应用于WLAN系统具有高线性度的基带Gm-C滤波器

本文介绍了一种应用于无线局域网(WLAN)收发机系统的跨导-电容(Gm-C)低通滤波器,该滤波器能够工作于低电压并具有高线性度。该射频发射器(Tx)中的滤波器采用截止频率为9.8MHz的三阶切比雪夫低通滤波器原形,在30MHz频率处的阻带衰减达到35dB。由于采用了工作在线性区MOS的伪差分跨导,此滤波器的IIP3可达9.5dBm之高。本电路采用0.35-μm CMOS工艺实现,滤波器的芯片面积为0.41mm0.17mm,工作在3.3V电源电压时所消耗电流为3.36mA 。     

低功耗跨导-电容滤波器及其调谐电路的设计

设计了一种以Nauta跨导为单元结构的5阶切比雪夫跨导-电容带通滤波器及其调谐电路.该电路应用于低中频结构的北斗卫星导航接收机射频前端.滤波器的中心频率为4.092MHz,带宽设计为±2.046 MHz.该滤波器采用锁相环结构的片上自动频率调谐电路,用TSMC0.13 μm RF CMOS工艺实现,芯片面积仅为0.24 mm2,可以在低电压下工作,电路总功耗仅为1.68 mW.     

应用于直接变频架构直播卫星调谐器中的具有宽调谐范围的连续时间低通滤波器

本文用0.35微米锗硅BiCMOS工艺设计了七阶巴特沃兹跨导电容低通滤波器及其片上自动调谐电路,该低通滤波器适用于采用直接变频架构的直播卫星调谐器。该滤波器的-3dB带宽截止频率具有从4MHz到40MHz的宽调谐范围。成功实现了一种新颖的片上自动调谐方案,用来调谐和锁定滤波器的-3dB带宽截止频率。测试结果表明,该滤波器具有-0.5dB的通带电压增益,+/- 5%的带宽精度,30nV/Hz1/2的等效输入噪声,-3dBVrms 通带电压三阶交调点,27dBVrms 阻带电压三阶交调点。I/Q正交两路滤波器及其调谐电路采用5V电源,在滤波器的-3dB带宽截止频率为20MHz的情况下,消耗电流13毫安,占用芯片面积0.5mm2。     

小型化宽阻带LTCC微波低通滤波器的设计与研制

先根据滤波器衰减量要求,理论分析确定滤波器的阶数及电路原理图,再用ADS软件优化仿真获得电路元件初始值,然后采用微波电磁场仿真软件HFSS对滤波器物理模型优化仿真,成功设计了一款3 d B截止频率为1 750 MHz、宽阻带频率2 035~6 700 MHz范围内衰减量大于20 dB的LTCC微波低通滤波器,并采用LTCC工艺制备该微波低通滤波器,尺寸为3.2 mm×1.6 mm×0.9 mm。制备样品实测结果与仿真吻合,说明采用该方法设计、研制小型化宽阻带LTCC微波低通滤波器是可行的。     

UHF RFID阅读器中可编程全差分低通滤波器的设计

基于TSMC 0.25 μm RF CMOS工艺,提出了一种应用于860～960 MHz UHF波段单片射频识别(RFID)阅读器的可编程全差分低通滤波器电路.该滤波器为6阶切比雪夫有源RC滤波器,其中的运放采用带共模反馈的全平衡差动放大器结构(FBDDA)实现了全差分的缓冲器.仿真结果表明:该电路可以通过3位信号控制位产生截止频率为400 kHz、600 kHz、800 kHz、1 MHz以及1.3 MHz的全差分低通滤波器,1 MHz处的点噪声为20 nV/Hz,1 dB输入压缩点为15 dBm,3.3 V电源电压下电路消耗总电流为4.86 mA.     

一种新型跨导-电容滤波器自调谐电路

提出了一种基于开关电容技术的跨导一电容(Gm-C)滤波器自调谐电路.与基于压控振荡器(VCO)和压控滤波器(VCF)的传统调谐电路不同,该自调谐电路具有更高的精度和更低的功耗,且电路结构简单.设计了一个9阶椭圆函数低通滤波器,通过该调谐电路,实现了截止频率的精确可调.     

0.13 μm CMOS宽带大动态范围六阶跨导电容低通滤波器

提出了一种适用于宽带大动态范围应用的六阶跨导电容低通滤波器。该滤波器为Chebyshev类型,采用开环级联结构来实现。通过一组开关电容阵列来补偿由工艺温度等因素引入的截止频率的偏差。实际测试结果表明,该滤波器的-3dB截止频率可调范围为30～100MHz,在500mVp-p输入信号幅度下,IM3为-48dB。电源电压为3V时,消耗电流25mA,芯片面积为0.5mm2。该滤波器采用TSMC0.13μm CMOS工艺实现。     

模拟跨阻低通滤波器的设计

跨阻滤波器的输入为电流信号,输出为电压信号.本文给出了跨阻滤波器的设计方法,并按照品质因数Q的低、中、高详细介绍了三种双二阶节跨阻低通滤波器的电路拓扑结构及其参数计算方法.二阶跨阻低通滤波器与传统滤波器相级联即可实现高阶跨阻低通滤波器.最后,通过高阶跨阻低通滤波器的设计实例,验证文中所给出的设计方法的有效性.     

一种用于WLAN收发器带有自动调谐系统的低功耗Gm-C滤波器

本文用0.35um CMOS工艺实现了一个用于WLAN收发器的六阶连续调谐巴特沃斯Gm-C低通滤波器。滤波器设计中采用了内部节点压缩技术来提高动态范围,还对滤波器的部分结构进行了有效的优化,极大地减小芯片的功耗和面积。测试结果显示滤波器的动态范围为77.5dB,群延时波纹小于16.3ns,截止频率精确度在3%以内,滤波器的带内三阶交调量（IIP3）为0dBm。在电源电压2.85V时,包括调谐电路在内的整个滤波器消耗电流仅为1.42mA（5MHz的截止频率）或2.81mA(10MHz的截止频率),而且版图面积仅为0.175mm2.     

具有精确恒定跨导偏置电路的Gm-C滤波器

改进了一种精确恒定跨导偏置电路,通过对电流和晶体管尺寸的设计使主电路跨导恒等于外接高精度电阻跨导,与传统结构相比具有更高的精度.将该偏置电路应用于无线传感网芯片中9阶Gm-C椭圆低通滤波器的设计,使该滤波器省去了片上调谐电路的设计,在降低功耗的同时提高了精度,节省了面积.设计基于SMIC 0.18μm 1.8 V 1P6M CMOS工艺,芯片面积仅为0.9 mm×0.22 mm,测试结果表明,该滤波器的截止频率与设计值相差在1%以内,输入噪声电压小于25 nV/√Hz,消耗电流仅为0.9 mA,满足无线传感网节,点芯片的要求.     

A highly linear baseband G_m-C filter for WLAN application

A low voltage,highly linear transconductance-C（G_m-C） low-pass filter for wireless local area network （WLAN） transceiver application is proposed.This transmitter（Tx） filter adopts a 9.8 MHz 3rd-order Chebyshev low pass prototype and achieves 35 dB stop-band attenuation at 30 MHz frequency.By utilizing pseudo-differential linear-region MOS transconductors,the filter IIP₃ is measured to be as high as 9.5 dBm.Fabricated in a 0.35μm standard CMOS technology,the proposed filter chip occupies a 0.41×0.17 mm² die area and consumes 3.36 mA from a 3.3-V power supply.     

零中频DVB/DAB/CMMB调谐器中可编程信道滤波器设计

介绍了应用于多模多频(DVB/DAB/CMMB)移动数字电视接收的可编程信道滤波器设计.滤波器采用0.1dB波纹的7阶切比雪夫(Chebyshev)Ⅰ型低通结构,截止频率1.8/2.5/3/3.5/4 MHz可编程,在偏离截止频率1.25/4 MHz的频点上,分别实现26/57 dB衰减.多级直流负反馈环路用于抵消因版...     

A low power high linearity baseband for a direct conversation CMMB tuner

An analog baseband circuit made in a 0.35-μm SiGe BiCMOS process is presented for China Multimedia Mobile Broadcasting (CMMB) direct conversion receivers. A high linearity 8th-order Chebyshev low pass filter (LPF) with accurate calibration system is used. Measurement results show that the filter provides 0.5-dB passband ripple, 4% bandwidth accuracy, and -35-dB attenuation at 6 MHz with a cutoff frequency of 4 MHz. The current steering type variable gain amplifier (VGA) achieves more than 40-dB gain range with excellent temperature compensation. This tuner baseband achieves an OIP3 of 25.5 dBm, dissipates 16.4 mA under a 2.8-V supply and occupies 1.1 mm2 of die size.     

A 4th-order reconfigurable analog baseband filter for software-defined radio applications

This paper presents a 4th-order reconfigurable analog baseband filter for software-defined radios.The design exploits an active-RC low pass filter（LPF） structure with digital assistant,which is flexible for tunability of filter characteristics,such as cut-off frequency,selectivity,type,noise,gain and power.A novel reconfigurable operational amplifier is proposed to realize the optimization of noise and scalability of power dissipation.The chip was fabricated in an SMIC 0.13μm CMOS process.The main filter and frequency calibration circuit occupy 1.8×0.8 mm² and 0.48×0.25 mm² areas,respectively.The measurement results indicate that the filter provides Butterworth and Chebyshev responses with a wide frequency tuning range from 280 kHz to 15 MHz and a gain range from 0 to 18 dB.An IIP3 of 29 dBm is achieved under a 1.2 V power supply.The input inferred noise density varies from 41 to 133 nV/（Hz）^1/2 according to a given standard,and the power consumptions are 5.46 mW for low band（from 280 kHz to 3 MHz） and 8.74 mW for high band（from 3 to 15 MHz） mode.     

片上自动调谐的可编程有源RC滤波器

研制了一款可编程6阶巴特沃斯有源RC滤波器.为提高滤波器中运算放大器的增益带宽积,设计了一种新型的前馈补偿运算放大器.为消除工艺偏差和环境变化对截止频率的影响,设计了一种片上数字控制频率调谐电路,并采用TSMC 0.18 μm CMOS工艺进行了流片.滤波器采用低通滤波结构,测试结果表明,3 dB截止频率为1～32 MHz,步进1 MHz,带内增益0 dB,带内纹波0.8 dB,2倍带宽处带外抑制不小于24 dBc,5倍带宽处带外抑制不小于68 dBc,滤波器等效输入噪声为340 nV/√Hz@1MHz,调谐误差为±3％.滤波器裸芯片面积0.87 mm×1.05 mm.采用1.8V电源电压,滤波器整体功耗小于20 mW.     

A widely tunable continuous-time LPF for a direct conversion DBS tuner

A continuous-time 7th-order Butterworth Gm-C low pass filter (LPF) with on-chip automatic tuning circuit has been implemented for a direct conversion DBS tuner in 0.35μm SiGe BiCMOS technology. The filter's -3 dB cutoff frequency f0 can be tuned from 4 to 40 MHz. A novel on-chip automatic tuning scheme has been successfully realized to tune and lock the filter's cutoff frequency. Measurement results show that the filter has -0.5 dB passband gain, +/- 5% bandwidth accuracy, 30 nV/Hz1/2 input referred noise, -3 dBVrms passband IIP3, and 27 dBVrms stopband IIP3. The I/Q LPFs with the tuning circuit draw 13 mA (with f0 = 20 MHz) from 5 V supply, and occupy 0.5 mm2.     

New CMOS realization of high performance Voltage Differencing Inverting Buffered Amplifier and its filter application

This paper describes a high performance voltage differencing inverting buffered amplifier (VDIBA). The transconductance of the proposed circuit is enhanced by using positive feedback technique with only two extra transistors used in active load. Moreover, the bandwidth of proposed circuit is enhanced by using resistive compensation technique. The performance of proposed VDIBA is demonstrated by detailed frequency analysis. Furthermore, it is shown that the transconductance can be enhanced up to 4.61 mS at biasing current of 300 µA. In addition, a third order low pass filter is given as an application example to confirm the high performance of the proposed VDIBA. The proposed low pass filter operates at natural pole frequency of 15 MHz. The proposed VDIBA and its filter application are implemented using TSMC 90 nm CMOS technology in Cadence virtuoso schematic composer at ±0.6 V supply voltage.     

包络跟踪电源优化设计与仿真

在移动通信3G/4G网络中,包络跟踪技术是提高射频功放效率的核心技术之一。从包络跟踪的相位失真问题入手,以降压变换器为拓扑,提出了以4阶贝塞尔低通滤波器传递函数为整体设计模型的包络跟踪电源设计方法,通过线性补偿控制实现对包络跟踪电源的控制。同时,依据线性控制单元在实际设计中可能遇到的问题,提出了一种更为适合实际应用的线性控制器设计方法。最后,通过软件Pspice对此包络跟踪电源进行仿真验证,以降带宽处理后的单载波1 MHz信道宽度的WCDMA包络信号作为跟踪参考信号,通过软件matlab的simulink仿真对包络跟踪电源进行验证,证明方案实际应用可行。     

一种基于LTCC的高性能超宽带带通滤波器

提出了一种基于LTCC技术的高性能超宽带带通滤波器的实现方法。该滤波器电路采用交织结构,同时只采用了4个谐振级,有效降低了通带内插入损耗,增大了滤波器带宽。借助电路仿真以及电磁场三维仿真软件进行电路优化,实际测试结果与仿真结果吻合较好,中心频率为1 080 MHz,带宽为500 MHz,在通带内插入损耗优于1.6 dB。由于该滤波器频率较低,属于UHF波段,波长较长,采用半集总半分布式结构实现了滤波器的小型化,封装尺寸仅为3.4 mm×4.8 mm×1.5 mm。     

A reconfigurable OTA-C baseband filter with wide digital tuning for GNSS receivers

The design of a digitally-tunable sixth-order reconfigurable OTA-C filter in a 0.18-μm RFCMOS process is proposed.The filter can be configured as a complex band pass filter or two real low pass filters.An improved digital automatic frequency tuning scheme based on the voltage controlled oscillator technique is adopted to compensate for process variations.An extended tuning range(above 8:1) is obtained by using widely continuously tunable transconductors based on digital techniques.In the complex band pas...