• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.739-745
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• 2009

This paper presents a design for trapezoidal planar UWB(Ultra Wide-band) antenna using symmetry meander line to realize broad bandwidth at low frequency region. The size of proposed design antenna is $15.5{\times}21{\times}1.6mm^3$ and dielectric substrate considered in design has 4.4 of relative permittivity. The calculated bandwidth is from 1.31 GHz to 10.83 GHz and the measured return loss is 1.5 GHz to 10.6 GHz at -10 dB below, and satisfies with the UWB antenna's bandwidth. The simulated and measured radiation patterns show fine agreement with each other at each frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.9
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• pp.851-857
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• 2002

A two-arm microstrip spiral antenna with a circular aperture on the ground plane that generates a circularly polarized conical beam is presented in this paper. We obtained circularly polarized conical beam by using two spirals that are excited in-phase from the microstrip feed lines. The main beam directions of the conical beam from the broadside are approximately 40$^{\circ}$ in the range from 5 GHz to 6.5 GHz, and 58$^{\circ}$ from 9 GHz to 11 GHz. Since the proposed antenna has omni-directional conical beam pattern, it is suitable for use in mobile communication systems.

• Journal of Navigation and Port Research
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• v.28 no.6
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• pp.503-507
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• 2004

We prepared EM wave absorbers by using recycled Sr ferrite for GHz frequency, and investigated the effects of carbon additions and preparation temperatures on their EM wave absorption properties. A Sr ferrite EM wave absorber with the ratio of Sr ferrite: silicon rubber: carbon = 80 : 13.6: 6.4 wt% prepared at 7$0^{\circ}C$ showed -24 dB at 9.4 GHz and -23 dB at 5.5 GHz for 2 mm and 3 mm thickness, respectively.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.8
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• pp.125-130
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• 2004

Various antennas have been developed to be used for UWB systems, However, Simultaneously meet omni-directional and low-VSWR requirements, essential for some applications such as UWB channel sounding. In this paper, we propose a novel wide band printed elliptic monopole antenna for UWB(Ultra wide Band). Wideband planar monopole disc antenna have been recently studied. The proposed antenna can cover m frequencies from 3.5GHz to 12GHz. it is determined from 10dB return loss. Antenna radiation pattern is omnidirectional at 3.5GHz - 10GHz. The antenna consists of the printed elliptical monopole disc with microstrip-line feed. Elliptic disc of antenna and ground height operate important to matching. The proposed antenna easy to construct UWB system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.2
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• pp.505-513
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• 1996

In this paper the dual-mode bandpass filters with a Chebyshev response are designed and manufactured at Ku-band as well as K-band. Manufactured filters are resonated by two independent orthogonal $TE_{113}$ circular-cavity modes and characterized by 4-pole Chebyshev function. One is operating at a center frequency of 12.5GHz with a bandwidth of 100MHz and the other, a center frequency of 19.25GHz with 120MHz, respectively. The measureed experimental results of a 12.5GHZ dual-mode filter ahve a 1.2dB intertion loss in the passband and 65dB out-of-rejection, and a 19.25GHz filter has a 1.55dB insertion loss and 70dB out-of-rejection. These experimantal results shoults show good agreements with the design specifications.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.221-227
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• 2013

In this paper, Satellite DMB/WiBro antenna and PCS/WiBro antenna improving indoor coverage for mobile services are designed and fabricated. Satellite DMB/WiBro bands repeater antenna and PCS/WiBro bands repeater antenna are proposed as a simple radiator with loading capacitor to generate LHCP(Left Hand Circular Polarization). The proposed antenna for Satellite DMB/WiBro and PCS/WiBro bands communication are fabricated by copper plate uploader type and substrate uploader type. The designed and fabricated antenna has a bandwidth of 70MHz at 1.816GHz~1.886GHz and bandwidth of 107MHz at 2.247GHz~2.354GHz. Maximum gain of radiation pattern was up to 5dBi.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.39-45
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• 2008

In this parer a branch type inverted-F structure antenna with dual-band is proposed. The proposed antenna has a size of about $70mm{\times}35mm{\times}0.8mm$ with a total mobile phone PCB for support and patch of about $12mm{\times}8mm{\times}0.8mm$. This antenna is designed to operate of frequency 2.45GHz and 5.8GHz, Bandwidth at each other frequency is satisfied $83MHz{\sim}100MHz$ in frequencies. Also, The designed and fabricated dual-band antenna for 2.45GHz, 5.8GHz have a gain between 2.0dBi and -1.0dBi at all bands.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.145-151
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• 2008

In this paper, a dual band microstrip antenna with similar radiation pattern for the satellite internet service is proposed. The proposed antenna has two Y-shaped slots on the microstrip patch that is fabricated on RO4003 substrate with a dielectric constant of 3.38 and a thickness of 0.508 mm, and operates in the 2 GHz and 5 GHz bands. The size of the antenna is $50\times47.5\times6.5\;mm^3$, and fed by coaxial cable. The measured bandwidths of the antenna are 2.398$\sim$2.507 GHz and 5.458$\sim$5.972 GHz for VSWR<2. The measured gains are 8.92 dBi and 7.74 dBi, respectively, for the lower and upper bands.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.2
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• pp.259-268
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• 2023

In this paper, it is said that the quality of wireless service has been improved by providing wireless service that can eventually overcome wired wires by using 2.4GHz band wireless access technology that supports 2.4/5GHz dual band. Increasing the maintenance cost incurred when building wireless CCTV, makes it possible to connect with existing CCTV, and study about expanding the service area of A/V surveillance system using CCTV.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.219-222
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• 2002

본 논문에서는 이중 대역 소형 평면 패치 안테나를 이용하여 5.6GHz 대역과 5.8GHz 대역에서 동작하는 이중 대역 안테나를 제안하였다. 안테나의 격리도 특성을 최소화하기 위해 서로 다른 급전선 구조를 이용하였고, 급전부에 개방스터브를 사용하여 VSWR $\leq$2를 기준으로 5.48 GHz 대역과 5.87 GHz대역에서 각각 3.1%와 2.73% 이상의 대역폭을 얻었으며, 격리도 특성은 두 대역에서 평균적으로 -27㏈를 얻었다