Chang-Fa Yang

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—In this paper, a ray-tracing method for waves propagating inside building structures is presented. Ray tubes are used to model the wave propagation and penetration and all the significantly reflected and transmitted ray tubes from interfaces are included. Also, the cross sections of the ray tubes at the field points are evaluated to find the spreading(More)
—In this paper, a planar circular patch array antenna that features electric fields focused in the near-field zone for 2.4 GHz radio frequency identification (RFID) applications is presented. This array antenna is implemented by using six circular patch elements and a microstrip feeding network with a proper input phase for each element. The array antenna(More)
Recent developments in the field of radio frequency technologies have led to numerous challenges in providing comprehensive performance for the next generation wireless networks. Meanwhile RFID as the one of important core technology in toward this future approach, have been implemented extensively for different kind applications. Those applications direct(More)
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