• Journal of Digital Contents Society
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• v.10 no.3
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• pp.389-393
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• 2009

In this paper, the single patch microstrip antenna and gap coupled broadband microstrip patch antenna using FDTD(Finite Difference Time Domain method) are analyzed. Mur's 2nd absorbing boundary condition to minimize reflected wave is applied. Return loss, voltage standing wave ratio, and input impedance by the length and width of driving patch, the length and width of parasitic patch, and the distance between driving patch and parasitic patch have been analyzed. Design parameters and radiation patterns of broadband antenna have been also shown.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.9 no.1
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• pp.39-44
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• 1984

Three types of parabolic antenna to reduce the sidelobes and backlobe are compared to determine the best suppressive effect under same conditions which are side rim loading parabilic antenna, flanged prabolic antenna. The hooded parabolic antenna adhered polyurethan form impregnated carbon powder in shows the best shape of suppressed the side back lobes that is 5 to 10 dB suppression of sidelobe and 15dB suppression of back lobe for E-plane.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.117-124
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• 2001

In this paper, the design of a U-slot array antenna for PCS base station has been implemented and studied. The U-slot antenna is a single layer type with an antenna volume smaller but a bandwidth lager than the designs utilizing parasitic patches, which exceed 17 % bandwidth, for the probe fed case. Designed U-slot array antenna has stable radiation patterns and an average gain above 12 dB across the PCS frequency band. In this paper, through the designing of a U-slot array antenna, we have presented the availability for PCS base station antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1094-1101
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• 2001

The design of a compact folded patch antenna with moderately broad bandwidth is presented in this paper. The proposed antenna has radiation characteristics that are similar to the conventional monopole antenna. However, since this antenna is designed in a planar form, it has smaller size than that of a conventional monopole antenna. We have investigated the resonance frequency and bandwidth characteristics of the proposed antenna by changing the antenna design parameters. The proposed planar form of a monopole antenna in this paper has 1.17 GHz bandwidth with a matching circuit at the center frequency of 6.05 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.89-95
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• 2004

In this paper, we proposed a multiple meander strip monopole antenna. Using meander strip structure, we could broaden the impedance bandwidth and reduce the antenna height. The proposed antenna has broad bandwidth, from 2.9 ㎓ to 10.85 ㎓, for VSWR $\leq$ 2 and has vertically polarized omnidirectional conical beam radiation pattern, which is suitable for UWB wireless systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.812-816
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• 2001

In this paper we designed a dual-frequency circular sector microstrip antenna fed microstrip line with orthogonal polarization. The operating frequencies and polarization characteristics of the proposed antenna is calculated by using a cavity model. The antenna operating at about 1.87 GHz and 2.42 GHz is fabricated and its S-parameters and radiation patterns are measured.

• The Journal of Engineering Research
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• v.1 no.1
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• pp.5-14
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• 1997

The purpose of thesis is to analyze the radiation characteristics of an offset gregorian antenna in order to design the satellite-loaded antenna. In order to compute the radiation pattern of the sub-reflector, the reflected wave is obtained by GO(Geometric Optics) at an arbitrary shaped sub-reflector. Then the total radiation EM wave is obtained by summing the diffracted fields obtained by UTD(Uniform Geometrical Theory of Diffraction) and the GO fields. In order to calculate the far field radiation pattern of the main reflector, the radiation integral equation is derived from the induced current density on reflector surface using PO(Physical Optics). The kernel is expanded in terms of Jacobi-Bessel series for increasing the computational efficiency, then the modified radiation integral is represented as the double integral equation independent of observation points. When the incident fields are assumed to be x-or y-polarized field, the characteristics of radiation patterns in the gregorian antenna is analyzed in case of the main reflector having the focal length of 62.4$\lambda$, diameter of 100$\lambda$, and offset height of 75$\lambda$, and the sub-reflector having the eccentricity of 0.501, the inter focal length og 32.8$\lambda$, the horn axis angle of $9^{\circ}$ and the half aperture angle of $15.89^{\circ}$. The cross-polarized level and side lobe level in the offset geogorian reflector are reduced by 30dB and 10dB, respectively, in comparison with those of the offset parabolic antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.12 s.115
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• pp.1189-1198
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• 2006

We analyze the radiated emission and mutual coupling problem from a single microstrip transmission line and double signal traces with various ground patterns. In this paper, it is shown that the reduction of the radiated emission from the signal traces can be accomplished by using the novel and compact patterns on the ground planes in a specific frequency band. The accuracy and validation of radiation mechanism from the transmission line on a novel ground plane are evaluated and explained by using a commercially available software and experiment, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.2
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• pp.247-256
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• 1999

The leaky wave emanated from the dielectric-coated parallel-plate waveguide with finite periodic thick slot in its upper plate is investigated theoretically for H-polarization case. For this structure, fields in slot regions are expressed as a summation of the parallel-plate waveguide TM modes, and in other regions are expressed in the spectral domain by use of the inverse Fourier transform. Boundary conditions at the interfaces are enforced, and the simultaneous linear equations are derived. The influences of the slot width, slot thickness, thickness of a dielectric coating, and finite slot number on the radiation characteristics (phase constant, leakage constant, radiation pattern) are examined. The results of the finite periodic slot are compared with those of the infinite extent structure and good agreement has been found.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.71-72
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• 2013

In this paper, a design method for a compact slot antenna for 5.8 GHz RFID band (5.725-5.875 GHz) is studied. The proposed slot antenna is size-reduced by bending both ends of the straight slot in "${\Gamma}$"-shape, and a rectangular feed patch is located inside the slot. The effects of slot length, location of feed patch, and width and length of feed patch on the antenna performance are examined. A prototype antenna with optimized parameters for 5.8 GHz band is fabricated on an FR4 substrate and tested experimentally. The experimental results show that the frequency band for a VSWR < 3 ranges 5.72-6.13 GHz (bandwidth 410 MHz), and it corresponds fairly well with the simulated band 5.64-5.97 GHz (bandwidth 330 MHz). The fabricated antenna shows good radiation performance such as maximum power density in both directions normal to the slot plane, and low cross-polarization level of < -20 dB.