Good Common-mode Rejection Research Articles

Research on weak signal readout systems for neutrinoless double-beta decay experiments based on bolometers

This paper develops a prototype signal readout system based on the physical mechanism and signal-to-noise ratio of the ultralow voltage signal characteristics of a bolometer. The preamplifier module is one of the key difficulties of the prototype: the internal resistance is as high as one hundred MΩ, the signal frequency band is susceptible to low-frequency noise, and the high energy resolution requires a high signal-to-noise ratio that is matching the input impedance to design a preamplifier with a good common-mode rejection ratio and low inherent noise. Therefore, the preamplifier circuit is designed with an instrument amplifier. At present, the energy resolution of the bolometer is 500 ~ 1000 nV (root mean square, rms) at the input of the signal readout system. According to the calculation, the theoretical value of the inherent noise at the input end is 394 nVrms, including a theoretical value for the equivalent input voltage noise of 166 nVrms, while the actual measurement value is less than 180 nVrms, which is basically consistent with the theoretical value. In addition, the signal gain (10,000) and frequency response of the prototype are experimentally verified. The experimental results show that the gain is 9400, and the frequency and waveform are not distorted within the allowable error range; all of these parameters meet the design requirement.

A New Type of Right-leg-drive Circuit ECG Amplifier Using New Operational Amplifier

The low-power consumption and low-noise sensor remain an important challenge in Electrocardiogram (ECG) sensor field. A new operational amplifier (op-amp) design is proposed in this study, and it is integrated into the traditional “right-leg-drive” circuit to cancel out the common-mode interference. Besides, the gain of this circuit can be controlled by adjusting the value of these resistors. Then, the traditional op-amp is redesigned to improve the performance of this circuit. Some improvements are made on the basis of the traditional sleeve-type cascade amplifier to obtain good gain and gain bandwidth. At the same time, power consumption is not too high. Meanwhile, to minimize the noise of the op-amp without using large value capacitors, pseudo-resistors are used. The right-leg-drive circuit is used in the overall process to ensure good common-mode rejection ratio (CMRR) performance. For the newly designed op-amp, its gain can reach 60db, and the operating frequency of the circuit is between 0.1HZ and 108HZ, and the error is no more than 10%. The differential mode gain of the overall circuit is 43.4db, and the error is within 5db. The total power consumption of the circuit is 3.17u watts, which is less than the specified maximum power consumption, and the total integrated input-referred noise is 3.786μVRMS, which is less than the specified maximum circuit noise. The total capacitor usage is 1nF, less than the specified maximum capacitor usage. To sum up, the ECG sensor is designed using the “right leg drive circuit” and a new type of amplifier is designed to eliminate common-mode interference and improve the performance of the amplifier.

A Fully Integrated K-Band Dual Down-Conversion Receiver for Radar Applications in 90 nm CMOS

A fully integrated K-band dual down-conversion receiver for phased array radar applications in 90 nm CMOS is presented. The receiver utilizes the dual down-conversion architecture to achieve superior performance. The integrated 1.15 GHz image-rejection filter (IRF) provides enough wideband (22 MHz) image rejection ratio at 140 MHz offset before the second down-conversion by utilizing the Q-enhancing and frequency staggering techniques to compensate the component loss. The low noise amplifier realizes the single-to-differential-ended conversion at the input with a transformer and achieves good common-mode rejection. The 70 MHz intermediate frequency baseband consists of two cascaded 3rd-order band-pass active RC filters (BPFs) and one automatic gain control (AGC) loop, with the integrator frequency compensation technique to lower down the requirements on the embedded Op-Amps. Two phase-locked loop (PLL) frequency synthesizers are integrated to provide the local oscillation (LO) signals for the down-conversions, where the matching of the charge-pump is improved by adding one extra current compensation branch. The measurements of the prototype show that the receiver converts the targeted mm-wave signal to 70 MHz intermediate frequency while achieving 8.3 dB noise figure (NF), 51-95 dB variable gain range and >45 dB image rejection ratio at 140 MHz offset with >22 MHz signal bandwidth. The receiver draws 74 mA current (excluding 2 PLLs) from the 1.2 V power supplies and occupies a core area of 4.58 × 0.53mm 2 (excluding 2 PLLs).

Reconfigurable low voltage low power dual-band self-cascode current-reuse quasi-differential LNA for 5G

This paper proposes a low noise amplifier (LNA) which can be reconfigured to operate in two frequency bands at low power. The LNA employs self-cascode devices in current-reuse configuration to enable lower supply voltage operation without compromising the gain. A quasi-differential structure is used to achieve high linearity and good common-mode rejection. The proposed LNA is designed to operate in (3.1–4.7 GHz: Band1) and (5.0–7.2 GHz: Band2) in the 5G frequency spectrum. It is implemented in 65 nm UMC-LL CMOS process technology using 0.6V, and its performance is evaluated using post layout, PVT and Monte Carlo simulations. The proposed LNA requires an area of 0.03276 mm2. The power dissipation, maximum gain, minimum noise figure, average IIP3, IIP2 of the LNA operating in Band1 and Band2 are found to be (0.97 ​mW, 17.6 ​dB, 2.20 ​dB, +0.72dBm, +46.49dBm) and (0.485 ​mW, 12.1 ​dB, 3.31 ​dB, +0.12dBm, +42.60dBm) respectively.

A sandwich-like differential B-dot based on EACVD polycrystalline diamond slice

In this article, we present a method of mass production of a standardized high-performance differential B-dot magnetic probe together with the magnetic field measurement in a pulsed current device with the current up to hundreds of kilo-Amperes. A polycrystalline diamond slice produced in an Electron Assisted Chemical Vapor Deposition device is used as the base and insulating material to imprint two symmetric differential loops for the magnetic field measurement. The SP3 carbon bond in the cubic lattice structure of diamond is confirmed by Raman spectra. The thickness of this slice is 20 μm. A gold loop is imprinted onto each surface of the slice by using the photolithography technique. The inner diameter, width, and thickness of each loop are 0.8 mm, 50 μm, and 1 μm, respectively. It provides a way of measuring the pulsed magnetic field with a high spatial and temporal resolution, especially in limited space. This differential magnetic probe has demonstrated a very good common-mode rejection rate through the pulsed magnetic field measurement.

Common-mode noise rejection using fringe-locking method in WEP test by simultaneous dual-species atom interferometers**Project supported by the National Natural Science Foundation of China (Grant Nos. 41127002, 11574099, and 11474115) and the National Basic Research Program of China (Grant No. 2010CB832806).

We theoretically investigate the application of the fringe-locking method (FLM) in the dual-species quantum test of the weak equivalence principle (WEP). With the FLM, the measurement is performed invariably at the midfringe, and the extraction of the phase shift for atom interferometers is linearized. For the simultaneous interferometers, this linearization enables a good common-mode rejection of vibration noise, which is usually the main limit for high precision WEP tests of the dual-species kind. We note that this method also allows for an unbiased determination of the gravity accelerations difference, which meanwhile is ready to be implemented.

Balanced UWB BPF with wideband common‐mode suppression

ABSTRACTIn this letter, a new balanced ultrawideband (UWB) bandpass filter (BPF) is proposed and designed using a slotline resonator (SLR) with radial end‐sections for better wideband response. The SLR is fed by microstrip lines, and the whole BPF circuit is deployed symmetrically across the plane of symmetry to provide balanced operation. When the BPF is excited differentially, the SLR half circuit behaves as a similar resonator of half width, and by locating its first three resonant modes in the passband, the desired UWB response can be achieved. Conversely, while the BPF is in common‐mode (CM) operation, the symmetry plane is virtually open‐circuited, and the SLR is incomplete in structure, rendering CM signal suppression very effective. In this design, bandstop filters are embedded in the feeding lines to increase the upper stopband bandwidth. The achieved performances for this proposed balanced UWB BPF are a 3‐dB fractional bandwidth of 114% and a minimum measured (simulated) in‐band insertion loss of 1.17 (0.92) dB for differential‐mode operation and very good CM rejection with an insertion loss of larger than 25 dB over 1–20 GHz frequency range. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2461–2464, 2015

Simple and Compact Balanced Bandpass Filters Based on Magnetically Coupled Resonators

A simple strategy is proposed to design differential-mode bandpass filters with good common-mode (CM) rejection using simple resonators. Specifically, the CM rejection is enhanced by using conventional open-loop resonators as well as folded stepped-impedance resonators without the addition of printed or lumped elements along the symmetry plane of the filter or the use of defected ground solutions. The novelty of the present proposal is that a good CM rejection is achieved by the use of magnetic coupling instead of the more commonly employed electrical coupling. Magnetic coupling inherently yields poorer CM transmission as requested by good differential filters. The resonators, due to their geometrical simplicity, can easily be cascaded to implement high-order filters. The use of simple geometries also simplifies the design methodology and makes final tuning based on electromagnetic simulation simpler or unnecessary.

The Proper Balance: Overview of Microstrip Wideband Balance Circuits with Wideband Common Mode Suppression

With the development of wireless communication technology, radiofrequency (RF) circuits and integrated circuits are becoming more complex and packing more functionality and signals into an ever closer space, with a high level of electromagnetic interaction between circuit nodes and interference/crosstalk from substrate coupling and free space [1]. Balanced/differential circuit technology has become more important in modern communication systems because of good commonmode rejection that leads to relatively high immunity to environmental noise when compared with the single-ended technology [1]-[3], as shown in Figure 1(a) and (b). For balanced circuits, the differential mode should have excellent out-of-band rejection and high selectivity for the desired frequency band, while the common mode should be suppressed over a wider frequency band. In the past few years, many microstrip balanced filters for single band and dual band with common-mode suppression have been realized [4]-[10], with different balanced networks, balanced driven antennas, balanced amplifiers, and mixers [11]-[18].

A novel via-free microstrip balanced-to-balanced diplexer for narrow-band applications

In this article, a new type of microstrip vias-free balanced-to-balanced diplexer suitable for narrow-band applications is presented. The structure of the balanced diplexer is based on two balanced bandpass filters designed for f1=1.1 GHz and f2=1.8 GHz and two transmission lines used to satisfy the open circuit conditions required in the diplexer's design. This diplexer exhibits good common-mode rejection ratio better than 40 dB at the passbands. The attenuation is better than 35 dB at the rejection bands. The isolation between output ports is better than 50 dB. Simulated and experimental results are compared with good agreement. The diplexer is easy of fabricate and integrate with others planar balanced devices. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:567–570, 2015

DUAL-BAND DIFFERENTIAL FILTER USING BROADBAND COMMON-MODE REJECTION ARTIFICIAL TRANSMISSION LINE

A new balanced dual-band bandpass fllter with strong common-mode rejection is presented in this paper. Common-mode rejection is provided by a section of a periodic microstrip difierential line that behaves as a low-pass fllter under common-mode operation. In contrast, the difierential line exhibits very good all-pass behavior under difierential mode operation. This structure is combined with a difierential dual-band bandpass fllter based on embedded resonators. Simulations and experiments conflrm that the combined structure has good common-mode rejection within the passbands of the dual-band difierential fllter.

AN ULTRA-WIDEBAND BALANCED BANDPASS FILTER BASED ON DEFECTED GROUND STRUCTURES

An ultra-wideband (UWB) balanced bandpass fllter (BPF) is proposed and designed using defected ground structures (DGSs). A multimode resonator on top layer with a coplanar waveguide on bottom layer is used to design a UWB BPF. U-shaped and H-shaped DGSs loaded with capacitor are used to design to provide common mode rejection within a lower band, while a set of dumbbell-shaped DGSs are utilized to provide common mode rejection within an upper-band. The proposed UWB balanced BPF shows the performance of good common mode rejection in and out of the UWB passband.

A 60-GHz Phased Array Receiver Front-End in 0.13-$\mu {\hbox{m}}$ CMOS Technology

This paper presents a fully integrated dual-antenna phased-array RF front-end receiver architecture for 60-GHz broadband wireless applications. It contains two differential receiver chains, each receiver path consists of an on-chip balun, ag <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> -boosted current-reuse low-noise amplifier (LNA), a sub-harmonic dual-gate down-conversion mixer, an IF mixer, and a baseband gain stage. An active all-pass filter is employed to adjust the phase shift of each LO signal. Associated with the proposed dual conversion topology, the phase shift of the LO signal can be scaled to one-third. Differential circuitry is adopted to achieve good common-mode rejection. The g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> -boosted current-reuse differential LNA mitigates the noise, gain, robustness, stability, and integration challenges. The sub-harmonic dual-gate down-conversion mixer prevents the third harmonic issue in LO as well. Realized in a 0.13-mum 1P8M RF CMOS technology, the chip occupies an active area of 1.1 times 1.2 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The measured conversion gain and input P1 dB of the single receiver path are 30 dB and -27 dBm , respectively. The measured noise figure at 100 MHz baseband output is around 10 dB. The measured phased array in the receiver achieves a total gain of 34.5 dB and theoretically improves the receiver SNR by 4.5 dB. The proposed 60 GHz receiver dissipates 44 mW from a 1.2 V supply voltage. The whole two-channel receiver, including the vector modulator circuits for built-in testing, consumes 93 mW from a 1.2 V supply voltage.

Carbon nanotubes vacuum field emission differential amplifier integrated circuits

A novel vacuum field emission differential amplifier integrated circuit (VFE diff-amp IC) utilising carbon nanotube (CNT) emitters is presented. A dual-mask microfabrication process is employed to achieve the VFE diff-amp IC by integrating identical CNT VFE transistors with built-in split gates and anodes. The pair of integrated amplifiers shows low gate turn-on voltage, large DC gain, a reasonable transconductance, and a good common-mode rejection ratio. The approach demonstrates a new way for development of temperature- and radiation-tolerant VFE integrated microelectronics.

An integrated CMOS interface for lambda sensor

Automotive pollution can be reduced by suitably controlling the mixture that is fed to the cylinders. This can be performed by means of a feedback loop including a lambda sond and a processing unit which controls the electronic fuel injectors. This paper describes a CMOS interface which adapts the output signal of a lambda sensor to allow its feeding into the processing unit. It provides a differential to a single-ended conversion with a good common mode rejection, a level shifting around a given reference voltage, and an accurate voltage gain. Both design considerations and the measurements performed on an integrated test structure are presented. The measured variation of the large-signal voltage gain for an input signal of 0 to 1 V is within /spl plusmn/5% when the input common mode voltage ranges from /spl minus/1 V to 1 V with respect to the negative supply voltage. An output voltage with a precision within /spl plusmn/1 mV is obtained in the presence of an input voltage corresponding to the stochiometric composition of the mixture. >

Digital-compatible high-performance operational amplifier with rail-to-rail input and output ranges

This paper presents a CMOS buffer amplifier which operates on a single 5-V power supply. The uniquely symmetrical design adds the following advantages: rail-to-rail linear, symmetrical operation at both the input and output; the output stage allows the use of gate channel capacitors of standard MOSFET's as the compensation capacitor saving die area from 80%/spl sim/93% in a standard single polysilicon digital process; large gain-bandwidth product; high power supply rejection ratio; good common-mode rejection ratio; and easy compact layout suitable for design automation (layout as a parametric cell, allows easy adaption to changing processes). The buffer is capable of driving 300 /spl Omega//spl par/100 pF with a loaded gain-bandwidth product of more than 4 MHz and a fully loaded slew rate of greater than 4 V//spl mu/S. >

An autoprotecting gate drive circuit for GTO thyristors

The authors present a gate drive circuit for gate turn-off thyristors which provides the combined functions of reliable switching, overcurrent protection to the device through on-state voltage monitoring, self-protection of the drive circuit by isolation against damage due to high voltage in the event of gate turn-off destruction, and galvanic isolation with good common mode rejection. The implementation details of the drive circuit used in conjunction with a gate turn-off thyristor chopper are included.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A fiber-optic interferometric seismometer

A fiber-optic interferometric sensor has been developed which consists of a seismic mass of 520 gm supported by two rubber mandrels, each wound with a single layer of single-mode optical fiber 6.5 m long. One end of each fiber is cleaved to enhance reflection. The other ends are interconnected via a fiber-to-fiber 3-dB coupler, forming a Michelson interferometer. When the case of the sensor is displaced, the fiber around one mandrel extends in length while the other contracts. The resulting "push-pull" mechanical operation of the sensor allows both legs of the interferometer to be active, providing good common mode rejection of spurious effects, as a reference leg is not required. This, together with the fact that the light traverses each leg of a Michelson interferometer twice due to reflection, provides the sensor with four times the sensitivity of a conventionally constructed interferometric sensor. Sensitivities of 8500 rad of optical phase shift per micrometer of case displacement have been measured above the mass-spring resonance, where the sensor operates as a seismometer. Below resonance the sensor operates as an accelerometer with a measured sensitivity of 10 500 rad/g, the highest reported to date. Including both thermodynamic and demodulator noise sources ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\approx 10 \mu</tex> rad/ <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\sqrt{Hz}</tex> ), below resonance the sensor has a detection threshold of 1 ng/ <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\sqrt{Hz}</tex> , a 20- dB improvement over the best existing conventional low noise vibration sensors.

Low-Noise, Wide-Band, Current-Pulse Preamplifiers for Neutron Counters

An improved, low-noise, wide-band current preamplifier was developed for use with a fission counter having a 100-nsec electron collection time. The signal-to-noise ratio of the preamplifier and its insensitivity to component parameter variations and temperature changes exceed that of any commercially available unit. A differential version was developed to exploit the balanced configuration of the counter. A 20% improvement in signal-to-noise ratio was obtained with good common-mode rejection from 50 kHz to 30 MHz.