一种5GHz WLAN CMOS正交调制器和上变频器的设计

Design of a 5-GHz WLAN CMOS Quadrature Modulator and Up-converter

介绍了应用于WLAN IEEE 802.11a的正交调制器和上变频器的设计,给出了详尽的优化方法。正交调制器在传统Gilbert单元的基础上,采用负反馈跨导放大器来提高线性度;上变频器采用RLC谐振网络作Gilbert单元负载来提高增益,增加电压输出摆幅。电路采用TSMC 0.18μm 6层金属混合信号/射频CMOS工艺实现。在1.8 V电源电压下,静态电流为30 mA。测试结果表明,在谐振频率点的1 dB压缩点P1-dB为-8 dBm,电压增益为-2.4 dB,本振泄漏小于-50 dBm。

A CMOS quadrature modulator and up-converter is designed, and design methodologies are described in detail. A current feedback loop is used for the quadrature modulator to improve the linearity with transconductor, and in the up-converter, an RLC resonant network is used as the load to improve the gain and increase the voltage range. Implemented in TSMC＇s 0. 18 μm 6-metal mixed-signal/RF CMOS technology, the circuit consumes 30 mA of current from a 1.8 V power supply. Test results show that, at the resonant frequency, the system exhibits an input 1-dB compression point of -8 dBm, a conversion gain of -2. 4 dB and a local leakage below -50 dB.