scholarly journals The 1.3mm Full-Stokes Polarization System at CARMA

2015 ◽  
Vol 04 (01n02) ◽  
pp. 1550005 ◽  
Author(s):  
Charles L. H. Hull ◽  
Richard L. Plambeck
Keyword(s):  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Position Angle ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
Beam Polarization ◽  
Circular Polarizer ◽  
Angle Measurements ◽  
Millimeter Wavelengths ◽  
And Performance

The CARMA 1.3[Formula: see text]mm polarization system consists of dual-polarization receivers that are sensitive to right- (R) and left-circular (L) polarization, and a spectral-line correlator that measures all four cross polarizations ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]) on each of the 105 baselines connecting the 15 telescopes. Each receiver comprises a single feed horn, a waveguide circular polarizer, an orthomode transducer (OMT), two heterodyne mixers, and two low-noise amplifiers (LNAs), all mounted in a cryogenically cooled dewar. Here we review the basics of polarization observations, describe the construction and performance of key receiver components (circular polarizer, OMT, and mixers — but not the correlator), and discuss in detail the calibration of the system, particularly the calibration of the R–L phase offsets and the polarization leakage corrections. The absolute accuracy of polarization position angle measurements was checked by mapping the radial polarization pattern across the disk of Mars. Transferring the Mars calibration to the well-known polarization calibrator 3C286, we find a polarization position angle of [Formula: see text] for 3C286 at 225[Formula: see text]GHz, consistent with other observations at millimeter wavelengths. Finally, we consider what limitations in accuracy are expected due to the signal-to-noise ratio, dynamic range, and primary beam polarization.

scholarly journals Recent Advances in Electrochemical and Optical Biosensors Designed for Detection of Interleukin 6

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 646 ◽  
Author(s):  
Munezza Ata Khan ◽  
Mohammad Mujahid
Keyword(s):  
Interleukin 6 ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
High Specificity ◽  
Detection Methods ◽  
Optical Biosensors ◽  
Integrated Electronics ◽  
Life Threatening ◽  
And Performance ◽  
Commercial Applications

Interleukin 6 (IL-6), being a major component of homeostasis, immunomodulation, and hematopoiesis, manifests multiple pathological conditions when upregulated in response to viral, microbial, carcinogenic, or autoimmune stimuli. High fidelity immunosensors offer real-time monitoring of IL-6 and facilitate early prognosis of life-threatening diseases. Different approaches to augment robustness and enhance overall performance of biosensors have been demonstrated over the past few years. Electrochemical- and fluorescence-based detection methods with integrated electronics have been subjects of intensive research due to their ability to offer a better signal-to-noise ratio, high specificity, ultra-sensitivity, and wide dynamic range. In this review, the pleiotropic role of IL-6 and its clinical significance is discussed in detail, followed by detection schemes devised so far for their quantitative analysis. A critical review on underlying signal amplification strategies and performance of electrochemical and optical biosensors is presented. In conclusion, we discuss the reliability and feasibility of the proposed detection technologies for commercial applications.

scholarly journals Technologies, Design, and Applications of Low-Noise Amplifiers at Millimetre-Wave: State-of-the-Art and Perspectives

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1222 ◽  
Author(s):  
Longhi ◽  
Pace ◽  
Colangeli ◽  
Ciccognani ◽  
Limiti
Keyword(s):  
Integrated Circuit ◽  
Noise Figure ◽  
State Of The Art ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
Wave State ◽  
Millimetre Wave ◽  
Monolithic Microwave Integrated Circuit ◽  
V Band ◽  
And Performance

An overview of applicable technologies and design solutions for monolithic microwave integrated circuit (MMIC) low-noise amplifiers (LNAs) operating at millimeter-wave are provided in this paper. The review starts with a brief description of the targeted applications and corresponding systems. Advanced technologies are presented highlighting potentials and drawbacks related to the considered possibilities. Design techniques, applicable to different requirements, are presented and analyzed. An LNA operating at V-band (59–66 GHz) is designed and tested following the presented guidelines, demonstrating state-of-the-art results in terms of noise figure (average NF < 2 dB). A state-of-the-art table, reporting recent results available in open literature on this topic, is provided and examined, focusing on room temperature operation and performance in cryogenic environment. Finally, trends versus frequency and perspectives are outlined.

scholarly journals NRAO 43-m telescope operation at 170-1700 MHz: a Bi-Static Radar Collaboration

2006 ◽  
Vol 2 (14) ◽  
pp. 367-367
Author(s):  
Glen Langston
Keyword(s):  
Dynamic Range ◽  
Wide Band ◽  
High Dynamic Range ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
Ionospheric Turbulence ◽  
Radio Stations ◽  
University Of Technology ◽  
Fm Radio ◽  
High Dynamic

AbstractThe NRAO 43m telescope has been refurbished and begun regular observations in the frequency range 170 - 1700 MHz. The 43 m operations support a Bi-Static Radar Collaboration to measure the Earth's ionospheric turbulence. Researchers from Chalmers University of Technology in Sweden have designed and built a unique design wide-band feed, 150 - 1700 MHz. Lincoln Laboratories/MIT has packaged the feed with room temperature low noise amplifiers. Lincoln Laboratories has installed a high-dynamic range RF system together with a wide-band sampler system. The NRAO operates the 43 m telescope according to schedules authored by Lincoln Laboratories. Currently the 43 m telescope is tracking spacecraft 48 hr a week. The tracking antenna operation is completely automated. A group at MIT/Haystack have installed a second radar experiment at the 43 m as well as an array of 6 ‘discone’ antennas. Their experiment is testing the use of reflected FM radio stations as probes of the ionosphere.

EVOLUTIONARY SEARCH FOR OPTIMIZED LNA COMPONENTS GEOMETRY

2014 ◽  
Vol 23 (01) ◽  
pp. 1450011 ◽  
Author(s):  
A. FATHIANPOUR ◽  
S. SEYEDTABAII
Keyword(s):  
Design Procedure ◽  
Search Space ◽  
Low Noise ◽  
Dual Band ◽  
Low Noise Amplifiers ◽  
Optimized Design ◽  
Fully Integrated ◽  
Approximate Search ◽  
Input Matching ◽  
And Performance

In this paper, an optimized design procedure based on genetic algorithm (GA) for automatic synthesis of dual-band concurrent fully integrated low-noise amplifiers (LNA) targeted to 802.16d @ 3.5 GHz and 802.11b, g @ 2.4 GHz standards is discussed. The algorithm delivers the circuit elements geometry, rather than their values, and bias levels to secure the best level of LNA gain, input matching, output matching and power consumption. Working on the components geometry level aims at considering the elements parasitic effects. The basic cascode and a current reuse folded cascode LNA's are tried. GA as an optimization engine is programmed in MATLAB and performance evaluation in 0.18 μm RF CMOS TSMC technology is ceded to HSPICE. Results indicate that the automated scheme well computes the desired circuit in an acceptable time span; otherwise, it may be explored by either tremendous manual trial and error or astronomical cycles of an exhaustive search. This is not accomplished without imposing certain approximate search space constraints.

scholarly journals In situtwo-dimensional imaging quick-scanning XAFS with pixel array detector

2011 ◽  
Vol 18 (6) ◽  
pp. 919-922 ◽  
Author(s):  
Hajime Tanida ◽  
Hisao Yamashige ◽  
Yuki Orikasa ◽  
Masatsugu Oishi ◽  
Yu Takanashi ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Low Noise ◽  
Array Detector ◽  
Large Area ◽  
Scanning Method ◽  
Two Dimensional Image ◽  
Pixel Array ◽  
Pixel Array Detector ◽  
Good Signal

Quick-scanning X-ray absorption fine structure (XAFS) measurements were performed in transmission mode using a PILATUS 100K pixel array detector (PAD). The method can display a two-dimensional image for a large area of the order of a centimetre with a spatial resolution of 0.2 mm at each energy point in the XAFS spectrum. The time resolution of the quick-scanning method ranged from 10 s to 1 min per spectrum depending on the energy range. The PAD has a wide dynamic range and low noise, so the obtained spectra have a good signal-to-noise ratio.

scholarly journals Making the Grade Choosing the Right CCD Camera Chip Grade

1999 ◽  
Vol 7 (2) ◽  
pp. 30-31
Author(s):  
Ted Inoue
Keyword(s):  
Dynamic Range ◽  
Fluorescent Microscopy ◽  
Ccd Camera ◽  
Low Noise ◽  
Image Deconvolution ◽  
Microscopy Imaging ◽  
Performance Specifications ◽  
Ratio Imaging ◽  
And Performance ◽  
The Right

Today, charge coupled devices (CCDs) have become the de-facto standard for scientific imaging, In fact, their potential for high resolution, sensitivity, wide dynamic range and low noise has made them the device of choice for most fluorescent microscopy imaging applications, This is especially true for quantitative microscopy applications such as ratio imaging, fluorescent in-situ hybridization and image deconvolution.However, choosing the most appropriate CCD camera for each application can be quite challenging given the broad range of features and performance specifications. This month's article focuses on a single characteristic of the CCD: the chip grade.

scholarly journals De-noising of an Image using Fuzzy Inference System and Performance Comparison with the Conventional system

2021 ◽  
Vol 2 (03) ◽  
pp. 164-168
Author(s):  
Ahmed Farhan ◽  
Rezwan us Saleheen ◽  
Chen Li Wei ◽  
Farhan Mahbub
Keyword(s):  
Fuzzy Inference System ◽  
Fuzzy Inference ◽  
Signal To Noise Ratio ◽  
Performance Comparison ◽  
Low Noise ◽  
Inference System ◽  
Noise Rate ◽  
And Performance ◽  
The One ◽  
Different Levels

Noise prevailing in the image can diminish the physical appearance of the objects existing within the image and make them frail. Present research emphasizes a fuzzy inference system eradicating several types of noise from the images. The investigation implies the utilization of different levels of Salt & Pepper noise. Followed by the pixel determination applying a mask, the disparity between the focused pixel's intensity with the minimum, average, and maximum power of the chosen window has been determined. Since two fuzzy valued outputs have been obtained to match them, the one provided by a low noise rate would demonstrate the more accurate filter for the selected window. Utilizing Matlab the Peak Signal-to-Noise ratio (PSNR) and Mean Square Error (MSE) are determined for evaluating the noise reduction performance. However, these values of PSNR and MSE obtained from this research are also compared with the conventional fuzzy filtering system.

scholarly journals A Digital Beamformer for the PHAROS2 Phased Array Feed

2020 ◽  
Vol 09 (03) ◽  
pp. 2050013
Author(s):  
A. Melis ◽  
R. Chiello ◽  
G. Comoretto ◽  
R. Concu ◽  
A. Magro ◽  
...  
Keyword(s):  
Phased Array ◽  
Low Frequency ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
Field Programmable ◽  
Programmable Gate Arrays ◽  
Processing Module ◽  
Primary Focus ◽  
Single Polarization ◽  
And Performance

PHased Arrays for Reflector Observing Systems (PHAROS) is a C-band (4–8[Formula: see text]GHz) Phased Array Feed (PAF) receiver designed to operate from the primary focus of a large single-dish radio astronomy antenna. It consists of an array of 220-element Vivaldi antennas ([Formula: see text] polarization), cryogenically cooled at roughly 20[Formula: see text]K along with low noise amplifiers (LNAs), and of analogue beamformers cryogenically cooled at roughly 80[Formula: see text]K. PHAROS2, the upgrade of PHAROS, is a PAF demonstrator developed in the framework of the Square Kilometer Array Advanced Instrumentation Program (SKA AIP) with the goal of investigating the potential of the PAF technologies at high frequencies in view of their possible application on the SKA dish telescopes. The PHAROS2 design includes new cryogenically cooled LNAs with state-of-the-art performance, a digital beamformer capable of synthesizing four beams from a sub-array of 24 single-polarization antenna elements, and a C-band multi-channel Warm Section receiver capable of analogue filtering and down-converting the signals from the antennas to a suitable frequency range at the input of the digital backend, providing an instantaneous bandwidth of 275[Formula: see text]MHz for each signal. In this paper, we describe the design and performance of the PHAROS2 digital backend/beamformer, based on the Italian Tile Processing Module (ITPM) hardware, which was initially developed for the SKA Low Frequency Aperture Array (LFAA). The backend was adapted to perform the beamforming for our PAF application. We describe the implementation of the beamformer on the Field Programmable Gate Arrays (FPGAs) of the ITPM and how the backend was successfully used to synthesize four independent beams, both in the laboratory (across the entire 275[Formula: see text]MHz instantaneous bandwidth) and during on-field observations at the BEST-2 array (across 16[Formula: see text]MHz instantaneous bandwidth), which is a subset of the Northern Cross Radio Telescope (located in the district of Bologna, Italy). The beamformer design allows re-scaling to a greater number of beams and wider bandwidths.

scholarly journals Apsu: a wireless multichannel receiver system for surface-NMR groundwater investigations

2018 ◽  
Author(s):  
Lichao Liu ◽  
Denys Grombacher ◽  
Esben Auken ◽  
Jakob Juul Larsen
Keyword(s):  
Data Acquisition ◽  
Dynamic Range ◽  
Dead Time ◽  
Signal To Noise Ratio ◽  
Noise Cancellation ◽  
Low Noise ◽  
Dipole Source ◽  
Central Unit ◽  
Long Distance ◽  
Receiver System

Abstract. Surface nuclear magnetic resonance (surface-NMR) has the potential to be an important geophysical method for groundwater investigations, but the technique suffers from poor signal-to-noise ratio (SNR) and long measurement times. We present a new wireless, multichannel surface-NMR receiver system (called Apsu) designed to improve SNR, field deployability and minimize instrument dead time. It is a distributed wireless system consisting of a central unit and independently operated data acquisition boxes each with three channels that measure either the NMR signal or noise for reference noise cancellation. Communication between the central unit and the data acquisition boxes is done through long distance WiFi and recordings are retrieved in real time. The receiver system employs differential coils with low-noise pre-amplifiers and high-resolution wide dynamic range acquisition boards. Each channel contains multi-stage amplifiers, short settling-time filters and two 24-bit analog-to-digital converters in dual-gain mode sampling at 31.25 kHz. The system timing is controlled by GPS clock and sample jitter between channels is less than 12 ns. Separated transmitter/receiver coils and continuous acquisition allow NMR signals to be measured with zero instrument dead time. In processed data, analog and digital filters causes an effective dead time of 4 ms. Synchronization with an independently operated transmitter system is done with a current probe monitoring the NMR excitation pulses. The noise density measured in a shorted-input test is 1.8 nV/√(Hz). We verify the accuracy of the receiver system with measurements of a magnetic dipole source and by comparing our NMR data with data obtained using an existing commercial instrument. The applicability of the system for reference noise cancellation is validated with field data.

Sign in / Sign up

Export Citation Format

Share Document