| Summary: | 碩士 === 清雲科技大學 === 電子工程所 === 100 === This dissertation proposes three Card-type tag antennas constructed with the Hilbert-curve loop is applied for HF/UHF RFID dual band. At first, using electromagnetic software (IE3D) to simulate the return loss, radiation pattern and distribution currents is carried. The antenna measurement in the anechoic chamber is obtained to verify its performance with the radiation patterns. Consequently, by tuning pad and stub matching circuit in the design is used to tuning resonated frequencies, impedance character for matching. The simulation software of the circuit (ADS) is used for the matching LC circuits. The matching LC circuits can be applied to the HF/UHF microchips. It is a compact and available tag antenna for HF/UHF RFID positioning applications. For application, the card-type HF/UHF dual-band RFID tag antenna with Hilbert-curve loop presents, the S21 frequency responses with -3dB bandwidth 2.2MHz at HF-band, S11 frequency responses -10dB bandwidth 25MHz at UHF-band. The directivity gains are 1.78 dBi for HF-band(13.56 MHz) and 2.23 dBi for UHF-band(865 MHz). Radiator patterns of dipole antenna are presenter at broadside in the X-Y cut plane and quasi-omnidirectional patterns are obtained in the Y-Z cut plane. The total size is 50mm *35mm can be applied for cards.
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