The design of a 3-V 900-MHz CMOS bandpass amplifier

A new bandpass amplifier which performs both functions of low-noise amplifier (LNA) and bandpass filter (BPF) is proposed for the application of 900-MHz RF front-end in wireless receivers. In the proposed amplifier, the positive-feedback Q-enhancement technique is used to overcome the low-gain low-Q characteristics of the CMOS tuned amplifier. The Miller-capacitance tuning scheme is used to compensate for the process variations of center frequency. Using the high-Q bandpass amplifier in the receivers, the conventional bulky off-chip filter is not required. An experimental chip fabricated by 0.8-μm N-well double-poly-double-metal CMOS technology occupies 2.6×2.0 mm² chip area. Under a 3 V supply voltage, the measured quality factor is tunable between 2.2 and 44. When the quality factor is tuned at Q=30, the measured center frequency of the amplifier is tunable between 869-893 MHz with power gain 17 dB, noise figure 6.0 dB, output 1 dB compression point at -30 dBm, third-order input intercept point at -14 dBm, and power dissipation 78 mW     

A 65 mW, 0.4–2.3 GHz Bandpass Filter for Satellite Receivers

A monolithic tunable bandpass filter for satellite receiver front-ends is presented. The center frequency of the bandpass filter can be tuned from 0.4 GHz to 2.3 GHz. The filter is constructed using four transconductor-C poly-phase filter sections and has a 50 dB variable gain range. At 20 dB attenuation and at 30 dB gain the measured 1 dB compression point is –21 dBm and –56 dBm, respectively. Measured input IP3 is –12 dBm. The noise figure is 15 dB at maximum gain. An on-chip I/Q oscillator tracks the center frequency and enables automatic tuning. The bandpass filter dissipates 65 mW with 5 Volt supply voltage and occupies 0.16 mm² chip area. The filter is realized in a standard 11 GHz f _t bipolar technology.     

基于OTA的有源Gm-C复数带通滤波器的设计

设计了一种基于OTA的有源Gm-C复数带通滤波器,用以实现射频前端芯片中的中频滤波和镜像抑制功能,该滤波器采用Gyrator结构,将低通原型滤波器中的集总电感用有源电感进行替换,并依据复数变换理论,对浮地电容和接地电容进行复数变换,实现带通滤波器.滤波器中心频率为4.1 MHz,1 dB带宽2 MHz,带内增益13.27 dB,1.5倍带宽处抑制在40 dB以上,镜像抑制度40 dB.Gm-C滤波器集成度高,功耗低,适合于高频应用,是当前集成中频滤波器的热点.     

A 10.7-MHz sixth-order SC ladder filter in 0.35-/spl mu/m CMOS technology

A sixth-order 10.7-MHz bandpass switched-capacitor filter based on a double terminated ladder filter is presented. The filter uses a multipath operational transconductance amplifier (OTA) that presents both better accuracy and higher slew rate than previously reported Class-A OTA topologies. Design techniques based on charge cancellation and slower clocks are used to reduce the overall capacitance from 782 down to 219 unity capacitors. The filter's center frequency and bandwidth are 10.7 MHz and 400 kHz, respectively, and a passband ripple of 1 dB in the entire passband. The quality factor of the resonators used as filter terminations is around 32. The measured (filter + buffer) third-intermodulation (IM3) distortion is less than -40 dB for a two-tone input signal of +3-dBm power level each. The signal-to-noise ratio is roughly 58 dB while the IM3 is -45 dB; the power consumption for the standalone filter is 42 mW. The chip was fabricated in a 0.35-/spl mu/m CMOS process; filter's area is 0.84 mm/sup 2/.     

An accurate quality factor tuning scheme for IF and high-Qcontinuous-time filters

A quality factor (Q) tuning technique for IF and high-Q continuous-time filter biquads is proposed. The method is based on the existing magnitude locked loop Q-tuning technique, but it utilizes a modified version of the continuous-time adaptive least-mean-squares algorithm to improve the attainable precision. The technique is resistant to center frequency tuning errors, and can use an easily generated clock pulse as its reference signal. Discrete component tests were conducted, with the Q value being tuned to within 1.1% in the worst case. A test chip consisting of a fourth-order bandpass filter at 10.7 MHz with biquad Q-values of 20 was fabricated in a 1.2-μm n-well CMOS process. Experimental results show that the proposed Q-tuning scheme improves on existing methods, with measured accuracies of less than 1% error     

Design and performance of a fully integrated bipolar 10.7-MHz analog bandpass filter

Design and experimental evaluation of a sixth-order fully integrated continuous-time 10.7-MHz bandpass filter are presented. Circuit performance is stabilized through on-chip tuning by a dual-loop master-slave control scheme that locks center frequency and bandwidth to an external reference signal. Difficulties in design and performance are discussed and corrections suggested where appropriate.     

A 10.7-MHz switched-capacitor bandpass filter

An experimental 10.7-MHz switched-capacitor bandpass filter is demonstrated that exhibits a 400-kHz bandwidth with a 42-MHz sampling rate. Basic design issues of such high-frequency filters are also addressed with emphasis on dynamic range and power constraints. A theoretical square relation between power and center frequency agrees well with experimental results. The sixth-order differential bandpass filter chip occupies 2 mm² using a 2.25-μm gate double-poly CMOS technology     

Design techniques for VHF/UHF high-Q tunable bandpass filters usingsimple CMOS inverter-based transresistance amplifiers

In this paper, CMOS inverter-based wideband transresistance R_m amplifiers are proposed and analyzed. Using the R_m amplifiers, tunable VHF/UHF R_m-C bandpass biquadratic filters can be designed. In these filters, the center frequency f₀ can be post-tuned by adjusting the control voltages of the R_m amplifiers. The pseudodifferential configuration uses the extra inversely connected and self-shorted inverters for Q enhancement. Experimental results have shown that the center frequency f₀ of the single-ended-output R_m-C bandpass biquad is 386 MHz (258 MHz) and Q=1.195 (Q=1.012) for ±2.5 V (±1.5 V) supply voltage. The power consumption is 24.83 mW (3.42 mW), and the dynamic range is 61 dB (55.5 dB). For pseudodifferential-output high-Q configuration, the measured quality factor Q can be as high as 360 with f₀=222.7 MHz. When Q=94, the power consumption is 56.2 mW and the measured dynamic range is 57.8 dB for 12.5 V supply voltage     

Bandpass Sigma–Delta Modulator Employing SAW Resonator as Loop Filter

Continuous-time bandpass (BP) sigma-delta modulators (SigmaDeltaMs) employing surface acoustic wave (SAW) resonators as loop filters are presented. Compared with the loop filters realized with G_m-C and LC resonators, the SAW resonator has the advantage of high-Q factor, wide resonant frequency range and accurate resonant frequency without the need for automatic tuning. With the proposed anti-resonance cancellation and loop filter phase compensation techniques, a second- and a fourth-order BP SigmaDeltaMs are demonstrated in a 0.35-mum CMOS technology. Both modulators are tested with 47.3-MHz off-chip SAW resonators. The second-order modulator attains a dynamic range of 57 dB and peak signal-to-noise distortion ratio (SNDR) of 54 dB and the fourth-order one achieves a dynamic range of 69 dB and peak SNDR of 66 dB, both in a 200-kHz signal bandwidth. The fourth-order modulator is also measured in a 3.84-MHz signal bandwidth and achieves a dynamic range of 52.5 dB and peak SNDR of 50 dB, an effective 8-bit resolution     

Photonic bandpass filters with high skirt selectivity and stopband attenuation

A new photonic signal processor topology that simultaneously achieves both a high-Q and a high skirt selectivity and stopband attenuation filter response is presented. It is based on a novel dual-cavity bandpass optical structure in which two pairs of active fiber Bragg grating cavities are used with an optical gain offset to control the poles and stopband attenuation characteristics of the filter. This concept enables a large improvement in the filter stopband attenuation, rejection bandwidth, and skirt selectivity to be realized. Measured results demonstrate both a narrow bandpass bandwidth of 0.4% of center frequency and a skirt selectivity factor of 16.6 for 40 dB rejection, which corresponds to a 6.5-fold improvement in comparison to conventional single cavity high-Q structures. To our knowledge, this is the best skirt selectivity reported for a photonic bandpass filter to date. The new photonic filter structure has been experimentally verified and excellent agreement between measured and predicted responses is shown.     

A 44-MHz wideband switched-capacitor bandpass filter using double-sampling pseudo-two-path techniques

A fully differential wideband sixth-order switched-capacitor bandpass filter is designed for channel selection in cable TV applications. A modified double-sampling pseudo-two-path technique is proposed to achieve a second-order wideband bandpass filter with a single opamp. Implemented in a standard double-poly four-metal 0.35-/spl mu/m CMOS process and operated at 176-MHz sampling frequency, the filter achieves a measured center frequency of 44 MHz with a bandwidth of 6.28 MHz and a dynamic range of 58.3 dB at 3% IM3. The filter consumes 92.5mW at a single 3.0-V supply and occupies a chip area of 0.52 mm /sup 2/.     

A 28-MHz wideband switched-capacitor bandpass filter with transmission zeros for high attenuation

A 28-MHz wideband switched-capacitor (SC) bandpass filter employs an N-path technique and implements transmission zeros in the transfer function to achieve high attenuation. A modified SC biquadratic filter architecture is proposed to achieve high-speed operation. Implemented in a 0.35-/spl mu/m CMOS process, the bandpass filter operates at 28-MHz center frequency with a 3.84-MHz bandwidth and adjacent-channel attenuation of more than 35 dB. At 3-V supply, the filter measures a dynamic range of 37 dB at the 1% THD3 point while dissipating 19.6-mW per pole and occupying a chip area of 1.65 mm/sup 2/.     

一种基于Gm-C的高Q值模拟中频带通滤波器设计与实现

设计并实现了一种基于Gm-C二次节(Biquad)结构的6阶切比雪夫Ⅰ型模拟中频带通滤波器,中心频率为46MHz,带宽为2.046MHz.其中Biquad结构中加入了负阻抗单元,增加输出阻抗,实现滤波器的高Q值(品质因数).跨导放大器(Operational transconductance amplifier,OTA)单元使用源极负反馈技术,优化了OTA的线性性能.整个滤波器电路采用0.35μm CMOS工艺实现.经过仿真验证,滤波器的通带纹波是2.704dB,1.5倍带宽处衰减大于21dB.在3.3V电源电压情况下,滤波器的总电流消耗为8.87mA.     

A Monolithic Low-Distortion Low-Loss Silicon-on-Glass Varactor-Tuned Filter With Optimized Biasing

A low-distortion varactor-tuned bandpass filter is demonstrated on a high-Q silicon-on-glass technology. The dc bias network is optimized to achieve high linearity, the center frequency of the filter tunes from 2.4 to 3.5 GHz, and the measured loss of the filter is 2-3 dB at 2 GHz, with a stopband rejection of 25 dB. The measured IIP3 of the filter was +46 dBm     

Switched-capacitor high-Q bandpass filters for IF applications

Experimental results for a sixth-order switched-capacitor bandpass filter with a selectivity Q of 55 at a center frequency of 3.1 MHz are presented. A simple noise analysis of active bandpass filters composed of coupled identical resonators is introduced to explain the dynamic range reduction in high-Q active filters resulting from loose high-Q couplings between resonators. Theoretical predictions of noise in coupled resonator-type bandpass filters agree well with measured results. The prototype chip occupies 2 mm/SUP 2/ and dissipates 45 mW with a single 5-V supply.     

A 10.7-MHz CMOS SC radio IF filter using orthogonal hardwaremodulation

FM radio receivers require an IF filter for channel selection, customarily set at an IF center frequency of 10.7 MHz. Up until now, the limitations of integrated radio selectivity filters in terms of power dissipation, dynamic range, and cost are such that it is still required to use an external ceramic 10.7-MHz bandpass filter. This paper demonstrates a CMOS switched-capacitor IF filter that can be integrated with most of the rest of the FM receiver, eliminating external components and printed circuit board area. This is made possible through a combination of two techniques: orthogonal hardware modulation, and delta-charge redistribution. It exhibits a tightly controlled center frequency with a Q of 55 and also contains a programmable gain. The filter occupies an area of 0.7 mm² in a 0.6 μm CMOS process with poly-poly capacitors. The new filter requires only 16 mW of power, and this is offset by elimination of the power needed in current designs to drive off-chip filters     

A 12-Pole Narrowband Highly Selective High-Temperature Superconducting Filter for the Application in the Third-Generation Wireless Communications

An ultra-selective high-temperature superconducting bandpass filter was designed and fabricated to satisfy the demands of the third-generation wireless communications. This filter was designed to have 12-pole quasi-elliptic response with 4.68-MHz bandwidth in the third-generation communications band (a fractional bandwidth of 0.0023). Full-wave simulations were conducted by using Sonnet software. A novel, compact, and low radiation resonator with a high-quality (Q) factor value was developed to reduce the parasitical coupling. In order to satisfy the demand of high band-edge steepness, three pairs of transmission zeros at finite frequencies were introduced in the cascaded quadruplet coupling structure. The filter was fabricated on a 2-in-diameter 0.43-mm-thick sapphire wafer with double-sided YBCO films. The measurements showed that the passband center frequency (f₀) of the filter is 2.038 GHz at 67 K with a midband insertion loss of 0.67 dB and the return loss better than 15 dB. The measured response of the filter also exhibited ultra-high band-edge steepness of 140-220 dB/MHz. Better than 60 dB of out-of-band rejections for frequencies very close to the band edge (|f-f₀|>2.7 MHz), better than 90 dB at frequencies 7.5 MHz away from the center frequency and up to 100 dB of wideband rejections were achieved     

High-frequency high-Q BiCMOS current-mode bandpass filter andmobile communication application

The design of a tunable high-frequency fully integrable current-mode bandpass filter is presented using a complementary high-performance BiCMOS process. The new architecture of this filter is based on impedance simulation and employs current controlled conveyors. The Q-factor and the center frequency can be electronically controlled with dc bias currents over a broad range of values, thus allowing easy tuning of this filter. An application to a mobile communication IF receiver channel centered at 85 MHz and with 1-MHz bandwidth based on the cascade of two identical second-order bandpass cells has been designed. Measurements show very interesting frequency performance (f ₀ tunable in the range 30-120 MHz and Q from 1-140) in conjunction with low power consumption (25 mW for the fourth-order filter with ±2.5 V supplies)     

A SiGe BiCMOS 24-GHz receiver front-end for automotive short-range radar

This paper presents a fully integrated SiGe BiCMOS 24-GHz receiver front-end implemented for a ultra-wideband automotive short-range radar sensor. The circuit consists of a homodyne I/Q down-converter and a 24-GHz synthesizer. The receiver front-end is able to achieve a power conversion gain as high as 30 dB and a 6-dB noise figure, while preserving high linearity performance thanks to a 1-bit gain control. The frequency synthesizer, which also includes an on-chip loop filter, guarantees a phase noise of −104 dBc/Hz at 1-MHz offset from the 24.125-GHz carrier and a 4.7-GHz tuning range from 20.4 to 25.1 GHz.     

Passive CCD resonator filters

Novel passive recursive CCD bandpass filters have been realized using standard two-level-polysilicon gate NMOS technology. A Chebyshev bandpass (w/SUB rel,/ /SUB 3/ /SUB dB/=3.1 percent) and a fully integrated CCD signal filter with an extremely narrow 3 dB bandwidth of 97 Hz (Q=1350) at 131.85 kHz center frequency were implemented by means of cascaded CCD resonators. The latter chip contains the necessary clock generation and biasing circuitry realized with dynamic circuit techniques to achieve low power consumption (40 mW per filter). Performing all filtering operations exclusively in the charge domain ensures filter passivity. An extremely stable center frequency and a bandwidth independently controlled by a capacitance ratio are the special advantages of such filters.