Browsing by Author "Hsiao, Cherng-Chyi"

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An adaptive multi-beam massive array architecture for 5G wireless
(2015)
Hwang, Ruey-Bing
;
Tsai, Yi-Che
;
Hsiao, Cherng-Chyi
;
資訊工程學系
;
電機學院
This paper reports an adaptive multi-beam forming architecture designed for 5G wireless communication system. As far as a beam-forming system is concerned, the adjustment of the phase angle and weighting on each radio frequency (RF) signal connected to antenna element should be taken into account. Here, the phased local oscillator (LO) is employed for replacing the commonly used phase shifter, and the baseband I-and Q-signal strength is altered for designating the weighting on the RF signal. Additionally, two procedures are performed for accomplishing the dynamical beam forming. Firstly, the switched-beam circuit on the subarray determine the desired radiation zone. Secondly, the beam-steering within the zone is then achieved by varying the phase angle of phased LO and the amplitude over the baseband I/Q signals. Notably, each of the steerable beam contributed by an array consisting of several subarrays can be independently generated to accomplish a massive array system having multiple steerable beams
An Impedance Matching Technique for Bandwidth Enhancement of Terminal Antennas
(2014)
Hsiao, Cherng-Chyi
;
Huang, Hsien-Tung
;
Hwang, Ruey-Bing
;
電機學院
;
電機工程學系
Built-in antennas for terminal devices are inherently electrically small which is usually difficult to meet satisfactorily the specifications in bandwidth and efficiency for applicable operation. A simplified real frequency technique was employed in this paper for impedance matching of a DVB-H antenna and a GSM 850/900 antenna. Trade off of antenna realized gain and band width has been considered to optimize the antenna performance.