• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.137-142
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• 2013

Direction of arrival is estimating for desire signal direction among received signal on antenna in spatial. In this paper, we were an estimation a receiving signal direction of arrival using multi beam forming in radar. We proposed, by signal direction of arrival estimation method, an algorithm which combine spatial correlation matrix weight value and beam steering algorithm in this paper. Through simulation, we were analysis a performance to compare general algorithm and proposal algorithm. In direction of arrival estimation, proposed algorithm is effectivity to decrease processing time because it is not doing an eigen decomposition. We showed that proposal algorithm improve more target estimation than general algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제41권5호
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• pp.77-83
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• 2004

Based on a Phased array technology, 2-dimensionally steerable base station antenna was developed at cellular band. The antenna, which consists of 2 by 5 radiating element, can provide 14㏈i gain with half power beam width of 0$^{\circ}$and 13$^{\circ}$ in horizontal and vertical plane respectively. It has beam scanning range of 0$^{\circ}$to 12$^{\circ}$in vertical down tilting and -15$^{\circ}$to 15$^{\circ}$in horizontal steering. The beam control Performance of antenna was verified by DM measurement on field trial.

• Journal of the Korea Computer Industry Society
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• 제5권2호
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• pp.261-268
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• 2004

This study to design an optimum phase implementing a 256 phase Opto-ULSI processor for multi-function capable optical networks. The design of an 8 phase processor is already in construction and will provide the Initial base for experimentation and characterisation. The challenge is to be able to compensate for the non-linearity of the liquid crystal, find an optimum phase, and implement a larger scale Opto-ULSI processor. This research is oriented around the initial development of an 8 phase Opto-ULSI processor that implements a Beam Steering (BS) Opto-ULSI processor (OUP) for integrated intelligent photonic system (IIPS), while investigating the optimal phase characteristics and developing compensation for the non-linearity of liquid crystal.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1418-1425
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• 2014

In ultrasonic medical imaging, spatial compounding of images is a technique where ultrasonic beam is steered to examine patient tissues in multiple angles. In the conventional ultrasonic diagnostic imaging, the steering of the ultrasonic beam is achieved electronically using the phased array transducer elements. In this paper, a spatial compounding approach is presented where the ultrasonic probe element is rotated mechanically and the beam steering is achieved mechanically. In the spatial compounding, target position is computed using the value of the rotation axis and the transducer array angular position. However, in the process of the rotation mechanism construction and the control system there arises the inevitable uncertainties in these values. These geometric parameter errors result in the target position error, and the consequence is a blurry compounded image. In order to reduce these target position errors, we present a spatial compounding scheme where error correcting transformation matrices are computed and applied to the raw images before spatial compounding to reduce the blurriness in the compounded image. The proposed scheme is illustrated using phantom and live scan images of human knee, and it is shown that the blurriness is effectively reduced.

• Proceedings of the KIEE Conference
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.981-983
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• 1998

In this paper, we present theoretical designs for a beam steering phased array antenna that uses a true time delay optical feeder. A variable true time delay is achieved by employing one tunable laser source and high dispersion fibers with different length. The wavelength tunable optical carrier propagation in a high-dipersion fiber realizes a true time delay, with the steering direction set by a single voltage controlling the wavelength. Beamsteering of a phased array antenna is obtained by controlling the tunable laser source. An employment of a high dispersion fiber response shows wide-band operation of beem steering antenna system.

• Journal of electromagnetic engineering and science
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• 제17권1호
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• pp.14-19
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• 2017

In this paper, a planar directional beam-switchable antenna with four orthogonal beam directions is proposed. The proposed antenna is designed with two crossed active elements and two parasitic elements for each direction. The design methodology is described on the basis of the Yagi-Uda method for the active and parasitic elements, respectively. By adjusting the effective electric lengths of the parasitic elements, the roles of a director and a reflector are exchanged with each other. The planar four-way beam-switchable Yagi-Uda antenna is implemented. From the experimental results. The proposed design method is verified for orthogonal radiation beam switching.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제18권6호
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• pp.620-628
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• 2007

An H-sector horn antenna has a constant beam coverage characteristic and it can be useful for application to a wide band phased array antenna system. In this paper, we designed a broadband E-plane H-sector horn phased-array antenna, which has a 3:1 bandwidth and ${\pm}60^{\circ}$ beam steering capability. An H-sector hem antenna was designed to have $30{\sim}50^{\circ}$ half-power beam width in the principal H-plane. The active reflection coefficient including mutual coupling was calculated using a waveguide simulator, and the active reflection characteristic was improved by mutual coupling over wide frequency range. Using these results, an $8{\times}1$ H-sector phased array antenna was fabricated. The measurement results for the half-power beam width in the principal H-plane and the active reflection coefficient showed a good agreement with the simulation results. The peak-value pattern in the steered radiation beams also agreed well with the active element pattern. The measured active reflection coefficients within the beam steering range are mostly less than 0.3 over the 3:1 frequency range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제30권1호
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• pp.45-53
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• 2019

In this paper, three types of array antennas for 5G mobile devices operating at 28 GHz were designed, and their performances were compared. The isolation between antenna elements was compared based on $S_{21}$. The $S_{21}$ of dipole, slot, and patch type are -13.76 dB, -16.88 dB, and -11.47 dB, respectively, with the slot-type antenna having the highest isolation. In order to compare the beam coverage performance, several characteristics such as beam width and maximum beam steering angle were analyzed. The analysis shows that the slot type has the widest steering angle of $63^{\circ}$ while the patch type has narrowest with $36^{\circ}$. In addition, to verify the performance of the antennas in the actual usage environment of the device, antenna characteristics in talk mode and data mode were analyzed through simulation. The results confirmed that the slot-type array antenna is the most suitable array antenna element for 28 GHz 5G mobile devices.

• The Journal of the Acoustical Society of Korea
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• 제22권6호
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• pp.489-495
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• 2003

Single towed line array receiver contains an ambiguity on conjugate bearings because of lacking aperture in transverse direction. To solve the left/right bearing ambiguity of line array receiver this paper proposed using single line array with fixed cardioid beam. Fixed cardioid beam has problem about back beam gain exists for steering beam inherent. Back beam is makes form on direction that is different from actually source so that reduced the performance of left/right bearing discrimination. In this paper, line way with adaptive cardioid beam for resolve problem of back beam gain is proposed. So the proposed method has more improved left/right bearing discrimination than fixed cardioid beam, Simulation results show the performance of the proposed method.

• Journal of Satellite, Information and Communications
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• 제11권4호
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• pp.107-113
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• 2016

In this paper, we suggest a design method of a wide-band Butler matrix working at 5.9 GHz for V2X communication antennas. Since V2X communication needs beam-forming and beam-steering antennas to make transportation systems, mobile comm platforms, saturated frequency-resources, and signal TX-and-RX smart, multi-functional, resolved, and efficient utmost, respectively, the proper Butler matrix and its radiating elements as a low-profile geometry are realized. The constitutive components of the basic Butler matrix of a narrow band are designed first. And then, it is extended to a wide-band version to make its frequency-shift less affected by the event of the antenna system being mounted on a car body. The beam-forming and beam-steering performance is presented as the common feature tagged along with the different bandwidths of the frequency responses as the comparison between the narrow- and wide-band cases.