• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.10
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• pp.1117-1127
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• 2012

In this paper, the monopole antenna for satisfying GSM900/DCS1800/PCS1900/UMTS2100 services is designed. We can get the characteristic of the low frequency bands by connecting the front patch to the back patch of the antenna and get the low frequency resonance band using a front patch slit. The proposed antenna total volume is $40{\times}98{\times}1.6\;mm^3$, and it is designed on the FR-4 substrate having a relative dielectric constant of 4.4. As measurement result after fabrication, showed that the resonant frequency bandwidths are 156 MHz(828~984 MHz), 708 MHz(1.476~2.184 GHz) based on the return loss of 10 dB, and the radiation patterns show as the omnidirectional shapes for the E-field and H-field. For analyzing the human effects, the proposed antenna is mounted on the mobile-phone case. The averaged peak SAR over 1 g and 10 g is simulated and measured when the input power is 0.25 W. We have checked the variation of the SAR values when the antenna is mounted 4 different directions, then checked the direction having a relatively higher SAR. The results also satisfied the limiting SAR values which are 1.6 W/kg and 2.0 W/kg averaged over 1 g and 10 g tissues respectively.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1613-1614
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• 2006

In this paper, a $4{\times}4$ rectangular patch array antenna operated at 20 GHz is implemented for the satellite communication. Two $2{\times}2$ subarrays are designed and more efficient $2{\times}2$ subarray is used for the design of $4{\times}4$ patch array. The sixteen patch antennas and microstrip feeding line are printed on the single-layered substrate. The spacing between the array elements is chosen to be $0.736{\lambda}$. HPBW (Half-Power Beam Width) is 17.6 degrees in the E-plane and 18.7 degrees in the H-plane with a gain of 17.2SdBi in the simulation results.

• Journal of Advanced Navigation Technology
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• v.12 no.5
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• pp.420-428
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• 2008

In this paper, Stack structure patch antenna has been designed and fabricated for wireless LAN applications. The patch and ground plane were used by PEC metal. It was 0.05 [mm] thick. In order to broaden the bandwidth of the antenna and improve of gain, the stack structured antenna with probe feed. The measured input return loss showed less than -10 [dB] at the broadband from 5100 to 6140 [MHz]. It's measured bandwidth was 1040 MHz. The gain of antenna in the E-plane and H-plane was 13 dBi and 3 dB beam width was $40^{\circ}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.509-516
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• 1999

In this paper, it is designed a microstrip U-slotted patch antenna with double resonances to enhance the bandwidth. In the design of an U-slotted patch antenna, there are considered the input impedance, the width of patch, the total length of the slot, the height of foam, the position of the probe and the radius of feed pin. The broadband behavior of antenna can be obtained by adjusting the length and width of the slot. The radiation from the antenna is linear polarized with the E-paine parallel to the vertical slots and the H plane parallel to horizontal slot. The radiation pattern, impedance locus, and VSWR of the antenna are calculated using "ENSEMBLE" software, and compared with the experimental results. Experimental results show that the bandwidth for VSWR $\le$ 2:1 is about 28.6%, a directivity 14.18dBi at 6.040GHz. 6.040GHz.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.6
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• pp.26-34
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• 2010

The mutual coupling of a pair of microstrip patch antennas on a finite grounded dielectric substrate is influenced by the diffracted field of surface waves from the edges of a substrate. The effective dielectric constant of a grounded dielectric substrate determines the distance between the antenna center and the edge of a substrate to obtain the minimum mutual coupling between a pair of microstrip patch antennas. The optimum substrate size with the minimum mutual coupling is easily calculated using the image method. The optimum substrate sizes using the linage method are in good agreement with the results obtained by the full wave simulation.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.293-296
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• 2005

This paper presents the design of linear and circular polarization baseball- shaped circular microstrip antenna (BCMA) with 3-dimensional structure using perturbation effect to reduce its size, which runs at 1.575GHz frequency bandwidth. As a result, the size of linear polarized antenna could be reduced up to 23.7% in patch diameter and 41.8% in its area. Linear polarized antenna has -26.04dB of return loss, 69MHz(4.38%) of -l0dB bandwidth, 4.51dBd of gain, and its -3dB beamwidth are 99$^{\circ}$ in E-plane, 83$^{\circ}$ in H-plane. Circular polarized antenna has -17.43dB of return loss, 113.7MHz(7.2%) of -l0dB bandwidth, 2dBd of gain, 2dB of axial ratio and its -3dB beamwidth are 87$^{\circ}$, 86$^{\circ}$ x-axis polarized, 80$^{\circ}$, 84$^{\circ}$ y-axis polarized. It has 82mm of diameter, which is 28.5% of linear polarized CMPA. Therefore, in this paper we verified that baseball-shaped 3-dimensional structure of circular microstrip patch antenna applied with perturbation effect is appropriate for miniaturization.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.211-214
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• 2007

In this paper, we have designed microstrip antenna if 800[MHz] band It will be able to integrate TRS(Trunked Radio System), GSM(Global System for Mobile telecommunication) band including the CDMA(Code Division Multiple Access) band we designed repeater and a base station antenna which is possible at the ship and marine of safety. It is improves a narrow bandwidth problem of microstrip antenna. It had U-shaped feeding structure at a rectangular patch And ground or feeding structure used between dielectric constant(${\varepsilon}_T$ = 2.1), patch or feeding structure used between dielectric constant(${\varepsilon}_T$ =1). So it used a duplex resonance effect Designed frequency bandwith(V5WR 2:1) if the antenna showed good characteristic of $780[MHz]{\sim}1.83[GHz]$ to 2.61[GHz]. Also the E-plan and H-plan all profit 9.4[dBi] above, the 3[dB] beam width showed the characteristic over the E-plan and H-plan $60^{\circ}$ to be improved.

• 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.416-422
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• 2006

In this paper, we have designed and favricated the high gain and wideband microstrip patch antenna including IEEE 802.11a. To widen the bandwidth of microstrip antenna, firstly we have used the microstrip line-coaxial probe feeding method and inserted a U-slot in the rectangular patch. Secondly, to improve the antenna gain, we have used a $2{\times}2$ array structure. From the measured results, wideband characteristics of 1 GHz bandwidth($5.110{\sim}6.142$ GHz) for VSWR<2 was obtained. The measured eain was 13 dBi in both the E-plane and H-plane at the frequency of 5.15 GHz, 5.35 GHz, 5.50 GHz, and 5.85 GHz.

• Journal of Biosystems Engineering
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• v.25 no.2
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• pp.97-106
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• 2000

To develop the grain moisture meter using microwave free space transmission technique, a 10.5GHz microwave signal with the power of 11mW generated by an oscillar with a dielectric resonator is transmitted to an isolator and radiated from a transmitting $2{\times}2$ microstrip patch array antenna into the sample holder filled with the 12 to 26%w.b. of Korean Hwawung paddy rice. the microwave signal, attenuated through the grain with moisture, is collected by a receiving $2{\times}2$ microstrip patch array antenna and detected using a Shottky diode with excellent high frequency characteristic. A pair of light and simple microstrip patch array antenna for measurement of grain moisture content is designed and implemented on atenflon substrate with trleative dielectric constant of 2.6 and thickness of 0.54 by using Ensemble ver. 4.02 software. The aperture of microstrip patch arrays is 41 mm width and 24mm high. The characteristics of microstrip patch antenna such as grain. return loss, and bandwidth are 11.35dBi, -38dB and 0.35GHz($50^{\circ}$ at far-field pattern of E and H plane. The width of the sample holder is large enough to cover the signal between the antennas temperature and bulk density respectively. The calibration model for measurement of grain moisture content is proposed to reduce the effects of fluectuations in bulk density and temperature which give serious errors for the measurements . From the results of regression analysis using the statistically analysis method, the moisture content of grain samples (MC(%)) is expressed in terms of the output voltage(v), temperature (t), and bulk density of samples(${\rho}b$)as follows ;$$MC(%)\;=\;(-3.9838{\times}10^{-8}{\times}v^{3}+8.023{\times}10^{-6}{\times}v^{2}-0.0011{\times}v-0.0004{\times}t+0.1706){\frac{1}{{\rho}b}}{\times}100$ Its determination coefficient, standard error of prediction(SEP) and bias were found to be 0.9855, 0.479%w.b. and -0.0.369 %w.b. respectively between measured and predicted moisture contents of the grain samples.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.3
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• pp.440-444
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• 2002

A microstrip patch antenna with circular polarization based on the Sierpinski fractal geometry is proposed. The Sierpinski fractal is composed of 3 equilaterial triangular patch and is easy to produce a circular polarization by sequentially rotation techniques. The characteristics of a 1x3 antenna array from Sierpinski geometry are investigated, i.e. port isolation and AR(axial Ratio).