一个高线性度的CMOS DVB-S前端芯片

提出了基于CMOS工艺的直接频率变换的DVB-S射频前端电路设计.设计采用了T型匹配网络的可变衰减器、具有单端到双端变换功能的低噪声放大器以及低噪声混频器.通过使用衰减器,系统处理线性度的能力得到很大的提高.设计和流片基于SMIC 0.18μm CMOS工艺.测试结果表明,该设计能够达到超过30dB的动态范围,噪声系数小于3dB,消耗电流为10mA.在低增益情况下,具有+20dBm的输入三阶交调能力.

A High Linearity CMOS DVB-S Front-End

A direct conversion CMOS DVB-S front-end employs a T-configuration variable attenuator,a single-todifferential low noise amplifier,and a low noise mixer. By innovative use of the attenuator, the linearity handling ability of the system is dramatically improved. The system is designed and fabricated in SMIC 0.18μm RF CMOS technology. The measurement data show that the front-end provides a total of more than 30dB dynamic range and a noise figure of 5dB in the wide frequency signal band. The prototype front-end consumes only 10mA and achieves an IIP3 of + 20dBm.