• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.501-505
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• 2008

In this paper, we present a multi-turn circular loop antenna for portable terrestrial DMB. In order to satisfy the two contradictory requirements of small antenna size and high receiving capability, the proposed antenna's diameter and turns are fixed to be 4 mm and 80 turns, respectively and its quality factor $\mathcal{Q}$ is set 1 in order to have high transfer function. The fabricated antenna length is 30 mm as small and its measured gain is -15 dBd. The antenna receiving power is verified by measurement very comparable with the receiving power of a commercial terrestrial DMB monopole antenna of length 190 mm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.55-56
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• 2017

In this paper, a wideband loop antenna is designed using a CPW feeding method for indoor digital TV applications. The proposed loop antenna consists of a square loop and two circular sectors which connect the loop with central feed points, and the CPW feed line is inserted in the lower circular sector. The CPW feed line is designed to match with the 75 ohm port impedance for DTV applications, and the ground slots are etched in order to improve the impedance matching in the middle frequency region. The optimized antenna is fabricated on FR4 substrate, and the experiment results show that it operates in the frequency band of 463-1,280 MHz for a VSWR < 2, which assures the operation in the DTV band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.4
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• pp.320-323
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• 2019

This paper examines a disadvantage of low-frequency magnetic shielding measurement based on MIL-STD-188-125-1. A rectangular loop antenna is proposed as an improvement over conventional circular loop antennas for measuring magnetic shielding. Simulation and experiment are used to demonstrate that the proposed rectangular loop outperforms the circular loop for a more reliable shielding measurement at low frequency range.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1492-1497
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• 2017

In this paper, a design method for a CPW-fed wideband loop antenna for indoor digital TV applications is studied. The proposed loop antenna consists of a square loop and two circular sectors which connect the loop with central feed points, and the CPW feed line is inserted in the lower circular sector. The CPW feed line is designed to match with the 75 ohm port impedance for DTV applications, and the ground slots are etched in order to improve the impedance matching in the middle frequency region. The effects of the gap between the circular sectors and the location and dimension of the ground slots on the input reflection coefficient and gain characteristics are examined to obtain the optimal design parameters. The optimized antenna is fabricated on FR4 substrate, and the experiment results show that it operates in the frequency band of 463-1,280 MHz for a VSWR < 2, which assures the operation in the DTV band.

• ETRI Journal
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• v.34 no.6
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• pp.974-977
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• 2012

In this letter, a small-sized ultra-high frequency (UHF) RFID tag antenna for a medical sample tube is proposed. The RFID tag antenna is designed and fabricated based on the circular loop antenna used in the UHF band (Korea standard, 917 MHz to 923.5 MHz). The tag antenna size is reduced using a circular meander stub. The antenna has a physical size of 8 mm, which is about ${\lambda}$/40 in electrical length. The proposed tag antenna is molded into a medical sample and multitag identification is performed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.73-74
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• 2016

In this paper, a design method for a wideband square loop antenna for Digital TV applications is studied. The proposed loop antenna is a square loop antenna combined with circular sectors to connect with central feed points. The input reflection coefficient and gain characteristics of the proposed antenna are analyzed to match with the 75 ohm input impedance for DTV applications. The optimized antenna is designed on FR4 substrate, and it operates in the frequency band of 470-1,300 MHz for a VSWR < 2, which assures the operation in the DTV band(470-806 MHz).

• Journal of the Korean Institute of Telematics and Electronics
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• v.11 no.6
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• pp.33-37
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• 1974

In this paper, the radiation characteristics for the array of a circular loop antenna is studied in moving media. The medium is assumed to be homogeneous, isotropic, and to move with a constant velocity much less than the speed of light. The integral equation for the current distribution is derived and the current functions is found by means of courier Series as a solution of the integral equation. The electric field is derived from the current on circular loop antenna and the Dyadic Green's Function in moving media. The numerical calculation of the electric field concerning to the two element antenna array,, in which one element is parasitic, is carried out. The field patterns are plotted from the computed values. As a result, the field patterns in moving media, compared with the patterns in stationary media, are found to decrease in the direction of media velocity and increase in the opposite direction, and the maximum directivity is shifted.

• ETRI Journal
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• v.31 no.1
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• pp.74-76
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• 2009

A new feeding method for the circular polarization (CP) dielectric resonator antenna (DRA) is proposed in this letter. Two orthogonal modes (${TE^x}_{{\delta}11}$, ${TE^y}_{1{\delta}1$) of the rectangular DRA are excited by a $90^{\circ}$ phase difference of the differential and common modes currents of the proposed feeding structure. To demonstrate the good CP performance of the proposed method, a right-hand CP DRA for a global positioning system was designed. The impedance bandwidth of the proposed antenna for $S_{11}$ < -10 dB and 3 dB axial ratio bandwidth are about 5.4% and 1.95% at 1.57 GHz, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.475-485
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• 2010

This paper proposes a novel concept for a microstrip resonator that can function as a filter and as an antenna at the same time. The proposed structure consists of an outer ring, an open loop-type inner ring, a circular patch, and three ports. The frequencies where the proposed structure works as a filter and as an antenna, respectively, are determined primarily by the radius of the inner ring and the circular patch. The measured results show that, when the microstrip resonator operates as a filtering device, this filter has about 15.1 % bandwidth at the center frequency of 0.63 GHz and a minimum insertion loss of 1.5 dB within passband. There are three transmission zeros at 0.52 GHz, 1.14 GHz, and 2.22 GHz. In the upper stopband, cross coupling - taking place at the stub of the outer ring - and the open loop-type inner ring produce one transmission zero each. The circular patch generates the dual-mode property of the filter and another transmission zero, whose location can be easily adjusted by altering the size of the circular patch. The proposed structure works as an antenna at 2.7 GHz, showing a gain of 3.8 dBi. Compared to a conventional patch antenna, the proposed structure has a similar antenna gain. At the resonant frequencies of the filter and the antenna, high isolation(less than -25 dB) between the filter port and the antenna port can be obtained.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.6 s.121
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• pp.591-601
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• 2007

In this paper, the miniaturized radio frequency identification(RFID) tag antennas used in UHF band$(908.5{\sim}914MHz)$ are designed and fabricated by using the circular loop antenna(CLA). Miniaturization of CLA was possible to transform the structure of circular loop into the structure of meander line. In the case of double meander line CLA is reduced up to 83% compared with the general type CLA. The $S_{11}$, -10 dB bandwidth, and gain of double meander line CLA were -11.9 dB, 12 MHz(1.3%), and -1.18 dBd. Also, a small half-wavelength CLA using double meander line is designed and fabricated for flat snack bag coated aluminum. The antenna is reduced up to 92.1% except ground. It shows the $S_{11}$ of -16.5 dB, -10 dB bandwidth of 48 MHz(5%) and gain of -0.58 dBd. The radiation pattern shows omni-directional pattern in z-y plane(x-axis pol.). Through this result, we can confirm that miniaturized type CLAs using meander lines are suitable for miniaturized RFIB tag antennas with the UHF band.