• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.143-151
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• 2010

In this paper, a novel rectangular patch antenna is proposed to have Zeroth Order Resonance(ZOR) generated based on the Metamaterial Complosite Right- and Left-Handed(CRLH) structure. Making the in-phase electric field over the entire antenna other than a half-wavelength as the fundamental resonance mode of a standard microstrip patch or its positive multiple, the metallic patch is suggested to be capacitively coupled with only one surrounding rectangular ring, different from the previous 1D ZOR antennas commonly having several metal cells in line. The performance of the proposed antenna is simulated by a 3D field solver that inputs the sizes of the physical structure corresponding to the equivalent circuit designed to have ZOR at 2.4 GHz. Consequently, the resonance frequency, the gain and the antenna efficiency are observed 2.4 GHz, 5 dB and 98%, respectively. Besides, the important property of the proposed antenna is addressed as the combination of the low profile as an advantage of microstrip patch antennas, and the omni-directional field pattern typical of monopole antennas.

• Journal of Advanced Navigation Technology
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• v.16 no.5
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• pp.766-772
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• 2012

In the present study, wideband microstrip monopole slot antennas which can be applied to the RF4CE Zigbee remote controller are designed. First I-shaped monopole slot antenna which has ${\lambda}g/4$ length at 2.45GHz is designed. In particular, a conducting via is used to connect the microstrip feed line and the ground plane surrounded with the etched slot for the bandwidth improvement. In order to reduce the antenna size, it is changed into L-shaped and T-shaped monopole slot antennas for which improve results of antenna performance are observed. In case of T-shaped monopole slot antenna, impedance bandwidth(VSWR<2) is about 3.32GHz, and also its radiation efficiency and gain is more than 90% and 2.1dBi respectively at whole operating frequency range. In particular, all of proposed monopole slot antennas have the end-fire radiations which has a maximum radiation power toward direction of open ends of monopole slots.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.9
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• pp.1005-1014
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• 2007

In this paper, The four types SRA(Sequential Rotated Array) antennas has been analyzed. Those are consisted of a 4-elements SRA, a 8-elements SRA, the $2{\times}2$ planer array SRA and the triple (4+8+4)-elements SRA. These LHCP SRA antennas are used a probe feeding multi-layer truncated microstrip antenna whose center frequency is 11.85 CHz. The cooperated feeding circuits are designed for feeding to each elements with equal amplitude and regular phase. Comparing with the each simulation results and experiment results of this 4-type SRA antennas, the triple (4+8+4)-elements SRA showed the most electrical characteristics in the degree of integration, high gain and low cross polarization.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.393-400
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• 2015

As the development and distribution of the intelligent transport system is spreading recently and some of the services are commercialized through a pilot project, interest in DSRC with high utilization is increasing and antennas for roadside and on board equipment are being studied. A single patch was used for a vehicle antenna due to the requests of miniaturization of size, but there was performance degradation in most cases due to miniaturization. In addition, some methods to improve performance have been used in the antennas that were previously researched using the arrays, but they have the disadvantages of bulkiness in size of the antennas when using the arrays. Therefore, in this paper, the CPW fed microstrip patch antenna with the simple structure of being compact and easy to produce, which can be used in the OBU of DSRC, was designed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.5
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• pp.278-282
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• 2000

This paper investigated that resonant frequencies of microstrip patch antenna were tunable when piezoelectric materals were used as the antenna substrates. The resonant frequencies of the antenna using the piezoelectric substrate were able to be controlled by applied voltage. The frequency variation of the air gap antenna was 16MHz when the voltage variation was 13[KV/cm], and the frequency variation of microstrip patch antenna made of $LiNbO_3$ substrate was 11MHz when voltage variation was 480[V/cm].

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.120-123
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• 1999

This paper presents the design method of EMC(Electromagnetic Coupling) microstrip array antenna for CS(Communication Satellite) system. Microstrip dipole antennas are attractive elements owing to the desirable properties such as simplicity, small size and linear polarization. From the optimum simulation results by the FDTD method[1], design parameters such as EMC dipole length, width, height and offset are discussed at 12CHz. The array characteristics of 5-elements and 10-elements array are also presented. By adjusting geometry of model antenna, we can design dual polarization EMC microstrip dipole antenna for CS system. Direction of nam beam is easily tilted by the control of distance between dipole elements.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.294-297
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• 2003

In this paper we designed and measured HTS antenna array for Direct Broadcast Satellite (DBS) system. HTS antennas fabricated in this work were a four-element, 11.67 ㎓z, high-Tc superconducting (HTS) microstrip antenna array with corporate feed network and circular polarization for direct broadcas- ting satellite (DBS) system. Our antennas was designed and built on a 0.5 mm thick YBa2Cu3O7-x (YBCO) /MgO substrate. The measurement results showed good axial ratio, wide bandwidth a remarkable improvement over their metal counterpart.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.492-495
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• 2003

This paper presents a novel method to reduce the size of microstrip patch antennas using shorting post and spiral shape. The spiral conductor shape of the proposed shorted patch antennas increases the length of the current patch for a given area. Two spiral shaped patch antennas with shorting post operating at 700 MHz bands are investigated experimentally.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.1
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• pp.37-44
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• 2009

In this paper, a TRS band(Trunked Radio System: $806{\sim}866\;MHz$) array antenna has a good front-to-back ratio characteristics for the mobile communication base station is proposed. The proposed array antenna is composed of the $5{\times}3$ radiated elements which are the microstrip dipole antennas with the cavity-backed reflector. For the validity of the proposed antenna, the $5{\times}3$ array antenna is designed, fabricated, and its radiation characteristics are measured. As a result of measurements, the antenna gain is over 13.3 dBi and the front-to-back ratio is over 40 dB at the useable frequency band. We confirm that the designed antenna can be used as the mobile communication base station antenna with the excellent back lobe characteristics.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.169-175
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• 2006

In this paper, a microstrip patch antenna with the T-shaped slits is designed and fabricated for GPS. The resonant frequency of the microstrip patch antenna with the slits is lower than that of a microstrip patch antenna without the slits so it can be reduced the size of patch. In order to calculate resonant frequency of the microstrip patch antenna with the slits, the resonant frequency formulas are derived from the surface current distribution on microstrip patch antenna. Using the Ensemble 6.0 simulation tool, the accuracy of approximate equations is verified. The microstrip patch antenna with the slits is designed by using these equations. The size of the designed antenna with T-shaped slits can be reduced to 29% compared with that without the slits. The microstrip patch antenna with slits have a very narrow bandwidth. In order to improve the narrow bandwidth of microstrip patch antennas with the slits, a microstrip patch antenna with rectangular slot is proposed. As the result of the measurements, the resonant frequency of the proposed microstrip patch antenna with the T-shaped slits is 1.575GHz and the bandwidth is about 50MHz.