50971. |
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50972. |
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50973. |
- Lui, Hoi-Shun, 1980, et al.
(författare)
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Improved mutual coupling compensation in compact antenna arrays
- 2010
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Ingår i: IET Microwaves, Antennas and Propagation. - : Institution of Engineering and Technology (IET). - 1751-8725 .- 1751-8733. ; 4:10, s. 1506-1516
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Tidskriftsartikel (refereegranskat)abstract
- A new method for the characterisation of receiving mutual impedances of compact arrays with omnidirectional antenna elements is proposed. Based on a large number of incident waves coming from different directions, the new method is able to calculate the receiving mutual impedances of omni-directional antennas based on a system of equations that characterise the received terminal voltages at different incident wave directions. In the new method, the receiving mutual impedances of all the antenna elements are calculated together in a single equation with the scattering effect from all antenna elements in the array being taken into account. Compared to the previous methods for the characterisation of the receiving mutual impedances, the new method preserves the boundary conditions of the original electromagnetic problem and produces much more accurate results on receiving mutual impedances, especially for compact antenna arrays. Direction finding examples based on the new method demonstrate its superior performance over existing methods.
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50974. |
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50975. |
- Lui, Hoi-Shun, 1980, et al.
(författare)
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Joint Time-Frequency Analysis of Transient Electromagnetic Scattering from a Subsurface Target
- 2012
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Ingår i: IEEE Antennas and Propagation Magazine. - 1045-9243. ; 54:5, s. 109-130
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Tidskriftsartikel (refereegranskat)abstract
- The complexity of transient electromagnetic scattering from objects in free space has been well known for years. Such complexity is mainly due to the high aspect dependency of the early-time response, and the interactions between the various scattering events. Attempts have been made to analytically and numerically study the transient scattering problem using time-frequency (TF) analysis. Using this technique, the occurrences of the scattering events and their frequency content can be revealed, which leads to further information about the actual scattering behavior. For the case of subsurface targets, the entire problem becomes more complicated with the introduction of a dielectric interface. Analytical solutions of such complicated electromagnetic problems are usually not available, and can only be numerically addressed in most cases. In this paper, a systematic study of transient scattering from some subsurface targets is presented. The various interactions between the target and the interface of the half-space can be clearly observed. The findings from this work have opened up some issues that are left for further investigation.
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50976. |
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50977. |
- Lui, Hoi-Shun, 1980, et al.
(författare)
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Matching Medium for Biomedical Microwave Imaging
- 2016
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Ingår i: 2015 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP).
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Konferensbidrag (refereegranskat)abstract
- The choice of matching medium in microwave imaging for biomedical applications is studied. A multi-layer planar human tissue is first used to investigate the amount electromagnetic wave is transmitted through the tissue model using different matching medium. This will give us further insights on wave propagation through human tissue, which assists us to determine to choice of matching medium. Image reconstruction of simplified human breast model with different matching medium using an inverse scattering algorithm will be used to verify our findings.
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50978. |
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50979. |
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50980. |
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