• ETRI Journal
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• v.25 no.5
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• pp.407-411
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• 2003

A dielectric superstrate layer above a microstrip patch antenna has remarkable effects on its gain and resonant characteristics. This paper experimentally investigates the effect of a superstrate layer for high gain on microstrip patch antennas. We measured the gain of antennas with and without a superstrate and found that the gain of a single patch with a superstrate was enhanced by about 4 dBi over the one without a superstrate at 12 GHz. The impedance bandwidths of a single patch with and without a superstrate for VSWR < 2 were above 11%. The designed $2{\times}8$ array antenna using a superstrate had a high gain of over 22.5 dB and a wide impedance bandwidth of over 17%.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.5 no.1
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• pp.43-59
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• 2006

A compact and broadband $4\times1$ array antenna was developed for 3G smart antenna system testbed. The $4\times1$ uniform linear away antenna was designed to operate at 1.885 to 2.2GHz with a total bandwidth of 315MHz. The array elements were based on the novel broadband L-probe fed inverted hybrid E-H (LIEH) shaped microstrip patch, which offers 22% size reduction to the conventional rectangular microstrip patch antenna. For steering the antenna beam, a commercial variable attenuator (KAT1D04SA002), a variable phase shifter (KPH350SC00) with four units each, and the corporate 4-ways Wilkinson power divider which was fabricated in-house were integrated to form the beamforming feed network. The developed antenna has an impedance bandwidth of 17.32% $(VSWR\leq1.5)$, 21.78% $(VSWR\leq2)$ with respect to center frequency 2.02GHz and with an achievable gain of 11.9dBi. The design antenna offer a broadband, compact and mobile solution for a 3G smart antenna testbed to fully characterized the IMT-2000 radio specifications and system performances.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.605-608
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• 2003

In This paper, the 4$\times$4 microstrip patch array antenna for millimeter-wave is designed and fabricated. Before that, a patch antenna is designed to analyze the property in the millimeter-wave. Also, the excitation is implemented using edge and prove feeding. The array method is used to design the 2x1 array with corporate feeding network. Measured antenna shows 12.77 dBi gain, 37.65 GHz center frequency, -29.78 return loss and 680 MHz band width.

• Journal of electromagnetic engineering and science
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• v.12 no.4
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• pp.247-253
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• 2012

This study presents a new, simple method for improving the front-to-back (F/B) ratio of a microstrip patch antenna. The back radiation of the microstrip patch antenna is reduced by removing some metallic parts around the ground plane and placing a new soft-surface configuration, consisting of an array of stand-up split-ring resonators on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional microstrip patch antenna with a full ground plane of the same size, our proposed microstrip patch antenna experimentally achieves an improved F/B ratio of 9.6 dB.

• Journal of Advanced Navigation Technology
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• v.11 no.1
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• pp.64-71
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• 2007

In this paper, we have designed and fabricated microstrip antenna of S-band for the wireless LAN and the ISM. It array $2{\times}2$ circular patch antenna elements at plane instead of conventional rectangular patch antenna elements. It optimized to size calculated of single patch antenna. The radiation elements distance is array $0.24{\lambda}$. The fabricated circular patch antenna decreased 8% of size compared to the conventional rectangular patch antenna. In the E-plane, designed circular microstrip patch $2{\times}2$ array antenna gain is 12.7[dBi], half power beam width is $40^{\circ}$ and in the H-plane, antenna gain is 12.1[dBi], half power beam width is $45^{\circ}$. Bandwidth is 250[MHz] (VSWR < 2).

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.167-171
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• 2011

In this paper, $2{\times}4$ microstrip patch antenna are proposed to implement K-band satellite communications. The microstrip feed line are inset into the radiation patch to match input impedance. Also the same current in each elements are excited by Kirchhoff's low. The elements distance of proposed array antenna are optimized $0.8{\lambda}_g$ to minimize a mutual coupling and maximize a gain. A power divider network are employed to distribute T-junction divider. As result, the proposed antenna get gain of 14[dBi] at 10.525[GHz].

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.326-332
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• 2006

In this study, the antenna was proposed for the omni-directional characteristic in horizontal plane. Therefore we proposed $1{\times}4$ microstrip patch array on cylindrical surface for studying microstrip patch antennas. This antenna is designed for 2.45GHz ISM band and applications. This antenna can be applied to the base station of wireless microphone and access point of wireless LAN. The length and width of the patch antenna and the width of the feed line were calculated by using the theory of microstrip patch antenna, by using the both the 2.5D and 3D EM simulators the optimized antenna characteristics are obtained. From result of measured, antenna's impedance of coaxial waveguide port was 51.915-j3.688 ${\Omega}$, the return loss was -31dB and VSWR was 1.081.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.779-783
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• 2012

In this paper, we studied the design and fabrication of $2{\times}2$ array-type microstrip patch antenna to be used in wireless communication systems operating at around 5GHz band. To obtain wide bandwidth and high gain, antenna parameters such as patch size, inter patch space are simulated by HFSS(High Frequency Structure Simulator). From these parameters, the $2{\times}2$ array-type microstrip patch antenna is fabricated using FR-4 substrate. The measured results of the antenna are as follows: The center frequency of 5.06GHz, insertion loss of -44dB, bandwidth of 200MHz, and VWSR of 1.1.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1739-1747
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• 1994

This study is concerned with a feeding method of microstrip patch antennas with different widths as feeding elements in order to obtain the appropriate radiation patterns of nonuniform array antennas. We analyze a microstrip patch antenna based on the transmission line model and derive that the ratio of current is equal to that of the input impedances of array antenna elements in case that the feed-line length between elements of array antenna is equal to the integer times of $\lambda_g$. We measure the radiation patterns of the nonuniform microstrip patch array antenna with 6 and 9 elements. The patterns measured are well agreed with the theoritically calculated patterns. Thus, this result can be utilized in the implementation of a feed network in nonuniform array antennas.

• Journal of electromagnetic engineering and science
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• v.6 no.1
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• pp.36-46
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• 2006

In this paper, we present a two-element circularly-polarized antenna array for UHF-band RFID reader applications. The antenna element in the array is a comer-truncated rectangular patch placed on a thick plastic-foam dielectric. The patch is fed on one of its edges by a microstrip line printed on a separate thin substrate. The array antenna is fed by a microstrip power divider. Parametric studies on the patch are carried out, from which an optimum design of a single antenna element is derived. The element spacing and the feed network of the array are investigated. A commercial electromagnetic software is employed in the analysis and design of the antenna. The designed array is fabricated and tested. Measurements show good performance characteristics of the fabricated antenna: a 11.2-dBi gain, a reflection coefficient of - 14 dB, an axial ratio less than 3 dB over 3-dB beamwidths of 40 and 60 degrees on two principal planes.