GNSS接收机带有滤波功能可变增益放大器的设计  

Design of variable gain amplifier with on-chip filter for GNSS receiver

作　　者：张维佳[1] 赵红东[1] 王博 申研 

机构地区：[1]河北工业大学信息工程学院,天津300401 [2]天津晶研科技有限公司,天津300000

出　　处：《电子设计工程》2010年第3期101-103,共3页Electronic Design Engineering

基　　金：天津市科技计划项目(08ZCKFGKX00300)

摘　　要：传统GNSS前端接收机系统中,可变增益放大器(VGA)不具备滤波功能,大多数选用片外滤波,这样系统增益和集成度降低,而系统集成的波器选频性能有限。为此,设计一种具有滤波功能的可变增益放大器,采用0.5μmSiGe HBT工艺,可控增益单元与Gm-C滤波单元集成一体,并运用4晶体管回转器结构实现滤波。电路驱动电压为3.3 V,电流为11.7 mA,线性增益控制范围为-26～62 dB,且电压控制范围为0～1.8 V,最小增益下输入1 dB压缩点为-4 dBm。可变增益放大器电路不仅具备大的增益控制范围,而且中频46 MHz处滤波性能良好,提高芯片的集成度,降低系统功耗。In the traditional GNSS front-end receiver system,the variable gain amplifier （VGA）doesn＇t have the filtering function,so the off-chip filter is often used in the system.Mostly the off-chip filtering is used to lower both of the system gain and the integration level,whereas the frequency-selective property of the system integration filter is limited.Thus,we designed a new type of VGA,which carried a filtering function.In this design,the VGA used 0.5μm SiGe HBT process technology,the controllable gain unit and the Gm-C filtering unit were integrated,and the filtering function was realized through the application of four transistors Gyrator structure.The circuit＇s driving voltage is 3.3V, the current is 11.7mA ,the range of the linear gain control is from-26dB to 62dB,and the range of the voltage control is from 0V to 1.SV.Under the smallest gain,the ldB compression point is -4dBm.The VGA circuit possesses not only a great range of gain control,but also a good filtering performance in IF 46MHz ,which will increase the integration level of the chip, and reduce the power consumption of the system.

关 键 词：微电子学与固体电子学 射频集成电路 SiGe HBT 可变增益放大器 GM-C滤波器 

分 类 号：TN773[电子电信—电路与系统]