差分时钟增益提高型N通道带通滤波器设计

Design of a differential clock gain-boosted N-path band-pass filter

针对传统N通道滤波器存在增益以及时钟的偶次谐波对滤波性能产生不利影响的问题,利用增益提高技术和差分时钟技术提出了一种增益提高型、时钟偶次谐波消除的N通道带通滤波器。在TSMC 90 nm工艺参数和1.2 V电源电压下对其进行Spectre模拟。结果表明,滤波器的增益高于9.8 d B,中心频率可调范围为0.2~2.2 GHz,S11>10 d B,IIP3>11 d B,阻带抑制为26 d B。电路结构简单,仅由反向器、开关和电容组成,且易于集成。

A differential clock gain-boosted N-path switched-capacitor band-pass filter is proposed in order to solve problems of low gain of the traditional N-path filter and adverse effect caused by the even harmonics of the clock frequency.Based on the technologies of gain-boosted and differential clock,even harmonics of the clock frequency is eliminated and the gain is increased.The filter is verified by Spectre simulations using TSMC 90 nm CMOS process parameters with 1.2 V supply voltages.The simulated results show that the center frequency can be tuned from 0.2 GHz to 2.2 GHz.Over the whole band,the filter gain is better than 9.8 dB,S 11 is>10 dB,NF is<2.7 dB and IIP 3 is>11 dB,while the ultimate rejection is>26 dB.The proposed filter only composes of inverters,switches and capacitors and therefore it is friendly with process scaling.