scholarly journals Multifunction waveform generator for EM receiver testing

2018 ◽  
Vol 7 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Kai Chen ◽  
Sheng Jin ◽  
Ming Deng
Keyword(s):  
Time Synchronization ◽  
Synthetic Data ◽  
Development Stage ◽  
Induced Polarization ◽  
Low Noise ◽  
Positive Zero ◽  
Frequency Range ◽  
Waveform Generator ◽  
Controlled Source ◽  
Long Period

Abstract. In many electromagnetic (EM) methods – such as magnetotelluric, spectral-induced polarization (SIP), time-domain-induced polarization (TDIP), and controlled-source audio magnetotelluric (CSAMT) methods – it is important to evaluate and test the EM receivers during their development stage. To assess the performance of the developed EM receivers, controlled synthetic data that simulate the observed signals in different modes are required. In CSAMT and SIP mode testing, the waveform generator should use the GPS time as the reference for repeating schedule. Based on our testing, the frequency range, frequency precision, and time synchronization of the currently available function waveform generators on the market are deficient. This paper presents a multifunction waveform generator with three waveforms: (1) a wideband, low-noise electromagnetic field signal to be used for magnetotelluric, audio-magnetotelluric, and long-period magnetotelluric studies; (2) a repeating frequency sweep square waveform for CSAMT and SIP studies; and (3) a positive-zero–negative-zero signal that contains primary and secondary fields for TDIP studies. In this paper, we provide the principles of the above three waveforms along with a hardware design for the generator. Furthermore, testing of the EM receiver was conducted with the waveform generator, and the results of the experiment were compared with those calculated from the simulation and theory in the frequency band of interest.

scholarly journals Multifunction waveform generator for EM receiver testing

2017 ◽  
Author(s):  
Kai Chen ◽  
Sheng Jin ◽  
Ming Deng
Keyword(s):  
Time Domain ◽  
Time Synchronization ◽  
Synthetic Data ◽  
Development Stage ◽  
Induced Polarization ◽  
Low Noise ◽  
Positive Zero ◽  
Waveform Generator ◽  
Controlled Source ◽  
Polarization Studies

Abstract. In many electromagnetic (EM) methods, such as magnetotelluric, spectrum induced polarization, time domain induced polarization, and controlled source audio magnetotelluric methods, it is important to evaluate and test the EM receivers during their development stage. To assess the performance of the developed EM receivers, controlled synthetic data that simulates the observed signals in different modes is required. Based on our testing, the frequency range, frequency precision, and time synchronization of the currently available function waveform generators in the market are deficient. This paper presents a multifunction waveform generator with three waveforms: (1) a wide-band low-noise electromagnetic field signal to be used for magnetotelluric, audio-magnetotelluric, and long period magnetotelluric studies; (2) a repeating frequency sweep square waveform for controlled source audio magnetotelluric and spectrum induced polarization studies; and (3) a positive-zero-negative-zero signal that contains primary and secondary fields for time domain induced polarization studies. In this paper, we provide the principles of the above three waveforms along with a hardware design for the generator. Furthermore, testing of the EM receiver was conducted with the waveform generator, and the results of the experiment were compared with those calculated from the simulation and theory in the frequency band of interest.

60 GHz-Band Low-Noise Amplifier

2017 ◽  
Vol 26 (05) ◽  
pp. 1750075 ◽  
Author(s):  
Najam Muhammad Amin ◽  
Lianfeng Shen ◽  
Zhi-Gong Wang ◽  
Muhammad Ovais Akhter ◽  
Muhammad Tariq Afridi
Keyword(s):  
Transmission Line ◽  
Quality Factor ◽  
Noise Figure ◽  
Cmos Technology ◽  
Low Noise ◽  
Constant Current ◽  
60 Ghz ◽  
Frequency Range ◽  
Constant Current Density ◽  
Chip Area

This paper presents the design of a 60[Formula: see text]GHz-band LNA intended for the 63.72–65.88[Formula: see text]GHz frequency range (channel-4 of the 60[Formula: see text]GHz band). The LNA is designed in a 65-nm CMOS technology and the design methodology is based on a constant-current-density biasing scheme. Prior to designing the LNA, a detailed investigation into the transistor and passives performances at millimeter-wave (MMW) frequencies is carried out. It is shown that biasing the transistors for an optimum noise figure performance does not degrade their power gain significantly. Furthermore, three potential inductive transmission line candidates, based on coplanar waveguide (CPW) and microstrip line (MSL) structures, have been considered to realize the MMW interconnects. Electromagnetic (EM) simulations have been performed to design and compare the performances of these inductive lines. It is shown that the inductive quality factor of a CPW-based inductive transmission line ([Formula: see text] is more than 3.4 times higher than its MSL counterpart @ 65[Formula: see text]GHz. A CPW structure, with an optimized ground-equalizing metal strip density to achieve the highest inductive quality factor, is therefore a preferred choice for the design of MMW interconnects, compared to an MSL. The LNA achieves a measured forward gain of [Formula: see text][Formula: see text]dB with good input and output impedance matching of better than [Formula: see text][Formula: see text]dB in the desired frequency range. Covering a chip area of 1256[Formula: see text][Formula: see text]m[Formula: see text]m including the pads, the LNA dissipates a power of only 16.2[Formula: see text]mW.

The variability of naturally occurring magnetic field levels: 10 Hz to 8 kHz

Geophysics ◽  
2010 ◽  
Vol 75 (6) ◽  
pp. F187-F197 ◽  
Author(s):  
Ben K. Sternberg
Keyword(s):  
Magnetic Field ◽  
Noise Level ◽  
Monsoon Season ◽  
Signal Frequency ◽  
Time Interval ◽  
Frequency Range ◽  
Noise Levels ◽  
Controlled Source ◽  
Naturally Occurring ◽  
Minimum Noise

The variability of naturally occurring magnetic fields in the frequency range from [Formula: see text] over a period of one year was studied. Contour plots for the [Formula: see text], [Formula: see text], and [Formula: see text] components and for frequencies of 10, 100, 1000, 2000, and 8000 Hz were produced. Average, minimum, maximum, and the standard deviations of these fields were also calculated for 12 distinctive time intervals. In the 1– to 8–kHz frequency range, the noise levels are typically higher at night. In the 10- to 100-Hz frequency range, the noise levels are typically higher during the day. During mid- to late-summer, there is frequent thunderstorm activity, known in the southwest United States as the monsoon season. The magnetic field levels are often very high during this time period. These variability ranges can be used to estimate the lowest levels of noise that may be encountered during field surveys, which iswhat the authors are looking for when running controlled-source electrical method surveys. These variability ranges can also be used to estimate the highest levels that may be encountered, which is what the authors are looking for when running natural-source electrical methods surveys, such as audio frequency magnetotelluric (AMT) surveys. These measurements of magnetic field strength variability show that better data for controlled-source electrical measurements can be obtained using the minimum noise level measurements, as opposed to using signal integration or signal averaging with all of the data. The minimum noise level is found by using frequency bins adjacent to the signal-frequency bin. Likewise, if one is interested in measuring the naturally occurring magnetic field data, using the maximum values during each time interval makes AMT measurements possible when the natural signal level is very low, particularly in the AMT dead zone around [Formula: see text].

A high-sensitivity strain/inertial seismograph installation

1970 ◽  
Vol 60 (6) ◽  
pp. 1803-1822 ◽  
Author(s):  
James E. Fix ◽  
John R. Sherwin
Keyword(s):  
Environmental Control ◽  
Earth Tide ◽  
High Sensitivity ◽  
Low Noise ◽  
Photographic Film ◽  
Noise Levels ◽  
Directional Response ◽  
Long Period ◽  
Phase Velocities ◽  
Short Period

Abstract A seismograph complex consisting of short-period (SP), long-period (LP), and extended long-period (XLP) inertial and strain seismographs has been installed. Recordings are made on magnetic tape and photographic film. Routine magnifications on the 20-trace, 16-mm film recorders for all three components are: SP inertial, 500 K; LP inertial, 100 K. The noise levels permit equivalent magnifications on the strain seismographs. The complex provides seismic wave discrimination by directional response, which is independent of period, and by detection of differences in phase velocities between P, S, Love, or Rayleigh arrivals. The strain seismographs use 40-m-long rods and moving coil transducers with generator constants of 32,000 v/m/sec. They sense waves of 5 × 10-13 strain at 30 sec and reject the 2 × 10-8 earth-tide strain. A low-noise preamplifier drives a filter assembly which provides SP, LP, and XLP strain outputs. The complex is installed in an abandoned mine 50 km southeast of Phoenix, Arizona. Environmental control is provided by burial at a depth of about 110 m in a quartz diorite, by sealing the mine, and by insulating the seismometers.

Marlim R3D: A realistic model for controlled-source electromagnetic simulations — Phase 2: The controlled-source electromagnetic data set

Geophysics ◽  
2019 ◽  
Vol 84 (5) ◽  
pp. E293-E299
Author(s):  
Jorlivan L. Correa ◽  
Paulo T. L. Menezes
Keyword(s):  
A Priori ◽  
Synthetic Data ◽  
Realistic Model ◽  
Earth Model ◽  
Data Sets ◽  
Data Set ◽  
Geoelectric Model ◽  
Controlled Source ◽  
The North ◽  
Electromagnetic Simulations

Synthetic data provided by geoelectric earth models are a powerful tool to evaluate a priori a controlled-source electromagnetic (CSEM) workflow effectiveness. Marlim R3D (MR3D) is an open-source complex and realistic geoelectric model for CSEM simulations of the postsalt turbiditic reservoirs at the Brazilian offshore margin. We have developed a 3D CSEM finite-difference time-domain forward study to generate the full-azimuth CSEM data set for the MR3D earth model. To that end, we fabricated a full-azimuth survey with 45 towlines striking the north–south and east–west directions over a total of 500 receivers evenly spaced at 1 km intervals along the rugged seafloor of the MR3D model. To correctly represent the thin, disconnected, and complex geometries of the studied reservoirs, we have built a finely discretized mesh of [Formula: see text] cells leading to a large mesh with a total of approximately 90 million cells. We computed the six electromagnetic field components (Ex, Ey, Ez, Hx, Hy, and Hz) at six frequencies in the range of 0.125–1.25 Hz. In our efforts to mimic noise in real CSEM data, we summed to the data a multiplicative noise with a 1% standard deviation. Both CSEM data sets (noise free and noise added), with inline and broadside geometries, are distributed for research or commercial use, under the Creative Common License, at the Zenodo platform.

Methods for the robust computation of the long-period seismic spectrum of broad-band arrays

2020 ◽  
Vol 222 (3) ◽  
pp. 1480-1501
Author(s):  
Ross C Caton ◽  
Gary L Pavlis ◽  
David J Thomson ◽  
Frank L Vernon
Keyword(s):  
Signal To Noise Ratio ◽  
Spectral Band ◽  
Broad Band ◽  
Low Noise ◽  
Small Aperture ◽  
Transient Signals ◽  
Seismic Arrays ◽  
Low Snr ◽  
Long Period ◽  
Student’S T

SUMMARY We describe array methods to search for low signal-to-noise ratio (SNR) signals in long-period seismic data using Fourier analysis. This is motivated by published results that find evidence of solar free oscillations in the Earth's seismic hum. Previous work used data from only one station. In this paper, we describe methods for computing spectra from array data. Arrays reduce noise level through averaging and provide redundancy that we use to distinguish coherent signal from a random background. We describe two algorithms for calculating a robust spectrum from seismic arrays, an algorithm that automatically removes impulsive transient signals from data, a jackknife method for estimating the variance of the spectrum, and a method for assessing the significance of an entire spectral band. We show examples of their application to data recorded by the Homestake Mine 3-D array in Lead, SD and the Piñon Flats PY array. These are two of the quietest small aperture arrays ever deployed in North America. The underground Homestake data has exceptionally low noise, and the borehole sensors of the PY array also have very low noise, making these arrays well suited to finding very weak signals. We find that our methods remove transient signals effectively from the data so that even low-SNR signals in the seismic background can be found and tested. Additionally, we find that the jackknife variance estimate is comparable to the noise floor, and we present initial evidence for solar g-modes in our data through the T2 test, a multivariate generalization of Student's t-test.

HIGH-PERFORMANCE SURFACE TRANSVERSE WAVE RESONATORS IN THE LOWER GHz FREQUENCY RANGE

2000 ◽  
Vol 10 (03) ◽  
pp. 735-792 ◽  
Author(s):  
IVAN D. AVRAMOV
Keyword(s):  
Phase Noise ◽  
Transverse Wave ◽  
High Power ◽  
Acoustic Waves ◽  
Power Efficiency ◽  
Surface Acoustic Waves ◽  
Low Noise ◽  
Propagation Loss ◽  
Range Data ◽  
Frequency Range

Since the first successful surface transverse wave (STW) resonator was demonstrated by Bagwell and Bray in 1987, STW resonant devices on temperature stable cut orientations of piezoelectric quartz have enjoyed a spectacular development. The tremendous interest in these devices is based on the fact that, compared to the widely used surface acoustic waves (SAW), the STW acoustic mode features some unique properties which makes it very attractive for low-noise microwave oscillator applications in the 1.0 to 3.0 GHz frequency range in which SAW based or dielectric resonator oscillators (DRO) fail to provide satisfactory performance. These STW properties include: high propagation velocity, material Q-values exceeding three times those of SAW and bulk acoustic waves (BAW) on quartz, low propagation loss, unprecedented 1/f device phase noise, extremely high power handling ability, as well as low aging and low vibration sensitivity. This paper reviews the fundamentals of STW propagation in resonant geometries on rotated Y-cuts of quartz and highlights important design aspects necessary for achieving desired STW resonator performance. Different designs of high- and low-Q, low-loss resonant devices and coupled resonator filters (CRF) in the 1.0 to 2.5 GHz range are characterized and discussed. Design details and data on state-of-the-art STW based fixed frequency and voltage controlled oscillators (VCO) with low phase noise and high power efficiency are presented. Finally, several applications of STW devices in GHz range data transmitters, receivers and sensors are described and discussed.

Design and modeling of an ultra-wideband low-noise distributed amplifier in InP DHBT technology

2019 ◽  
Vol 11 (7) ◽  
pp. 635-644 ◽  
Author(s):  
T. Shivan ◽  
E. Kaule ◽  
M. Hossain ◽  
R. Doerner ◽  
T. Johansen ◽  
...  
Keyword(s):  
Noise Figure ◽  
Impedance Matching ◽  
Low Noise ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Collector Current ◽  
Noise Sources ◽  
Distributed Amplifier ◽  
Double Heterojunction ◽  
High Bandwidth

AbstractThis paper reports on an ultra-wideband low-noise distributed amplifier (LNDA) in a transferred-substrate InP double heterojunction bipolar transistor (DHBT) technology which exhibits a uniform low-noise characteristic over a large frequency range. To obtain very high bandwidth, a distributed architecture has been chosen with cascode unit gain cells. Each unit cell consists of two cascode-connected transistors with 500 nm emitter length and ft/fmax of ~360/492 GHz, respectively. Due to optimum line-impedance matching, low common-base transistor capacitance, and low collector-current operation, the circuit exhibits a low-noise figure (NF) over a broad frequency range. A 3-dB bandwidth from 40 to 185 GHz is measured, with an NF of 8 dB within the frequency range between 75 and 105 GHz. Moreover, this circuit demonstrates the widest 3-dB bandwidth operation among all reported single-stage amplifiers with a cascode configuration. Additionally, this work has proposed that the noise sources of the InP DHBTs are largely uncorrelated. As a result, a reliable prediction can be done for the NF of ultra-wideband circuits beyond the frequency range of the measurement equipment.

scholarly journals A wideband cryogenic microwave low-noise amplifier

2020 ◽  
Vol 11 ◽  
pp. 1484-1491
Author(s):  
Boris I Ivanov ◽  
Dmitri I Volkhin ◽  
Ilya L Novikov ◽  
Dmitri K Pitsun ◽  
Dmitri O Moskalev ◽  
...  
Keyword(s):  
Power Dissipation ◽  
Coplanar Waveguide ◽  
Noise Temperature ◽  
High Electron Mobility Transistor ◽  
Low Noise ◽  
High Electron ◽  
Frequency Range ◽  
Noise Amplifier ◽  
On Chip

A broadband low-noise four-stage high-electron-mobility transistor amplifier was designed and characterized in a cryogen-free dilution refrigerator at the 3.8 K temperature stage. The obtained power dissipation of the amplifier is below 20 mW. In the frequency range from 6 to 12 GHz its gain exceeds 30 dB. The equivalent noise temperature of the amplifier is below 6 K for the presented frequency range. The amplifier is applicable for any type of cryogenic microwave measurements. As an example we demonstrate here the characterization of the superconducting X-mon qubit coupled to an on-chip coplanar waveguide resonator.

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