基于双重增益控制技术的超宽带可变增益放大器的设计与实现

摘要

To achieve an ultra-wide band variable gain amplifier ( UWB-VGA ) with the wide gain variable range and a good gain flatness for each varied gain possible in the UWB frequency band, a dual gain control ( DGC) technology, which is composed of an amended current mirror gain control structure and a dynamic signal feedback gain control structure, was proposed. Based on the proposed DGC technology, an ultra-wide band variable gain amplifier for 3. 0 -6. 0 GHz band was designed. Both the schematic and the layout of the UWB-VGA were completed. Considering the parasitic and coupling effects of the layout, device structure and process, package generation in the RF band, the electromagnetic co-simulation of schematic and layout was implemented by momentum simulation tools. Results show that by adjusting the two control voltages of the dual gain control unit, the wide variable range of gain and good gain flatness in the frequency of 3. 0-6. 0 GHz are obtained. The gain variation range gets 5. 5 dB and the gain flatness is less than or equal to ± 2. 5 dB for every variable gain when the dynamic signal feedback gain control voltage Vctrl 2 is 5. 00 V and the amended current mirror gain control voltage Vctrl 1 changes from 2. 50 V to 3. 20 V. S11 and S22 are less than -10. 0 dB, and the input and output match well in the frequency of 3. 0-6. 0 GHz.%为实现超宽带可变增益放大器( ultra-wide band variable gain amplifier,UWB-VGA)在超宽频带下大的增益变化范围和每个变化增益在超宽频带范围内良好的增益平坦度,提出了一种适用于超宽带可变增益放大器的双重增益控制(dual gain control,DGC)技术,由改进型电流镜增益控制结构和动态增益反馈控制结构共同实现. 基于双重增益技术,设计了应用于3. 0~6. 0 GHz频带下的超宽带可变增益放大器,完成超宽带可变增益放大器的电路结构原理图和版图的设计. 考虑在射频波段下版图、器件结构、工艺及封装产生中存在的寄生效应和耦合效应,对电路结构原理图和版图进行Momentum 电磁联合仿真. 结果表明:联合调整双重增益控制单元的2个控制电压Vctrl 1和 Vctrl 2 ,超宽带可变增益放大器在3. 0~6. 0 GHz频段范围内可以同时获得大的增益变化范围和良好的增益平坦度,当动态信号反馈增益控制电压Vctrl 2为5. 00 V时,改进型电流镜增益控制电压Vctrl 1从2. 50 V变化到3. 20 V时,超宽带可变增益放大器的增益变化幅度为5. 5 dB,每个变化增益的平坦度≤± 2. 0 dB,S11 、S22都小于-10. 0 dB,输入输出匹配良好.