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Your search keyword '"Jorgensen, Erik"' showing total 78 results
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78 results on '"Jorgensen, Erik"'

21. A Design Method for Mode-Selective Waveguide Couplers in Dual-Polarized Wideband Matched-Feed Antennas.

Author

Palvig, Michael Forum, Breinbjerg, Olav, Meincke, Peter, and Jorgensen, Erik

Subjects
APERTURE antennas, ANTENNA feeds, POLARIZATION (Electricity), REFLECTOR antennas, COAXIAL waveguides
Abstract

A novel type of multihole directional coupler is presented as well as a design method involving novel procedures. The device couples two orthogonal TE11 modes in a circular waveguide into two orthogonal TE21 modes with specified excitations in a surrounding coaxial waveguide, which has the circular waveguide as the inner conductor. A simple, novel analytical procedure is used to determine azimuthal hole positions, such that each of the input modes couples to only the desired coaxial TE21 mode. The method is applied to a specific coupler which is designed to couple −14 dB to both higher order coaxial modes in the band from 10 to 14 GHz. The suppression of undesired modes is generally better than 40 dB. The coupler is intended for broadband dual-polarized matched feeds, which are able to compensate for the intrinsically high cross polarization of offset single reflector antenna systems. [ABSTRACT FROM PUBLISHER]

Published
2018
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37. Analysis of printed reflectarrays using extended local periodicity

Author

Zhou, Min, Sorensen, Stig Busk, Jorgensen, Erik, Meincke, Peter, Kim, Oleksiy S., Breinbjerg, Olav, Zhou, Min, Sorensen, Stig Busk, Jorgensen, Erik, Meincke, Peter, Kim, Oleksiy S., and Breinbjerg, Olav

Abstract

An analysis technique for improved modeling of a printed reflectarray is proposed. The technique is based on a periodic approach where periodicity is applied on an extended unit cell, which includes the actual elements surrounding the element under consideration. An offset reflectarray sample has been manufactured and measured, and comparison of simulations and measurements is presented to verify the proposed technique.

Published
2011

45. Design and Optimization of a Single-Layer Planar Transmit-Receive Contoured Beam Reflectarray With Enhanced Performance.

Author

Zhou, Min, Borries, Oscar, and Jorgensen, Erik

Subjects
REFLECTARRAY antennas, MOMENTS method (Statistics), ANTENNAS (Electronics), ARTIFICIAL satellites, DESIGN
Abstract

This paper presents the design and optimization of a 1.2-meters single-layer planar contoured beam reflectarray in Ku-band. The reflectarray is optimized to fulfill the requirements of a Direct Broadcast Satellite mission, which covers a South American coverage in both transmit and receive frequency bands for dual linear polarization. The reflectarray is designed using a direct optimization approach where all the array elements are optimized simultaneously, thus resulting in a design with enhanced performance compared to designs obtained using a phase-only optimization approach. The reflectarray fulfills all the coverage requirements in both transmit and receive frequency bands and the performance is validated by means of full-wave Method of Moments simulations. [ABSTRACT FROM PUBLISHER]

Published
2015
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48. Design tool for high-performance rotationally symmetric reflector antennas.

Author

Jorgensen, Erik and Meincke, Peter

Abstract

Rotationally symmetric reflector systems are attractive candidates for realizing compact high-gain antennas with low manufacturing costs, low sidelobes, and low cross polarization. The typical application areas are point-to-point communication links, satellite terminals, and radar systems. These compact systems often employ two reflectors in a classical axially displaced reflector configuration [1], or alternatively, a single reflector with a backward radiating hat feed [2] or splash-plate feed [3]. A common feature of these compact systems is that they include a very tight integration of feed, subreflector, dielectric support structure, and main reflector, which leads to a resonant structure that cannot be analyzed and designed using ray-optical methods. Instead, a full-wave model is needed to analyze the performance of the system with sufficient accuracy and consequently, the full-wave model is also needed when numerically optimizing the antenna performance. Commercially available software for general 3D problems lead to prohibitively long run-times that do not allow numerical optimization. Instead, the rotational symmetry of the structure has been used to formulate the Body-of-Revolution Method of Moments (BoR-MoM) [4], including various formulations for composite metallic/dielectric structures [5]. The MoM problem in [4] was discretized using triangular basis functions and this formulation has been inherited by most later works, including [5]. This low-order discretization typically requires 15 unknowns per wavelength to achieve accurate results, leading to a typical analysis time of 30–60 seconds per frequency for a compact hat-feed antenna. This analysis speed is sufficient for many purposes, but not for full optimization of the combined system including the surface shape of the main reflector, the features of the feeding waveguide, the shape of the dielectric support, and the fine details on the feed hat or the subreflector. [ABSTRACT FROM PUBLISHER]

Published
2012

49. Multilevel Fast Multipole Method for Higher Order Discretizations.

Author

Borries, Oscar, Meincke, Peter, Jorgensen, Erik, and Hansen, Per Christian

Subjects
DISCRETIZATION methods, INTEGRAL equations, ELECTROMAGNETIC wave scattering, HIGH-order derivatives (Mathematics), MOMENTS method (Statistics)
Abstract

The multi-level fast multipole method (MLFMM) for a higher order (HO) discretization is demonstrated on high-frequency (HF) problems, illustrating for the first time how an efficient MLFMM for HO can be achieved even for very large groups. Applying several novel ideas, beneficial to both lower order and higher order discretizations, results from a low-memory, high-speed MLFMM implementation of a HO hierarchical discretization are shown. These results challenge the general view that the benefits of HO and HF-MLFMM cannot be combined. [ABSTRACT FROM PUBLISHER]

Published
2014
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50. The Generalized Direct Optimization Technique for Printed Reflectarrays.

Author

Zhou, Min, Sorensen, Stig B., Kim, Oleksiy S., Jorgensen, Erik, Meincke, Peter, Breinbjerg, and Toso

Subjects
ANTENNAS (Electronics), MATHEMATICAL optimization, ALGORITHMS, SPECTRUM analysis, TELECOMMUNICATION research
Abstract

A generalized direct optimization technique (GDOT) for the design of printed reflectarrays using arbitrarily shaped elements with irregular orientation and position is presented. The GDOT is based on the spectral domain method of moments (SDMoM) assuming local periodicity (LP) and a minimax optimization algorithm. The accuracy of the LP-SDMoM for the design of reflectarrays with irregularly positioned and oriented array elements has been verified by comparisons with full wave method of moments. Three contoured beam reflectarrays, forming a high-gain beam on a European coverage area, have been designed: a broadband design, a circularly polarized design using the variable rotation technique, and a design with irregularly positioned array elements. The latter has been manufactured and measured at the DTU-ESA Spherical Near-Field Antenna Test Facility. An very good agreement between simulated and measured patterns have been obtained, showing accuracies that are comparable to those obtained for conventional shaped reflectors. [ABSTRACT FROM PUBLISHER]

Published
2014
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