• Journal of Satellite, Information and Communications
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• v.7 no.1
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• pp.97-101
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• 2012

The TC&R(Telemetry, Command & Ranging) antennas should have the hemispherical omni antenna patterns to make sure that the communication link between the satellite and the ground station can be established under whatever satellite attitude during after launch to on-orbit mission. The hemispherical omni-antennas are typically placed on the +z axis and -z axis of the satellite to provide the spherical omni patterns. The S-band qaudrifilar helix antennas having RHCP and LHCP hemispherical omni pattern are designed to meet the antenna gain and the axial ratio requirements. To investigate the omni-antenna pattern characteristics depending on four cases of antenna polarization combination placed on the +z axis and -z axis, the antenna pattern of each case is analyzed. Based on the result, after installing the designed RHCP and LHCP S-band omni-antennas on the +z axis and -z axis of the satellite, the combined antenna gain is obtained and finally analyzed in conjunction with the communication link influence.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.401-407
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• 2006

In this paper, we present a small-sized and light weighted dual-band antenna for an access point of 2.4/5 GHz dual-band WLAN(Wireless Local Area Network). The antenna for WLAN should show the characteristic of omni-directional radiation pattern. First, to obtain the omni-directional radiation pattern the proposed dual-band antenna has an orthogonal inverted triangular type element at the center and locates four resonating elements symmetrically around it. Also, for the purpose of easy manufacturing and miniaturization of the antenna, we changed the central element which had the orthogonal inverted triangular type structure into the plate type. Measured $S_{11}$ for the proposed dual-band plate type antenna showed characteristic which was less then -12.8 dB for WLAN frequency bands. Measured results for the maximum gain showed 3.17 dBi at 2.44 GHz, 5.38 dBi at 5.77 GHz with omni-directional radiation pattern. The implemented antennas showed applicable performances for the access point of WLAN.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.8
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• pp.443-446
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• 2004

In this paper, a multi-band ceramic chip antenna for WLAN(Wireless LAN) applications is designed. The design target is to obtain 0 dBi of coverage gain with omni directional radiation pattern. The antenna is fabricated using Low Temperature Co-fired Ceramic(LTCC) technology. The size of the chip antenna is $2.2{\times}9.65{\times}1.02$mm. The measured antenna gain is 1 dBi at 2.44 GHz and 0.5 dBi at 5.5 GHz. The omni directional radiation pattern for the two operating bands is obtained. The measured bandwidth(S11=-10 dB) are 90 MHz at 2.44 GHz and 1280 MHz at 5.5 GHz respectively

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9A
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• pp.934-940
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• 2008

In this paper, an antenna accessible to the Hepta-Band (GPS, DCS, PCS, UMTS, Wibro, Bluetooth and S-DMB) is designed and fabricated. To get broadband characteristics with small size, we propose a structure of Coplanar Waveguide-fed with Ground, which is based on a monopole antenna. Simulation is performed by adjusting the size of distance between a length of radiation patch and ground plane. The designed antenna satisfies the frequency bandwidth of 1.430Hz$\sim$2.9GHz(67.89%), the gain of $1.3{\sim}3.7dBi$ and an omni-directional radiation pattern at VSWR<2.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.344-346
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• 2004

KOMPSAT-2 (Korea Multi Purpose Satellite 2) which is scheduled to launch in 2005 year will communicate with KARI TTC (Tracking, Telemetry, and Command) station flying along sun synchronous orbits (685 km). The command from KARI TTC passes S-band omni-antenna, RF assembly, and transponder and finally reachs OBC (On Board Computer). The telemetry from KOMPSAT-2 arrives at KARI TTC through inverse procedure. In this paper, RF compatibility test between KOMPSAT-2 and KARI TTC station is demonstrated. RF interface for this test was established through real space and uplink signal test and downlink signal test and uplink & downlink signal test were performed.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.1
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• pp.1-4
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• 2012

In this paper, the planar type modified folded loop antennas for S-DMB band is proposed. The proposed antenna consisted of opened center of a conventional closed loop and folded terminal of microstrip line to inside loop antenna. The sizes proposed antenna was minimized by folding the terminal of the loop. Also, It was minimized reactance value by increasing capacitances between coupled microstrip line. Therefore the proposed antennas compacted about 20% than a conventional loop antenna and increased efficiency of antenna. The proposed antennas got an omni-directional pattern, the antenna gain was 3.67 [dBi] and the bandwidth was 900 MHz (2.6-3.56 GHz) with VSWR${\leq}$2 from the simulated and the measured results. The frequency utilization coefficient was 29.9 %. These properties could satisfy the S-DMB band.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.221-224
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• 2005

In this paper, We have designed, fabricated and measured a stacked planar antenna for Ultra-Wideband communication. Radiation parts of the antenna have exponential curve and fed by strip feeding network. We have used the HFSS of Ansoft to simulate the antenna. It was designed to work on a substrate Teflon of thickness 1.575mm and relative permittivity 3.2. The proposed antenna covered the entire UWB band( 3.1GHz $\sim$ 10.6GHz ) for S11$\leq$l0dB. Also the proposed antenna show a good characteristics, linear phase, omni -directional pattern lot UWB applications. Besides the measured results have a reasonable agreement with the simulated results.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1169-1176
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• 2018

The C-band omni-directional antenna for drone control is mounted on the top or bottom and used to configure the communication link. The communication link is affected by the LOS depending on the mounting position of the omni-directional antenna. In this paper, two kinds of embedded antennas were designed with a commercial simulation tool CST MWS, and EM analysis was performed to consider the mounting environment. Also, we propose the PTMP ground antenna to control a large number of drones. The ground antenna has a communication link of 30km, and it consists of four sector antennas in the horizontal direction and one directional antenna at the top.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.11
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• pp.99-104
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• 2003

We are designed and fabricated the Printed dual monopole antenna with CPW feeder for PCS and IMT2000 band. In this paper il proposed modified dual monopole antenna that is transform conventional monopole antenna to get dual band frequency. The dual monopole antennas had broad bandwidth and omni -directional radiation patterns in construct with conventional monopole antenna. On a monopole operated a stub to other monopole antenna, we could obtain easy an impedance matching. It is increased band width of impedance. The antenna bandwidth is about 150MHz(1.74 ∼1.89〔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 be got not only 1.75∼1.87〔GHz〕 PCS band but also 1.92∼2.17 〔GHz〕).GHz〕).

• 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.