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The images captured by a plane-array type infrared detector, formed by integrating a large-scale probe array and readout circuits via interconnection, is distorted by two types of superimposed nonuniform noises caused by the probe and readout circuitry. These nonuniform noises arise from the detector's constituent materials, fabrication processes, and other defects. In addition, the output response of an infrared detector is limited by the dynamic range of the circuit, the low and high ends of the output signal exhibit strong nonlinearities. To overcome the impact of detector response nonlinearity and achieve simultaneous correction for two different types of nonuniformities in infrared images, in this study, we proposed a novel correction method. First, the pixel points of all images are reordered according to their pixel values to provide a uniform reorganisation data. Then, the linear correlated region based on the recombined data is extracted using a judgment algorithm that processes the linear correlations of multiple regions to simulate the detector's response curve and find the nonuniformity correction coefficient of each pixel. Experiments on simulated noisy and real images show that our method accurately eliminates nonuniform IR noise without causing blurring and provides optimal peak signal-to-noise ratio and structural similarity.

The recording and analysis of biomagnetic fields have widespread applications in medical research and diagnostics. Wearable magnetic field sensors offer a noncontact and portable method for sensing biopotentials. This article presents a readout circuit in 180-nm CMOS for strain-modulated multiferroic vector magnetic field sensors. By utilizing a demodulator-first architecture, the circuit bandwidth and dynamic range requirements are greatly reduced allowing for a low power consumption of 5.9 mW. The circuit bandwidth is from 76 mHz to 2.2 kHz, allowing for measurement across the range of interest for biomagnetic signals. Utilizing a modulation noise cancellation technique, the noise performance of the sensor system is significantly improved, and the sensor modulation amplitude can be increased, resulting in improved sensor sensitivity. Measurements for the sensor-readout system demonstrate a 144 pT/ $\surd $ Hz magnetic noise floor at 1 kHz. The noise and power consumption are significantly lower than alternative magnetic sensor systems of similar volume.

Deep brain stimulation (DBS) devices capable of measuring differential local field potentials ( $\partial $ LFP) enable neural recordings alongside clinical therapy. Efforts to identify oscillatory correlates of various brain disorders, or disease readouts, are growing but must proceed carefully to ensure readouts are not distorted by brain environment. In this report we identified, characterized, and mitigated a major source of distortion in $\partial $ LFP that we introduce as mismatch compression (MC). Using in vivo, in silico, and in vitro models of MC, we showed that impedance mismatches in the two recording electrodes can yield incomplete rejection of stimulation artifact and subsequent gain compression that distorts oscillatory power. We then developed and validated an opensource mitigation pipeline that mitigates the distortions arising from MC. This work enables more reliable oscillatory readouts for adaptive DBS applications.

Deep brain stimulation (DBS) devices capable of measuring differential local field potentials ($\partial $ LFP) enable neural recordings alongside clinical therapy. Efforts to identify oscillatory correlates of various brain disorders, or disease readouts, are growing but must proceed carefully to ensure readouts are not distorted by brain environment. In this report we identified, characterized, and mitigated a major source of distortion in $\partial $ LFP that we introduce as mismatch compression (MC). Using in vivo, in silico, and in vitro models of MC, we showed that impedance mismatches in the two recording electrodes can yield incomplete rejection of stimulation artifact and subsequent gain compression that distorts oscillatory power. We then developed and validated an opensource mitigation pipeline that mitigates the distortions arising from MC. This work enables more reliable oscillatory readouts for adaptive DBS applications. [ABSTRACT FROM AUTHOR]

The biochemical processes in the body, including wound healing, are influenced by pH. When skin is damaged, in the inflammation phase, the pH of the skin is under pH 6.0, and in the granulation and spontaneous reepithelization phase, the pH of the skin oscillates between 6 and 8. If there is a frequent change in the wound dressing, it will make the damage to the skin hard to cure, especially for chronic wounds. In this article, we design and implement a highly sensitive micro-electro-mechanical-system (MEMS) cavity-based pH image biosensor of a $100\times100$ array with an integrated readout circuit in a CMOS bulk technology. Based on the proposed pH fringing electrical field model, we predict and optimize the performance of the proposed sensor pattern with cavity structure for operation frequency and various pH ions. The proposed pH biosensor with MEMS cavity structure exhibits a high sensitivity of 201 mV/pH, low drift voltage over time of 2.08 mV, a fast response time of 5 s, high precise repetition of 98.9%, and a pH image of 20 frame rate/s. Since the sensor is a $100\times100$ array, it displays a detailed change in the pH image of wound exudate to identify the inflammation stage under pH 6 or spontaneous reepithelization above pH 6 to indicate the need to change the dressing, reducing the clinician’s wasted resources on frequency change of wound dressings. [ABSTRACT FROM AUTHOR]

Objective: The objective of the paper is to present a novel systematic approach for the design and development of a portable, low-voltage low-power resistive sensor measurement system with high sensitivity. The goal of the proposed system is to be able to measure the $\Delta {R}/{R}_{s}$ for a wide range of baseline resistance of sensor ${R}_{s}$ ($1 {k}\Omega $ to $1 {M}\Omega $ i.e. 3 orders of magnitude) with high resolution and programmable sensitivity. Method: An auto-calibrated resistive sensor interface using a novel half-bridge based circuit is presented. The square-wave excitation and square-wave demodulation technique are utilised to reduce the power consumption of the proposed technique. Moreover, the sensitivity of the system is fully auto-calibrated for a wide range of base resistors. Results: With a supply voltage of 3.3 V and bandwidth of 10 Hz, the developed system is able to measure a minimum $\Delta {R}/{R}_{s}$ of about 20 ppm for $100 {k}\Omega $ base resistance. Overall, the power consumption of the developed system is 36.3 mW (for four channels). Significance: The system is useful for low-voltage low-power sensor nodes as a highly sensitive readout for the resistive sensor arrays. In addition, the developed system is useful for the stain sensors in the development of flexible hybrid electronics for wearable applications. [ABSTRACT FROM AUTHOR]

This article presents a fully integrated Cryo-CMOS system on chip (SoC) for quantum computing. The proposed SoC integrates a radio frequency (RF) pulse modulator for qubit state manipulation, a multi-tone signal generator and a coherent receiver for qubit state readout, and 22 DACs for high-speed voltage pulsing of qubit gates. By adopting frequency division multiplexing and direct digital synthesis (DDS), the RF pulse modulator can control up to 16 qubits over a single RF line, and the readout receiver can detect the state of up to six qubits simultaneously. The proposed SoC also integrates a microcontroller for low latency on-chip signal processing and increased flexibility in implementing quantum instruction sets. A detailed analysis of qubit-state readout fidelity and the impact of finite DAC resolution on two-qubit gate fidelity is also included in this article, together with an electrical specification summary. The SoC is implemented in Intel’s 22 nm FFL fin field-effect transistor (FinFET) process, and it is characterized both at room and 4 K temperatures. The performance of each specific block is measured, with the readout characterized in a loop-back configuration. Generation of the control signals required for a full Rabi oscillation experiment is also demonstrated. This article also describes the cryogenic thermalization techniques used to integrate the SoC in the dilution refrigerator and shows temperature measurements during operation. [ABSTRACT FROM AUTHOR]

The new LHCb Vertex Locator (VELO) for LHCb, comprising a new pixel detector and readout electronics, will be installed in 2021 for data taking in Run 3 at the LHC. The electronics centers around the “VeloPix” ASIC at the front-end operating in a trigger-less readout at 40MHz. A custom serializer, called gigabit wireline transmitter (GWT), and associated custom protocol have been designed for the VeloPix. The GWT data are sent from the serializers of the VeloPix at a line rate of 5.12 Gb/s, reaching a total data rate of 2–3 Tb/s for the full VELO detector. Data are sent over 300-m optic-fiber links to the control and readout electronics cards for deserialization and processing in Intel Arria 10 FPGAs. Because of the VeloPix trigger-less design, latency variances up to 12 $\mu \text{s}$ can occur between adjacent datagrams. It is therefore essential to buffer and synchronize the data in firmware prior to onward propagation or suffer a huge CPU-processing penalty. This article will describe the architecture of the readout firmware in detail with focus given to the resynchronization mechanism and techniques for cauterization. Issues found during readout commissioning, and scaling resource utilization, along with the their solutions, will be illustrated. The latest results of the firmware data-processing chain can be presented as well as the verification procedures employed in simulation. Challenges for the next generation of the detector will also be presented with ideas for a readout processing solution. [ABSTRACT FROM AUTHOR]

Surface roughness that is an inherent character of deposited films determines contact resistance at layer interfaces and thus may play a critical role in write and readout operations of phase-change electrical probe memory comprising multiple stacked layers. The surface roughness of different layered components was therefore simulated and their impact on resulting temperature, write/read current, and bit size was evaluated. It was revealed that using capping layer with larger root-mean-square and denser roughness significantly decreases the temperature and write/read current, and therefore forms a written bit embedded inside the active layer, while surface roughness of active layer, bottom electrode, and substrate have a negligible effect on electro-thermal characteristic and phase-transformation extent of the probe memory. To trigger optimum readout current and exempt from tip wear, probe tip was suggested to penetrate into the capping layer by 0.2 nm for the densest roughness of 3 nm root-mean-square.

In this paper we present a $\mu $ -Coriolis mass flow sensor with differential capacitive readout, which can reduce the effect of common mode vibrations caused by external disturbances. The device consists of two silicon nitride micro-channel loops mechanically connected through two membranes. The sensor is actuated using Lorentz forces, inducing rotation of the sensor’s micro-channels. Coriolis forces of opposite sign are subsequently generated in the two channel loops. Thus, any common mode vibration can be distinguished from vibration induced by mass flow through the channels. Capacitive readout structures surround the sensor to detect these vibrations. A piezo-electric resonator is placed in close proximity to the sensor to generate artificial external disturbance. Flow measurements are executed to compare the differential readout method to a single ended readout with and without external disturbances. The flow sensitivity is unaffected. However, the mean deviation of the output signal is 60-70% lower when using the differential readout compared to single ended readout when external disturbances are induced. The effect of external disturbances on the zero flow stability is reduced by approximately 64% by using the differential readout. Full elimination of the effect is not possible due to non-linearity of the readout capacitors. Reducing non-linearity of the readout could further improve performance, e.g. by implementing (piezo-resistive) strain gauges on top of the micro-channel. [ABSTRACT FROM AUTHOR]

This article proposes a new technique to reduce the readout noise in charge-coupled devices (CCDs). The objective is to minimize the common noise between the channels. This noise is either induced by the readout electronics or by the environment, and it could be present in small (single CCD and a few channels) or large systems (dozens of CCDs and hundreds of channels). By interleaving the video signals, we show that it is possible to reduce the readout noise by around 50% without sacrificing output channels at the expense of a moderate increase of the readout time, which is less compared with other techniques. Up until now, similar approaches have used half of the output stages only for noise measurement doubling the total readout time of the sensor. Simulations and experimental results are presented to validate the proposed approach. Moreover, the technique is measured using a Skipper CCD, and its operation is validated together with the ability of the Skipper sensor for nondestructively reading, several times, the same pixel charge. With the combination of both techniques, we achieve deep subelectron readout noise levels (0.1 e−). [ABSTRACT FROM AUTHOR]

The Jiangmen Underground Neutrino Observatory (JUNO) is a next-generation experiment designed to study the neutrino mass hierarchy, one of the open questions in particle physics. The entire experimental system includes the detector system, the electronics system, and the data acquisition (DAQ) system. Dataflow is the core of JUNO DAQ system. Readout system and event building (EB) system are two key aspects of dataflow. Based on the requirements analysis of JUNO DAQ, this paper proposes a data-flow schema of distributed network readout and second-level EB. Focusing on the performance requirements of JUNO DAQ, the performance of the readout and EB module, the number of readout processes and EB processes deployed on each node, the ratio of readout nodes and EB nodes, and scalability of the two modules are discussed in detail. The results of the research provide a reference for further optimization of the JUNO DAQ data-flow framework. [ABSTRACT FROM AUTHOR]

The achievable acquisition rates of modern triggered nuclear physics experiments are heavily dependent on the readout software, in addition to the limits given by the utilized hardware. This paper presents an asynchronous readout scheme that significantly improves the livetime of an otherwise synchronous triggered Versa Module Eurocard Bus-based data acquisition system. A detailed performance analysis of this and other readout schemes, in terms of the basic data transfer operations, is described. The performance of the newly developed scheme as well as synchronous schemes on two systems has been measured. The measurements show excellent agreement with the detailed description. For the second system, which previously used a synchronous readout, the deadtime ratio is at a 20-kHz trigger request frequency reduced by 30% compared to the nearest contender, allowing 10% more events to be recorded in the same time. The interaction between the network and readout tasks for single-core processors is also investigated. A livetime ratio loss of a few percents can be observed, depending on the size of the data chunks given to the operating system kernel for network transfer. With appropriately chosen chunk size, the effect can be mitigated. [ABSTRACT FROM AUTHOR]

New design studies have been carried out for a readout plane for gas electron multiplier detectors using zigzag patterns that can significantly reduce the readout channel count while preserving excellent spatial resolution for tracking detectors. While zigzag patterns have been used in a number of applications, these studies were designed to investigate the fundamental limits of charge sharing between the electrodes to optimize the spatial resolution and minimize the nonuniformities across the readout plane, while exploring the limits of manufacturing capabilities for producing the readout board. Simulation studies were carried out to optimize the readout electrode structure, and readout boards were produced with similar zigzag designs that were tested in the laboratory using a scanning X-ray source. These studies were aimed at developing a readout board for the new time projection chamber for the sPHENIX experiment at relativistic heavy ion collider, but can readily be used in other applications, including various micropattern gas detectors, such as Micromegas. [ABSTRACT FROM AUTHOR]

In order to read out current signals from large-scale arrays of transition edge sensors (TES), microwave SQUID multiplexers (MW-MUX) have been developed by several groups. Reduction of crosstalk induced in the multiplexer is important in order to maintain the energy resolution or the noise equivalent power of detector arrays. In the present study, crosstalk between channels in MW-MUX with five different designs is experimentally evaluated. The resonance frequency separation is ten times as large as the resonator bandwidth. Without flux-ramp modulation, crosstalk between two adjacent channels neighboring in position decreases to ≍1 × 10–3 with increasing resonance frequency separation to ≍100 MHz. Crosstalk between SQUID channels neighboring in resonance frequency also decreases to 4 × 10–3 with increasing the distance to 2.5 mm. We show that nonlinear error can occur due to the crosstalk with flux-ramp modulation. Flux readings from a well-designed multiplexer exhibit crosstalk of less than 1 mΦ0 peak-to-peak and nonlinear errors of less than 2 mΦ0 peak-to-peak, which is sufficient for the readout of the gamma-ray TES arrays being developed. These results can provide guidelines for suppressing both the crosstalk and the nonlinear error to less than the criterion of TES spectrometers with typical energy-resolving ability. [ABSTRACT FROM PUBLISHER]

We present the first measurement results of a highly scaled, 90-nm silicon–germanium heterojunction bipolar transistor (SiGe HBT) operating at cryogenic temperatures as low as 70 mK. The SiGe HBT exhibits a transistor-like behavior down to 70 mK, but below 40 K, the transconductance suggests the presence of non-equilibrium transport mechanisms. Despite the non-ideal base current at cryogenic temperatures, a $dc$ current gain (\beta) > 1$ is achieved for I_{C} > 1 nA, suggesting that ultra-low-power low-noise amplifiers should be viable. Exposure of the SiGe HBT to strong magnetic fields (±14 T) is also presented to help understand the nature of the non-ideal current. [ABSTRACT FROM PUBLISHER]

Capacitive sensors have profoundly found their way in everyday life. Devices and instrumentation ranging from specialty equipment to smartphones all employ in one way or the other a capacitive sensor and its associated readout circuit, making the latter ubiquitious. We present a capacitive readout system that automatically adapts its range to the unknown measured capacitance, thereby extending its functional input range, as well as its application and instrumentation compatibility. The proposed system achieves a constant resolution for a range of input capacitance up to 690 pF. [ABSTRACT FROM AUTHOR]

Resistive sensor arrays have been increasingly adopted in wearable electronic applications, which require low-complexity and low-energy circuits. However, current readout strategies for resistive sensor arrays require additional electrical components, such as transistors, diodes, multiplexers, op-amps, switches, current sources, and A/D converters, leading to a considerable increase in circuit complexity, power consumption, system instability, and crosstalk error. To address the problem, this paper proposes a new approach, which determines sensor resistance values by establishing and solving resistance matrix equations of sensor arrays. Unlike conventional approaches, it allows crosstalk currents in arrays to avoid additional components that are originally used for eliminating crosstalk currents and minimizing crosstalk error. Meanwhile, it takes advantage of on-chip resources of wearable platforms, thereby reducing redundant chips. It was implemented on a prototype of 10 × 10 textile resistive sensor array, which was taken in a sensing cushion for sitting pressure monitoring of chair bound people. Experimental results on this array platform showed the new approach achieved a satisfactory accuracy (0.61% ± 0.41%), as well as a low crosstalk error (2.77% ± 0.61%). The fabricated sensing cushion also exhibited a relatively low pressure measurement error (6.30% ± 0.75%). Compared with other approaches, the proposed approach demonstrated the lowest circuit complexity on a microcontroller based wearable platform, and a sufficient sensor capacity. It is ideal for a wide range of applications like wearable or implantable sensing, presenting a reference for the design of low-complexity and low-crosstalk error wearable systems based on resistive sensor arrays. [ABSTRACT FROM PUBLISHER]

In this paper, we describe a new neuro-inspired, hardware-friendly readout stage for the liquid state machine (LSM), a popular model for reservoir computing. Compared to the parallel perceptron architecture trained by the p-delta algorithm, which is the state of the art in terms of performance of readout stages, our readout architecture and learning algorithm can attain better performance with significantly less synaptic resources making it attractive for VLSI implementation. Inspired by the nonlinear properties of dendrites in biological neurons, our readout stage incorporates neurons having multiple dendrites with a lumped nonlinearity (two compartment model). The number of synaptic connections on each branch is significantly lower than the total number of connections from the liquid neurons and the learning algorithm tries to find the best ‘combination’ of input connections on each branch to reduce the error. Hence, the learning involves network rewiring (NRW) of the readout network similar to structural plasticity observed in its biological counterparts. We show that compared to a single perceptron using analog weights, this architecture for the readout can attain, even by using the same number of binary valued synapses, up to 3.3 times less error for a two-class spike train classification problem and 2.4 times less error for an input rate approximation task. Even with 60 times larger synapses, a group of 60 parallel perceptrons cannot attain the performance of the proposed dendritically enhanced readout. An additional advantage of this method for hardware implementations is that the ‘choice’ of connectivity can be easily implemented exploiting address event representation (AER) protocols commonly used in current neuromorphic systems where the connection matrix is stored in memory. Also, due to the use of binary synapses, our proposed method is more robust against statistical variations. [ABSTRACT FROM PUBLISHER]

The 4th-generation readout system based on VAS_UM/TAT4 ASICs for 3-D position sensitive CdZnTe/HgI2 detector arrays has been developed and tested. Each VAS_UM/TAT4 chip is a 129-channel self-triggered monolithic Application Specific Integrated Circuit (ASIC). One 3-D position-sensitive detector module consists of one CdZnTe or HgI2 gamma-ray spectrometer, and one VAS_UM/TAT4 ASIC mounted on a 2.2 cm × 2.2 cm front-end board. Each detector has an array of 11 by 11 pixel anodes fabricated on the anode surface with an area up to 2 cm × 2 cm. The detector and the front-end board are connected by three pairs of 42-pin connectors for easy assembly and component replacement. Up to nine detector modules can be plugged into a single motherboard to form a 3 by 3 detector array. The VAS_UM/TAT4 chip can read out both the amplitude of induced charge on each electrode and the electron drift time needed for reconstructing energy deposition and three-dimensional coordinates of each radiation interaction. Three different sets of VAS_UM/TAT4 chips with different dynamic ranges and shaping times were fabricated for gamma-ray spectroscopy in CdZnTe and HgI2. These are the first ASIC readout systems that allow multiple 3-D position sensitive CdZnTe/HgI2 detector modules to be tiled together, to achieve a detection volume greater than 50 cm³ on a single detector plane. Multiple planes of detector arrays can be operated together to achieve more than 100 cm³ detection volume on a single system. In this paper, the VAS_UM/TAT4 ASIC systems are described and their test results are reported. [ABSTRACT FROM AUTHOR]

Optical technology was early proposed to attain information density higher than 10 Gb/in2 with fast data transfer for storage of video, audio, or computer data either using holography or bit-by-bit memory architectures. We present how the concepts and technological issues have progressed at THOMSON-CSF and in other laboratories for the demonstration of an optical pickup enabling the readout of a 30-min TV program recorded as microtips on a spinning disc. The main technical breakthroughs are presented until first commercial success was achieved with the compact optical audio disc (CD) and evolution toward the optical CD-ROM and the DVD. Future research directions for achieving extremely high capacity in a compact system are also discussed [ABSTRACT FROM PUBLISHER]

The obtainable spatial resolution of a scanning SQUID microscope depends among others on the effective SQUID area. An effective area of only a few /spl mu/m/sup 2/ is desirable as it allows for a spatial resolution of a few /spl mu/m. SQUIDs with conventional tunnel junctions are not suitable for this task, since tunnel junctions usually have a relatively large area and are therefore sensitive to magnetic fields themselves. A SQUID with nanobridges as weak links provides very small junction areas of below 0.1 /spl mu/m/sup 2/. When making use of the thermal hysteresis in the I-V-characteristics of these bridges, a SQUID relaxation oscillator can be realised. In such a self-oscillating SQUID (SOS) the oscillation frequency depends periodically on the applied magnetic flux. By reading out the frequency change instead of a voltage change, a simple and compact SQUID readout results. As a first application of such micro-SQUIDs, a scanning SQUID microscope was built and the magnetic field of a nickel tip with 100 nm apex radius was measured. [ABSTRACT FROM PUBLISHER]

In the current generation of high-T/sub c/ bolometers the thermal conductance is often chosen for a short time-constant rather than for optimal sensitivity. We describe a novel bolometer bias and readout scheme that promises to relax this constraint. Voltage bias of the superconductor results in strong negative electrothermal feedback that greatly reduces the time-constant of the bolometer. We estimate that a decrease of more than one order of magnitude in time-constant should be possible with existing high-T/sub c/ thermometers. We give theoretical estimates of the performance gain with voltage bias for several bolometers that have been reported in the literature. We find cases where the sensitivity can be greatly improved (by changing the thermal conductance) while holding the time constant fixed and others where the bolometer can be made much faster while maintaining the sensitivity. [ABSTRACT FROM PUBLISHER]