scholarly journals Practical Limits in the Sensitivity-Linearity Trade-off for Radio Telescope Front Ends in the HF and VHF-low Bands

2016 ◽  
Vol 05 (02) ◽  
pp. 1650004 ◽  
Author(s):  
R. H. Tillman ◽  
S. W. Ellingson ◽  
J. Brendler
Keyword(s):  
Radio Telescope ◽  
Integrated Circuit ◽  
Noise Temperature ◽  
Low Frequency ◽  
Low Noise ◽  
Primary Concern ◽  
Radio Telescopes ◽  
Small Component ◽  
Trade Off ◽  
System Temperature

Radio telescope front ends must have simultaneously low noise and sufficiently-high linearity to accommodate interfering signals. Typically these are opposing design goals. For modern radio telescopes operating in the HF (3–30[Formula: see text]MHz) and VHF-low (30–88[Formula: see text]MHz) bands, the problem is more nuanced in that front end noise temperature may be a relatively small component of the system temperature, and increased linearity may be required due to the particular interference problems associated with this spectrum. In this paper, we present an analysis of the sensitivity-linearity trade-off at these frequencies, applicable to existing commercially-available monolithic microwave integrated circuit (MMIC) amplifiers in single-ended, differential, and parallelized configurations. This analysis and associated findings should be useful in the design and upgrade of front ends for low frequency radio telescopes. The analysis is demonstrated explicitly for one of the better-performing amplifiers encountered in this study, the Mini-Circuits PGA-103, and is confirmed by hardware measurements. We also present a design based on the Mini-Circuits HELA-10 amplifier, which is better-suited for applications where linearity is a primary concern.

A High Uniformity Readout Integrated Circuit for Infrared Focal Plane Array Applications

2014 ◽  
Vol 602-605 ◽  
pp. 2632-2636
Author(s):  
Tong Zhou ◽  
Tao Dong ◽  
Yan Su ◽  
Yong He
Keyword(s):  
Integrated Circuit ◽  
Focal Plane ◽  
Infrared Image ◽  
Low Frequency ◽  
Low Noise ◽  
Focal Plane Arrays ◽  
Cmos Process ◽  
Readout Integrated Circuit ◽  
Practical Applications ◽  
High Uniformity

Infrared focal plane arrays (IRFPA) suffer from inherent low frequency and fixed patter noise (FPN). To achieve high quality infrared image by mitigating the FPN of IRFPAs, a novel low-noise and high uniformity readout integrated circuit (ROIC) has been proposed. A correlated double sampling (CDS) with single capacitor method has been adopted in the ROIC design which can effectively reduce the FPN, KTC and 1/f noise. A 4×4 experimental readout chip has been designed and fabricated using the SMIC 0.18 μm CMOS process. Both the function and performance of the proposed readout circuit have been verified by experimental results. The test results show that the proposed ROIC has a good performance in practical applications.

Low-frequency noise correlations in lateral pnp bipolar transistors

1992 ◽  
Vol 70 (10-11) ◽  
pp. 1112-1117
Author(s):  
A. Nathan ◽  
E. Charbon ◽  
W. Kung ◽  
A. Salim
Keyword(s):  
Integrated Circuit ◽  
Low Frequency ◽  
Intrinsic Noise ◽  
Low Noise ◽  
Bipolar Transistors ◽  
Current Gain ◽  
Low Noise Amplifiers ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Low Frequencies

Measurement results of low-frequency noise behaviour, and in particular, the noise correlations in lateral pnp bipolar transistors are presented for various bias conditions in both forward active and saturation regimes. The correlation in output collector noise is very high with a value close to unity only when the device is in medium injection. At extremely high injection, the degree of coherence degrades, depicting a behaviour similar to the forward current gain of the device. This degradation can be attributed to emitter-crowding effects. The correlation in output noise can be exploited to drastically suppress the intrinsic noise, particularly at low frequencies, making such devices useful for the input stage of amplifiers; the first step towards realisation of ultra low-noise amplifiers in standard integrated circuit technology.

scholarly journals A Tri-band Low-noise Cryogenic Receiver for Geodetic VLBI Observations with VGOS Radio Telescopes

2019 ◽  
Author(s):  
José A. López-Pérez ◽  
Félix Tercero-Martínez ◽  
José M. Serna-Puente ◽  
Beatriz Vaquero-Jiménez ◽  
María Patino-Esteban ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Very Long Baseline Interferometry ◽  
Low Noise ◽  
Radio Telescopes ◽  
Geospatial Information ◽  
Ka Band ◽  
Geodetic Vlbi ◽  
Long Baseline ◽  
Vlbi Observations ◽  
X Band

This paper shows the development of a simultaneous tri-band (S: 2.2 - 2.7 GHz, X: 7.5 - 9 GHz and Ka: 28 - 33 GHz) low-noise cryogenic receiver for geodetic Very Long Baseline Interferometry (geo-VLBI) which has been developed by the technical staff of Yebes Observatory (IGN) laboratories in Spain. The receiver was installed in the first radio telescope of the Red Atlántica de Estaciones Geodinámicas y Espaciales (RAEGE) project, which is located in Yebes Observatory, in the frame of the VLBI Global Observing System (VGOS). After this, the receiver was borrowed by the Norwegian Mapping Autorithy (NMA) for the commissioning of two VGOS radiotelescopes in Svalbard (Norway). A second identical receiver was built for the Ishioka VGOS station of the Geospatial Information Authority (GSI) of Japan, and a third one for the second RAEGE VGOS station, located in Santa María (Açores Archipelago, Portugal). The average receiver noise temperatures are 21, 23 and 25 Kelvin and the measured antenna efficiencies are 70%, 75% and 60% in S-band, X-band and Ka-band, respectively.

scholarly journals Cosmic Microwave Background at Low Frequencies

2002 ◽  
Vol 199 ◽  
pp. 58-65 ◽  
Author(s):  
R. Subrahmanyan
Keyword(s):  
Cosmic Microwave Background ◽  
Radio Telescope ◽  
Low Frequency ◽  
Cosmological Models ◽  
Large Element ◽  
Radio Telescopes ◽  
Next Generation ◽  
Microwave Background ◽  
Low Frequencies

The next generation low-frequency radio telescopes may probe cosmological models by means of observations of the cosmic microwave background (CMB). I discuss the prospects for observations of CMB imprints —- recombination lines from the epoch of recombination, μ distortions and angular temperature anisotropies —- at low frequencies. A future low-frequency radio telescope, like the proposed SKA, may be capable of attempting some difficult CMB measurements because of the large collecting area and large element numbers; however, this will require a telescope design that will allow specialized calibration strategies and will give emphasis to the control of spurious responses.

scholarly journals Experimental Verification of the Concept of Using LOFAR Radio-Telescopes as Receivers in Passive Radiolocation Systems

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2043
Author(s):  
Julia Kłos ◽  
Konrad Jędrzejewski ◽  
Aleksander Droszcz ◽  
Krzysztof Kulpa ◽  
Mariusz Pożoga ◽  
...  
Keyword(s):  
Signal Processing ◽  
Radio Telescope ◽  
Experimental Verification ◽  
Low Frequency ◽  
Radar System ◽  
Passive Radar ◽  
Radio Telescopes ◽  
Digital Radio ◽  
Radio Broadcasting ◽  
Theoretical Considerations

The paper presents a new idea of using a low-frequency radio-telescope belonging to the LOFAR network as a receiver in a passive radar system. The structure of a LOFAR radio-telescope station is described in the context of applying this radio-telescope for detection of aerial (airplanes) and space (satellite) targets. The theoretical considerations and description of the proposed signal processing schema for the passive radar based on a LOFAR radio-telescope are outlined in the paper. The results of initial experiments verifying the concept of a LOFAR station use as a receiver and a commercial digital radio broadcasting (DAB) transmitters as illuminators of opportunity for aerial object detection are presented.

scholarly journals Technology developments for a large-format heterodyne MMIC array at W-band

2012 ◽  
Vol 4 (3) ◽  
pp. 299-307 ◽  
Author(s):  
Matthew Sieth ◽  
Sarah Church ◽  
Judy M. Lau ◽  
Patricia Voll ◽  
Todd Gaier ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Noise Temperature ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
Multichip Modules ◽  
Large Format ◽  
Coupled Line ◽  
W Band ◽  
Receiver System ◽  
A Chain

We report on the development of W-band (75–110 GHz) heterodyne receiver technology for large-format astronomical arrays. The receiver system is designed to be both mass producible, so that the designs could be scaled to thousands of receiver elements, and modular. Most of the receiver functionality is integrated into compact monolithic microwave integrated circuit (MMIC) amplifier-based multichip modules. The MMIC modules include a chain of InP MMIC low-noise amplifiers, coupled-line bandpass filters, and sub-harmonic Schottky diode mixers. The receiver signals will be routed to and from the MMIC modules on a multilayer high-frequency laminate, which includes splitters, amplifiers, and frequency triplers. A prototype MMIC module has exhibited a band-averaged noise temperature of 41 K from 82 to 100 GHz and a gain of 29 dB at 15 K, which is the state-of-the-art for heterodyne multichip modules.

scholarly journals An ultra-wide bandwidth (704 to 4 032 MHz) receiver for the Parkes radio telescope

2020 ◽  
Vol 37 ◽  
Author(s):  
George Hobbs ◽  
Richard N. Manchester ◽  
Alex Dunning ◽  
Andrew Jameson ◽  
Paul Roberts ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Low Frequency ◽  
Wide Bandwidth ◽  
Beam Shape ◽  
System Noise ◽  
Receiver System ◽  
System Temperature ◽  
Frequency Coverage ◽  
Data Files ◽  
Continuous Frequency

Abstract We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band ( ${\sim}60\%$ ), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.

scholarly journals A Low frequency Southern Sky Survey Using the Mauritius Radio Telescope

2002 ◽  
Vol 199 ◽  
pp. 25-31
Author(s):  
N. Udaya Shankar
Keyword(s):  
Radio Telescope ◽  
Low Frequency ◽  
Fourier Synthesis ◽  
North East ◽  
The North ◽  
Sky Survey ◽  
Correlation Receiver ◽  
Complex Correlation ◽  
Right Ascension ◽  
East West

The Mauritius Radio Telescope (MRT) is a Fourier synthesis instrument which has been built to fill the gap in the availability of deep sky surveys at low radio frequencies in the southern hemisphere. It is situated in the north-east of Mauritius at a southern latitude of 20°.14 and an eastern longitude of 57°.73. The aim of the survey with the MRT is to contribute to the database of southern sky sources in the declination range −70° ≤ δ ≤ −10°, covering the entire 24 hours of right ascension, with a resolution of 4' × 4'.6sec(δ + 20.14°) and a point source sensitivity of 200 mJy (3σ level) at 151.5 MHz.MRT is a T-shaped non-coplanar array consisting of a 2048 m long East-West arm and a 880 m long South arm. In the East-West arm 1024 fixed helices are arranged in 32 groups and in the South arm 16 trolleys, with four helices on each, which move on a rail are used. A 512 channel, 2-bit 3-level complex correlation receiver is used to measure the visibility function. At least 60 days of observing are required for obtaining the visibilities up to the 880 m spacing. The calibrated visibilities are transformed taking care of the non-coplanarity of the array to produce an image of the area of the sky under observation.This paper will describe the telescope, the observations carried out so far, a few interesting aspects of imaging with this non-coplanar array and present results of a low resolution survey (13' × 18') covering roughly 12 hours of right ascension, and also present an image with a resolution of 4' × 4'.6sec(δ + 20.14°) made using the telescope.

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