• Journal of electromagnetic engineering and science
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• v.18 no.3
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• pp.154-159
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• 2018

In this paper, electromagnetic radiation from a slot array antenna enclosed by a Von Karman radome is analyzed by using the ray tracing method and Huygens's principle. We consider the rectangular slot array antenna and the Von Karman radome. The radiation patterns are calculated by using the surface currents of the radome to illustrate the electromagnetic behaviors of the radome-enclosed waveguide slot array antenna.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.642-646
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• 2016

A wearable antenna made using conductive tape on paper is presented in this paper. The proposed antenna is composed of a half-wavelength conducting dipole strip and a parasitic conducting strip on the A4 copy paper. The antenna is fed at the center of the dipole strip by an SMA connector. The configuration of the proposed antenna changes according to the origami method. Therefore the radiation patterns of the antenna vary according to whether or not the paper is folded. This approach solves the problem that the reception ratio of the signal decreases because of null points in the antenna radiation pattern. The reflection coefficient and the radiation pattern of the proposed antenna at 900 MHz are evaluated using an EM simulation and measurements. It was shown that the proposed paper antenna has reconfigurable characteristics at 900 MHz when utilizing the origami method.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.343-346
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• 1998

In this paper a radiation problem for a finite microstrip antenna structure is analyzed. For the analysis of finite structures we utilize the equivalent volume current. Intergral equation for the unknown equivalent volume current induced on a finite microstrip structure is derived and solved by the use of conjugate gradient-fast fourier. transform (CG-FFT) method. Some numerical examples are radiation patterns derived by the equivalent volume current solved by the conjugate gradient-fast fourier transform.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.483-489
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• 2011

In this paper, we propose a new antenna, which has wide bandwidth, good radiation patterns, and high-gain characteristics. We analysis the antenna using FDTD(Finite Difference Time Domain) method. And the antenna parameters are optimized to get maximum bandwidth. From the measured results, the bandwidth of the antenna is 0.839 octave, for the S11${\leq}$-10 dB. And the measured cross polarization level of the proposed antenna is less than -25 dB at the center frequency. Experimental data of the return loss and the radiation pattern of the proposed antenna are also presented, and the experimental bandwidth characteristics are relatively in good agreement with the FDTD results. The proposed antenna can be applied to MIMO, LAN, biomedical instruments, broadcasting-network system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.11
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• pp.93-98
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• 2003

In this paper, we designed a printed square loop antenna for operating of PCS and IMT2000 band. The proposed antenna has omni-directional radiation patterns with broad bandwidth, similar to the conventional antenna, to easy feed on composing single planar. We obtain an ideal impedance matching and increase bandwidth. An antenna bandwidth is about 150MHz(1.74∼l.89〔GHz〕) at 1$^{st}$ resonance frequency and 290MHz(1.95∼2.24GHz) at 2$^{nd}$ resonance frequency on VSWR(equation omitted)1.5, and then we can obtain not only 1.73∼l.87 〔GHz〕 PCS band but also 1.92∼2.17 (GHz) IMT2000 band. band.

• Journal of IKEEE
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• v.24 no.2
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• pp.536-542
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• 2020

This paper presents a nature-inspired wideband sprout-leaf shaped antenna with end-fire radiation pattern. A sprout-leaf shape angled-radiator was designed for wide beamwidth radiation patterns for motion detection sensors. An extended and truncated ground plane was used as a reflector for end-fire radiation patterns. To feed the balanced radiator, a broadband microstrip (MS) to coplanar stripline (CPS) balun was utilized with excellent amplitude and phase balance. The proposed antenna demonstrates wide frequency bandwidth from 8.5 to 14.5 GHz with wide beamwidth and the radiation efficiency of 90%. The measured gain is from 4 to 5 dBi and front-to-back ratio was 10 to 20 dB. It has been shown that the proposed antenna can be used for imaging sensors, phased array systems, and radars that require a wide bandwidth and a directional radiation pattern.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.7
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• pp.719-725
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• 2008

In this paper, we have proposed a printed monopole antenna using parasitic elements. The broadband characteristics of the antenna is obtained by using the printed monopole and parasitic elements. To confirm the broadband characteristics of the antenna, of have designed and fabricated the proposed antenna. The return loss and radiation patterns are measured in the frequency range of$0.8{\sim}1.2\;GHz$. The measured results show that the proposed antenna has return loss less than -10 dB in the operating frequency band and the radiation pattern is the dipole-like patterns. The antenna gain varies from 1.7 to 4.6 dBi in the operating frequency band. Thus, the proposed antenna can be used for the broadband repeater antenna $0.806{\sim}0.960\;GHz$(TRS-800, CDMA and GSM-900).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.5
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• pp.187-196
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• 2003

Effects of Airgap and anisotropy substrate on input impedance and radiation pattern of rectangular microstrip patch antenna are studied in terms of an integral equation formulation. The input impedance and radiation pattern of microstrip patch antenna is investigated by using Galerkin's moment method in solving the integral equation. Sinusoidal functions are selected as basis functions, which resemble in the actual standing wave on the Patch. From the numerical results, the variation of input impedance and radiation patterns in the variation of air gap thickness, anisotropy ratio of substrate, and relative permittivity of anisotropy substrate are presented.

• Journal of electromagnetic engineering and science
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• v.18 no.1
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• pp.29-34
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• 2018

An antipodal Vivaldi antenna with a compact parasitic patch to overcome radiation performance degradations in the high-frequency band is proposed. For this purpose, a double asymmetric trapezoidal parasitic patch is designed and added to the aperture of an antipodal Vivaldi antenna. The patch is designed to efficiently focus the beam toward the end-fire direction at high frequencies by utilizing field coupling between the main radiating patch and the inserted parasitic patch. As a result, this technique considerably improves the gain and stability of radiation patterns at high frequencies. The proposed antenna has a peak gain greater than 9 dBi over the frequency range of 6-26.5 GHz.

• Journal of electromagnetic engineering and science
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• v.7 no.3
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• pp.116-121
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• 2007

Novel design of a wideband monopole antenna for DVB-H service is presented. The proposed antenna is designed based on a monopole antenna. It consists of folded monopole and parallel parasitic element. The folded segment of the folded monopole makes the antenna shorter. The length of the parasitic element obtains additional resonance frequencies. The gap distance between the folded monopole and the parasitic element is a key parameter to control impedance matching for wideband operation. The antenna has wide band performance, good impedance and radiation characteristics from 470 MHz to 870 MHz. The measured return loss for operating frequencies over DVB-H band is better than 10 dB. Good radiation patterns are also obtained. The measured results are compared with calculated results using Ansoft HFSS(High Frequency Structure Simulator).