• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.171-175
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• 2013

In this paper was The dielectric constant of 4.4 and thickness of 0.6mm FR-4 substrate were implanted including the L-Slot in microstrip patch antenna to design a microstrip patch antenna for LTE. The proposed antenna is $180{\times}180$ compact and $46{\times}36$ lightweight compared to existing antenna and This antenna can be used as transmission ommidirectional radiation pattern of propagation was compared to the input return loss than -10dB (VSWR 2:1) to allow communication from the resonant frequency band.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.275-280
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• 1999

Deep-water sonar transducers of FFR (Free Flooded Ring) type have been designed using a coupled FE-BEM. The proposed sonar transducers are composed of piezoelectric ceramic tubes and structural steel materials for simple fabrication. In order to have an omnidirectional beam pattern around 30 kHz, a conic steel is placed below a piezoelectric tube or a steel disc is placed between two piezoelectric tubes. The dynamics of the sonar transducer is modelled in three dimensions and is analyzed with external electrical excitation conditions. Various results are available such as directivity patterns and transmitting voltage responses. The most optimal structure and dimensions of the steel material were calculated, so that the beam patterns of the sonar transducers had +/- 3 dB omnidirectivity at 30 kHz.

• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.8 s.111
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• pp.713-718
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• 2006

We designed and fabricated, in this paper, a quintuple band folded monopole antenna for the mobile phone handset that can be provided multiple mobile services. Antenna design was based on the compensation of series antenna capacitance with the expansion of physical antenna length by the proper folding structure. It's shown that this antenna satisfies quintuple service band as CDMA/GSM/DCS/USPCS/WCDMA, and is more cost competitive than conventional metal plate pressing method by applying on flexible PCB technology. Measured maximum gain on quintuple band were $-2.51{\sim}+1.82 dBi$, and radiation patterns were also shown nearly omnidirectional on all bands.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.117-123
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• 2014

In order to provide a mobile robot with omnidirectionality, various types of omnidirectional wheels have been developed. This paper deals with an improved design and structural analysis of a Mecanum wheel, which is the type of omnidirectional wheels most commonly used in industrial fields. A geometric formulation for manufacturingthe Mecanum wheel is presented and two types of Mecanum wheels are designed and fabricated in this research. While conventional assembled-type Mecanum wheels have a complicated structure and the high possibility of mutual interference between sub-components, a unified type of Mecanum wheel reduces the number of sub-components and increases the degree of structural rigidity. The stress and strain properties of the two designs are compared to confirm the quantitative improvement of the new design by a commercial structural analysis tool. The analysis results show that the unified type of Mecanum wheel has properties superior to the assembled type of Mecanum wheel in terms of its ability to reduce interference.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.19-24
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• 2014

In this paper, a multiband LTE antenna satisfying LTE octa-band is proposed. The proposed antenna consists of a modified PIFA structure and a folded monopole which has the height of 4 mm. Each parts operates at lower and upper LTE band. Measured bandwidth(6 dB return loss) was 118 MHz(870~988 MHz) at the lower band and 1,107 MHz(1,650~2,757 MHz) at the upper band. The proposed antenna has a omni-directional radiation pattern and measured peak gains were 3.21 dBi at the lower band and 4.19 dBi at the upper band, respectively. The proposed antenna is expected to be utilized for future LTE-advanced system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1558-1564
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• 2004

This paper shows the design of Active antenna which appled to 5.5GHz RF module for local wireless communication system. The LNA, which was designed Super low noise HJ FET of NE3210S01, is used to obtain a good noise figure characteristics. And the microstrip patch antenna was designed to obtain omnidirectional antenna characteristics. The measured LNA gain is 15 dB, input & output return loss is under -20 dB and VSWR under 1.5. The Single microstrip patch antenna input return loss is under -29 45, VSWR under 1.2.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.983-990
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• 2010

In this paper, we designed and implemented the MIMO antenna for LTE(Long Term Evolution), supposed to be a next generation communications network, DCS1800, DCS1900 and WCDMA. Using conventional monopole antenna with MD material results in good characteristics, miniaturization for LTE band and as well as broadbanding for DCS, WCDMA band. The performance of the proposed MIMO antenna shows VSWR < 2, under -10 dB of isolation and the gain is -1.66 ~ 1.33 dBi for LTE(Long Term Evolution), DCS1800, DCS1900 and WCDMA, which has omnidirectional radiation pattern.

• 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.

• Journal of Sensor Science and Technology
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• v.18 no.3
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• pp.185-189
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• 2009

In this paper, we present design and analysis of the omni-directional linear piezoelectric actuator which was consisted of one actuator using the half-wave vibrator. Through calculating vibration speeds on each sector of the actuator, the displacement of contact point of the actuator is theoretically confirmed to be about 33 nm. To confirm an applicable possibility of omni-directional linear piezoelectric actuator, elliptical motion for linear movement, displacement of the tip, changing directions and admittance characteristics are simulated by ATILA. Compared with theoretical result, we obtained similar data with displacement of 32.5 nm at contact point. And then the actuator is simulated elliptical trajectories for linear motions and changing directions according to combination of input signal.