• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.516-521
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• 2022

In this paper, a compact 4-bit chipless RFID(radio frequency identification) tag using a modified ELC(electric field-coupled inductive-capacitive) resonator and multiple slot resonators is proposed. The modified ELC resonator uses an interdigital-capacitor structure in the conventional ELC resonator to lower the resonance peak frequency of the RCS. The multiple slot resonators are designed by etching three slots with different lengths into an inverted U-shaped conductor. The resonant peak frequency of the RCS for the modified ELC resonator is 3.216 GHz, whereas those of the multiple slot resonators are set at 4.122 GHz, 4.64 GHz, and 5.304 GHz, respectively. The proposed compact four-bit tag is fabricated on an RF-301 substrate with dimensions of 50 mm×20 mm and a thickness of 0.8 mm. Experiment results show that the resonant peak frequencies of the fabricated four-bit chipless RFID tag are 3.285 GHz, 4.09 GHz, 4.63 GHz, and 5.31 GHz, respectively, which is similar to the simulation results with errors in the range between 0.78% and 2.16%.

• Journal of electromagnetic engineering and science
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• v.16 no.3
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• pp.194-197
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• 2016

An eight-element compact low-profile multi-input multi-output (MIMO) antenna is proposed for wireless local area network (WLAN) mobile applications. The proposed antenna consists of eight inverted-F antennas with an isolation-enhanced structure. By inserting the isolation-enhanced structure between the antenna elements, the slot and capacitor pair generates additional resonant frequency and decreases mutual coupling between the antenna elements. The overall size of the proposed antenna is only $33mm{\times}33mm$, which is integrated into an area of just $0.5{\lambda}{\times}0.5{\lambda}$. The proposed antenna meets 5-GHz WLAN standards with an operation bandwidth of 4.86 - 5.27 GHz and achieves an isolation of approximately 30 dB at 5 GHz. The simulated and measured results for the proposed antenna are presented and compared.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.50-55
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• 2008

In this paper, multi-band internal antenna which can adjust both resonant frequency and input impedance of antenna as using lumped inductor between shoring plate and ground plane is proposed. The structure of proposed antenna consists of PIFA (Planar Inverted F Antenna) structure and half-wavelength loaded line structure and has two shorting plates and one feeding plate. One shorting plate is shared. The operating frequency bands of designed antenna are GSM, GPS in the PIFA structure and DCS, US-PCS, W-CDMA in half-wave loaded line structure as varying the inductor value in 2.2nH, 3.3nH, and 4.7nH. As varying the inductor value in the shared shorting plate, input impedance of antenna is varied. To minimize the gain variation of antenna as adding lumped element, the inductor value is restricted at maximum of 6.8nH. The maximum gain of proposed antenna is measured as -1.60dBi in the GSM band, -1.16dBi in the GPS band, and 1.41dBi in the DCS/US-PCS/W-CDMA band.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9A
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• pp.900-905
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• 2006

In this paper, PIFA antenna for $2.40{\sim}2.482GHz\;and\;5.75{\sim}5.85GHz$ is designed, fabricated, and measured. The prototype consist of hair-pin and short-pin. To obtain suitable bandwidth, the form layer is inserted between ground plane and substrate. Important parameters in the design are hair-pin length, width, position, air-gap height, and feed point position. From these parameters optimized, a PIFA antenna is fabricated and measured. The measured results of the antenna are obtained as follows results. The resonant frequency of the fabrication PIFA antenna is 2.37GHz and 5.86GHz bandwidth for approximately 90MHz with 350MHz(VSWR<2.0) and the gain is $1.91{\sim}4.37dBi$. H-plan and E-plan at 2.4GHz and 5.8GHz are shown as $52.83^{\circ},\;85.90^{\circ}\;and\;68.68^{\circ},\;52.143^{\circ}$ respectively.