| 1. |
- 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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| 2. |
- 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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| 3. |
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| 4. |
- 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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| 5. |
- 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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| 6. |
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| 7. |
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| 8. |
- 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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| 9. |
- Kristensson, Gerhard, et al.
(författare)
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Radiation efficiency and surface waves for patch antennas on inhomogeneous substrat
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this paper the surface wave characteristics, as well as the radiation efficiency and the directivity of a patch antenna, with a given current distribution, located on top of an inhomogeneous, isotropic substrate are calculated. The substrate is infinite in the lateral directions and inhomogeneous with respect to the height coordinate. The surface waves in the substrate are analyzed using the propagator technique and residue calculus. The propagators and the residues are found by solving two sets of systems of ordinary differential equations (ODEs). Several dispersion curves of the surface waves for inhomogeneous substrates are calculated. The radiation efficiency and the directivity are compared with the corresponding quantities of a printed antenna on a homogenized substrate. Moreover, some alternative ways of calculating the reflection dyadic of an inhomogeneous substrate are presented in a series of appendices.
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| 10. |
- Kristensson, Gerhard, et al.
(författare)
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Radiation efficiency and surface waves for patch antennas on inhomogeneous substrates
- 2003
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Ingår i: IEE Proceedings - Microwaves Antennas and Propagation. - : Institution of Engineering and Technology (IET). - 1350-2417. ; 150:6, s. 477-483
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Tidskriftsartikel (refereegranskat)abstract
- Surface wave characteristics and radiation efficiency are calculated for a patch antenna with a given current distribution and located on top of an inhomogeneous, isotropic substrate. The substrate is infinite in the lateral directions and inhomogeneous with respect to the height coordinate. The surface waves in the substrate are analysed using the propagator technique and residue calculus. The propagators and the residues are found by solving two sets of systems of ordinary differential equations (ODEs). Several dispersion curves of the surface waves for inhomogeneous substrates are calculated. The radiation efficiency is compared with the corresponding quantities of a printed antenna on a homogeneous substrate.
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