低中频GPS接收机中低通滤波器的设计与实现

Design and implementation of a 5th Butterworth LPF in Low-IF GPS receiver

采用SMIC0.18μm工艺,实现了一个截止频率可调谐,带品质因数(Q值)补偿的五阶巴特沃兹低通滤波器,截止频率在9 MHz,50 MHz处抑制在70dB以上,,通带增益变化在0.3 dB以内,面积0.4 mm2,功耗12 mW。此低通滤波器已经成功地应用在GPS低中频接收机中。

With the technology of SMIC 0. 18 μm, a modified circuit of a Q-compensated 5th Butterworth LPF is implemented,which has a cut-off frequency at 9MHz, and an attenuation of 70 dB plus at 50 MHz. It has a passband gain variation within 0. 3 dB, occupies an area of 0. 4 mm^2 , and has power dissipation of 12 mW. The LPF has been successfully applied to GPS Low-IF receiver.