Showing papers on "Noise (radio) published in 2021"

First demonstration of 6 dB quantum noise reduction in a kilometer scale gravitational wave observatory

Abstract: Photon shot noise, arising from the quantum-mechanical nature of the light, currently limits the sensitivity of all the gravitational wave observatories at frequencies above one kilohertz. We report a successful application of squeezed vacuum states of light at the GEO 600 observatory and demonstrate for the first time a reduction of quantum noise up to 6.03±0.02 dB in a kilometer scale interferometer. This is equivalent at high frequencies to increasing the laser power circulating in the interferometer by a factor of 4. Achieving this milestone, a key goal for the upgrades of the advanced detectors required a better understanding of the noise sources and losses and implementation of robust control schemes to mitigate their contributions. In particular, we address the optical losses from beam propagation, phase noise from the squeezing ellipse, and backscattered light from the squeezed light source. The expertise gained from this work carried out at GEO 600 provides insight toward the implementation of 10 dB of squeezing envisioned for third-generation gravitational wave detectors.

Three-Wave Mixing Kinetic Inductance Traveling-Wave Amplifier with Near-Quantum-Limited Noise Performance

Abstract: A high gain, high power handling, broadband amplifier with simultaneous near-quantum-limited performance is demonstrated.

Heterojunction structures for reduced noise in large-area and sensitive perovskite x-ray detectors.

Abstract: Polycrystalline perovskites can be readily fabricated into large areas using solution depositions; however, they suffer from large dark currents that are tens to hundreds times higher than industri...

A Comodulation Analysis of Atmospheric Energy Injection Into the Ground Motion at InSight, Mars

Abstract: Seismic observations involve signals that can be easily masked by noise injection. For InSight, NASA's lander on Mars, the atmosphere is a significant noise contributor for two thirds of a Martian ...

Real-time low noise distributed acoustic sensing in 171 km low loss fiber

Abstract: We demonstrate distributed acoustic sensing (DAS) by interrogation of Rayleigh backscattering from fibers with long linearly frequency modulated pulses and coherent detection This system provides sustained real-time phase demodulation without inline amplification over a range of 148 km in standard single mode fiber and up to 171 km in low-loss OFS TeraWave SCUBA 125 fiber This is the longest reported range for DAS measurements The optical dynamic range of the recording is 57 dB With a 10 km fiber, we obtain a record-low interrogation noise above 50 Hz (rms average over position) of 134 and 89 µrad/√Hz with gauge lengths (equal to spatial resolution) of 10 and 34 m, respectively A total harmonic distortion of −42 dB (rms average over position) is demonstrated with a gauge length of 10 m

Reducing scattered light in LIGO's third observing run

Abstract: Noise due to scattered light has been a frequent disturbance in the Advanced LIGO gravitational wave detectors, hindering the detection of gravitational waves. The non stationary scatter noise caused by low frequency motion can be recognized as arches in the time-frequency plane of the gravitational wave channel. In this paper, we characterize the scattering noise for LIGO's third observing run O3 from April, 2019 to March, 2020. We find at least two different populations of scattering noise and we investigate the multiple origins of one of them as well as its mitigation. We find that relative motion between two specific surfaces is strongly correlated with the presence of scattered light and we implement a technique to reduce this motion. We also present an algorithm using a witness channel to identify the times this noise can be present in the detector.

Characterization of the stochastic signal originating from compact binary populations as measured by LISA

Abstract: The Laser Interferometer Space Antenna (LISA) mission, scheduled for launch in the early 2030s, is a gravitational wave observatory in space designed to detect sources emitting in the milli-Hertz band In contrast to the present ground based detectors, the LISA data are expected to be a signaldominated, with strong and weak gravitational wave signals overlapping in time and in frequency Astrophysical population models predict a sufficient number of signals in the LISA band to blend together and form an irresolvable foreground noise In this work, we present a generic method for characterizing the foreground signals originating from a given astrophysical population of coalescing compact binaries Assuming idealized detector conditions and perfect data analysis technique capable of identifying and removing the bright sources, we apply an iterative procedure which allows us to predict the different levels of foreground noise

Evidence for line-of-sight frequency decorrelation of polarized dust emission in Planck data

Abstract: If a single line of sight (LOS) intercepts multiple dust clouds with different spectral energy distributions and magnetic field orientations, then the frequency scaling of each of the Stokes Q and U parameters of the thermal dust emission may be different, a phenomenon we refer to as LOS frequency decorrelation We present first evidence for LOS frequency decorrelation in Planck data using independent measurements of neutral-hydrogen (HI) emission to probe the 3D structure of the magnetized interstellar medium (ISM) We use HI-based measurements of the number of clouds per LOS and the magnetic field orientation in each cloud to select two sets of sightlines: (i) a target sample of pixels that are likely to exhibit LOS frequency decorrelation and (ii) a control sample of pixels that lack complex LOS structure We test the null hypothesis that LOS frequency decorrelation is not detectable in Planck 353 and 217 GHz polarization data at high Galactic latitudes We reject the null hypothesis at high significance based on data that show that the combined effect of polarization angle variation with frequency and depolarization are detected in the target sample This detection is robust against the choice of cosmic microwave background (CMB) map and map-making pipeline The observed change in polarization angle due to LOS frequency decorrelation is detectable above the Planck noise level The probability that the detected effect is due to noise alone ranges from 5 × 10−2 to 4 × 10−7 , depending on the CMB subtraction algorithm and treatment of residual systematic errors; correcting for residual systematic errors consistently increases the significance of the effect Within the target sample, the LOS decorrelation effect is stronger for sightlines with more misaligned magnetic fields, as expected With our sample, we estimate that an intrinsic variation of ~15% in the ratio of 353 to 217 GHz polarized emission between clouds is sufficient to reproduce the measured effect Our finding underlines the importance of ongoing studies to map the three-dimensional structure of the magnetized and dusty ISM that could ultimately help component separation methods to account for frequency decorrelation effects in CMB polarization studies

Spurious Rollover of Wave Attenuation Rates in Sea Ice Caused by Noise in Field Measurements

Abstract: The effects of instrument noise on estimating the spectral attenuation rates of ocean waves in sea ice are explored using synthetic observations in which the true attenuation rates are known explic...

Theory of optically detected spin noise in nanosystems

Abstract: Theory of spin noise in low dimensional systems and bulk semiconductors is reviewed. Spin noise is usually detected by optical means, continuously measuring the rotation angle of the polarization plane of the probe beam passing through the sample. Spin noise spectra yield rich information about the spin properties of the system including, for example, $g$-factors of the charge carriers, spin relaxation times, parameters of the hyperfine interaction, spin-orbit interaction constants, frequencies and widths of the optical resonances. The review describes basic models of spin noise, methods of its theoretical description, and their relation with the experimental results. We also discuss the relation between the spin noise spectroscopy, the strong and weak quantum measurements and the spin flip Raman scattering, and analyze similar effects including manifestations of the charge, current and valley polarization fluctuations in the optical response. Possible directions for further development of the spin noise spectroscopy are outlined.

Dispersive-wave induced noise limits in miniature soliton microwave sources.

Abstract: Compact, low-noise microwave sources are required throughout a wide range of application areas including frequency metrology, wireless-communications and airborne radar systems. And the photonic generation of microwaves using soliton microcombs offers a path towards integrated, low noise microwave signal sources. In these devices, a so called quiet-point of operation has been shown to reduce microwave frequency noise. Such operation decouples pump frequency noise from the soliton’s motion by balancing the Raman self-frequency shift with dispersive-wave recoil. Here, we explore the limit of this noise suppression approach and reveal a fundamental noise mechanism associated with fluctuations of the dispersive wave frequency. At the same time, pump noise reduction by as much as 36 dB is demonstrated. This fundamental noise mechanism is expected to impact microwave noise (and pulse timing jitter) whenever solitons radiate into dispersive waves belonging to different spatial mode families. Here the authors explore the noise spectrum of soliton microcomb when the pump is decoupled from the solitons motion by balancing the Raman shift with the emitted dispersive wave. Based on the analysis of the phase noise and the soliton repetition rate, they identify the uncorrelated thermal fluctuations as underlying mechanism.

Investigation of Noise Spectrum and Radiated EMI in High Switching Frequency Flyback Converters

Abstract: This paper investigates noise spectrums and radiated EMI in high-frequency gallium nitride (GaN) integrated circuit (IC)-based active clamp flyback (ACF) converters. Influential factors for the noise spectrums are investigated, including the switching frequency, dv/dt and waveform symmetry, voltage magnitude, duty cycle, etc. Moreover, in the radiated EMI frequency range, the relationship between spectrum valleys and dv/dt is analyzed. In the investigated GaN IC-based ACF, the voltage spectrums and radiated EMI with high line and low line input voltages are analyzed and investigated experimentally.

Low noise 400 W coherently combined single frequency laser beam for next generation gravitational wave detectors.

Abstract: Design studies for the next generation of interferometric gravitational wave detectors propose the use of low-noise single-frequency high power laser sources at 1064 nm. Fiber amplifiers are a promising design option because of their high output power and excellent optical beam properties. We performed filled-aperture coherent beam combining with independently amplified beams from two low-noise high-power single-frequency fiber amplifiers to further scale the available optical power. An optical power of approximately 400 W with a combining efficiency of more than 93% was achieved. The combined beam contained 370 W of linearly polarized TEM00-mode and was characterized with respect to the application requirements of low relative power noise, relative beam pointing noise, and frequency noise. The noise performance of the combined beam is comparable to the single amplifier noise. This represents, to our knowledge, the highest measured power in the TEM00-mode of single frequency signals that fulfills the low noise requirements of gravitational wave detectors.

The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2

Abstract: Context. We investigated the source of a type III radio burst storm during encounter 2 of NASA’s Parker Solar Probe (PSP) mission.Aims. It was observed that in encounter 2 of NASA’s PSP mission there was a large amount of radio activity and, in particular, a noise storm of frequent, small type III bursts from 31 March to 6 April 2019. Our aim is to investigate the source of these small and frequent bursts.Methods. In order to do this, we analysed data from the Hinode EUV Imaging Spectrometer, PSP FIELDS, and the Solar Dynamics Observatory Atmospheric Imaging Assembly. We studied the behaviour of active region 12737, whose emergence and evolution coincides with the timing of the radio noise storm and determined the possible origins of the electron beams within the active region. To do this, we probed the dynamics, Doppler velocity, non-thermal velocity, FIP bias, and densities, and carried out magnetic modelling.Results. We demonstrate that although the active region on the disc produces no significant flares, its evolution indicates it is a source of the electron beams causing the radio storm. They most likely originate from the area at the edge of the active region that shows strong blue-shifted plasma. We demonstrate that as the active region grows and expands, the area of the blue-shifted region at the edge increases, which is also consistent with the increasing area where large-scale or expanding magnetic field lines from our modelling are anchored. This expansion is most significant between 1 and 4 April 2019, coinciding with the onset of the type III storm and the decrease of the individual burst’s peak frequency, indicating that the height at which the peak radiation is emitted increases as the active region evolves.

Steady active control of noise radiation from highly heated supersonic jets.

Abstract: The goal of the present investigation is to study the effect of using fluid inserts for noise control at high exhaust temperatures by performing a sequence of large eddy simulations on a typical military-style nozzle, both with and without fluid inserts, at jet inlet total temperature ratios of 2.5, 5, and 7. An exact physics-based splitting of the jet flow-field into its hydrodynamic, acoustic, and thermal components reveals clear evidence of a reduction in the radiation efficiency of Mach waves from the controlled jet. This effect is far more pronounced at afterburner conditions, where the location of the maximum noise reduction is observed to shift upstream with increase in jet temperature, thus matching the maximum location of the jet OASPL directivity. Moreover, the maximum noise reduction achieved at afterburner conditions exceeds that obtained at lower exhaust temperatures. This is encouraging and shows that the effectiveness of the fluid inserts improves with an increase in jet exhaust temperature. Furthermore, by accounting for the effect of bleeding off bypass air for the fluid inserts in the LES simulation, this noise reduction is predicted to be achieved at a conservative thrust loss estimate of under 2% at both laboratory and afterburner operating conditions.

Intrinsic amplitude-noise suppression in fiber lasers mode-locked with nonlinear amplifying loop mirrors.

Abstract: In this Letter, we investigate steady states of fiber lasers mode-locked with a nonlinear amplifying loop mirror that have an inherent amplitude-noise-suppression mechanism. Due to the interaction of the sinusoidal transmission function with the fluctuating intracavity pulse amplitude, we show that under specific preconditions, this mechanism may lead to a detectable difference in relative intensity noise at the reflected and transmitted output port of the laser. We present systematic intensity noise measurements with a nonlinear fiber-based system that replicates a single roundtrip in the laser cavity. The experimental results and simulations clearly show a reduction of the intracavity amplitude fluctuations up to 4 dB for certain steady states.

Mitigation of phase noise and Doppler-induced frequency offsets in coherent random amplitude modulated continuous-wave LiDAR

Abstract: We present a detailed analysis of techniques to mitigate the effects of phase noise and Doppler-induced frequency offsets in coherent random amplitude modulated continuous-wave (RAMCW) LiDAR. The analysis focuses specifically on a technique which uses coherent dual-quadrature detection to enable a sum of squares calculation to remove the input signal’s dependence on carrier phase and frequency. This increases the correlation bandwidth of the matched-template filter to the bandwidth of the acquisition system, whilst also supporting the simultaneous measurement of relative radial velocity with unambiguous direction-of-travel. A combination of simulations and experiments demonstrate the sum of squares technique’s ability to measure distance with consistently high SNR, more than 15 dB better than alternative techniques whilst operating in the presence of otherwise catastrophic phase noise and large frequency offsets. In principle, the technique is able to mitigate any sources of phase noise and frequency offsets common to the two orthogonal outputs of a coherent dual-quadrature receiver including laser frequency noise, speckle-induced phase noise, and Doppler frequency shifts due to accelerations.

Computational prediction and analysis of rotor noise generation in a turbulent wake

Abstract: Large-eddy simulation is combined with the Ffowcs Williams–Hawkings equation to investigate the noise generation by a 10-bladed rotor ingesting the turbulent wake of a circular cylinder in a low-Mach-number flow. Two rotor advance ratios corresponding to zero thrust and a thrusting condition are considered. The computed sound pressure levels agree well with the experimental measurements at Virginia Tech over a wide range of frequencies. The broadband acoustic spectra exhibit a strong tonal peak at the cylinder vortex-shedding frequency, a second peak at the rotor blade passing frequency, and a minor peak at the trailing-edge vortex-shedding frequency. Consistent with experimental results, the rotor at the thrusting advance ratio produces stronger sound than that at zero thrust. The blade acoustic dipole strength increases with the radial distance to the hub until near the blade tip. Fluctuating velocities in the wake are responsible for virtually all the rotor acoustic response except at the blade-passing frequency, where the mean wake velocity defect also makes a strong contribution. Blade-to-blade correlations and coherence of dipole sources are relatively weak. The classical Sears theory is shown to provide a reasonable prediction of the rotor turbulence-ingestion noise at the important mid-frequencies, based on which the appropriate Mach number scaling for the ingestion noise is identified. Distortions of wake turbulence by the rotor are found to be relatively small, and including their effect on the upwash velocity only slightly improves the Sears theory prediction.

Experiments and low-order modelling of intermittent transitions between clockwise and anticlockwise spinning thermoacoustic modes in annular combustors

Abstract: Annular combustion chambers of gas turbines and aircraft engines are subject to unstable azimuthal thermoacoustic modes leading to high amplitude acoustic waves propagating in the azimuthal direction. For certain operating conditions, the propagating direction of the wave switches randomly. The strong turbulent noise prevailing in gas turbine combustors is a source of random excitation for the thermoacoustic modes and can be the cause of these switching events. A low-order model is proposed to describe qualitatively this property of the dynamics of thermoacoustic azimuthal modes. This model is based on the acoustic wave equation with a destabilizing thermoacoustic source term to account for the flame’s response and a stochastic term to account for the turbulent combustion noise. Slow-flow averaging is applied to describe the modal dynamics on times scales that are slower than the acoustic pulsation. Under certain conditions, the model reduces formally to a Fokker-Planck equation describing a stochastic diffusion process in a potential landscape with two symmetric wells: One well corresponds to a mode propagating in the clockwise direction, the other well corresponds to a mode propagating in the anticlockwise direction. When the level of turbulent noise is sufficient, the stochastic force makes the mode jump from one well to the other at random times, reproducing the phenomenon of direction switching. Experiments were conducted on a laboratory scale annular combustor featuring 12 hydrogen-methan flames. System identification techniques were used to fit the model on the experimental data, allowing to extract the potential shape and the intensity of the stochastic excitation. The statistical predictions obtained from the Fokker–Planck equation on the mode’s behaviour and the direction switching time are in good agreement with the experiments.

Noise analysis in the European Pulsar Timing Array data release 2 and its implications on the gravitational-wave background search.

Abstract: The European Pulsar Timing Array (EPTA) collaboration has recently released an extended data set for six pulsars (DR2) and reported evidence for a common red noise signal. Here we present a noise analysis for each of the six pulsars. We consider several types of noise: (i) radio frequency independent, "achromatic", and time-correlated red noise; (ii) variations of dispersion measure and scattering; (iii) system and band noise; and (iv) deterministic signals (other than gravitational waves) that could be present in the PTA data. We perform Bayesian model selection to find the optimal combination of noise components for each pulsar. Using these custom models we revisit the presence of the common uncorrelated red noise signal previously reported in the EPTA DR2 and show that the data still supports it with a high statistical significance. Next, we confirm that there is no preference for or against the Hellings-Downs spatial correlations expected for the stochastic gravitational-wave background. The main conclusion of the EPTA DR2 paper remains unchanged despite a very significant change in the noise model of each pulsar. However, modelling the noise is essential for the robust detection of gravitational waves and its impact could be significant when analysing the next EPTA data release, which will include a larger number of pulsars and more precise measurements.

Observation of ballistic upstream modes at fractional quantum Hall edges of graphene

Abstract: The structure of edge modes at the boundary of quantum Hall (QH) phases forms the basis for understanding low energy transport properties. In particular, the presence of ``upstream'' modes, moving against the direction of charge current flow, is critical for the emergence of renormalized modes with exotic quantum statistics. Detection of excess noise at the edge is a smoking gun for the presence of upstream modes. Here we report on noise measurements at the edges of fractional QH (FQH) phases realized in dual graphite-gated bilayer graphene devices. A noiseless dc current is injected at one of the edge contacts, and the noise generated at contacts at $L= 4\,\mu$m or $10\,\mu$m away along the upstream direction is studied. For integer and particle-like FQH states, no detectable noise is measured. By contrast, for ``hole-conjugate'' FQH states, we detect a strong noise proportional to the injected current, unambiguously proving the existence of upstream modes. The noise magnitude remaining independent of length together with a remarkable agreement with our theoretical analysis demonstrates the ballistic nature of upstream energy transport, quite distinct from the diffusive propagation reported earlier in GaAs-based systems. Our investigation opens the door to the study of upstream transport in more complex geometries and in edges of non-Abelian phases in graphene.

Acoustic multi-layer Helmholtz resonance metamaterials with multiple adjustable absorption peaks

Abstract: The single Helmholtz resonator obtains only one absorption peak in the broad frequency range, which limits its application in reducing the noise with multiple spectra. This paper reports an acoustic multi-layer Helmholtz resonance metamaterial, which can achieve multiple absorption peaks at given low-frequency targets. Meanwhile, through adjusting structural parameters of the multi-layer Helmholtz resonator, its impedance can be altered correspondingly to realize the absorption of noise with the multi groups of specific frequencies. In this paper, in order to achieve fine absorption performance with the specific frequencies of 100 and 400 Hz for a substation noise source, the sound absorption principle of a classical Helmholtz resonator with the embedded aperture is introduced theoretically, and then two series of multi-layer Helmholtz resonance structures with different parameters are designed. Thickness of the multi-layer structure is only 1/30th of the working wavelength, and two groups of resonance peaks are generated at 100 and 400 Hz, respectively. A finite element model of the multi-layer Helmholtz resonator is constructed to simulate its absorption performance. The samples are fabricated through the 3D light-curing printing, and their sound absorption performances are detected by the standing wave method. The simulation results are in good agreement with the experimental data, and two peaks with near-perfect absorptions are achieved at the target frequencies. The multi-layer Helmholtz resonator for achievement of three groups of absorption peaks is proposed later. This work provides an effective method to design a sound absorber with multiple absorption peaks, which can promote the application of acoustic metamaterials.

Four-year Cosmology Large Angular Scale Surveyor (CLASS) Observations: On-sky Receiver Performance at 40, 90, 150, and 220 GHz Frequency Bands

Abstract: The Cosmology Large Angular Scale Surveyor (CLASS) observes the polarized cosmic microwave background (CMB) over the angular scales of 1$^\circ \lesssim \theta \leq$ 90$^\circ$ with the aim of characterizing primordial gravitational waves and cosmic reionization. We report on the on-sky performance of the CLASS Q-band (40 GHz), W-band (90 GHz), and dichroic G-band (150/220 GHz) receivers that have been operational at the CLASS site in the Atacama desert since June 2016, May 2018, and September 2019, respectively. We show that the noise-equivalent power measured by the detectors matches the expected noise model based on on-sky optical loading and lab-measured detector parameters. Using Moon, Venus, and Jupiter observations, we obtain power-to-antenna-temperature calibrations and optical efficiencies for the telescopes. From the CMB survey data, we compute instantaneous array noise-equivalent-temperature sensitivities of 22, 19, 24, and 56 $\mathrm{\mu K}_\mathrm{cmb}\sqrt{\mathrm{s}}$ for the 40, 90, 150, and 220 GHz frequency bands, respectively. These noise temperatures refer to white noise amplitudes, which contribute to sky maps at all angular scales. Future papers will assess additional noise sources impacting larger angular scales.

A 2-Channel 136-156 GHz Dual Down-Conversion I/Q Receiver with 30 dB Gain and 9.5 dB NF Using CMOS 22nm FDSOI

Abstract: This paper presents a D-band 2-channel dual downconversion receiver front-end with a sliding IF architecture in 22nm FDSOI process. A fully-differential D-band low-noise amplifier (LNA) followed by an active double-balanced mixer is first used and down-converts the 137–157 GHz RF signal to an intermediate frequency (IF) of 31–40 GHz. The IF signal is split into I and Q channels and is down-converted to zero-IF output I/Q signals using a passive mixer for low 1/f noise. A x6 LO (17.5 GHz to 35 GHz and to 105 GHz) chain is included on the chip and provides the required LO for both mixers. The receiver achieves a measured peak gain of 27-30 dB, a noise figure of 9-10.5 dB at 136–154 GHz, a simulated output flicker noise corner frequency of 25 kHz and consumes 395 mW for both channels and the LO chain. The measured input P1dB is −29 dBm resulting in a high SNR for wide bandwidth signals. A measured EVM of 4.3-4.8% was achieved at 1–2 Gbaud for 16-QAM and 64-QAM waveforms. To the authors' knowledge, this work presents the first D-band CMOS I/Q receiver with application areas in dual-polarized receivers for point-to-point systems and digital beamforming MIMO arrays.

The Polarization of Ambient Noise on Mars

Abstract: Seismic noise recorded at the surface of Mars has been monitored since February 2019, using the InSight seismometers. This noise can reach −200 dB. It is 500 times lower than on Earth at night and it increases of 30 dB during the day. We analyze its polarization as a function of time and frequency in the band 0.03–1 Hz. We use the degree of polarization to extract signals with stable polarization independent of their amplitude and type of polarization. We detect polarized signals at all frequencies and all times. Glitches correspond to linear polarized signals which are more abundant during the night. For signals with elliptical polarization, the ellipse is in the horizontal plane below 0.3 Hz. In the 0.3-1Hz high frequency band (HF) and except in the evening, the ellipse is in the vertical plane and the major axis is tilted. While polarization azimuths are different in the two frequency bands, they both vary as a function of local hour and season. They are also correlated with wind direction, particularly during the daytime. We investigate possible aseismic and seismic origins of the polarized signals. Lander or tether noise can be discarded. Pressure fluctuations transported by wind may explain part of the HF polarization but not the tilt of the ellipse. This tilt can be obtained if the source is an acoustic emission coming from high altitude at critical angle. Finally, in the evening when the wind is low, the measured polarized signals may correspond to the seismic wavefield of the Mars background noise.

Low Noise Amplifier With 7-K Noise at 1.4 GHz and 25 °C

Abstract: This article describes a low noise amplifier which is believed will have a transformative impact because of the following characteristics: 1) the noise temperature at a physical temperature of 25 °C is a factor of 4 lower than typical commercial LNAs; 2) the noise decreases to 4.5 K at a temperature of −40 °C, a temperature realizable with solid-state coolers; 3) the LNA has an integrated, extremely stable noise source to facilitate measurement of system noise temperature; and 4) the amplifier is powered by a dc voltage and controlled by a tone signal on the RF output cable thus requiring no additional wiring. The amplifier benefits systems in the low microwave frequency range with low background temperature, such as those for space communications and radio astronomy, but without the capital and maintenance costs of cryogenic systems. This article describes the construction and test results with an emphasis on the manufacturability and accuracy of the noise measurements. Finally, the noise of a system deploying the LNA is described.