Low Noise Performance Research Articles

Sub-1-dB and Wideband SiGe BiCMOS Low-Noise Amplifiers for <inline-formula> <tex-math notation="LaTeX">$X$ </tex-math> </inline-formula>-Band Applications

In this paper, a design methodology for SiGe HBT-based low-noise amplifiers (LNAs) is proposed that can be utilized for both sub-1-dB noise figure (NF) and wide bandwidth as an alternative to the conventional simultaneous input noise and power matching technique. This paper focuses on the removal of the series base inductor and the inclusion of an output matching network as a design parameter that can be used to achieve both sub-1dB NF and wide bandwidth. The effects of the mentioned design parameters on NF and bandwidth are described and analyzed, including the comparison of results with the conventional design technique. To demonstrate the validity of the analysis and impact of utilizing base-to-collector capacitance on LNA performance metrics, two different LNAs implemented in a 0.13- $\mu \text{m}$ SiGe technology. The first LNA achieves a lower than 1-dB NF with 26-dB gain at 8.5 GHz, and the second LNA exhibits wideband operation, with a better than 10-dB return losses in the range of 8–35 GHz and lower than 3-dB NF from 6 to 20 GHz. The sub-1-dB LNA reaches −17.3 dBm of input-referred compression point (IP1dB), with a power consumption of 62 mW and an area of 0.795 mm2. The wideband LNA achieves 17.6 dB of peak gain with a 48.5-mW power consumption and 0.69-mm2 chip area. To the best of our knowledge, this paper achieves the best NF performance in the literature utilizing a SiGe technology, while the wideband LNA exhibits the best operational bandwidth, together with a reasonable low-noise performance.

Ultraviolet photodetector based on Au doped TiO2 nanowires array with low dark current

Au nanoparticles doped TiO2 nanowires (NWs) arrays with an average diameter of 100 nm were synthesized through a facile solvothermal method. Thereafter, metal/semiconductor/metal (MSM) structured detectors with Ag electrodes were fabricated on these NWs. The ultraviolet (UV) sensing characteristics of pure TiO2 and Au-doped ones (Au-TiO2) were investigated. Compared with pure TiO2, the Au-TiO2 NWs based device shows a much lower dark current of 1.5 nA at 3 V bias. The low dark current mechanism might be due to the promoted directional transmission of carriers induced by Au doping. The photoresponse is nearly one order of magnitude under 360 nm monochromatic illumination. The Au-TiO2 NWs detector with simple fabrication process, low noise and good overall performance provides a broad way in fabricating UV imaging arrays.

34-GBd Linear Transimpedance Amplifier for 200-Gb/s DP-16-QAM Optical Coherent Receivers

High spectral efficiency offered by the coherent optical communication links makes them attractive for the next-generation optical communication links. Using advanced modulation schemes such as dual-polarization quadrature-amplitude modulation (DP-QAM) data rates beyond 200 Gb/s can be achieved. A key component of such links is the wide-bandwidth and high-linearity coherent optical receiver. In this paper, we present a fully differential (FD) optical receiver architecture consisting of a variable-gain transimpedance amplifier (VG-TIA) followed by a VG amplifier (VGA). The proposed optical receiver employs a dual-feedback automatic gain control (AGC) loop that controls both the front-end VG-TIA and the following VGA to achieve both low-noise and high-linearity operation. A new photodiode (PD) dc current cancellation scheme is developed and implemented for the full differential front-end TIA. A prototype dual-TIA chip is fabricated in a 0.13- $\mu \text{m}$ SiGe BiCMOS process. The presented TIA achieves 20-pA/ $\sqrt {\text {Hz}}$ input-referred noise (IRN) density, 27-GHz, 3-dB bandwidth, and 1.5% total harmonic distortion (THD) at 1-mApp input PD current and 500-mVpp output voltage swing. This enables the 34-GBd operation with the bit error rate (BER) of $10^{-10}$ and $5.4\times 10^{-4}$ using DP-QPSK and DP-16-QAM formats at optical signal-to-noise ratios (OSNRs) of 25 and 30 dB, respectively, demonstrating the 100- and 200-Gb/s single wavelength optical coherent receiver operation. The dual-TIA chip occupies an area of $1.4\,\,\text {mm}\times 1.6$ mm and consumes 313 mW per channel at 34 GBd from a 3.3-V supply.

Compact low-noise passively mode-locked Er-doped femtosecond all-fiber laser with 2.68 GHz fundamental repetition rate.

A passively mode-locked Er-doped fiber laser with a fundamental repetition rate of 2.68GHz is reported. The oscillator operating at a central wavelength of 1558.35nm has a compact, robust structure and low-noise performance. The timing jitter integrated from 30MHz down to 300Hz is 82.5fs, and the timing jitter performance is analyzed based on the theory model. The amplification and compression of the high repetition rate optical pulses are also investigated. After a three-stage amplifier, the average power is boosted to 430mW. Meanwhile, based on the nonlinear self-phase modulation effect, the spectral bandwidth is broadened from 7.56 to 19.2nm, and the corresponding pulse width is compressed to 244fs.

Study on adaptive technology for flow regulation of cooling water system

Through the transient simulation analysis of flowmaster, the flow characteristic method of ship cooling system pipe network was studied, and the pipe network was optimized by adding bypass branch, which was consisted of the flow balancing accembly. The results show that the bypass branch can automatically balance the flow rate of the system, the system can adapt to the change of different working conditions, the pump group can work stably at the rated point, and the flow rate of each user can be guaranteed within 3m/s. The system realizes self-adaptive control. The simulation results were verified by experiments. It provided a design idea for the stable and low noise operation of a typical ship cooling system.

90-Gb/s NRZ Optical Receiver in Silicon Using a Fully Differential Transimpedance Amplifier

We present the design and implementation of a 90 -Gb/s non-return-to-zero (NRZ) direct detection optical receiver that consists of a low-noise transimpedance amplifier (TIA), fabricated in a 55-nm SiGe BiCMOS technology, and a Ge photodiode integrated into a Silicon Photonic integrated circuit. Low-noise broadband operation is achieved using a fully differential TIA that provides the photodiode reverse bias. 50-, 56-, and 64-Gb/s NRZ operation is demonstrated at bit-error ratios (BERs) below $10^{-12}$ at sensitivities of $-$ 12.3-, $-$ 11.2-, and $-$ 11.1-dBm optical modulation amplitude (OMA) while consuming 128, 141, and 157 mW, respectively. Furthermore, a BER below $10^{-12}$ is achieved at 80 Gb/s with a sensitivity of $-$ 6.1 dBm (OMA) at 165 mW, and operation below KP4-FEC $({2.4 \times {10}^{-4}})$ is demonstrated up to 90 Gb/s with a sensitivity of $-$ 7.1 dBm (OMA) while consuming 222 mW. All BERs were measured in real time and without DSP or equalization to compensate the receiver. The presented receiver achieves the best reported sensitivities up to 90 Gb/s, at the second-lowest power consumption, and is the first reported integrated optical RX up to 90 Gb/s that is tested in real time without any equalization or DSP to compensate the receiver. The presented optical receiver is ideally suited for upcoming short-reach applications.

Nd:YVO4 high-power master oscillator power amplifier laser system for second-generation gravitational wave detectors.

Ultrastable high-power laser systems are essential components of the long baseline interferometers that detected the first gravitational waves from merging black holes and neutron stars. One way to further increase the sensitivity of current generation gravitational wave detectors (GWDs) is to increase the laser power injected into the interferometers. In this Letter, we describe and characterize a 72 W and a 114 W linearly polarized, single-frequency laser system at a wavelength of 1064 nm, each based on single-pass Nd:YVO4 power amplifiers. Both systems have low power and frequency noise and very high spatial purity with less than 10.7% and 2.9% higher order mode content, respectively. We demonstrate the simple integration of these amplifiers into the laser stabilization environment of operating GWDs and show stable low-noise operation of one of the amplifier systems in such an environment for more than 45 days.

Low Phase Noise Feedback Oscillators Utilizing High-Q SIW Filter with Dielectric Loading

Abstract High-Q substrate integrated waveguide (SIW) resonator and its application to low phase noise oscillators are focused in this paper. By drilling air holes in the substrate, SIW bandpass filters (BPFs) with high Q factor could be achieved. This SIW filter is embedded into the feedback loop to be treated as a frequency stabilization element in designing the oscillator. The complex quality factor (Qsc)-peak frequency of the filter is chosen as the final oscillation frequency to obtain low phase noise performance. Moreover, air boxes are utilized instead of the air holes in the substrate to design another oscillator with lower phase noise performance and good harmonic suppression. Two low phase noise oscillators based on fourth-order SIW BPFs with dielectric loading have been studied, demonstrated and fabricated to verify the design concept.

Sources of torque ripple and their influence in BLDC motor drives

Abstract In automotive applications brushed DC motor is often used because of its simplicity and low price. It is very quiet motor, easy to control and serves as actuators with an overall short operating time. Brushless DC (BLDC) motors have less wear and probability of failure, higher efficiency, but need a more complex control algorithm than a DC motor drive. So brushless DC motor is most suitable for applications demanding long-term continuous duty like fuel pumps. Brushed DC motor is often used also in seat ventilation and in some HVAC (heating, ventilation, and air conditioning) compressors and blowers where low noise operation is required. There is an effort to replace this brushed DC motor with low-cost BLDC motor. But problem of these low-cost BLDC motors is in produced torque ripple, vibrations and acoustic noise. Therefore, sources of torque ripple and their suppression has to be identified. This article will be focused on identification of main sources of torque ripple caused by construction and control of BLDC motor. Sources such as cogging torque, waveform of Back-EMF in combination with waveform of phase currents (type of control technique), dead-time and commutation of currents will be investigated. Impact of these sources will be identified on real BLDC motor and also torque ripple, vibrations and acoustic noise will be evaluated in this article.

Low-Noise Schottky Junction Trigate Silicon Nanowire Field-Effect Transistor for Charge Sensing

Silicon nanowire (SiNW) field-effect transistors (SiNWFETs) are of great potential as a high-sensitivity charge sensor. The signal-to-noise ratio (SNR) of an SiNWFET sensor is ultimately limited by the intrinsic device noise generated by carrier trapping/detrapping processes at the gate oxide/silicon interface. This carrier trapping/detrapping-induced noise can be significantly reduced by replacing the noisy oxide/silicon interface with a Schottky junction gate (SJG) on the top of the SiNW. In this paper, we present a tri-SJG SiNWFET (Tri-SJGFET) with the SJG formed on both the top surface and the two sidewalls of the SiNW so as to enhance the gate control over the SiNW channel. Both experiment and simulation confirm that the additional sidewall gates in a narrow Tri-SJGFET indeed can confine the conduction path within the bulk of the SiNW channel away from the interfaces and significantly improve the immunity to the traps at the bottom buried oxide/silicon interface. Therefore, the optimal low-frequency noise performance can be achieved without the need for any substrate bias. This new gating structure holds promises for further development of robust SiNWFET-based charge sensors with low noise and low operation voltage.

A 2.2 to 2.9 GHz Complementary Class-C VCO With PMOS Tail-Current Source Feedback Achieving – 120 dBc/Hz Phase Noise at 1 MHz Offset

The performance of low-powered transceivers is required to meet stringent specifications for an advanced wireless radio application. It is critical for a voltage-controlled oscillator (VCO) to meet multi-standard and multiple frequency operation with low-power consumption and amplitude enhanced complementary mode of operation. This paper proposes a novel technique for wide tuning range in a complementary class-C VCO employing a capacitive-source degeneration (CSD) to meet multi-standard operation for low-power transceivers. The technique that employs two sets of symmetrical split PMOS biased current source operating in the subthreshold region achieves the desired low phase noise (PN) performance at a tuning range of 2.2-2.9 GHz with a supply headroom of 1.2 V. The control of the dc bias point reduces the conduction angle, which improves the current efficiency, power consumption, and PN. Concurrently, an auxiliary -g m NMOS only class-B oscillator is incorporated to mitigate the start-up issue of the class-C VCO. At the center frequency of 2.45 GHz, the proposed VCO achieves a power consumption of 1.73 mW, phase noise of -120 dBc/Hz at the 1-MHz offset, and a figure-of-merit (FoM) of 185.41 dBc/Hz at 1 MHz. The total active chip area is only 0.3-mm 2 excluding bond pads. The proposed VCO serves as a promising solution for low-power wireless communication systems.

An analog-to-digital converter and intelligent controller for use in a DAQ system processing PMT signals from very high energy astrophysics experiments

Abstract Modern instrumentation for very high energy gamma-ray astronomy and astrophysics requires efficient and precise digitization of PMT signals from Cherenkov light generated by incoming cosmic ray particles over the energy range from hundreds of GeV up to several hundred TeV. This dynamic range of more than 1000 is coupled with a requirement for very low noise operation. We have developed modern multi-channel analog-to-digital converters (model BPA-8) together with a data acquisition system, managed with an intelligent crate-controller (model K-167) which controls the measurement modules. The electronics described in this paper is accepted to be used to record PMT signals with high precision and efficiency, allowing reliable extraction and precise analysis of Cherenkov signals from high energy gamma-rays emitted by astrophysical objects.

Low phase-noise oscillator based on SIW bandpass filter implementing at the Qsc-peak frequency

ABSTRACTIn this paper, a novel low phase-noise oscillator employing an substrate integrated waveguide (SIW) bandpass filter (BPF) embedded with a complementary spiral resonator (CSR) is proposed. The Qsc-peak frequency is chosen for the design of the oscillator to achieve optimal phase noise performance. The CSR exited by TM01 mode has been etched on the top metal of the circular cavity. Three transmission poles and three transmission zeros can be obtained by the proposed SIW BPF which is regarded as the frequency stabilization element. Meanwhile, a short summary about how to obtain a high Qsc-factor to achieve low phase noise performance has been illustrated. A C-band oscillator using a field effect transistor has been designed and experimentally demonstrated at 5.71 GHz with a 147.6 dBc/Hz phase noise at 1 MHz offset frequency. Moreover, the output power is −1.49 dBm with a figure of merit of −209.2 dBc/Hz and less than −32.8 dBm spurious harmonics is obtained.

Design of low phase-noise oscillators based on microstrip triple-band bandpass filter using coupled lines resonator

This paper presents new low phase noise oscillators employing a triple-band bandpass filter as a frequency stabilization element into the feedback loop. In addition, using triple-band bandpass filter (TB-BPF); three oscillators can be easily achieved separately, only by changing the length of the transmission line in feedback loop. The oscillators are designed at the spectrum-based quality factor (Qs) peak frequencies of bandpass filter to achieve low phase noise performance. Also, the oscillation frequencies of the oscillators are designed at 3.4, 4.33 and 6.89 GHz, resulting in achieving the simulated phase noise of these oscillators are −166, −154 and −150 dBc/Hz at the 1-MHz offset frequency respectively. The oscillator with 3.4 GHz carrier frequency is fabricated and the measured results show the 10.7 dBm output power and phase noise is −163 dBc/Hz at 1-MHz frequency offset. The figure of merit of the fabricated oscillator at 1 MHz offset frequency is −218.9 dBc/Hz.

Analysis and Design of a CMOS Ultra-High-Speed Burst Mode Imager with In-Situ Storage Topology Featuring In-Pixel CDS Amplification.

This paper presents an in-situ storage topology for ultra-high-speed burst mode imagers, enabling low noise operation while keeping a high frame depth. The proposed pixel architecture contains a 4T pinned photodiode, a correlated double sampling (CDS) amplification stage, and an in-situ memory bank. Focusing on the sampling noise, the system level trade-off of the proposed pixel architecture is discussed, showing its advantages on the noise, power, and scaling capability. Integrated with an AC coupling CDS stage, the amplification is obtained by exploiting the strong capacitance to the voltage relation of a single NMOS transistor. A comprehensive noise model is developed for optimizing the trade-off between the area and noise. As a proof-of-concept, a prototype imager with a 30 µm pixel pitch was fabricated in a CMOS 130 nm technology. A 108-cell memory bank is implemented allowing dense layout and parallel readout. Two types of CDS amplification stages were investigated. Despite the limited memory capacitance of 10 fF/cell, the photon transfer curves of both pixel types were measured over different operation speeds up to 20 Mfps showing a noise performance of 8.4 e−.

A New Wide-band Low-voltage Low-noise Amplifier with Gain Boosted and Noise Optimized Techniques

This work develops a new CMOS wide-band low-voltage low-noise amplifier (LNA). The proposed LNA uses negative feedback and gain boosted technique to increase its high-frequency gain to achieve high gain and wide bandwidth simultaneously. The proposed LNA uses mirror bias technique to achieve full output swing, and its operating current does not change due to changes in the supply voltage. The two-stage structure can improve the gain flatness, high gain, and low noise figure. Therefore, the developed LNA provides high gain, low noise, wide bandwidth, and good gain flatness performance. The operating bandwidth of the proposed LNA is between 1.5 and 3.5 GHz. The measured gain of the LNA is higher than 15 dB, the measured input third-order intercept points (IIP3) is –7 dBm, the noise figure of the proposed LNA is less than 4.2 dB, and the power dissipations of the LNA is 8 mW at 1 V supply voltage. The proposed LNA is implemented in a Taiwan Semiconductor Manufacturing Company 0.18-μm RF CMOS process. The chip area is 0.28 mm2.

Improvements in electrical properties, low frequency noise and detection performance of a Mn-based bilayer thin film infrared detector

Experimental studies about low frequency 1/f noise and detection performance of Mn-based monolayer and bilayer structured detectors produced by Radio Frequency (RF) sputtering method have been carried out. Mn1.56Co0.96Ni0.48O4 (MCN) thick film (10 μm) was deposited on sapphire substrate to produce infrared detector by using sacrificial layer techniques. An MCN thin film (1 μm) detector and an Mn1.56Co0.96Ni0.48O4-Mn1.56Co0.80Cu0.16Ni0.48O4 (MCN-MCCN) bilayer thin film detector were also constructed by using wet chemical etching methods. The XRD results exhibited that the three samples all showed spinel structures. The varied temperature characters of the MCN and bilayer film samples were examined by voltage-current measurements ranging 250–320 K, and the characteristic temperature values were derived from the R-T curve. All three detectors showed similar temperature coefficient of resistance at about −3.5%K−1 at 295 K. The low frequency noise spectra of all three detectors were all conducted, where the bilayer film detector showed half the noise value than that of the MCN thin film sample. The detector fabricated by the MCN-MCCN bilayer film showed large response to 1550 nm laser radiation, as well as good thermal sensing ability to a blackbody. It is found that the response speed of the bilayer detector is one order faster than the MCN thick film detectors, where the time constant is about 0.17 ms. The detectivity of the MCN-MCCN detector was estimated to be on the order of 107 cm∙Hz0. 5/W. Simple considerations on bias voltage and thermal conductance G are given for further improvements by using the thermal isolation structures.

Low‐noise dynamic comparator circuit with selectable input‐referred thermal noise voltage

A new method for reducing input-referred thermal noise of dynamic comparator circuit without increasing load capacitance as commonly used in the conventional method is proposed. An implementation circuit with selectable low-noise mode operation is presented, which enable both low-noise mode and standard mode operation by a single circuit. Simulation in 180 nm CMOS process technology shows that the proposed new method and circuit topology can achieve up to 90% increase in gain of comparator first stage, resulting in up to 40% decrease in input-referred thermal noise voltage, compared with a conventional circuit with similar load capacitance. The proposed circuit is also able to operate with similar performance as the conventional circuit when low-noise mode operation is not necessary.

Fast and accurate data collection for macromolecular crystallography using the JUNGFRAU detector

The accuracy of X-ray diffraction data is directly related to how the X-ray detector records photons. Here we describe the application of a direct-detection charge-integrating pixel-array detector (JUNGFRAU) in macromolecular crystallography (MX). JUNGFRAU features a uniform response on the subpixel level, linear behavior toward high photon rates, and low-noise performance across the whole dynamic range. We demonstrate that these features allow accurate MX data to be recorded at unprecedented speed. We also demonstrate improvements over previous-generation detectors in terms of data quality, using native single-wavelength anomalous diffraction (SAD) phasing, for thaumatin, lysozyme, and aminopeptidase N. Our results suggest that the JUNGFRAU detector will substantially improve the performance of synchrotron MX beamlines and equip them for future synchrotron light sources.

Effects of sidewall spacer layers on thermal and low frequency noise performance of SOI UTB MOSFETs

In this paper we investigate the impact of sidewall spacer dielectric constant and length on the noise behavior of SOI UTB MOSFETs using numerical simulation techniques. The important electrical parameters of devices such as drain current, transconductance are computed and utilized to obtain normalized power spectral density of drain current, noise resistance and minimum noise figure of SOI UTB MOSFETs. Our investigations manifest that thermal noise as well as low frequency noise parameters can be reduced considerably by employing spacer layers with high dielectric constant and low value of spacer length (~ 5 nm). The minimum noise figure NFmin for thermal noise is obtained as low as 1.2 dB at frequency of 1 GHz by setting 1.2 V at the gate and drain terminals.