| 1. |
- Albani, M, et al.
(författare)
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Concepts for polarising sheets & “dual-gridded” reflectors for circular polarisation
- 2011
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Ingår i: 2010 Conference Proceedings ICECom, 20th International Conference on Applied Electromagnetics and Communications. - 9789536037582 - 9781612849980 ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- C-, Ku- and Ka-band communications and broadcast satellites use so-called dual-gridded reflector antennas for linear polarisation to provide independent reflector surfaces and/or independent feeds for the two orthogonal polarisations. This paper describes initial work to extend this concept to circular polarisation. First we set up preliminary specifications and identify several antenna concepts based upon planar transmission sheet polarisers. Next we identify a number of polarisers of which the most promising is the meander-line, the L+C strip-grids and the parallel-plate polariser. Finally we review the conclusions of the analyses and preliminary designs of the sheet polarisers - on the antenna level as part of a reflector antenna system, on the polariser level, and on the sheet level inside the polariser.
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| 2. |
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| 3. |
- Andersson, Michael, et al.
(författare)
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Stabilization of evanescent wave propagation operators
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a stabilized scheme that solves the wave propagation problem in a general bianisotropic, stratified medium. The method utilizes the concept of propagators, i.e., the wave propagation operators that map the total tangential electric and magnetic fields from one plane in the slab to another. The scheme transforms the propagator approach into a scattering matrix form, where a spectral decomposition of the propagator enables separation of the exponentially growing and decaying terms in order to obtain a well-conditioned formulation. Multilayer structures can be handled in a stable manner using the dissipative property of the Redheffer star product for cascading scattering matrices. The reflection and transmission dyadics for a general bianisotropic medium with an isotropic half space on both sides of the slab are presented in a coordinate-independent dyadic notation, as well as the reflection dyadic for a bianisotropic slab with perfect electric conductor backing (PEC). Several numerical examples that illustrate the performance of the stabilized algorithm are presented.
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| 4. |
- Bondarik, Alexander, et al.
(författare)
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60 GHz Microstrip Antenna Array on PTFE Substrate
- 2012
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Ingår i: 6th European Conference on Antennas and Propagation (EUCAP), 2012. - 9781457709180 ; , s. 1016-1018
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Konferensbidrag (refereegranskat)abstract
- A microstrip antenna array design for 60 GHz central frequency is presented, with simulated and measured results in good agreement. The antenna is fabricated on a flexible substrate and intended for integration with circuit module to form a wireless communication system.
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| 5. |
- Bondarik, Alexander, et al.
(författare)
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A Bond Wire Connection Implementation at mm-Wave Active Microstrip Antenna
- 2019
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1531-1309. ; 29:6, s. 427-429
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Tidskriftsartikel (refereegranskat)abstract
- A bond wire to microstrip line transition, featuring two impedance transformers, is presented for a mm-wave microstrip antenna and power amplifier (PA) integration using conventional bond wires. Simulated return loss bandwidth for the transition is 4 GHz with a minimum insertion loss of 1 dB. Measurement results for the designed active antenna are compared with measurements for a passive antenna and a standalone PA. The maximum gain is 29 dBi, compared with 16.7-dBi passive antenna maximum gain. The half-power gain bandwidth is 7%. The measured active antenna radiation pattern is in good agreement with simulations. The maximum deembedded PA output power is close to 9 dBm.
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| 6. |
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| 7. |
- Bondarik, Alexander, et al.
(författare)
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Gridded Parasitic Patch Stacked Microstrip Antenna With Beam Shift Capability for 60 GHz Band
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A microstrip antenna design is introduced in which a rectangular microstrip patch is coupled electromagnetically with a gridded rectangular patch placed above. The gridded patch consists of nine identical rectangular parts separated by a distance which is much smaller than a free space wavelength for a central frequency. The antenna is designed to operate in the 60 GHz band and is fabricated on a conventional PTFE (polytetrafluoroethylene) thin substrate. The antenna return loss bandwidth is comparable to a single parasitic patch aperture coupled antenna, while the proposed antenna gain is higher. Measurement results are in good agreement with simulation. Measured 10 dB return loss bandwidth is from 54 GHz up to 67 GHz. It fully covers the unlicensed band around 60 GHz. The measured antenna realized gain at 60 GHz is close to 8 dB, while the simulated antenna radiation efficiency is 85%. A simple beam shifting method is possible for this antenna structure by connecting adjacent outside parts in the gridded patch. The designed antenna is suitable for a high speed wireless communication system in particular for a user terminal in a fifth generation (5G) cellular network.
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| 8. |
- Bondarik, Alexander, et al.
(författare)
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Gridded parasitic patch stacked microstrip array antenna for 60 GHz band
- 2020
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Ingår i: IET Microwaves, Antennas and Propagation. - : Institution of Engineering and Technology (IET). - 1751-8725 .- 1751-8733. ; 14:8, s. 712-717
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Tidskriftsartikel (refereegranskat)abstract
- An array antenna design based on a gridded parasitic patch stacked microstrip antenna element is presented. The radiating part in the top layer of one antenna element has nine rectangular metal patches placed in a grid with three rows and three columns with a separation of 0.1 mm between the patches. Two means of realising the array are investigated. In a regular 2 × 2 concept, the parasitic patches of individual elements are placed next to each other, forming on the top layer a uniform grid of parasitic patches with six rows and six columns. In an alternative concept named as shared array, neighbouring antenna elements share one row and one column of parasitic patches, forming on the top layer a uniform grid of parasitic patches with five rows and five columns. The antenna arrays are designed for the 60 GHz band. The measured bandwidth is 13.8 GHz for the single antenna, 15.3 GHz for the 2 × 2 array, and 12.4 GHz for the shared array. The measured realised gain at 60 GHz is 6 dBi for the single antenna, 11 dBi for the 2 × 2 array, and 10.5 dBi for the shared array. The measured radiation patterns have good agreement with simulations.
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| 9. |
- Bondarik, Alexander, et al.
(författare)
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Implementation of UC-EBG Structure for 60 GHz Gridded Parasitic Patch Stacked Microstrip Antenna
- 2015
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Ingår i: 2015 9th European Conference on Antennas and Propagation (EuCAP). - 9788890701856 ; , s. 1-5
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Konferensbidrag (refereegranskat)abstract
- A uniplanar-compact electromagnetic band-gap (UC-EBG) structure is implemented at 60 GHz on a conventional PTFE (polytetrafluoroethylene) substrate. The structure surrounds a stacked microstrip antenna with gridded parasitic patch. The UC-EBG implementation results in about 5 dB decrease in the antenna E-plane normalized radiation pattern for angles along the substrate. The measured antenna gain increase at 60 GHz is 1.5 dB. Measured results are in good agreement with simulation. The design can be used for fifth generation (5G) wireless communication systems to reduce the antenna interference with other components.
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| 10. |
- Bondarik, Alexander, et al.
(författare)
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Investigation of Reconfigurability for a Stacked Microstrip Patch Antenna Pattern Targeting 5G Applications
- 2015
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Ingår i: 2015 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications (APWC). - 9781479978090 ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- A pattern reconfigurable stacked microstrip patch antenna is presented for 60GHz central frequency. The antenna reconfigurability is realized using shorting pins in the antenna radiating aperture. Investigation is presented for different shorting pins locations. Influence on the antenna radiation pattern and return loss is studied. Measurement results for the antenna prototype agree with simulation results. The proposed antenna can be used in a next generation cellular systems.
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