• ETRI Journal
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• v.36 no.6
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• pp.1062-1065
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• 2014

A novel substrate-integrated waveguide (SIW) cavity-backed slot antenna is proposed in this study to achieve enhanced-gain performance. The peak gain is remarkably improved with the use of an SIW cavity and metallic superstrate. The superstrate comprises a single rectangular slot window and two half-wavelength patches. The gain can be enhanced by combining the in-phase radiating fields. Further, the 10 dB bandwidth of the proposed antenna ranges from 2.32 GHz to 2.49 GHz, which covers the wireless local area network band. The measured peak gain is 9.44 dBi at 2.42 GHz.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.314-319
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• 2015

The conventional geometry of a plate microstrip resonator is made up of a single metallic patch, which is printed on a monolayer dielectric substrate. Its arrangement is simple and easy to make, but it is limited in its functional abilities. Many searches have been realized to improve the bandwidth and the gain of the microstrip resonators. Among the various configurations proposed in the open literature, the stacked geometry seems to be very promising. By appropriate design, it is able to provide the operation in dual frequency mode, wide bandwidth enough and high gain. The theoretical investigations of structures composed of two stacked anti-reflection coatings, enhanced metallic coatings are available in the literature, however, for the stacked configurations involving three metallic coatings or more, not to exact or approximate analysis was conducted due to the complexity of the structure.

• Journal of electromagnetic engineering and science
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• v.17 no.3
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• pp.133-137
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• 2017

In this study, a 28-GHz U-slot array antenna for a wideband communication system is proposed. The U-slot patch antenna structure consists of a patch, two U-shaped slot, and a ground plane. With the additional U-slot, the proposed antenna has around 10% of bandwidth at -10 dB. To increase gain, the U-slot antenna is arrayed to $2{\times}2$. The proposed antenna is designed and fabricated. The $2{\times}2$ array antenna volume is $41.3mm{\times}46mm{\times}0.508mm$. The proposed antenna was measured and compared with the simulation results to prove the reliability of the design. The bandwidth and gain of the measurement results are 3.35 GHz and 13 dBi, respectively and the operating frequency is around 28 GHz.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.2 s.344
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• pp.76-80
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• 2006

In this paper, broadband balanced amplifier has been realized with Three-Arm Branch $90^{\circ}$ Hybrid Coupler at center frequency 2GHz. $90^{\circ}$ Hybrid Branch-Line Coupler has been compared with Three-Arm Branch $90^{\circ}$ Hybrid Coupler. The bandwidth VSWR and gain or proposed amplifier have been 480MHz, 1.06 and 15.47dB, respectively.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.79-85
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• 2010

In this paper, a directive antenna design with a combination of electric-magnetic radiators for an radio frequency identification(RFID) system is presented. To generate a directive antenna radiation pattern, a structure combining a dipole and loop antenna is presented. A reader antenna and tag antenna are proposed for the RFID system. For the reader antenna, the frequency bandwidth defined by $S_{11}$<-10 dB is approximately from 820~990 MHz. The forward and backward gain differences are 1.5~2 dBi. For the tag antenna, the frequency bandwidth is approximately from 860~920 MHz with a maximum gain of 3.58 dBi at 910 MHz. In both cases, directive radiation characteristics are observed.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.596-600
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• 1992

In CLOS guidance, feedback compensation of the Coriolis acceleration is used to reduce miss distance. This paper presents the effects of the bandwidth of target and missile on the optimal Coriolis acceleration compensation. A state space formulation of CLOS guidance is used to implement CLOS guidance in feedback form. And the LQR control method is applied to find the optimal feedback gain. From the analysis of the Riccati equations of the optimal control, the following facts are observed: When the target is agile, the optimal gain is reduced, since the compensation becomes ineffective. The missile bandwidth also affects the Coriolis accleration compensation. Narrower missile requires more compensation for the Coriolis acceleration.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.413-417
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• 2003

In this paper, a series-fed microstrip array antenna utilized a sub-array with a waveguide slot feeding is presented. This sub-array can reduce the feed loss compared with a full microstrip feed network. The sub-array has been designed both for a broad reflection bandwidth and a flat gain bandwidth from 40.5 GHz to 43.5 GHz. The $24{\times}24$ array antenna has been implemented with the maximum gain of 32.4 dBi.

• Journal of electromagnetic engineering and science
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• v.6 no.3
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• pp.165-170
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• 2006

In this paper, magneto-dielectric material is proposed to use for minimizing antenna size. One examle of very small antenna is presented to prove this with antenna's area of $0.078\lambda_0\times0.016\lambda_0$, and just moderate values of permittivity and permeability while the return loss can reach - 38 dB at the resonant frequency. The parameters of dielectric material for that best performance are $\varepsilon_r=1.71-j0.004$, and $\mu_r=2.39-j2.58$. Besides, this material also has ability to control the trade-off between the gain and bandwidth while keeping the antenna size unchanged.

• Journal of electromagnetic engineering and science
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• v.11 no.3
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• pp.227-233
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• 2011

This paper describes the development of a broadband quasi-Yagi antenna using a folded dipole driver. The antenna is designed on a low-permittivity substrate to reduce the surface wave effect, and hence the gain can be enhanced easily by adding directors. The folded dipole driver is connected to a 50-${\Omega}$ microstripline via a simple broadband microstrip-to-coplanar stripline transition with a quarter radial stub. The key motivation for the use of a folded dipole is to increase the input impedance at the driver, allowing a smaller mismatch loss between the antenna driver and the coplanar stripline feed. The proposed antenna has a measured bandwidth of 4.67~6.26 GHz for the -10 dB reflection coefficient, and a flat gain of 4.86~5.15 dB within the bandwidth.

• International Journal of Computer Science & Network Security
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• v.23 no.10
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• pp.67-72
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• 2023

This paper portrays the design and optimization of a wideband four element triangular dielectric resonator antenna (TDRA) using PSO. The proposed antenna's radiation characteristics were extracted using Ansoft HFSS software. At a resonant frequency of 5-7 GHz, the four element antenna provides nearly 21 percent bandwidth and the optimized gives 5.82 dBi peak gain. The radiation patterns symmetry and uniformity are maintained throughout the operating bandwidth. for WLAN (IEEE 802.16) and WiMAX applications, the proposed antenna exhibits a consistent symmetric monopole type radiation pattern with low cross polarisation. The proposed antenna's performance was compared to that of other dielectric resonator antenna (DRA) shapes, and it was discovered that the TDRA uses a lot less radiation area to provide better performance than other DRA shapes and PSO optimized antenna increases the gain of the antenna