Optimization and Realization of Quadruple-Ridge Flared Horn With New Spline-Defined Profiles as a High-Efficiency Feed From 4.6 GHz to 24 GHz

Dong, Bin; Yang, Jian; Dahlstrom, Jens; Flygare, Jonas; Pantaleev, Miroslav; Billade, Bhushan

doi:10.1109/tap.2018.2874673

Cited by 26 publications

(18 citation statements)

References 16 publications

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“…The measured reflection coefficient is lower than -10 dB over most of the band for both polarizations with an isolation of -25 dB ( Fig. 7 in [4]).…”

Section: Feed Designmentioning

confidence: 95%

“…1(c). The quadpieces clamp the opposite ridges together for alignment, with a new edge-extrude feature to ensure good electrical contact [4]. The QRFH is intrinsically linearly dual-polarized and the Band B design is fed with two orthogonal single-ended 50 Ω coaxial ports inserted through one ridge and terminated in the opposite ridge for respective polarization.…”

Section: Feed Designmentioning

confidence: 99%

“…Due to the separation of the feed in sections, individual parts could be optimized separately followed by a final optimization of all sections simultaneously. The advantage of a spline-defined profile is the customized shape that can improve the wideband performance compared to an analytic profile [4]. In Fig.…”

Section: A Spline-defined Profilementioning

confidence: 99%

“…The spline-defined profile of Band B produces a nearconstant beamwidth over the frequency band and improved feed beam pattern symmetry. In [4] the aperture sub-efficiencies from a prime-focus simulation of the Band B feed are analyzed and show improvements compared to analytic QRFH profiles. The improved beam performance could be explained by the aperture mode content inside the horn, and we analyzed this for both TE modes and TM modes.…”

Section: B Aperture Mode Contentmentioning

confidence: 99%

“…The two wideband feed packages within WBSPF, Band A (JLRAT/CETC54) and Band B (Onsala/Chalmers), are based on Quad-ridge Flared Horn (QRFH) technology covering 1.6-5.2 GHz and 4.6-24 GHz respectively. The Band B QRFH was developed using spline-defined profiles for UWB and highfrequency performance [4].…”

Section: Introductionmentioning

confidence: 99%

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Wideband single pixel feed system over 4.6–24 GHz for the Square Kilometre Array

Flygare

Dong

Yang

et al. 2019

2019 International Conference on Electromagnetics in Advanced Applications (ICEAA)

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We present the Band B feed system over 4.6-24 GHz designed for the Square Kilometre Array (SKA) reflector for radio astronomy applications. The feed is a Quad-ridge Flared Horn (QRFH) with a customized shape based on spline-defined profiles to achieve improved wideband performance. The feed system shows high aperture efficiency and sensitivity on the SKA reflector in predictions based on measured feed beam patterns. We present the feed design overview, cryogenic dewar concept and measurement of receiver noise (10-20 K) with wideband lownoise amplifiers, and full system simulation of the performance.Index Terms-quad-ridge flared horn, ultra-wideband feed, spine-defined profile, radio astronomy, sensitivity.

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“…The measured reflection coefficient is lower than -10 dB over most of the band for both polarizations with an isolation of -25 dB ( Fig. 7 in [4]).…”

Section: Feed Designmentioning

confidence: 95%

Section: Feed Designmentioning

confidence: 99%

Section: A Spline-defined Profilementioning

confidence: 99%

Section: B Aperture Mode Contentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Wideband single pixel feed system over 4.6–24 GHz for the Square Kilometre Array

Flygare

Dong

Yang

et al. 2019

2019 International Conference on Electromagnetics in Advanced Applications (ICEAA)

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Efficient optimization of wideband reflector feed antennas for optimal receiving sensitivity

Mokhupuki

Villiers

2020

Int J Numerical Modelling

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Wideband reflector antenna feeds are a geometrically complex class of antennas, requiring a variety of design parameters to describe their form. This casts the optimization of such structures as a high-dimensionality problem. The antenna responses are also difficult to predict and must be determined via computationally expensive full-wave electromagnetic simulations. This paper proposes a surrogate-based optimization approach for the design of wideband feed antennas. Beginning with high-fidelity goal function data from a global search space, the framework nominates a number of local search regions where separate, formal, multifidelity optimizations are performed. The formulated goal function maximizes the receiving sensitivity, while ensuring that the reflection coefficient response satisfies a predefined criterion. An approximate, fast-to-evaluate coarse model of the goal function, based on a series of surrogate models estimating the feed and reflector antenna responses, is formulated.Most of the optimization burden is shifted to the coarse model, where highfidelity samples are adaptively added to the regions of the design space where the coarse model performs well or where the sampling is sparse. As a design example, the optimization of a quad-ridge flared horn feed antenna, on a Square Kilometre Array reflector system, is presented to highlight the efficacy of the method. K E Y W O R D S characteristic basis function pattern method, quad-ridge flared horn antenna, reflector antennas, surrogate-based optimization | INTRODUCTIONIn the field of radio astronomy, there exists a need for high fidelity, wideband, single-pixel reflector feed antennas with an operational bandwidth exceeding one octave. A feed meeting such requirements would allow new-generation radio telescope projects, such as the Square Kilometre Array (SKA), 1 to reduce their total number of feeds per reflector-due to the wide bandwidth of each feed-and still maintain their predefined performance specifications. The primary benefit of this is a reduction of system costs; furthermore, the simultaneous coverage of wider bandwidths would also enable the pursuit of more ambitious science goals.

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Water vapour radiometry in geodetic very long baseline interferometry telescopes: assessed through simulations

Forkman

Flygare

Elgered

2021

J Geod

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The accuracy of geodetic Very Long Baseline Interferometry (VLBI) is affected by water vapour in the atmosphere in terms of variations in the signal propagation delay at the different stations. This “wet” delay may be estimated directly from the VLBI data, as well as from independent instruments, such as collocated microwave radiometers. Rather than having stand-alone microwave radiometers we have, through simulations, evaluated the possibility to use radiometric data from the VLBI receiver in the VGOS telescopes at the Onsala Space Observatory. The advantage is that the emission from water vapour, as sensed by the radiometer, originates from the same atmospheric volume that delays the VLBI signal from the extra-galactic object. We use simulations of the sky brightness temperature and the wet delay together with an assumption of a root-mean-square (rms) noise of the receiver of 1 K, and observations evenly spread between elevation angles of 10$$^\circ $$ ∘ –90$$^\circ $$ ∘ . This results in an rms error of the estimated equivalent zenith wet delay of the order of 3 mm for a one frequency algorithm, used under cloud free conditions, and 4 mm for a two frequency algorithm, used during conditions with liquid water clouds. The results exclude rainy conditions when the method does not work. These errors are reduced by a factor of 3 if the receiver error is 0.1 K meaning that the receivers’ measurements of the sky brightness temperature is the main error source. We study the impact of ground-noise pickup by using a model of an existing wideband feed. Taking the algorithm uncertainty and the ground noise pickup into account we conclude that the method presented will be useful as an independent estimate of the wet delay to assess the quality of the wet delays and linear horizontal gradients estimated from the VLBI data themselves.

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Optimization and Realization of Quadruple-Ridge Flared Horn With New Spline-Defined Profiles as a High-Efficiency Feed From 4.6 GHz to 24 GHz

Cited by 26 publications

References 16 publications

Wideband single pixel feed system over 4.6–24 GHz for the Square Kilometre Array

Wideband single pixel feed system over 4.6–24 GHz for the Square Kilometre Array

Efficient optimization of wideband reflector feed antennas for optimal receiving sensitivity

Water vapour radiometry in geodetic very long baseline interferometry telescopes: assessed through simulations

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