| 1. |
- Stjernman, Anders, et al.
(författare)
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Multi-Objective Optimization of MIMO Antenna Systems
- 2009
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Ingår i: Antennas and Propagation, 2009. EuCAP 2009. 3rd European Conference on. - 9781424447534 ; , s. 1758 -1762
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Konferensbidrag (refereegranskat)abstract
- This paper discusses the use of multi-objective optimization in the context of designing a dual antenna system for diversity reception or MIMO communication on a mobile platform in the recently released communication band 750-800 MHz. The performance of such systems is highly dependent on the received signal levels and also on the correlation between the signals. Also, from a radio-engineering point of view, there are limitations on the S-parameters of the design. Further, the antennas also need to share space with other devices on the platform, which adds requirements on the size of the antennas. All these aspects often lead to conflicting requirements, which traditionally are dealt with in the optimization by weighting the different requirements into a single requirement. That approach has several disadvantages including that no trade-off discussion between the different requirements can be made. Multi-objective optimization avoids these disadvantages and has the benefit that the decision of optimal design is made by the antenna engineer then all possibilities and limitations are known.
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| 2. |
- Bolin, Thomas, et al.
(författare)
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Two-antenna receive diversity performance in indoor environment
- 2005
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 41:22, s. 1205-1206
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Tidskriftsartikel (refereegranskat)abstract
- Receive diversity gain performance of a two-antenna setup in an office environment is reported. The terminal is handheld in front of the user simulating a data mode scenario while walking around. The dual polarised base station sector antenna is placed at the end of a corridor. The results indicate that experimentally achieved diversity performance is similar to previously predicted theoretical data.
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| 3. |
- Derneryd, Anders, et al.
(författare)
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A 23 GHz sector antenna for point-to-multipoint communications
- 2005
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Ingår i: 18th International Conference on Applied Electromagnetics and Communications, Conference Proceedings. - ZAGREB : KOREMA. ; , s. 297-300
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Konferensbidrag (refereegranskat)abstract
- A broadband and compact antenna concept for a point-to-multipoint communication system at millimeter-wave frequencies is presented. The antenna consists of a rectangular feed waveguide, an H-plane parallel plate horn, an enclosed parabolic reflector section, a radiation slot aperture, and corrugated external baffles. The bandwidth is 2.9 GHz corresponding to a relative bandwidth of 12.6 % at 23 GHz for a return loss better than 10 dB of a prototype. The overall dimensions of the manufactured antenna are 200 mm by 14 7 mm by 50 mm.
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| 4. |
- Derneryd, Anders, et al.
(författare)
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Antenna signal correlation and its relation to the impedance matrix
- 2004
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 40:7, s. 401-402
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Tidskriftsartikel (refereegranskat)abstract
- Theory is presented that extends the analysis to signal correlation between any antennas in an array of elements. It is generalised to include non-identical elements and arbitrary load termination of passive antenna ports. The method is related to the power balance concept and based on the antenna impedance matrix.
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| 5. |
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| 6. |
- Derneryd, Anders, et al.
(författare)
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Application of gain-bandwidth bounds on loaded dipoles
- 2009
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Ingår i: IET Microwaves, Antennas & Propagation. - : Institution of Engineering and Technology (IET). - 1751-8725. ; 3:6, s. 959-966
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Tidskriftsartikel (refereegranskat)abstract
- Physical limitations based only on antenna volume, form factor and material parameters are applied to electrically small antennas in the form of single dipoles. The upper bound on the gain-bandwidth product is solely determined by the polarisability matrix that characterises the antenna when it is immersed in a uniform applied static field. The polarisability, and hence the bandwidth, is increased by loading the dipole arms close to their ends. The half-power impedance bandwidth is increased from 5 to 13% by moving the coils from the centre to the ends of the dipole arms. The introduction of a stub-matching further improves the bandwidth but the physical limit is not reached. Finally, a dual-resonance dipole antenna is analysed. It is observed that a second resonance hardly reduces the bandwidth of the first resonance if the resonances are separated more than 1.7 times in frequency.
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| 7. |
- Derneryd, Anders, et al.
(författare)
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Mobile and terminal antennas
- 2003
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Ingår i: Antenn 03. Nordic Antenna Symposium. Conference Proceedings. ; , s. 37-38
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This project deals with the analysis of antennas for mobiles and terminals in the form of a patch element on a grounded substrate. A special case of this antenna element is the PIFA-element. The analysis is based on the propagator method, a vector generalisation of the transmission line theory, that has been extended to the analysis of surface waves in inhomogeneous permittivity profiles. Analyses of combined antenna radiation pattern and propagation channel characteristics have been initiated in order to demonstrate the performance advantage of exploiting two-antenna signals on a terminal for diversity or interference suppression. A generic two-antenna terminal is presented in this paper which improves capacity on reception. Signal correlation coefficients that depend on the mutual coupling are calculated.
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| 8. |
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| 9. |
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| 10. |
- Derneryd, Anders, et al.
(författare)
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Signal correlation including antenna coupling
- 2004
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 40:3, s. 157-159
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Tidskriftsartikel (refereegranskat)abstract
- Mutual coupling effects between antenna elements on signal correlation are reported. A simple expression is derived to compute the correlation coefficient from the far-field radiation patterns including the characteristics of the propagation environment and the terminating impedance. It is shown that the mutual coupling between closely spatially separated dipoles call lead to increased signal decorrelation.
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