摘要
提出了一种应用于多模卫星导航系统的5阶Gm-C复数滤波器,其带宽可设置为2 MHz和4 MHz,带内增益为10 dB,对带外信号和镜像信号均有40 dB的衰减,可以满足GPS、北斗、Galileo和GLONASS四种不同导航系统的要求。同时,引入一种新的低功耗滤波器自动调谐电路,可以对温度、工艺变化等各种因素引起的滤波器中心频率和带宽的偏差进行精确校正,保证了滤波器的正常工作和射频前端的性能。
A 5th-order Gm-C complex filter with a novel tuning approach was proposed for multi-mode satellite navigation system,which operated at the center frequency of 4.092 MHz and in the bandwidth of 4 MHz or 2 MHz with gain of 10 dB.The filter can reject the out-band signal more than 40 dB with image rejection of 40 dB,which meet the requirements of different navigation systems.A novel tuning circuit was introduced to detect and automatically calibrate offset of centre frequency and bandwidths caused by environment,process and temperature,which ensured normal operation of the filter and guaranteed performance of the RF front-end.
出处
《微电子学》
CAS
CSCD
北大核心
2011年第2期219-222,229,共5页
Microelectronics
