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.

scholarly journals Design of an L-Band Cross-Dipole Phased Array Feed for FAST

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Yubing Han ◽  
Luoqing Zhong
Keyword(s):  
Radio Telescope ◽  
High Performance ◽  
Phased Array ◽  
Low Cost ◽  
Dipole Antenna ◽  
Field Of View ◽  
System Model ◽  
Beam Formation ◽  
The World ◽  
L Band

The Five-Hundred-Meter Aperture Spherical Telescope (FAST) is a Chinese megascience project that aims to build the largest single dish radio telescope in the world. Given its multiple simultaneous beam formation, phased array feed (PAF) is widely used to extend the field of view and enhance the survey speed of the radio telescope. In this study, a broadband and low cost PAF element using cross-dipole antenna at L-band is designed based on the requirement of the FAST. The antenna is fed by two microstrip baluns which have high performance and is easy to manufacture compared to the traditional coaxial balun. A simple system model is also introduced to evaluate the PAF performance. The measured results of the fabricated element and the simulations of the system performance validate the effectiveness of element design.

IMAGINE project: a low cost, high performance, monolithic passive mm-wave imager front-end

2012 ◽  
Author(s):  
N. Alexander ◽  
P. Frijlink ◽  
J. Hendricks ◽  
E. Limiti ◽  
S. Löffler ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Front End

Low-cost and high-performance front-end module for WLAN

2009 ◽  
Author(s):  
Jyh-Rong Lin ◽  
Yeung Yeung ◽  
Ruonan Wang ◽  
Bin Xin ◽  
Lydia Leung ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Front End ◽  
Front End Module

scholarly journals RF System-on-Package (SOP) Development for Compact Low Cost Wireless Front-End Systems

2003 ◽  
Author(s):  
M. Tentzeris ◽  
J. Laskar
Keyword(s):  
Wireless Lan ◽  
High Performance ◽  
Low Cost ◽  
Patch Antennas ◽  
Organic Substrates ◽  
Q Factor ◽  
Rf System ◽  
Front End ◽  
Organic Packages ◽  
Front End Module

This paper presents the development of RF System-on-Package (SOP) architectures for compact and low cost wireless radio front-end systems. A novel 3D integration approach for SOP-based solutions for wireless communication applications is proposed and utilized for the implementation of a C band Wireless LAN (WLAN) RF front-end module by means of stacking LTCC substrates using μBGA technology. LTCC designs of high-performance multilayer embedded bandpass filters and novel stacked cavity-backed patch antennas are also reported. In addition, the fabrication of very high Q-factor inductors and embedded filter in organic substrates demonstrate the satisfactory performance of multilayer organic packages. The well known full-wave numerical techniques of FDTD and MRTD are used for the modeling of adjacent lines crosstalk, of the Q-factor of embedded passives and for the accurate simulation of MEMS structures.

Shooting Down the Server Front-End Bottleneck

2020 ◽  
Vol 38 (3-4) ◽  
pp. 1-30
Author(s):  
Rakesh Kumar ◽  
Boris Grot
Keyword(s):  
High Performance ◽  
State Of The Art ◽  
Low Cost ◽  
Branch Prediction ◽  
Control Flow ◽  
Trade Off ◽  
Front End ◽  
Working Set ◽  
And Performance ◽  
Fundamental Limitation

The front-end bottleneck is a well-established problem in server workloads owing to their deep software stacks and large instruction footprints. Despite years of research into effective L1-I and BTB prefetching, state-of-the-art techniques force a trade-off between metadata storage cost and performance. Temporal Stream prefetchers deliver high performance but require a prohibitive amount of metadata to accommodate the temporal history. Meanwhile, BTB-directed prefetchers incur low cost by using the existing in-core branch prediction structures but fall short on performance due to BTB’s inability to capture the massive control flow working set of server applications. This work overcomes the fundamental limitation of BTB-directed prefetchers, which is capturing a large control flow working set within an affordable BTB storage budget. We re-envision the BTB organization to maximize its control flow coverage by observing that an application’s instruction footprint can be mapped as a combination of its unconditional branch working set and, for each unconditional branch, a spatial encoding of the cache blocks around the branch target. Effectively capturing a map of the application’s instruction footprint in the BTB enables highly effective BTB-directed prefetching that outperforms the state-of-the-art prefetchers by up to 10% for equivalent storage budget.

Comparison of UV- and Derivative-Spectrophotometric and HPTLC UVDensitometric Methods for the Determination of Amrinone and Milrinone in Bulk Drugs

2020 ◽  
Vol 16 (3) ◽  
pp. 246-253
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Stefan Kruszewski
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Low Cost ◽  
Uv Spectra ◽  
Derivative Spectrophotometry ◽  
Therapeutic Monitoring ◽  
Bulk Drug ◽  
Layer Chromatography ◽  
Standard Solutions

Background: Spectrophotometry and thin layer chromatography have been commonly applied in pharmaceutical analysis for many years due to low cost, simplicity and short time of execution. Moreover, the latest modifications including automation of those methods have made them very effective and easy to perform, therefore, the new UV- and derivative spectrophotometry as well as high performance thin layer chromatography UV-densitometric (HPTLC) methods for the routine estimation of amrinone and milrinone in pharmaceutical formulation have been developed and compared in this work since European Pharmacopoeia 9.0 has yet incorporated in an analytical monograph a method for quantification of those compounds. Methods: For the first method the best conditions for quantification were achieved by measuring the lengths between two extrema (peak-to-peak amplitudes) 252 and 277 nm in UV spectra of standard solutions of amrinone and a signal at 288 nm of the first derivative spectra of standard solutions of milrinone. The linearity between D252-277 signal and concentration of amironone and 1D288 signal of milrinone in the same range of 5.0-25.0 μg ml/ml in DMSO:methanol (1:3 v/v) solutions presents the square correlation coefficient (r2) of 0,9997 and 0.9991, respectively. The second method was founded on HPTLC on silica plates, 1,4-dioxane:hexane (100:1.5) as a mobile phase and densitometric scanning at 252 nm for amrinone and at 271 nm for milrinone. Results: The assays were linear over the concentration range of 0,25-5.0 μg per spot (r2=0,9959) and 0,25-10.0 μg per spot (r2=0,9970) for amrinone and milrinone, respectively. The mean recoveries percentage were 99.81 and 100,34 for amrinone as well as 99,58 and 99.46 for milrinone, obtained with spectrophotometry and HPTLC, respectively. Conclusion: The comparison between two elaborated methods leads to the conclusion that UV and derivative spectrophotometry is more precise and gives better recovery, and that is why it should be applied for routine estimation of amrinone and milrinone in bulk drug, pharmaceutical forms and for therapeutic monitoring of the drug.

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