• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.627-633
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• 2000

In this paper, new printed-type inverted F antenna is designed and fabricated to gain the ideal radiation pattern of a rocket-borne antenna which is expected to show the omni-directional pattern characteristic in rear direction. The radiation pattern of this antenna is measured in condition that the antenna is mounted on the side of the fin which is located on the tail of a rocket or a missile. Measurement result shows that the improved symmetrical radiation pattern is obtained with respect to the radiation pattern of the existing inverted F antenna. Besides parasite element which can be operated as reflector is attached in front of the antenna with the distance between the antenna and the parasite element $\lambda$/8. The result shows that the ratio of the front to the rear radiation level is improved by 8 dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.7
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• pp.625-632
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• 2002

In this paper, a wide band modified inverted-F type antenna printed on a high dielectric ceramic material is designed and fabricated. This antenna is designed to have optimum antenna characteristics analyzing the effects of design parameters such as printed antenna pattern, ceramic dielectric material dimension and dielectric constant on antenna characteristics using the commercial simulation tool HFSS. The fabricated antenna's width, length and height are 8 mm, 8 mm and 3 mm, respectively. Measurement results show that it has -10 dB bandwidth of 270 MHz which satisfies the IMT-2000 bandwidth required for handset and that its maximum radiation gain is 2 dBi.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.57-63
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• 2014

In this paper, we have proposed a wide band antenna for manpack SDR(Software Defined Radio). The proposed antenna consists of feeding post, flexible gooseneck and two radiating elements composed of a upper and lower radiators. The upper radiator has a longer electrical length than the lower radiator in order to operate in the lower frequency. Also, the resonant frequency and impedance characteristics of the antenna can be adjusted independently for two radiators. Therefore, the proposed antenna can be achieved wide impedance bandwidth by the combination of two independent resonance modes. To analyze the characteristics of the antenna in the design process is employed the equivalent circuit theory and EM(Electro-Magnetic) simulation. The measurement results show that the proposed antenna have the sufficient wide bandwidth, above -3.4dBi of the gain and fairly good radiation pattern over the wide bandwidth.

• Journal of Broadcast Engineering
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• v.23 no.6
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• pp.925-930
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• 2018

In this paper, we present a low profile dual-microstripline-fed double 4-arrayed meander monopole antenna with a cross-type element back by separated four-segments mesh-type reflector. The cross-type element and separated four-segments mesh-type reflector leads to enhance radiation patterns and antenna gain characteristics. The measurement value of the proposed antenna show that it has dipole-like radiation pattern characteristics. The experimental peak gain of fabricated antenna is about 2.89 dBi, which presents relatively high gain characteristics for a low profile(small-size) one. This antenna can be applied mobile RFID(radio frequency identification) readers, small medical instruments, broadcasting and home-networking operations, and other low profile high-gain systems.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.320-324
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• 2015

Mutual coupling between antenna elements of a linear microstrip patch antenna array positioned along the H-plane including the effect of edge reflections is investigated. Simple formulas are presented for the estimation of the grounded dielectric substrate size with minimum mutual coupling. The substrate sizes calculated by these formulas are in good agreement with those obtained by the full-wave simulation and experimental measurement. The substrate size with minimum mutual coupling is a function of the effective dielectric constant for surface waves and the distance between the antenna centers. The substrate size with minimum mutual coupling decreases as the effective dielectric constant for surface waves on a finite grounded dielectric substrate increases.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.331-337
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• 2015

A novel fully-printed microstrip antenna with negative first resonance and dual polarization is proposed. The radiator is printed on the 1-layer substrate instead of multilayers. The -1st resonance results from a composite right- and left-handed(CRLH) structure that has a circumferentially interlocked gap capacitively coupling a patch with a shorted-ring. This compact antenna is provided with a dual-polarization capability by creating two orthogonal linear polarizations in one body with coaxial feeds. The design is carried out by doing full-wave EM field simulation which is compared with the measurement of the fabricated antenna prototype. The measured results give the gain of 5 dBi and the efficiency of 78% at the -1st resonance mode as the center frequency of a downlink channel of the bandwidth over 20 MHz with 29 dB polarization isolation for mobile communication.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.77-79
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• 2012

The paper deals with the approximate analysis of printed antenna like superconductor antenna. Analysis of antenna with polarization current in dielectric layer using Moment method. This approximation is very useful for printed antenna on dielectric plane with low dielectric constant. In this paper, we compared numerical results of this method with measurement results.

• Journal of electromagnetic engineering and science
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• v.17 no.3
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• pp.113-119
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• 2017

The application of compressive sensing (CS) to a radar imaging system based on a frequency-scanned microstrip leaky wave antenna is investigated. First, an analytical model of the system matrix is formulated as the basis for the inversion algorithm. Then, $L_1-norm$ minimization is applied to the inverse problem to generate a range-azimuth image of the scene. Because of the antenna length, the near-field effect is considered in the CS formulation to properly image close-in targets. The resolving capability of the combined frequency-scanned antenna and CS processing is examined and compared to results based on the short-time Fourier transform and the pseudo-inverse. Both simulation and measurement data are tested to show the system performance in terms of image resolution.

• ETRI Journal
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• v.37 no.1
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• pp.21-25
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• 2015

A miniaturized triple-band antenna suitable for wireless USB dongle applications is proposed and investigated in this paper. The presented antenna, simply consisting of a circular-arc-shaped stub, an L-shaped stub, a microstrip feed line, and a rectangular ground plane has a compact size of $16mm{\times}38.5mm$ and is capable of generating three separate resonant modes with very good impedance matching. The measurement results show that the antenna has several impedance bandwidths for S11 ${\leq}$ -10 dB of 260 MHz (2.24 GHz to 2.5 GHz), 320 MHz (3.4 GHz to 3.72 GHz), and 990 MHz (5.1 GHz to 6.09 GHz), which can be applied to both 2.4/5.2/5.8 GHz WLAN bands and 3.5/5.5 GHz WiMAX bands. Moreover, nearly-omni-directional radiation patterns and stable gain across the operating bands can be obtained.