm,动态功耗小于155 mW.该可变增益放大器拓扑在满足项目需求的同时为减小可变增益放大器的附加相移提供了一种思路.

A wideband low additional phase shift variable gain amplifier based on 130 nm BiCMOS(Bipolar Complementary Metal Oxide Semiconductor)process is proposed.The design adopts a combined structure of variable gain amplifer and switching attenuator.The variable gain amplifier is based on a broadband,high-efficiency feedback amplifier,and the gain control is realized by changing the bias current.The application of the switching attenuator broadens the gain range as well as reduces the bias variation range,thus optimizes the additional phase shift under different states.The simulated results after layout parasitic parameters extraction show that,under 1.6 V supply voltage,the gain flatness of the variable gain amplifier is less than±0.75 dB in the frequency range of 3.5~11 GHz.The gain range is-22~10 dB,and the gain step value is 0.5 dB.The noise figure is less than 6.5 dB,and the additional phase shift under different gain states is less than±5°.The output power at 1 dB compression point of the circuit is greater than 12 dBm,and the dynamic power consumption is less than 155mW.This variable gain amplifier topology not only meets the requirements of the project,but also provides an idea for reducing the additional phase shift of the variable gain amplifier.