Digital Beamforming Focal Plane Arrays for Radio Astronomy and Space-Borne Passive Remote Sensing
Doktorsavhandling, 2017

Dense Phased Array Feeds (PAFs) for reflector antennas have numerous advantages over traditional cluster feeds of horns in a one-horn-per-beam configuration, especially in RF-imaging applications which require multiple simultaneously formed and closely overlapping beams. However, the accurate analysis and design of such PAF systems represents a challenging problem, both from an EM-modeling and beamforming optimization point of view. The current work addresses some of these challenges and consists of two main parts. In the first part the mutual interaction effects that exist between a PAF consisting of many densely packed antenna elements and an electrically large reflector antenna are investigated. For that purpose the iterative CBFM-PO method has been developed. This method not only allows one to tackle this problem in a time-efficient and accurate manner, but also provides physical insight into the feed-reflector coupling mechanism and allows to quantify its effect on the antenna impedance and radiation characteristics. Numerous numerical examples of large reflector antennas with various representative feeds (e.g. a single dipole feed and complex PAFs of hundreds of elements) are also presented and some of them are validated experimentally. In order to analyze electrically large feeds efficiently, a domain-decomposition approach to Krylov subspace iteration, where macro basis functions (or characteristic basis functions) on each subdomain are naturally constructed from the different segments of the generating vectors, is also proposed. The second part of the thesis is devoted to the optimization of PAF beamformers and covers two application examples: (i) microwave satellite radiometers for accurate ocean surveillance; and (ii) radio telescopes for wide field-of-view sky surveys. Based on the initial requirements for future antenna systems, which are currently being formulated for these applications, we propose various figures-of-merits and describe the corresponding optimal beamforming algorithms that have been developed. Studies into these numerical examples demonstrate how optimal beamforming strategies can help to greatly improve the antenna system characteristics (e.g. beam efficiency, side-lobe level and sensitivity in the presence of the noise) as well as to reduce the complexity of the beam calibration models and overall phased array feed design.

beamforming

spaceborne radiometers

radio telescopes

phased array feeds

reflector antenna feeds

feed-reflector interaction

Room EE, floor 6, Hörsalsvägen 11, Chalmers University of Technology
Opponent: Professor Bart Smolders, Eindhoven University of Technology, The Netherlands

Författare

Oleg Iupikov

Chalmers, Signaler och system, Kommunikationssystem, informationsteori och antenner, Antennsystem

Design of a Push-Broom Multi-Beam Radiometer for Future Ocean Observations

9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015,; (2015)

Paper i proceeding

Improving the Calibration Efficiency of an Array Fed Reflector Antenna through Con-strained Beamforming

IEEE Transactions on Antennas and Propagation,; Vol. 61(2013)p. 3538 - 3545

Artikel i vetenskaplig tidskrift

A Plane Wave Approximation in the Computation of Multiscattering Effects in Reflector Systems

7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013,; (2013)p. 3828-3832

Paper i proceeding

Dense focal plane arrays for pushbroom satellite radiometers

8th European Conference on Antennas and Propagation, EuCAP 2014; The Hague; Netherlands; 6 April 2014 through 11 April 2014,; (2014)p. 3536-3540

Paper i proceeding

An Optimal Beamforming Algorithm for Phased-Array Antennas Used in Multi-Beam Spaceborne Radiometers

9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015,; (2015)

Paper i proceeding

Towards the understanding of the interaction effects between reflector antennas and phased array feeds

2012 International Conference on Electromagnetics in Advanced Applications (ICEAA), Cape Town, WP, South Africa, 2-8 Sept 2012,; (2012)p. 792-795

Paper i proceeding

Domain-Decomposition Approach to Krylov Subspace Iteration

IEEE Antennas and Wireless Propagation Letters,; Vol. 15(2016)p. 1414-1417

Artikel i vetenskaplig tidskrift

Novel Multi-Beam Radiometers for Accurate Ocean Surveillance

Proceedings of the 8th European Conference on Antennas and Propagation, EUCAP 2014, The Hague, The Netherlands, April 2014,; (2014)

Paper i proceeding

Fast and Accurate Analysis of Reflector Antennas with Phased Array Feeds Including Multiple Reflections between Feed and Reflector

IEEE Transactions on Antennas and Propagation,; Vol. 62(2014)p. 3450 - 3462

Artikel i vetenskaplig tidskrift

M. V. Ivashina, O. A. Iupikov, C. Cappellin, K. Pontoppidan, P. H. Nielsen, N. Skou, S. S. Søbjærg, B. Fiorelli, “Enabling High-sensitivity Near-land Radiometric Measurements With Multi-beam Conical Scanners Employing Phased Arrays”

O. A. Iupikov, M. V. Ivashina, N. Skou, C. Cappellin, K. Pontoppidan, and K. van ’t Klooster, "Multi-Beam Focal Plane Arrays with Digital Beamforming for High Precision Space-Borne Remote Sensing"

O. A. Iupikov, A. A. Roev, M. V. Ivashina, “Prediction of Far-Field Pattern Characteristics of Phased Array Fed Reflector Antennas by Modeling Only a Small Part of the Array – Case Study of Spaceborne Radiometer Antennas”

Styrkeområden

Informations- och kommunikationsteknik

Ämneskategorier

Beräkningsmatematik

Inbäddad systemteknik

Annan elektroteknik och elektronik

ISBN

978-91-7597-579-5

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4260

Utgivare

Chalmers tekniska högskola

Room EE, floor 6, Hörsalsvägen 11, Chalmers University of Technology

Opponent: Professor Bart Smolders, Eindhoven University of Technology, The Netherlands