Multifrequency Cryogenically Cooled Front-End Receivers for the Westerbork Synthesis Radio Telescope

1982 ◽  
Vol 30 (2) ◽  
pp. 201-209 ◽  
Author(s):  
J.L. Casse ◽  
E.E.M. Woestenburg ◽  
J.J. Visser
Keyword(s):  
Radio Telescope ◽  
Front End

scholarly journals The multi frequency front end: a new type of front end for the Westerbork Synthesis Radio Telescope

1991 ◽  
Vol 131 ◽  
pp. 42-46
Author(s):  
G.H. Tan
Keyword(s):  
Radio Telescope ◽  
Local Oscillator ◽  
Frequency Bands ◽  
Front End ◽  
New Type

AbstractThe Westerbork Synthesis Radio Telescope will be equipped with new front ends. These front ends will cover 8 frequency bands in the range from 250 MHz to 8.6 GHz. For the frequency bands above 1.2 GHz the sensitivity of the instrument will be drastically improved. Two independent local oscillator systems make it possible to observe in two frequency bands simultaneously.

scholarly journals Pulsar timing at Kalyazin (Russia)

2000 ◽  
Vol 177 ◽  
pp. 57-60
Author(s):  
O.V. Doroshenko ◽  
Yu.P. Ilyasov ◽  
V.V. Oreshko
Keyword(s):  
General Relativity ◽  
Local Time ◽  
Radio Telescope ◽  
Orthogonal Polarization ◽  
Hydrogen Maser ◽  
Radio Pulsars ◽  
Time Service ◽  
Binary Pulsars ◽  
Front End ◽  
Pulsar Timing

AbstractRegular timing observations of millisecond and binary pulsars are made with the 64-m radio telescope at Kalyazin (Russia). Filterbank 160-channel receiver is used for observations at 0.6 GHz in two circular orthogonal polarization. Precise local time service (based upon a rubidium standards and hydrogen maser) is used for measurements of Times-of-Arrival (TOA) from radio pulsars. A local time scale is compared by GPS and TV-systems with the basic AT-scales (UTC(USNO) and UTC(SU)) within an accuracy about 50nsper day. Recently the second 1.4 GHz receiver (250 kHz × 64 channels) was constructed and installed at Kalyazin radio telescope. There is a possibility to combine a part of the 1.4 GHz back-end with the 2.2 GHz front-end to produce timing observations at three frequencies simultaneously. We present a results of precise timing observations conducted by the Kalyazin pulsar system. Most of data were obtained at 0.6 GHz in 1997–1999. The data will be used for valuable applications in fundamental metrology, interstellar medium, general relativity and pulsar physics itself.

scholarly journals A New 100-GHz Band Front-End System with a Waveguide-Type Dual-Polarization Sideband-Separating SIS Receiver for the NRO 45-m Radio Telescope

2008 ◽  
Vol 60 (3) ◽  
pp. 435-443 ◽  
Author(s):  
Taku Nakajima ◽  
Takeshi Sakai ◽  
Shin’ichiro Asayama ◽  
Kimihiro Kimura ◽  
Masayuki Kawamura ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Dual Polarization ◽  
Sis Receiver ◽  
Front End ◽  
Waveguide Type ◽  
Band Front

scholarly journals Radio telescope total power mode: improving observation efficiency

2020 ◽  
Vol 643 ◽  
pp. A126
Author(s):  
Laurent Pagani ◽  
David Frayer ◽  
Bruno Pagani ◽  
Charlène Lefèvre
Keyword(s):  
Radio Telescope ◽  
Signal To Noise Ratio ◽  
Local Oscillator ◽  
Reduction Technique ◽  
Total Power ◽  
Line Intensities ◽  
Front End ◽  
Power Mode ◽  
Baseline Removal ◽  
Green Bank Telescope

Aims. Radio observing efficiency can be improved by calibrating and reducing the observations in total power mode rather than in frequency, beam, or position-switching modes. Methods. We selected a sample of spectra obtained from the Institut de Radio-Astronomie Millimétrique (IRAM) 30-m telescope and the Green Bank Telescope (GBT) to test the feasibility of the method. Given that modern front-end amplifiers for the GBT and direct Local Oscillator injection for the 30 m telescope provide smooth pass bands that are a few tens of megahertz in width, the spectra from standard observations can be cleaned (baseline removal) separately and then co-added directly when the lines are narrow enough (a few km s−1), instead of performing the traditional ON minus OFF data reduction. This technique works for frequency-switched observations as well as for position- and beam-switched observations when the ON and OFF data are saved separately. Results. The method works best when the lines are narrow enough and not too numerous so that a secure baseline removal can be achieved. A signal-to-noise ratio improvement of a factor of √2 is found in most cases, consistent with theoretical expectations. Conclusions. By keeping the traditional observing mode, the fallback solution of the standard reduction technique is still available in cases of suboptimal baseline behavior, sky instability, or wide lines, and to confirm the line intensities. These techniques of total-power-mode reduction can be applied to any radio telescope with stable baselines as long as they record and deliver the ONs and OFFs separately, as is the case for the GBT.

scholarly journals Low-Cost L-Band Receiving System Front-End for Irbene RT-32 Cassegrain Radio Telescope

2019 ◽  
Vol 56 (3) ◽  
pp. 50-61
Author(s):  
M. Bleiders ◽  
A. Berzins ◽  
N. Jekabsons ◽  
K. Skirmante ◽  
Vl. Bezrukovs
Keyword(s):  
Spectral Line ◽  
Radio Telescope ◽  
High Performance ◽  
Low Cost ◽  
Horn Antenna ◽  
Antenna System ◽  
Feed System ◽  
Front End ◽  
L Band ◽  
Multiple Receiver

Abstract Irbene RT-32 radio telescope is one of the main instruments operated by Ventspils International Radio Astronomy Center (VIRAC), which is used for participation in VLBI and single-dish mode observations, including European VLBI Network (EVN) and other astronomy projects such as recently started research on small bodies of solar system, which involves weak spectral line detection at L-band. Since start of the operation as a radio telescope, single C-X band receiver has been available at RT-32, but regular demand for L-band frequencies has been received due to its importance in spectral line science. In case of RT-32 geometry, optimum dimensions of L-band feed antenna system are inconveniently large and its installation without significant feed cone rebuilding is complicated. While work is currently ongoing to redesign the feed cone for multiple receiver support and to develop high performance L-band feed system, temporal, compact and low-cost receiver has been built and installed laterally to secondary focus, which in sense of performance and functionality has been proven to be appropriate for most of the current needs. Receiver is based on small parabolic reflector allowing one to use a compact dual circular polarized horn antenna, which together with a Cassegrain antenna forms a three-mirror system. Front-end is uncooled that allows reducing operational and maintenance costs, while still providing acceptable noise performance. Practical tests show average overall sensitivity of 750 Jy at 1650 MHz in terms of system effective flux density (SEFD). The paper describes the development of the receiver and presents the main results of performance characterization obtained at Irbene RT-32.

Fundamentals of a Radio Telescope

2020 ◽  
pp. 33-55
Author(s):  
Kim Ho Yeap ◽  
Kazuhiro Hirasawa
Keyword(s):  
Radio Telescope ◽  
Local Oscillator ◽  
Orthogonal Polarization ◽  
Processing Unit ◽  
Radio Waves ◽  
Front End ◽  
Astronomical Instruments ◽  
Corrugated Horn ◽  
Working Principle ◽  
Feed Horns

In radio astronomy, radio telescopes are used to collect radio waves emanated from cosmic sources. By analyzing these signals, the properties of the sources could be unraveled. A telescope typically consists of the following astronomical instruments: a primary and a secondary reflector, receiver optics which usually includes a lens or a pair of mirrors and a pair of feed horns (one for each orthogonal polarization [or simply a corrugated horn with an orthomode transducer OMT]), waveguides, a mixer circuit, a local oscillator, amplifiers, a detector circuit, and a data processing unit. This chapter provides a concise but complete overview of the working principle of the astronomical instruments involved in the construction of a radio telescope. The underlying physics of the components in a radio telescope, ranging from the antenna to the front-end and back-end systems, are illustrated.

22 GHz Observations with the Resurfaced Central 17 m of the Parkes Radio Telescope

1976 ◽  
Vol 3 (1) ◽  
pp. 61-63 ◽  
Author(s):  
J. L. Caswell ◽  
R. A. Batchelor ◽  
W. M. Goss ◽  
R. F. Haynes ◽  
S. H. Knowles ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Radio Telescope ◽  
Noise Temperature ◽  
Parametric Amplifier ◽  
Total System ◽  
High Frequencies ◽  
Second Stage ◽  
System Noise ◽  
Front End ◽  
5 Ghz

At the centre of the Parkes 64—m radio telescope a region of diameter 17 m has recently been resurfaced to improve its efficiency at high frequencies. The first measurements using this section have been made at 22 GHz, in observations of both continuum sources and water tfapour masers. For these observations the receiver front-end used a mixer cooled in liquid nitrogen, followed by a 5 GHz cryogenic parametric amplifier as a second stage. The option of switching against an offset horn was available and the total system noise temperature was ∽ 750 K.

Sign in / Sign up

Export Citation Format

Share Document