Design Of Preamplifier Research Articles

Design and Testing of a Fast-Response Preamplifier

This article presents the design of a high-speed, low-noise preamplifier specifically intended for amplifying high-frequency weak electrical signals. Firstly, a thorough analysis was conducted on common types of preamplifiers, and it was proposed to adopt a charge-sensitive preamplifier as a solution for signal output amplification. Subsequently, a specific circuit was carefully designed and thoroughly analyzed to ensure it meets the strict requirements of low noise and nanosecond-level response. To verify the feasibility of the designed amplification circuit, an actual circuit board was fabricated and electronic tests were conducted. The test results revealed that the electronic noise of the amplifier was only 5mV, and the signal response time was within 5ns, fully demonstrating its excellent performance.

Enhancing Preamplifier Design for Acoustic Emission Detection Instrument

With the development of the industry, the safety of pressure vessels is crucial for both production and personnel safety. The application of acoustic emission testing technology as a dynamic non-destructive testing method in the detection of pressure vessels is becoming increasingly prevalent. This paper presents the design of a low-frequency acoustic emission preamplifier with a frequency range of 30KHz to 200KHz and a gain of 20dB. The preamplifier is composed of amplification circuits, power supply circuits, and filtering components. By utilizing the PXR04 series high-sensitivity resonant acoustic emission sensor and Texas Instruments' OPA333 operational amplifier, along with a clever power supply design, effective signal amplification and system stability are ensured. Experimental results validate the correctness of the design, providing a feasible and effective solution for enhancing the performance of acoustic emission testing equipment.

Optimizing hydrophone-preamplifier systems: Theoretical design, computational analysis, and experimental validation for towed array applications

Hydrophone response parameters greatly influence the design of pre-amplifier and analog to digital conversion (ADC) components. Here, we show a comprehensive methodology for the modeling of hydrophone response, focusing on the theoretical, computational, and experimental approach for low and high frequency SONAR applications. Theoretical calculation of hydrophone response based on electromechanical properties is compared with Finite Element Analysis (FEA) and experimental measurement. An electrical equivalent hydrophone simulator Butterworth-Van Dyke (BVD) circuit is constructed based on admittance and susceptance measurements to represent the transducer's electrical behavior for testing pre-amplifier and ADC response without the presence of environmental or hydrophone noise. This model facilitates a systematic approach to towed array front-end design with hardware in the loop to update models to improve performance prediction. Measurements of the constructed transducer system validate the theoretical and computational models, providing insights into real-world performance.

Photomultiplier Tubes for Programmable Logic Controller Foreign Object Sorting System and Its Performance Analysis

The photoelectric foreign object sorting system is a comprehensive device developed to remove foreign objects from target substances, integrating photoelectric, computer, and mechanical technologies. This system combines photoelectric, computer image, and mechanical technologies to identify materials based on color and appearance, utilizing the scattered light returned from the scanned object for detection and recognition. This work designs a photoelectric foreign object sorting system for food and tobacco. This system takes photomultiplier tubes as the main photoelectric devices and a programmable logic controller (PLC) as the control unit. The hardware components of this system include the design of a low-noise preamplifier, conditioning circuit, ADC data acquisition module, and PLC-external circuit connections. In simulation experiments, testing is conducted on the low-noise preamplifier, considering the significant impact of the collected signals on subsequent analysis. Amplitude-frequency and phase-frequency tests show that the circuit signal output of this module is stable. There are no oscillations in the time domain, and no occurrences of overshooting or ringing in frequency. The noise indicates that the signal noise of this module is relatively low. During the debugging process, ADA4896 is selected, and a black-and-white alternating stripe with a 3 mm spacing is used as the scanning object. As expected, the first-stage amplification results of the low-noise preamplifier show a range of 2 mV with some DC components in the output voltage. In its second-stage amplification, the fine scale reaches 10 mV, and the output signal can represent the physical characteristics of the scanned object.

Design of Preamplifier for Ultrasound Transducers

In diagnostic ultrasound imaging applications, preamplifiers are used as first-stage analog front-end amplifiers for ultrasound transducers because they can amplify weak acoustic signals generated directly by ultrasound transducers. For emerging diagnostic ultrasound imaging applications, different types of preamplifiers with specific design parameters and circuit topologies have been developed, depending on the types of the ultrasound transducer. In particular, the design parameters of the preamplifier, such as the gain, bandwidth, input- or output-referred noise components, and power consumption, have a tradeoff relationship. Guidelines on the detailed design concept, design parameters, and specific circuit design techniques of the preamplifier used for ultrasound transducers are outlined in this paper, aiming to help circuit designers and academic researchers optimize the performance of ultrasound transducers used in the diagnostic ultrasound imaging applications for research directions.

A 87 dB SNR and THD+N 0.03% HiFi Grade Audio Preamplifier

This paper presents a significant contribution to high-fidelity audio technology through the comprehensive design and implementation of an advanced audio-grade preamplifier integrated with a high-performance digital-to-analog converter (DAC). The versatility of the digital section allows seamless integration of audio sources from Universal Serial Bus (USB), Bluetooth, or Sony-Philips Digital interface (SPDIF). In addition, the preamplifier accommodates various analog sources, offering flexibility to users. The unique architecture features an innovative resistor network-based DAC and precision components in the analog section, paving the way for achieving unparalleled audio fidelity. The measured distortion values are remarkably low, with a total harmonic distortion plus noise (THD+N) of only 0.03%. Furthermore, the system exhibits a signal-to-noise ratio (SNR) of 87 dB, comparable to industry benchmark. The hardware design sections went into meticulous details, providing an in-depth exploration of each block of the project. The inclusion of test and measurement data from the actual prototype enhances the credibility of the proposed work. This research not only showcases the theoretical operation of the preamplifier and DAC stage but also validates the practical implementation through many rounds of testing and validation. Our proposed work contributes to the field of high-fidelity audio by presenting a novel solution that is comparable to industry standards. The design’s adaptability to many different audio sources, coupled with robust performance metrics, positions it as a benchmark in the field of audio reproduction. The measurement results and findings presented in this paper are poised to influence future advancements in HiFi audio technology.

Design of a Thick Gas Electron Multiplier based photon pre-amplifier

In this paper we present the design of a photon pre-amplifier based on a photo-cathode coated Thick Gas Electron Multiplier (THGEM). Such device is crucial in application where a weak light signal produced in a radiation detector must be amplified so that it can be carried to a photo-detector by means of optical fibres. An example of a device where a light signal must be amplified is a gamma-ray Cherenkov detector for fusion power measurements in magnetic confinement devices. In such application the active part of the detector must be located very close the plasma, typically in a harsh radiation environment where standard photodetectors cannot operate. The photon pre-amplifier allows to increase the signal generated in the active part of the detector so that it can be easily detected by the photodetector located outside the harsh environment. We present the conceptual design of a THGEM based photon pre-amplifier supported by Garfield++ simulations. The device working principle is the following: primary photons impinge on the photo-cathode and extract electrons that are accelerated by the THGEM electric field. Upon collisions with the accelerated electrons, the gas molecules in the pre-amplifier are brought to excited states and de-excite emitting scintillation photons. Since each electron excites multiple gas molecules, the scintillation photons outnumber the primary photons, leading to the amplification. In addition, we present the first observation of measurements of Nitrogen gas scintillation in a THGEM device. We devised an experimental setup consisting of a vacuum chamber containing a THGEM and an alpha particle source. The vacuum chamber is filled with pure nitrogen and is coupled to a photomultiplier tube via a view-port to detect the scintillation photons generated in the THGEM. For sake of simplicity the electrons that induce the scintillation are generated by the ionization track of an alpha particle rather than by the THGEM photo-cathode coating. A good qualitative agreement between simulations and experiment has been found, however no quantitative conclusions can be made due to the lack of N2 excitation cross sections in the Garfield++ code.

Design of Radiation Resistant Pre-amplifier for fusion reactors

The research of controlled nuclear fusion is not a simple process. The upcoming accomplishment of ITER means the beginning of a new phase of controlled nuclear fusion, which is building a fusion reactor. The operating electronics related to fusion reactors need to adapt to harsh environment and minimize the risk of any possible irradiation. Pre-amplifiers are widely used for signal conditioning in various diagnostic systems. And if not shielded, they would be easily damaged in a environment with strong radiation. In this study, a kind of Radiation Resistant Pre-amplifier (RRP) has been designed and manufactured. To verify its performance under radiation, tests in both gamma and neutron fields were carried out. And the performance of RRP is compared with that of an Ordinary Pre-amplifier (OP). The RRP was irradiated with gammas from a Co-60 source up to an accumulated dose of 1MGy, and was also irradiated with neutrons under a tandem accelerator up to a total neutron flux of 1013 n/cm2. The test results prove a performance improvement of radiation hardness on the RRP. And shielding optimization has been discussed with the circumstances of ITER port cell area in this paper. The RRP could better adapt to the complex irradiation environment of fusion reactors and possibly reduce shielding in the future.

Analysis and Design of a Microphone Preamplifier for Mobile Applications

A design of an on-chip ac-coupling preamplifier for mobile applications is presented. A microphone preamplifier should have a large input impedance to mitigate the effective-gain reduction caused by the microphone’s non-zero output impedance. From a review of previously reported microphone preamplifier structures in terms of input impedance, feasibility of on-chip ac-coupling, and noise performance, we chose an inverting amplifier structure with capacitive feedback. In addition, to provide dc bias path, we used off-state MOSFET switches as pseudo-resistors of very large resistance in the giga-ohm range. The large resistance enables on-chip ac-coupling with sufficient noise performance. A fast start-up is achieved by turning-on the switch for a short period during the preamplifier start-up. The gain of the preamplifier can be programmed from 0 dB to 21 dB with 3 dB steps. A 2-stage pseudo-class-AB amplifier was adopted to reduce power consumption. The proposed preamplifier was implemented using a 28 nm CMOS process and achieves 107 dB dynamic range in a 20 kHz bandwidth under 0 dB gain setting and balanced differential input signal. The preamplifier dissipates a power of 270 μW with a 1.8 V supply.

Design of Receiver Preamplifier with Bandwidth Adjustment Capabilities

Design of Receiver Preamplifier with Bandwidth Adjustment Capabilities

Design and Construction of Novel Instrumentation for Low-Field MR Tomography

Abstract Magnetic resonance imaging (MRI) is a very popular tool for diagnostic applications and research studies. Low-field MR scanners, usually with an open design, are suitable for claustrophobic and obese patients, as well as for children, who may be fearful in closed MR scanners. However, these types of scanners provide lower spatial resolution and a lower signal-to-noise ratio (SNR) if compared with the same examination performed at the same time at high field scanners. It is dominantly caused by the low field strength and other factors, such as radiofrequency noise. Therefore, a long measurement time is usually necessary. This research paper is focused on the development of novel probes and preamplifiers for low-field MR scanners to improve SNR, and thus, shorten the measurement time. In this study, we describe the design of a high impedance preamplifier and a high temperature superconductor (HTS) coil. This novel instrumentation was compared with uncooled and cooled copper coils. Improvement in SNR in the case of an HTS coil is reported.

Design and experimental demonstration of a high conversion efficiency OPCPA pre-amplifier for petawatt laser facility

We present the design and experiment of a broadband optical parametric chirped-pulse amplifier (OPCPA) which provides high conversion efficiency and good beam quality at 808 nm wavelength. Using a three-dimensional spatial and temporal numerical model, several design considerations necessary to achieve high conversion efficiency, good beam quality and good output stability are discussed. To improve the conversion efficiency and broaden the amplified signal bandwidth simultaneously, the nonlinear crystal length and OPCPA parameters are analyzed and optimized with the concept of dissipating amplified idler between optical parametric amplification (OPA) of two crystals configuration. In the experiment, an amplifier consisting of two OPCPA stages of ‘L’ type configuration was demonstrated by using the optimized parameters. An amplified signal energy of 160 mJ was achieved with a total pump-to-signal efficiency of 35% (43% efficiency for the OPCPA stage 2). The output bandwidth of signal pulse reached 80 nm and the signal pulse was compressed to 24 fs. The energy stability reached 1.67% RMS at 3% pump energy variation. The optimized OPCPA amplifier operates at a repetition rate of 1 Hz and is used as a front-end injection for the main amplifier of SG-II 5PW laser facility.

A High Sensitivity Preamplifier for Quartz Tuning Forks in QEPAS (Quartz Enhanced PhotoAcoustic Spectroscopy) Applications.

All the preamplifiers dedicated for Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS) applications that have so far been reported in the literature have been based on operational amplifiers working in transimpedance configurations. Taking into consideration that QEPAS sensors are based on quartz tuning forks, and that quartz has a relatively high voltage constant and relatively low charge constant, it seems that a transimpedance amplifier is not an optimal solution. This paper describes the design of a quartz QEPAS sensor preamplifier, implemented with voltage amplifier configuration. Discussion of an electrical model of the circuit and preliminary measurements are presented. Both theoretical analysis and experiments show that use of the voltage configuration allows for a substantial increase of the output signal in comparison to the transimpedance circuit with the same tuning fork working in identical conditions. Assuming that the sensitivity of the QEPAS technique depends directly on the properties of the preamplifier, use of the voltage amplifier configuration should result in an increase of QEPAS sensitivity by one to two orders of magnitude.

Development of high resolution linear-cut beam position monitor for heavy-ion synchrotron of KHIMA project

A beam position monitor with high precision and resolution is required to control the beam trajectory for matching to the injection orbit and acceleration in a heavy-ion synchrotron. It will be also used for measuring the beta function, tune, and chromaticity. Since the bunch length at heavy ion synchrotron is relatively long, a few meters, a boxlike device with plates of typically 20cm length is used to enhance the signal strength and to get a precise linear dependence with respect to the beam displacement. Especially, the linear-cut beam position monitor is adopted to satisfy the position resolution of 100µm and accuracy of 200µm for a nominal beam intensity in the KHIMA synchrotron of ∼7×108 particles for the carbon beams and ∼2×1010 for the proton beams. In this paper, we show the electromagnetic design of the electrode and surroundings to satisfy the resolution of 100µm, the criteria for mechanical aspect to satisfy the position accuracy of 200µm, the measurement results by using wire test-bench, design and measurement of a high input impedance pre-amplifier, and the beam-test results with long (∼1.6μs) electron beam in Pohang accelerator laboratory (PAL).

Prototype of IGZO-TFT preamplifier and analog counter for pixel detector

IGZO-TFT (Indium Galium Zinc Oxide-Thin Film Transistor) is a promising technology for controlling large display areas and large area sensors because of its very low leakage current in the off state and relatively low cost. IGZO has been used as a switching gate for a large area flat-panel detector. The photon counting capability for X-ray medical imaging has been investigated and expected for low-dose exposure and material determination. Here the design and fabrication of a charge sensitive preamplifier and analog counter using IGZO-TFT processes and its performance are reported for the first time to be used for radiation photon counting applications.

Design of a 3T preamplifier which stability is insensitive to coil loading

In MRI (magnetic resonance imaging), preamplifiers are needed to amplify signals obtained from MRI receiver coils. Under various loading conditions of the corresponding receiver coils, preamplifiers see different source impedance at their input and may become unstable. Therefore preamplifiers which stability is not sensitive to coil loading are desirable. In this article, a coil-loading-insensitive preamplifier for MRI is presented, derived from an unstable preamplifier. Different approaches to improve stability were used during this derivation. Since a very low noise factor is essential for MRI preamplifiers, noise contributions from passive components in the MRI preamplifier have to be considered during the stabilization process. As a result, the initially unstable preamplifier became stable with regard to coil loading, while other MRI requirements, as the extremely low noise factor, were still fulfilled. The newly designed preamplifier was manufactured, characterized and tested in the MRI spectrometer. Compared to a commercially available preamplifier, the newly designed preamplifier has similar imaging performance but other advantages like smaller size and better stability. Furthermore, presented stabilization approaches can be generalized to stabilize other unstable low-noise amplifiers.

Low-Noise Preamplifier Design Considerations for Large Area High Capacitance Solid-State Neutron Detectors

In this paper, the design of a low noise charge sensitive preamplifier, suitable for high capacitance solid-state neutron detector arrays, is described. Noise considerations related to arraying multiple detectors in either series or parallel are also presented. Using the designed preamplifier, an energy resolution of 12 keV FWHM in Si is achieved with 1 nF equivalent detector capacitance and $10~\mu\hbox{S} $ shaping time. Additionally, a novel preamplifier topology, which utilizes a capacitance canceling input stage, is presented. Detailed analysis of the capacitance cancelling stage is discussed with special consideration given to its use with a charge sensitive preamplifier. Up to a 15% decrease in noise is demonstrated using the capacitance cancelling technique.

The Design Of The Ultrasonic Nondestructive Testing System Based On The EMAT

This paper introduces a kind of based on the electromagnetic acoustic transducer (EMAT) metal pipeline detection system, fusion of two dimensional orientation, shape unique technological innovation, implementation of various metal pipe wall corrosion situation of rapid, accurate, fully automated non-destructive testing.In the aspect of hardware design, single-chip microcomputer control was achieved by C language programming the launch of the pulse signal. Pulse signal was sent to launch circuit, ultrasonic signal. Design of preamplifier, controllable gain amplifier two-stage amplifier circuit for receiving signal is amplified. Including data acquisition circuit detection circuit and A/D conversion circuit, single chip microcomputer and the LabVIEW platform via A serial port communication agreement. In the aspect of software design, the design of the EMAT pipe nondestructive testing system based on LabVIEW human-computer interaction interface.

Design and Realization of Pre-Amplifier and Filters for on-Board Radar System

Today's warfare situation incorporates a considerable measure of innovative weaponry and every nation is attempting to outmaneuver the other utilizing high engineering, henceforth it is of most extreme criticalness to be at the front line of the bleeding edge innovation and having the best weapons conceivable to secure the country. One of the innovations which give the one having it the high ground is Radio Detection and Ranging (RADAR) engineering. Radar is an object recognition framework that uses electromagnetic waves to recognize the range, vehicles, climate developments and landscape. A radar framework incorporates a transmitter which radiates an arrangement of EM pulses. These pulses are transmitted in a directional pattern using a suitable high-gain antenna. The radar then uses a collector, normally joined with the same radio wire, to catch any returned pulses being reflected from items showing up in the reception apparatus' field of perspective. The transmitter, antenna and recipient are connected utilizing a circulator. This guarantees that all the transmitter power is sent to the radio wire whilst all the reflected power came back to the reception apparatus. The echo signal coming back to the receiver is a high recurrence signal in Ghz extent having low adequacy. The processing of this sort of signal is extremely troublesome and henceforth it needs to be down changed over into an Intermediate Frequency (IF) signal whose reach is in Mhz. This down transformation is carried out utilizing a super heterodyne receiver. Most radar receivers use megahertz Intermediate Frequency (IF) with a value around 30 and 75 megahertz. Ground based radar is utilized for missile tracking framework to get its range and angular position to block and destroy. Precision of these radars is not sufficient to hit and crush, so the rocket itself is provided with onboard radar to track the target, block it buzzing around and pulverize. Radar signal handling of onboard radar is carried out in both simple and advanced modes, The latter mode of signal preparing is much simple to actualize changes and up gradation. But the IF signal before digitization needs to be amplified to get enough signal strength and filtered to select the desired. This paper exhibits the design and realization of an amplifier and filters to process the received signal at IF level of a locally available radar framework. MULTISIM is utilized to confirm the channel qualities and intensification variable.

Design and operation of a cryogenic charge-integrating preamplifier for the MuSun experiment

The central detector in the MuSun experiment is a pad-plane time projection ionization chamber that operates without gasamplification in deuterium at 31 K; it is used to measure the rate ofthe muon capture process μ−+d→n+n+νμ. Anew charge-sensitive preamplifier, operated at 140 K, has beendeveloped for this detector. It achieved a resolution of4.5 keV(D2) or 120 e− RMS with zero detector capacitance at1.1 μ s integration time in laboratory tests. In theexperimental environment, the electronic resolution is 10 keV(D2)or 250 e− RMS at a 0.5 μ s integration time. The excellentenergy resolution of this amplifier has enabled discrimination betweensignals from muon-catalyzed fusion and muon capture on chemicalimpurities, which will precisely determine systematic corrections dueto these processes. It is also expected to improve the muon trackingand determination of the stopping location.