A 3rd-order Butterworth active-RC complex band-pass filter was presented for Zig Bee(IEEE802.15.4) transceiver applications. The filter adopted cascaded complex pole stages to realize the 3 MHz bandwidth with a centre...A 3rd-order Butterworth active-RC complex band-pass filter was presented for Zig Bee(IEEE802.15.4) transceiver applications. The filter adopted cascaded complex pole stages to realize the 3 MHz bandwidth with a centre frequency of 2 MHz which was required by the Zig Bee transceiver applications. An automatic frequency tuning scheme was also designed to accommodate the performance deterioration due to the process, voltage and temperature(PVT) variations. The whole filter is implemented in a 0.18 μm standard process and occupies an area of 1.3 mm×0.6 mm. The current dissipation is 1.2 m A from a 1.8 V single power supply. Measurement results show that the image rejection ratio(IRR) of the filter is 24.1 d B with a pass-band ripple less than 0.3 d B. The adjacent channel rejection is 29.8 d B@7 MHz and alternate channel rejection 47.5 d B@12 MHz, respectively.展开更多
A low power,highly linear active-RC filter is presented.This filter is synthesized from a low pass 6 order Chebyshev RLC ladder,and exhibits a reconfigurable bandwidth（10 MHz,50 MHz）.In order to meet the high cutoff...A low power,highly linear active-RC filter is presented.This filter is synthesized from a low pass 6 order Chebyshev RLC ladder,and exhibits a reconfigurable bandwidth（10 MHz,50 MHz）.In order to meet the high cutoff frequency（50 MHz） and strict adjacent channel rejection requirements,a novel operational amplifier based on a new compensation technique is used,which optimizes high frequency filter performance and minimizes current consumption.This filter is fabricated in a 0.18μm CMOS process,the measurement results indicate that the filter provides 10 MHz and 50 MHz selectable bandwidth,and excellent adjacent channel rejection：-15.3 dB at 12.5 MHz with 10 MHz cutoff frequency,-8.3 dB at 60 MHz with 50 MHz cutoff frequency,three times out-band rejection more than 60 dB while the in-band ripple is less than 1 dB.展开更多
An eighth order active-RC filter for low-IF and zero-IF DVB tuner applications is presented, which is implemented in Butterworth biquad structure. An automatic frequency tuning circuit is introduced to compensate the ...An eighth order active-RC filter for low-IF and zero-IF DVB tuner applications is presented, which is implemented in Butterworth biquad structure. An automatic frequency tuning circuit is introduced to compensate the cut-off frequency variation using a 6-bit switched-capacitor array. Switched-resistor arrays are adopted to cover different cut-off frequencies in low-IF and zero-IF modes. Measurement results show that precise cut-off frequencies at 2.5, 3, 3.5 and 4 MHz in zero-IF mode, 5, 6, 7 and 8 MHz in low-IF mode can be achieved, 60 dB frequency attenuation can be obtained at 20 MHz, and the in-band group delay agrees well with the simulation. Two-tone testing shows the in-band IM3 achieves -52 dB and the out-band IM3 achieves -55 dB with -11 dBm input power. This proposed filter circuit, fabricated in a SMIC 0.18μm CMOS process, consumes 4 mA current with 1.8 V power supply.展开更多
This paper presents an 8th order active-RC elliptic low-pass filter（LPF） for a direct conversion China Mobile Multimedia Broadcasting（CMMB） tuner with a 1 or 4 MHz -3 dB cutoff frequency（f_（-3dB））.By using a n...This paper presents an 8th order active-RC elliptic low-pass filter（LPF） for a direct conversion China Mobile Multimedia Broadcasting（CMMB） tuner with a 1 or 4 MHz -3 dB cutoff frequency（f_（-3dB））.By using a novel gain-bandwidth-product（GBW） extension technique in designing the operational amplifiers（op-amps）, the proposed filter achieves 71 dB stop-band rejection at 1.7f_（-3dB） to meet the stringent CMMB adjacent channel rejection（ACR） specifications while dissipates only 2.8 mA/channel from a 3 V supply,its bias current can be further lowered to 2 mA/channel with only 0.5 dB peaking measured at the filter＇s pass-band edge.Elaborated common-mode（CM） control circuits are applied to the filter op-amp to increase its common-mode rejection ratio （CMRR） and effectively reject the large signal common-mode interference.Measurement results show that the filter has 128 dBμV_（rms） in-band IIP3 and more than 80 dB passband CMRR.Fabricated in a 0.35-μm SiGe BiCMOS process,the proposed filter occupies a 1.19 mm^2 die area.展开更多
A reconfigurable complex band-pass （CBP）/low-pass （LP） active-RC filter with a noise-shaping technique for wireless receivers is presented. Its bandwidth is reconfigurable among 500 kHz, 1 MHz and 4 MHz in LP mode...A reconfigurable complex band-pass （CBP）/low-pass （LP） active-RC filter with a noise-shaping technique for wireless receivers is presented. Its bandwidth is reconfigurable among 500 kHz, 1 MHz and 4 MHz in LP mode and 1 MHz, 2 MHz and 8 MHz in CBP mode with 3 MHz center frequency. The Op-Amps used in the filter are realized in cell arrays in order to obtain scalable power consumption among the different operation modes. Furthermore, the filter can be configured into the 1st order, 2nd order or 3rd order mode, thus achieving a flexible filtering property. The noise-shaping technique is introduced to suppress the flicker noise contribution. The filter has been implemented in 180 nm CMOS and consumes less than 3 mA in the 3rd 8 MHz-bandwidth CBP mode. The spot noise at 100 Hz can be reduced by 14.4 dB at most with the introduced noise-shaping technique.展开更多
This paper describes a low-pass reconfigurable baseband filter for GSM, TD-SCDMA and WCDMA multi-mode transmitters. To comply with 3GPP emission mask and limit TX leakage at the RX band, the out- of-band noise perform...This paper describes a low-pass reconfigurable baseband filter for GSM, TD-SCDMA and WCDMA multi-mode transmitters. To comply with 3GPP emission mask and limit TX leakage at the RX band, the out- of-band noise performance is optimized. Due to the distortion caused by the subthreshold leakage current of the switches used in capacitor array, a capacitor bypass technique is proposed to improve the filter＇s linearity. An automatic frequency tuning circuit is adopted to compensate the cut-off frequency variation. Simulation results show that the filter achieves an in-band input-referred third-order intercept point （IIP3） of 47 dBm at 1.2-V power supply and the out-of-band noise can meet TX SAW-less requirement for WCDMA ＆ TD-SCDMA. The baseband filter incorporates -40 to 0 dB programmable gain control that is accurately variable in 0.5 dB steps. The filter＇s cut-off frequency can be reconfigured for GSM/TD-SCDMA/WCDMA multi-mode transmitter. The implemented baseband filter draws 3.6 mA from a 1.2-V supply in a 0.13 μm CMOS process.展开更多
An analog baseband circuit for a direct conversion wireless local area network（WLAN） transceiver in a standard 0.13-μm CMOS occupying 1.26 mm^2 is presented.The circuit consists of active-RC receiver（RX） 4th orde...An analog baseband circuit for a direct conversion wireless local area network（WLAN） transceiver in a standard 0.13-μm CMOS occupying 1.26 mm^2 is presented.The circuit consists of active-RC receiver（RX） 4th order elliptic lowpass filters（LPFs）,transmitter（TX） 3rd order Chebyshev LPFs,RX programmable gain amplifiers （PGAs） with DC offset cancellation（DCOC） servo loops,and on-chip output buffers.The RX baseband gain can be programmed in the range of -11 to 49 dB in 2 dB steps with 50-30.2 nV/（Hz）^（1/2） input referred noise（IRN） and a 21 to -41 dBm in-band 3rd order interception point（IIP3）.The RX/TX LPF cutoff frequencies can be switched between 5 MHz,10 MHz,and 20 MHz to fulfill the multimode 802.11b/g/n requirements.The TX baseband gain of the I/Q paths are tuned separately from -1.6 to 0.9 dB in 0.1 dB steps to calibrate TX 1/Q gain mismatches.By using an identical integrator based elliptic filter synthesis method together with global compensation applied to the LPF capacitor array,the power consumption of the RX LPF is considerably reduced and the proposed chip draws 26.8 mA/8 mA by the RX/TX baseband paths from a 1.2 V supply.展开更多
基金Projects(61334003,61274026) supported by the National Natural Science Foundation of ChinaProject(K5051225006) supported by the Fundamental Research Fund for the Central Universities,China
文摘A 3rd-order Butterworth active-RC complex band-pass filter was presented for Zig Bee(IEEE802.15.4) transceiver applications. The filter adopted cascaded complex pole stages to realize the 3 MHz bandwidth with a centre frequency of 2 MHz which was required by the Zig Bee transceiver applications. An automatic frequency tuning scheme was also designed to accommodate the performance deterioration due to the process, voltage and temperature(PVT) variations. The whole filter is implemented in a 0.18 μm standard process and occupies an area of 1.3 mm×0.6 mm. The current dissipation is 1.2 m A from a 1.8 V single power supply. Measurement results show that the image rejection ratio(IRR) of the filter is 24.1 d B with a pass-band ripple less than 0.3 d B. The adjacent channel rejection is 29.8 d B@7 MHz and alternate channel rejection 47.5 d B@12 MHz, respectively.
基金supported by the Major Specialized Program of National Science and Technology of China(Nos.Z11/1100054111004, 2010ZX03007-002-03)
文摘A low power,highly linear active-RC filter is presented.This filter is synthesized from a low pass 6 order Chebyshev RLC ladder,and exhibits a reconfigurable bandwidth（10 MHz,50 MHz）.In order to meet the high cutoff frequency（50 MHz） and strict adjacent channel rejection requirements,a novel operational amplifier based on a new compensation technique is used,which optimizes high frequency filter performance and minimizes current consumption.This filter is fabricated in a 0.18μm CMOS process,the measurement results indicate that the filter provides 10 MHz and 50 MHz selectable bandwidth,and excellent adjacent channel rejection：-15.3 dB at 12.5 MHz with 10 MHz cutoff frequency,-8.3 dB at 60 MHz with 50 MHz cutoff frequency,three times out-band rejection more than 60 dB while the in-band ripple is less than 1 dB.
基金Project supported by the National High Technology Research and Development Program of China (No.2007AA01Z282)
文摘An eighth order active-RC filter for low-IF and zero-IF DVB tuner applications is presented, which is implemented in Butterworth biquad structure. An automatic frequency tuning circuit is introduced to compensate the cut-off frequency variation using a 6-bit switched-capacitor array. Switched-resistor arrays are adopted to cover different cut-off frequencies in low-IF and zero-IF modes. Measurement results show that precise cut-off frequencies at 2.5, 3, 3.5 and 4 MHz in zero-IF mode, 5, 6, 7 and 8 MHz in low-IF mode can be achieved, 60 dB frequency attenuation can be obtained at 20 MHz, and the in-band group delay agrees well with the simulation. Two-tone testing shows the in-band IM3 achieves -52 dB and the out-band IM3 achieves -55 dB with -11 dBm input power. This proposed filter circuit, fabricated in a SMIC 0.18μm CMOS process, consumes 4 mA current with 1.8 V power supply.
文摘This paper presents an 8th order active-RC elliptic low-pass filter（LPF） for a direct conversion China Mobile Multimedia Broadcasting（CMMB） tuner with a 1 or 4 MHz -3 dB cutoff frequency（f_（-3dB））.By using a novel gain-bandwidth-product（GBW） extension technique in designing the operational amplifiers（op-amps）, the proposed filter achieves 71 dB stop-band rejection at 1.7f_（-3dB） to meet the stringent CMMB adjacent channel rejection（ACR） specifications while dissipates only 2.8 mA/channel from a 3 V supply,its bias current can be further lowered to 2 mA/channel with only 0.5 dB peaking measured at the filter＇s pass-band edge.Elaborated common-mode（CM） control circuits are applied to the filter op-amp to increase its common-mode rejection ratio （CMRR） and effectively reject the large signal common-mode interference.Measurement results show that the filter has 128 dBμV_（rms） in-band IIP3 and more than 80 dB passband CMRR.Fabricated in a 0.35-μm SiGe BiCMOS process,the proposed filter occupies a 1.19 mm^2 die area.
基金Project supported by the National Science and Technology Major Projects of China(No.2012ZX03004007)the National Natural Science Foundation of China(Nos.61020106006,61076029)
文摘A reconfigurable complex band-pass （CBP）/low-pass （LP） active-RC filter with a noise-shaping technique for wireless receivers is presented. Its bandwidth is reconfigurable among 500 kHz, 1 MHz and 4 MHz in LP mode and 1 MHz, 2 MHz and 8 MHz in CBP mode with 3 MHz center frequency. The Op-Amps used in the filter are realized in cell arrays in order to obtain scalable power consumption among the different operation modes. Furthermore, the filter can be configured into the 1st order, 2nd order or 3rd order mode, thus achieving a flexible filtering property. The noise-shaping technique is introduced to suppress the flicker noise contribution. The filter has been implemented in 180 nm CMOS and consumes less than 3 mA in the 3rd 8 MHz-bandwidth CBP mode. The spot noise at 100 Hz can be reduced by 14.4 dB at most with the introduced noise-shaping technique.
基金Project supported by the Important National Science & Technology Specific Projects(No.2009ZX01031-003-002)the National High Technology Research and Development Program of China(No.2009AA011605)
文摘This paper describes a low-pass reconfigurable baseband filter for GSM, TD-SCDMA and WCDMA multi-mode transmitters. To comply with 3GPP emission mask and limit TX leakage at the RX band, the out- of-band noise performance is optimized. Due to the distortion caused by the subthreshold leakage current of the switches used in capacitor array, a capacitor bypass technique is proposed to improve the filter＇s linearity. An automatic frequency tuning circuit is adopted to compensate the cut-off frequency variation. Simulation results show that the filter achieves an in-band input-referred third-order intercept point （IIP3） of 47 dBm at 1.2-V power supply and the out-of-band noise can meet TX SAW-less requirement for WCDMA ＆ TD-SCDMA. The baseband filter incorporates -40 to 0 dB programmable gain control that is accurately variable in 0.5 dB steps. The filter＇s cut-off frequency can be reconfigured for GSM/TD-SCDMA/WCDMA multi-mode transmitter. The implemented baseband filter draws 3.6 mA from a 1.2-V supply in a 0.13 μm CMOS process.
文摘An analog baseband circuit for a direct conversion wireless local area network（WLAN） transceiver in a standard 0.13-μm CMOS occupying 1.26 mm^2 is presented.The circuit consists of active-RC receiver（RX） 4th order elliptic lowpass filters（LPFs）,transmitter（TX） 3rd order Chebyshev LPFs,RX programmable gain amplifiers （PGAs） with DC offset cancellation（DCOC） servo loops,and on-chip output buffers.The RX baseband gain can be programmed in the range of -11 to 49 dB in 2 dB steps with 50-30.2 nV/（Hz）^（1/2） input referred noise（IRN） and a 21 to -41 dBm in-band 3rd order interception point（IIP3）.The RX/TX LPF cutoff frequencies can be switched between 5 MHz,10 MHz,and 20 MHz to fulfill the multimode 802.11b/g/n requirements.The TX baseband gain of the I/Q paths are tuned separately from -1.6 to 0.9 dB in 0.1 dB steps to calibrate TX 1/Q gain mismatches.By using an identical integrator based elliptic filter synthesis method together with global compensation applied to the LPF capacitor array,the power consumption of the RX LPF is considerably reduced and the proposed chip draws 26.8 mA/8 mA by the RX/TX baseband paths from a 1.2 V supply.
