Optimizing Processing Time of Radio-Astronomy Antenna Simulations Using FEKO

The far-field pattern of a geometrically large and complex antenna used in low-frequency radio astronomy is computationally expensive to simulate on electromagnetic simulators, such as FEKO. For example, one station of the Square Kilometer Array, which consists of 256 log-periodic antenna elements, will take years to simulate using the full CAD model for the full operational frequency band. This paper focuses on reducing the simulation time for a single antenna element by simplifying the simulation model, thus decreasing the number of unknowns that have to be solved in a simulation. An iterative process for optimizing the simplification of such an element is described, while keeping the reflection coefficient within 1 dB absolute mean deviation of the measured data. After four iterations, the amount of unknowns to be solved, which includes the number of triangles and segments, was reduced from 29,307 to 11,991. This decreased the computation time by 86.5%, making array simulations feasible. Using the techniques described in the paper, other antenna constructions can benefit from it and be simulated more efficiently.

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Integrated circular optical phased array

EPJ Web of Conferences ◽

10.1051/epjconf/202125501004 ◽

2021 ◽

Vol 255 ◽

pp. 01004

Author(s):

Qiankun Liu ◽

Tom Smy ◽

Ahmad Atieh ◽

Pavel Cheben ◽

Alejandro Sánchez-Postigo ◽

...

Keyword(s):

Phased Array ◽

Field Pattern ◽

Antenna Element ◽

Sidelobe Suppression ◽

Integrated Optical ◽

Optical Phased Arrays ◽

Optical Phased Array ◽

Element Array ◽

The Individual ◽

Far Field Pattern

Existing OPAs are typically based on 2D rectangular arrays or 1D linear arrays. Both approaches present a limited field-of-view (FOV) due to the presence of the grating lobes when the element spacing is larger than λ/2. To address the need for an increased steering range, we propose a new design strategy of an OPA system utilizing a 2D circular phased array, with a substantially increased FOV. We present a circular OPA using a demonstrated antenna element design, with an 820-element array. A steering range ΩSR calculated as a solid angle of 0.51π sr, and an angular beamwidth of 0.22°, was achieved. The array exhibits a sidelobe suppression larger than 10 dB, and a FOV of 2π sr. Although the performance is limited by the far field pattern of the individual antenna we chose, our circular OPA achieved, to the best of our knowledge, the largest steering range reported to date compared to the state-of-the-art integrated optical phased arrays reported in literature.

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Low-frequency technology for a lunar interferometer

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2019.0575 ◽

2020 ◽

Vol 379 (2188) ◽

pp. 20190575 ◽

Cited By ~ 1

Author(s):

Kristian Zarb Adami ◽

I. O. Farhat

Keyword(s):

Radio Frequency ◽

Signal Detection ◽

Radio Astronomy ◽

Lunar Surface ◽

Low Frequency ◽

Radio Interferometer ◽

Radio Frequency Interference ◽

The Moon ◽

Single Antenna ◽

Global Signal

This work sketches a possible design architecture of a low-frequency radio interferometer located on the lunar surface. The design has evolved from single antenna experiments aimed at the global signal detection of the epoch of reionization (EoR) to the square kilometre array (SKA) which, when complete, will be capable of imaging the highly red-shifted H 1 -signal from the cosmic dawn through to the EoR. However, due to the opacity of the ionosphere below 10 MHz and the anthropogenic radio-frequency interference, these terrestrial facilities are incapable of detecting pre-ionization signals and the moon becomes an attractive location to build a low-frequency radio interferometer capable of detecting such cosmological signals. Even though there are enormous engineering challenges to overcome, having this scientific facility on the lunar surface also opens up several new exciting possibilities for low-frequency radio astronomy. This article is part of a discussion meeting issue ‘Astronomy from the Moon: the next decades’.

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Near-field to far-field pattern measurements for a low-frequency FR-ORA

2015 International Conference on Electromagnetics in Advanced Applications (ICEAA) ◽

10.1109/iceaa.2015.7297134 ◽

2015 ◽

Author(s):

Eman O. Farhat ◽

Kristian Z. Adami ◽

Anthony K. Brown ◽

Yongwei Zhang ◽

Charles V. Sammut

Keyword(s):

Near Field ◽

Low Frequency ◽

Field Pattern ◽

Far Field ◽

Far Field Pattern

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New Radio Science Facilities for Compact Objects

Symposium - International Astronomical Union ◽

10.1017/s0074180900180738 ◽

2004 ◽

Vol 218 ◽

pp. 113-120

Author(s):

J. M. Cordes

Keyword(s):

Radio Astronomy ◽

Low Frequency ◽

Compact Objects ◽

Telescope Array ◽

Radio Science ◽

New Concepts ◽

Pulsar Timing ◽

New Radio ◽

Square Kilometer Array

In a throwback to the early days in radio astronomy, new concepts for radio telescopes are being considered as next-generation facilities. The Low-Frequency Array (LOFAR) and the Square-Kilometer Array (SKA) are two particular projects that will incorporate innovations in hardware and software. Along the way to these projects, major surveys for pulsars and transients and/or follow-up pulsar timing observations will be conducted with the ALFA multibeam system at Arecibo, the Allen Telescope Array (ATA), the Extended VLA (EVLA) and with SKA prototype systems that include the European MBRACE project (Multibeam Radio Astronomy Concept Experiment) and China's FAST (500m Aperture Spherical Telescope). These projects are discussed here in the context of anticipated science drivers.

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Triangular Slot-Loaded Wideband Planar Rectangular Antenna Array for Millimeter-Wave 5G Applications

Electronics ◽

10.3390/electronics10070778 ◽

2021 ◽

Vol 10 (7) ◽

pp. 778

Author(s):

Iftikhar Ahmad ◽

Houjun Sun ◽

Umair Rafique ◽

Zhang Yi

Keyword(s):

Antenna Array ◽

Millimeter Wave ◽

Communication Systems ◽

Ground Plane ◽

Simulated Data ◽

Impedance Bandwidth ◽

Antenna Element ◽

Single Antenna ◽

Rectangular Patch ◽

Half Power

This paper presents a design of a triangular slot-loaded planar rectangular antenna array for wideband millimeter-wave (mm-wave) 5G communication systems. The proposed array realizes an overall size of 35.5 × 14.85 mm2. To excite the array elements, a four-way broadband corporate feeding network was designed and analyzed. The proposed array offered a measured impedance bandwidth in two different frequency ranges, i.e., from 23 to 24.6 GHz and from 26 to 45 GHz. The single-antenna element of the array consists of a rectangular patch radiator with a triangular slot. The partial ground plane was used at the bottom side of the substrate to obtain a wide impedance bandwidth. The peak gain in the proposed array is ≈12 dBi with a radiation efficiency of >90%. Furthermore, the array gives a half-power beamwidth (HPBW) of as low as 12.5°. The proposed array has been fabricated and measured, and it has been observed that the measured results are in agreement with the simulated data.

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Effect of transverse mode structure on the far field pattern of metal-metal terahertz quantum cascade lasers

Journal of Applied Physics ◽

10.1063/1.3043795 ◽

2008 ◽

Vol 104 (12) ◽

pp. 124513 ◽

Cited By ~ 14

Author(s):

P. Gellie ◽

W. Maineult ◽

A. Andronico ◽

G. Leo ◽

C. Sirtori ◽

...

Keyword(s):

Quantum Cascade Lasers ◽

Transverse Mode ◽

Field Pattern ◽

Far Field ◽

Mode Structure ◽

Quantum Cascade ◽

Metal Metal ◽

Far Field Pattern ◽

Cascade Lasers

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Far-field patterns of line sources mounted between four-dielectric substrates

Canadian Journal of Physics ◽

10.1139/p92-023 ◽

1992 ◽

Vol 70 (2-3) ◽

pp. 173-178 ◽

Cited By ~ 1

Author(s):

Ioanna Diamandi ◽

Costas Mertzianidis ◽

John N. Sahalos

Keyword(s):

Remote Sensing ◽

Line Source ◽

Dielectric Substrate ◽

Microstrip Antennas ◽

Field Pattern ◽

Substrate Thickness ◽

Far Field ◽

Dielectric Substrates ◽

Field Patterns ◽

Far Field Pattern

The far-field pattern characteristics of line sources lying between the slabs of a four-dielectric substrate configuration are presented. The patterns are calculated for several cases of the substrate thickness as well as for several line-source locations. The considerations that are made give useful applications in remote sensing and microstrip antennas.

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