一种应用于WiMAX接收机的CMOS可变增益放大器

摘要

实现了一种应用于WiMAX无线接收机中频部分的单级可变增益放大器.由于采用电流平方技术,该结构能以较少的级联数,实现系统所需的固定增益变化范围,以达到降低总功耗的目的.该电路采用0.13 μm CMOS工艺进行流片,总面积为0.6 x0.4 mm2.测试结果表明,当控制电压从0.5V变化到1V时,VGA的增益变化范围为-20 ～ 25 dB,其3 dB带宽大于15 MHz,IIP3为-21 ～5 dBm,在1.2V电源电压下功耗为3.6 mW.%A single-stage variable gain amplifier for WiMAX receiver is implemented. By adopting current squaring technique, the VGA provides a large variable gain range compared to other single-stage VGAs. As a result, the proposed structure can achieve a given variable gain range with less stages and the whole power consumption is reduced. The chip is fabricated in 0. 13μm CMOS process, occupies 0. 6×0. 4 mm2, and consumes 3. 6 mW power from 1.2 V supply. Experimental results show that a continuous gain range from - 20 dB to 25 dB is achieved when the control voltage varies from 0. 5 V to 1 V. Furthermore, the VGA provides a 3 dB bandwidth greater than 15 MHz and the measured IIP3 value is in the range -21 dBm to 5 dBm.