| 61. |
- Helander, Jakob, et al.
(författare)
-
Performance Analysis of Millimeter-Wave Phased Array Antennas in Cellular Handsets
- 2016
-
Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1536-1225 .- 1548-5757. ; 15, s. 504-507
-
Tidskriftsartikel (refereegranskat)abstract
- This letter discusses the usage of high-gain steerable antenna arrays operating at millimeter-wave (mmWave) frequencies for future cellular networks (5G). Based on the probable outline of the 5G networks, a method for characterizing phased array antennas in cellular handsets has been introduced. For analyzing the performance, the total scan pattern of the array configuration together with its respective coverage efficiency are essential to consider in order to compare different antenna designs and topology approaches with each other. Two design approaches and subarray schemes of these have been considered in order to illustrate the relevance of such a characterization method. The results show the importance of evaluating potential array antennas in such manners. The method can be applied to much more complex system models, where polarization diversity, hand and body effect, and statistical modeling of the channel may be included.
|
|
| 62. |
|
|
| 63. |
|
|
| 64. |
- Ioannidis, Andreas, et al.
(författare)
-
On the dispersion equation for a homogeneous, bi-isotropic waveguide of arbitrary cross-section
- 2009
-
Ingår i: Microwave and Optical Technology Letters. - : Wiley. - 0895-2477 .- 1098-2760. ; 51:11, s. 2701-2705
-
Tidskriftsartikel (refereegranskat)abstract
- In this article, we consider the propagation problem inside a waveguide filled with a homogeneous bi-isotropic material. The cross section of the waveguide is assumed arbitrary. By using the classical theory for the 2D Helmholtz equation in the cross section and the null-field approach, we obtain the dispersion equation in an implicit form. The final equation is a potential candidate for the solution of the direct and the inverse propagation problems.
|
|
| 65. |
|
|
| 66. |
|
|
| 67. |
|
|
| 68. |
- Karlsson, Anders, et al.
(författare)
-
Frequency selective structures with stochastic deviations
- 2007
-
Ingår i: Progress in Electromagnetics Research-Pier. - 1070-4698. ; 74, s. 141-155
-
Tidskriftsartikel (refereegranskat)abstract
- This paper deals with the performance of frequency selective structures with defects. A frequency selective structure is in this case a periodic pattern of apertures in a conducting plate. The plate can be of arbitrary thickness. The defects can be due to deviations in the placing of the apertures, in the material parameters, or in the shape of the apertures. First, the perturbation to the far field pattern from a deviation in one aperture is analyzed. It is then shown how this affects the mean scattered power from the structure. Numerical illustrations of the perturbed. fields on the structure are given.
|
|
| 69. |
- Karlsson, Anders, et al.
(författare)
-
Frequency Selective Structures with Stochastic Deviations
- 2003
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper deals with the performance of frequency selective structures with defects. A frequency selective structure is in this case a periodic pattern of apertures in a conducting plate. The plate can be of arbitrary thickness. The defects can be by deviations in the placing of the apertures, in the material parameters, or in the shape of the apertures. First the perturbation to the far- field pattern from a deviation in one aperture is analyzed. Then a statistical analysis is performed for a frequency selective structure where the apertures have a stochastic variation.
|
|
| 70. |
- Kristensson, Gerhard, et al.
(författare)
-
Direct and inverse scattering for transient electromagnetic waves in nonlinear media
- 1998
-
Ingår i: Inverse Problems. - : IOP Publishing. - 0266-5611 .- 1361-6420. ; II, s. 587-589
-
Tidskriftsartikel (refereegranskat)abstract
- Nonlinear propagation of electromagnetic waves is an important problem in optics. Often the properties of the nonlinear media are not fully understood. The solution of an inverse problem can provide an aid to that understanding. An inverse transmission problem is posed; it is one of reconstructing the medium parameters, by measurement of a wave that has been propagated through the nonlinear medium. The nonlinear medium is assumed to be homogeneous and isotropic. The methods have application to nonlinear optics, and the numerical results for both the direct and inverse problems presented are based on the nonlinear Kerr effect, which is observed in the optical wavelength band. However, the mathematical techniques that are developed are applicable to any set of nonlinear first-order equations. The method is therefore model independent.
|
|
