• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.3
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• pp.180-185
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• 2005

Microstrip antennas generally have a lot of advantages that are thin profile, lightweight, low cost, and conformability to a shaped surface application with integrated circuitry. In addition to military applications, they have become attractive candidates in a variety of commercial applications such as mobile satellite communications, the direct broadcast system (DBS), global positioning system (GPS), and remote sensing. Recently, many of the researches have been achieved for improving the impedance bandwidth of microstrip antennas. The basic form of the microstrip antenna, consisting of a conducting patch printed on a grounded substrate, has an impedance bandwidth of $1\~2\%$. For improvement of narrow bandwidth of microstrip patch, we were designed U-slot microstrip patch antenna in this paper. This antenna had wide bandwidth for all personal communication services (PCS) and IMT-2000. For the design of U-slot microstrip patch antenna using a finite difference time domain(FDTD) method. This numerical method could get the frequency property of U-slot patch antenna and the electromagnetic fields of slots.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.33-39
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• 2021

In this study, we tried to find the correlation of the parameters and dual resonance of U-slot microstrip patch antenna with L-shaped Inset-feed structure and design broadband antenna using them. In the first step, we classified cases where dual resonance occurs through changes in antenna parameters that affect antenna performance. In the second step, we correlated each antenna parameter to the location and intensity of the resonance point, and 3 dB bandwidth. Next, antenna simulation confirmed the process of designing to have wide bandwidth using the correlation in the second step previously presented in the U-slot antenna case with narrow bandwidth. Finally, we fabricated a designed antenna and demonstrated the validity of antenna bandwidth broadening through the correlation analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.219-222
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• 2006

In this paper, we have designed 800MHz band broadband antenna which is improves of microstrip antenna narrow bandwidth problem including the CDMA band and be able to integrated the GSM and TRS band will design. It used the duplex resonance effect it had the L-Shaped feeding structure which adds the u-slot. It was measured that the frequency bandwidth of the designed antenna which is planed $897MHz\sim1013MHz$ with 215MHz(23.8%). And the antenna gain is 9.3dBi, 3dB beam width $60^{\circ}$ in both the E-plane and H-plane.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.998-1002
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• 2006

In this paper, we have designed 800MHz band broadband antenna which is improves of microstrip antenna narrow bandwidth problem including the CDMA band and be able to integrated the GSM and TRS band will design. It used the duplex resonance effect it had the L-Shaped feeding structure which adds the u-slot. It was measured that the frequency bandwidth of the designed antenna which is planed $897MHz\sim1013MHz$ with 215MHz(23.8%). And the antenna gain is 9.3dBi, 3dB beam width $60^{\circ}$ in both the E-plane and H-plane.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.5
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• pp.428-434
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• 2009

In this paper, we propose an U-slot microstrip antenna with the U-shaped parasitic patches. U-slot and parasitic patches make two resonant frequencies and one additional resonant frequency, respectively, so that the impedance band-width of the antenna is expanded. The size of radiator part is $64{\times}53\;mm^2$ and the entire size of the antenna is $150{\times}150{\times}11.5\;mm^3$. The measured bandwidth is $1.85{\sim}2.40\;GHz$. Thus, our antenna can be used for DCS1900, WCDMA and WiMax services. The radiation characteristic is almost same in the bandwidth, the beam width is about $60^{\circ}$, and the gain is more than 7 dBi.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.85-91
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• 2010

In this paper, a new microstrip antenna using asymmetric U-shaped slotted ground is proposed for a switchable circular polarization sense. The proposed antenna is achieved a circularly polarization from orthogonal E-field distributions with 90 degree phase difference due to the asymmetrical U-shaped slot. Moreover, the circular polarization sense of the proposed antenna can be easily switchable with changing the symmetric plane of the U-shaped slots. As a result, the proposed antenna is implemented by two PIN diodes with two different bias condition for ON/OFF states. The measured axial ratios are about 1.5 dB without the dependence of the polarization sense and 3-dB axial ratio bandwidth are achieved 29 MHz with respect to about 1.2 % at 2.46 GHz operating frequency.

• Journal of electromagnetic engineering and science
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• v.17 no.2
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• pp.57-64
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• 2017

In this paper, an asymmetric compact multiband slot antenna is proposed for global positioning system (GPS), worldwide interoperability for microwave access (WiMAX), and wireless area network (WLAN) applications. The top plane, a ground is composed of a rectangular slot with a trapezoidal-like stub, an inverted U-shaped slot at the right side of the rectangular slot, an inverted L-shaped slot at the left side of the rectangular slot, and three stubs. The proposed antenna is fed by an asymmetric cross-parasitic strip on the bottom plane. By properly designing the slots and stubs, four resonant frequency bands are achieved with -10 dB reflection coefficient bandwidths of 50 MHz, 400 MHz, 390 MHz, and 830 MHz in the 1.57 GHz GPS band, 2.4 GHz WLAN band, 3.5 GHz WiMAX band, and 5.5 GHz WLAN bands, respectively. The antenna has a total compact size of $13mm{\times}32mm{\times}0.8mm$. Simulated and measured results indicate that the proposed antenna has sufficient bandwidth and good radiation performance in each band.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.2
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• pp.69-74
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• 2000

The bandwidth of microstrip slot antenna with T-shaped feed line was a wider than one of the conventional feeding structure. When the slot antenna with bi-directional radiator wants to radiate only one direction, the reflector must be set up seperately. But this antenna doesn't need set up reflector. And then we proposed to a new method of a directional slot radiator with a cross-shaped feedline including the reflector using 2-layers dielectric materials. It is calculated waves and electric field distribution in the time domain by using FDTD method. We also are calculated return loss, VSWR, input impedance, and radiation pattern in the frequency domain by Fourier transforming the time domain results, respectively. It was found that the bandwidth of this antenna changes as length($\I_s$) and width($\W_s$) of slot, length of the horizontal feedline($\I_d$), length of the vertical feedline($\I_u$) and offset sensitively. After optimizing the parameters of design, the maximum bandwidth was measured as 1,850MHz at the center frequency 2.5 GHz.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.937-942
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• 2018

This paper maximizes the research on broadband characteristics by using air layer instead of using microstrip structure of radiation part with U-shaped slot patched inside and microstrip antenna in order to make the microstrip antenna to have broadband characteristics. Experimental results show that the VSWR is 1.4 or less than the mobile communication frequency band(820~950MHz) and the gain of the antenna is 8.2dBd. This means that the antenna can be miniaturized, and it can be used in the wireless communication fields, and the mobile communication fields for other frequency bands in the future.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.88.2-88
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• 2002

1. introduction 2. FDTD Method 3. Guidelines 4. Simulation Result 5. Conclusion