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Designing and feeding multiple characteristic modes in small terminals at frequencies below 1 GHz

Miers, Zachary LU ; Li, Hui LU and Lau, Buon Kiong LU (2013) 8th COST IC1004 Management Committee Meeting
Abstract
Designing multiple antennas in small terminals at frequency bands below 1 GHz is challenging due to severe mutual coupling among antenna elements. The severe coupling is often the result of simultaneous excitation of the fundamental characteristic mode of the terminal chassis by more than one antenna element. In this work, through the use of characteristic mode analysis, we propose to solve the coupling problem in a two-step procedure. First, by manipulating the chassis structure it is possible to create more than one characteristic mode which resonate at frequencies below 1 GHz. Second, proper feeding of individual modes is required as not to excite both modes through a single feed. By exploiting characteristic field properties, single... (More)
Designing multiple antennas in small terminals at frequency bands below 1 GHz is challenging due to severe mutual coupling among antenna elements. The severe coupling is often the result of simultaneous excitation of the fundamental characteristic mode of the terminal chassis by more than one antenna element. In this work, through the use of characteristic mode analysis, we propose to solve the coupling problem in a two-step procedure. First, by manipulating the chassis structure it is possible to create more than one characteristic mode which resonate at frequencies below 1 GHz. Second, proper feeding of individual modes is required as not to excite both modes through a single feed. By exploiting characteristic field properties, single mode feeds can be achieved. To demonstrate our design concept and its practicality, we show the opportunistic use of the metallic bezel popular in smartphone designs. In this design we effectively obtain two characteristic modes that are efficiently excited by separate coupling elements at 0.81 GHz. Due to the inherent orthogonality of the modes, proper excitation of these modes by two antenna elements will result in orthogonal radiation patterns and high isolation between the antenna ports. Therefore, the proposed approach enables the effective use of the chassis to achieve MIMO antennas with good performance. (Less)
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conference name
8th COST IC1004 Management Committee Meeting
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English
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yes
id
3245335b-4da6-4fb1-be45-9a4b9c9f5ba3
date added to LUP
2016-04-14 17:56:11
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2016-04-15 10:43:56
@misc{3245335b-4da6-4fb1-be45-9a4b9c9f5ba3,
  abstract     = {Designing multiple antennas in small terminals at frequency bands below 1 GHz is challenging due to severe mutual coupling among antenna elements. The severe coupling is often the result of simultaneous excitation of the fundamental characteristic mode of the terminal chassis by more than one antenna element. In this work, through the use of characteristic mode analysis, we propose to solve the coupling problem in a two-step procedure. First, by manipulating the chassis structure it is possible to create more than one characteristic mode which resonate at frequencies below 1 GHz. Second, proper feeding of individual modes is required as not to excite both modes through a single feed. By exploiting characteristic field properties, single mode feeds can be achieved. To demonstrate our design concept and its practicality, we show the opportunistic use of the metallic bezel popular in smartphone designs. In this design we effectively obtain two characteristic modes that are efficiently excited by separate coupling elements at 0.81 GHz. Due to the inherent orthogonality of the modes, proper excitation of these modes by two antenna elements will result in orthogonal radiation patterns and high isolation between the antenna ports. Therefore, the proposed approach enables the effective use of the chassis to achieve MIMO antennas with good performance. },
  author       = {Miers, Zachary and Li, Hui and Lau, Buon Kiong},
  language     = {eng},
  month        = {09},
  title        = {Designing and feeding multiple characteristic modes in small terminals at frequencies below 1 GHz},
  year         = {2013},
}