Low-noise Hybrid Research Articles

Aerodynamic Investigation of Propulsion Integration for a Low Noise Hybrid Wing-Body with Podded UHBR Turbofan Engines

The presented work examines the aerodynamic challenges of podded ultra high-bypass engines installed on a short/mid range low noise hybrid wing body configuration. After assessing the initial engine integration design, sensitivity studies regarding the impact of the freestream Mach number, engine position, and the engine incidence angle on the interference drag are discussed. Then, shape modifications of the nacelle and the center-body based on 2D RANS optimizations are presented. The results indicate that in order to reduce the initially massive interference drag, the overall aircraft design either has to allow for a modified engine position or for reshaping of the center-body’s upper surface. With the latter, an overall drag reduction of –44 % was achieved.

A 1.41-pJ/b 224-Gb/s PAM4 6-bit ADC-Based SerDes Receiver With Hybrid AFE Capable of Supporting Long Reach Channels

A 224-Gb/s pulse amplitude modulation 4-level (PAM4) ADC-based SerDes receiver (RX) is implemented in a 5-nm FinFET process. The RX consists of a low-noise hybrid analog front-end (AFE) that incorporates both inductive peaking and source degeneration, a 64-way time-interleaved ADC, digital equalization consisting of an up to 30 tap feed-forward equalizer (FFE), optional decision-feedback equalizer (DFE), and a clock-data-recovery (CDR) loop utilizing a 14-GHz digitally controlled oscillator (DCO). The RX was characterized for medium-to-long reach channels (20.6-, 27-, 31.4-, and 38-dB insertion loss at Nyquist) with a corresponding pre-forward error correction (FEC) bit error rates of 1.9E-11, 5.2E-10, 1.2E-8, and 6E-7, respectively. The analog power consumption of the RX is 1.41 pJ/b.

Low Noise Hybrid Nanopore with Engineered OmpG and Bilayer MoS2

Hybrid nanopores combine the durability of a solid-state nanopore with the precise structure of a biological nanopore. When a DNA strand is pulled electrophoretically through a solid-state nanopore it can be sensed using the ionic blockade current produced by each translocating molecule. However, owing to the lack of chemical specificity and pore size reproducibility, solid-state nanopore sensing suffers from poor repeatability. Biological nanopores which have a constant geometry ensure sensitive and repeatable sensing. In this study, hybrid nanopores were formed by insertion of a engineered outer membrane porin G (eOmpG) in a bilayer (BL) molybdenum disulfide (MoS2) solid-state nanopore. Engineered outer membrane porin G (eOmpG) is used as the biological counterpart of the hybrid nanopore due to its uniform cylindrical geometry and controlled gating useful for specific detection of label-free analytes. BL MoS2 is used as the solid-state support for the hybrid construct owing to its surface charge and 2D layered properties, which ensures a stable support with low capacitive noise, favorable for precise sensing. To realize the hybried nanopore a single eOmpG was electrophoretically pulled through a 3.4 nm BL MoS2 solid-state nanopore at neutral pH and +80 mV trans bias. A hybrid BL MoS2-eOmpG nanopore was found to demonstrate 32% lower noise levels with nearly 1.9 times improved in the signal-to-noise ratio (SNR) and 6.5 times longer dwell times for dA30 molecular sensing compared to the BL MoS2 solid-state nanopore. Thus, the low-noise biocompatible platform of the hybrid BL MoS2-eOmpG nanopore can be used for highly resolved biomolecular sensing.

Statistically correcting dynamical electron scattering improves the refinement of protein nanocrystals, including charge refinement of coordinated metals.

Electron diffraction allows protein structure determination when only nanosized crystals are available. Nevertheless, multiple elastic (or dynamical) scattering, which is prominent in electron diffraction, is a concern. Current methods for modeling dynamical scattering by multi-slice or Bloch wave approaches are not suitable for protein crystals because they are not designed to cope with large molecules. Here, dynamical scattering of nanocrystals of insulin, thermolysin and thaumatin was limited by collecting data from thin crystals. To accurately measure the weak diffraction signal from the few unit cells in the thin crystals, alow-noise hybrid pixel Timepix electron-counting detector was used. The remaining dynamical component was further reduced in refinement using a likelihood-based correction, which was introduced previously for analyzing electron diffraction data of small-molecule nanocrystals and was adapted here for protein crystals. The procedure is shown to notably improve the structural refinement, in one case allowing the location of solvent molecules. It also allowed refinement of the charge states of bound metal atoms, an important element in protein function, through B-factor analysis of the metal atoms and their ligands. These results clearly increase the value of macromolecular electron crystallography as a complementary structural biology technique.

Low-Noise Hybrid Frequency Synthesizers Based on Direct Digital and Direct Analog Synthesis

Hybrid frequency synthesizers based on direct methods of digital and analog synthesis were examined. The possibilities of applying synthesizers as heterodynes of modern spectrum analyzers built on the superheterodyne plan were studied. The possibility of using a hybrid synthesizer as the heterodyne of the first cascade of spectrum analyzers was analyzed. The requirements for heterodynes of the first cascades of the mixing of spectrum analyzers are provided. A structural diagram of a broadband heterodyne generating frequencies in the range 4000–8000 MHz with a step not exceeding 1 Hz is presented. Formulas to calculate the fundamental frequency relations in the heterodyne structure were developed. A mathematical model of the power spectrum density of phase noises as a function of the offset frequency from the carrier was developed. With the aid of the created model, the noise characteristics of the proposed layout was examined. It is shown that at offset frequencies over 1 kHz from the carrier, a hybrid synthesizer based on direct digital and analog methods of synthesis has an advantage at a phase noise level 5–30 dB over low-noise heterodynes of modern spectrum analyzers. The advantages of the suggested layout by which the hybrid synthesizer is capable of improving the technical characteristics of modern spectrum analyzers are defined.

Low-noise hybrid frequency synthesizers based on direct digital and direct analog synthesis

The research of the possibility of using hybrid frequency synthesizers based on direct digital and direct analog methods of frequency synthesis as heterodynes of modern spectrum analyzers constructed according to the superheterodyne scheme is presented. The main advantages of such synthesizers over traditionally used heterodyne schemes based on direct digital and indirect frequency synthesis methods are shown. The requirements for the heterodynes of the first mixing stages of spectrum analyzers are presented. A block diagram of a wideband heterodyne generating a frequency range from 4000 MHz to 8000 MHz with a step not exceeding 1 Hz is proposed. Formulas for calculating the main frequency ratios in the structure of the heterodyne have been developed. A mathematical model of phase noise power spectral density (PSD) depending on the offset frequency from the carrier is developed. The noise characteristics of the proposed scheme are studied using the model. It is determined that at the output frequency of the heterodyne equal to 4521,4 MHz, the level of phase noise PSD is: minus 90 dBc/Hz at the offset frequency equal to 100 Hz; minus 140 dBc/Hz at the offset frequency equal to 100 kHz. It is shown that the hybrid synthesizer based on direct digital and direct analog synthesis methods has an advantage in the level of phase noise from 5 to 30 dB over the low-noise heterodynes of modern spectrum analyzers at frequencies above 1 kHz from the carrier. Additional advantages of the proposed scheme are a simple architecture, low power consumption and high frequency tuning speed due to the absence of phaselocked loops in the structure of the heterodyne.

고성능 레이다용 저잡음 하이브리드 주파수합성기 설계 및 제작

고성능 레이다용 저잡음 하이브리드 주파수합성기 설계 및 제작

Low-noise hybrid frequency synthesizers for 5G technology

This paper presents the results of structural design and analysis of the noise characteristics of a low-noise hybrid frequency synthesizer based on direct digital and indirect synthesis methods for using as a shaper of harmonic signals for fifth generation telecommunication systems transceivers. The hybrid synthesizer is based on a phase-locked loop (PLL) with DDS operating on fundamental frequency images. Due to this, the hybrid synthesizer generates a wide range of output frequencies with high frequency resolution, as well as a low level of phase noise and discrete side components of the spectrum of the output signal.

A new diffractometer for diffuse scattering studies on the ID28 beamline at the ESRF.

A new diffractometer is now available to the general user community at the ESRF. The new diffractometer is a side station of the high-resolution inelastic X-ray scattering spectrometer on beamline ID28 and is located in the same experimental hutch. Both instruments can be operated simultaneously. The new diffractometer combines a fast and low-noise hybrid pixel detector with a variable diffraction geometry. The beam spot on the sample is 50 µm × 50 µm, where focusing is achieved by a combination of Be lenses and a KB mirror. Wavelengths from 0.5 to 0.8 Å can be used for the diffraction experiments. The setup is compatible with a variety of sample environments, allowing studies under non-ambient conditions. The diffractometer is optimized to allow a rapid survey of reciprocal space and diffuse scattering for the identification of regions of interest for subsequent inelastic scattering studies, but can also be employed as a fully independent station for structural studies from both powder and single-crystal diffraction experiments. Several software packages for the transformation and visualization of diffraction data are available. An analysis of data collected with the new diffractometer shows that the ID28 side station is a state-of-the-art instrument for structural investigations using diffraction and diffuse scattering experiments.

High-performance small- and wide-angle X-ray scattering (SAXS/WAXS) experiments on a multi-functional laboratory goniometer platform with easily exchangeable X-ray modules

Small-angle X-ray scattering (SAXS) is a well-established, versatile technique for the analysis of nanoscale structures and dimensions, e.g., in liquid dispersions, thin solid objects or powder samples. When combined with wide-angle X-ray scattering (WAXS), complementary information about the atomic structure can be obtained. SAXS experiments traditionally require dedicated instruments to achieve the desired angular resolution, sensitivity, stability, and speed of measurement. Here we demonstrate how a multi-functional laboratory goniometer platform, as widely being used for powder X-ray diffraction and for a variety of related techniques, can be configured with pre-aligned X-ray modules that enable advanced SAXS/WAXS experiments, without compromising the exceptional versatility of the instrument. Line and point collimation setups, as well as quick and easy switching between them, are readily possible. Key components are a detachable, evacuated beam path and a high-resolution, low-noise hybrid pixel area detector, in combination with a hardware interface design that allows to configure the instrument with different X-ray modules without the need for re-alignment. Software for SAXS data reduction and analysis was developed. The good SAXS/WAXS performance and the derived analytical results were verified on various test samples, such as gold nanoparticles, colloidal silica, liposomes, dilute protein solutions, and solid polymer samples. It is believed that this novel approach to SAXS/WAXS instrumentation will help to make this powerful structure analysis technique more widely accessible and affordable for multi-user laboratories.

A 3.3-MHz fast-response load-dependent-on/off-time buck-boost DC-DC converter with low-noise hybrid full-wave current sensor

A 3.3-MHz current mode control buck-boost DC-DC converter is proposed in this work. Composed of comparator control and load-dependent on/off time modulation technique, the converter can achieve a faster load transient response by reducing the delay from 2.7 μs to 1.5 μs during constant on/off time. Thus, the comparator can take effect faster. To fulfill a fixed frequency operation to reduce electromagnetic interference (EMI), a frequency controller locks the switching frequency to 3.3 MHz. Also, a hybrid full-wave current sensor is proposed to achieve current mode control. The proposed hybrid current sensor inherits good AC performance from a filter-based current sensor and good DC performance from a SenseFET-based one. As a result, state switching between high-side sensing and low-side sensing will not induce large spiking on the current sensor output. Moreover, the DC accuracy of current sensing will not be affected by the DC resistance (DCR) of the inductor.

A Low Phase Noise Voltage-Controlled Oscillator with Harmonic Suppression Based on LTCC Technology

In this paper, a low phase noise hybrid integrated voltage-controlled oscillator (VCO) module with harmonic suppression based on LTCC technology is presented. This is the first report about the hybrid integrated VCO module based on the LTCC substrate in china mainland. The design is simulated and optimized by the ansoft designer and the ansoft HFSS software. To miniaturize the VCO module, two capacitors and an inductor that adjust the oscillation frequency and two capacitors as feedback capacitors are buried in the LTCC substrate. Three resistances for direct current bias are made on the surface of the LTCC substrate. Also the low-pass filter that used for harmonic suppression is embedded in the LTCC substrate. The VCO module achieves an output power of more than 10 dBm in a tuning range between 1000-1200MHz. The measured phase noise is lower than -112.2 dBc/Hz at 10KHz offset between 1000-1200MHz. The overall dimension is as small as 8 mm×7 mm×3.5 mm.

Low noise, dual gain preamplifier with built in spectroscopic pulser for highly segmented high-purity germanium detectors

We present a fast and very low noise hybrid front-end electronic device consisting of a complex charge sensitive preamplifier with a built in fast reset circuitry and a very accurate spectroscopy p...

An Advanced Preamplifier for Highly Segmented Germanium Detectors

We present a fast low-noise hybrid charge-sensitive preamplifier for germanium position-sensitive gamma-ray detectors. In conjunction with a bulky 36-fold segmented detector it provided an excellent resolution of 1.71/1.77 keV fwhm on the 1.17/1.33MeV60Co lines. The preamplifier rise time, as measured at the test bench, is as fast as 7.5 ns, with a detector capacitance of 21 pF and with a 5 m 50 Omega twisted-pair cable connected at its output. The dynamic range of the preamplifier input stage is as large as 92 dB, ranging from 0.275 fC to 9.9 pC, i.e., from 5 keV to 180 MeV in terms of photon energy. On signals larger than 2 MeV a fast reset (~ 10 MeV/mus) is enforced to reduce the system dead time. An estimate of the amplitude of such large signals is derived from the reset time, still obtaining a high resolution. Using this technique we achieved an energy resolution of 0.3% at 16.7 MeV

A highly stable low-RIN hybrid Brillouin/erbium amplified laser source

We demonstrate a low-noise all-fiber hybrid Brillouin/erbium amplified source consisting of a Brillouin/erbium fiber laser with a subsequent Brillouin amplifier to boost the power and reduce the noise. The same single-mode fibers used in the fiber laser and the amplifier lead to the same amount of Stokes frequency shifts in spite of the environmental variation, ensuring stable Brillouin amplification. The hybridly amplified source features temperature insensitivity, low noise, potentially high power, and low cost. The relative intensity noise of the hybridly amplified source is /spl sim/10 dB lower than that of the erbium-doped fiber amplifier (EDFA)-based source at radio frequencies >200 MHz due to the filtering characteristics of the Brillouin amplification. Compared with an EDFA amplified fiber system, the spurious-free dynamic range of an analog transmission system employing such a laser source is improved by 7.7 dB owning to the lower RIN.

Characteristics of low noise hybrid fiber amplifier

The characteristics of hybrid fiber amplifier (HFA) are investigated. HFA is composed of three stages: short-length EDFA pre-stage, DCF Raman amplifier, and power boosting EDFA. HFA has low noise figure, high output power, and also wide input power dynamic range. Gain control method of HFA is presented experimentally, and the transient gain excursion is suppressed to less than 0.5dB at 3dB channel add-drop. HFA can be used as line amplifier in optical transmission link even combined with distributed Raman amplifier due to wide input power dynamic range. The transmission performance of HFA is better than EDFA by more than 1.0dB of Q-factor in 720km SMF transmission.

Intermodulation and Noise Suppression of a Linearized, Low-Noise Hybrid Microwave Amplifier

A new type of microwave amplifier module, consisting of a solid-state amplifier, a predistortion linearizer, and a traveling-wave-tube (TWT), is realized. Measurements show a noise figure of 2.2 dB at 9.5 GHz and the third-order intermodulation distortion ratio of 53 dBc at 10 dB back off from P1 dB point.

Transient effects and gain-control method in low-noise dispersion-compensating hybrid fiber amplifier

Transient effects in low-noise dispersion-compensating hybrid fiber amplifier (DC-HFA) are presented to show the combined dynamics of erbium-doped fiber amplifier and fiber Raman amplifier. Transient features in surviving signal channel are analyzed with numerical simulation in each stage of DC-HFA. A gain-control method that utilizes the transit time of dispersion-compensating fiber is suggested and it has the advantages of enough time for the gain-control electronics and lower noise figure in surviving channels.

97/02088 Design and construction of a vapor-free and low-noise hybrid cooling tower with environmentally friendly water treatment by ozone for a gas and steam power station in the Netherlands

97/02088 Design and construction of a vapor-free and low-noise hybrid cooling tower with environmentally friendly water treatment by ozone for a gas and steam power station in the Netherlands

Design and performance of low-noise hybrid superconductor/semiconductor 7.4 GHz receiver downconverter

Low noise receivers play critical role in space applications. Thin film high-critical-temperature-superconducting (HTS) passive circuits were combined with GaAs microwave devices to achieve ultra low noise and small size receiver downconverter at 77 K. HTS pre-select filter, a cryogenic mixer, and a hybrid oscillator with an HTS resonator were designed, fabricated and interconnected to produce a low-noise hybrid superconductor/semiconductor 7.4 GHz microwave receiver. When cooled to 77 K, the downconverter plus cables inside a cryogenic refrigerator had a noise figure of approximately 0.7 dB with conversion gain of 18 dB. In addition to reduce noise figure, advantages of small size and low power consumption are observed due to the use of HTS circuits in the downconverter.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>