• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.3
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• pp.175-181
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• 2004

In order to increase the coupling efficiency of the Power and Phase of the active Phase way antenna, we have fabricated the active phased-array antenna which is coupled by the transmission line, and investigated the relationship between the length of the coupling transmission line and coupling power and phase. The following three types of driving method -(1) giving the frequency difference between the two active antenna, (2) applying the input signal to the one side of the two antennas, and changing the eigen frequency of the other side antenna, (3) appling the different phase inputs to the active antennas was investigated. The experimental results showed that the interval of the antenna elements has not affected the power and the phase of the antenna.

• Journal of electromagnetic engineering and science
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• v.5 no.2
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• pp.49-60
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• 2005

In this paper, an efficient performance enhancement scheme for an adaptive antenna array under the flat and the frequency-selective Rayleigh fadings is proposed. The proposed signal enhancement scheme is the modified linear signal estimator which combines the rank N approximation by reducing noise eigenvalues(RANE) and Toeplitz matrix approximation(TMA) methods into the linear signal estimator. The proposed performance enhancement scheme is performed by not only reducing the noise component from the signal-plus-noise subspace using RANE but also having the theoretical property of noise-free signal using TMA. Consequently, the key idea of the proposed performance enhancement scheme is to greatly enhance the performance of an adaptive antenna array by removing all undesired noise effects from the post-correlation received signal. The proposed performance enhancement scheme applies at the Wiener maximal ratio combining(MRC) method which has been widely used as the conventional adaptive antenna array. It is shown through several simulation results that the performance of an adaptive antenna array using the proposed signal enhancement scheme is much superior to that of a system using the conventional method under several environments, i.e., a flat Rayleigh fading, a fast frequency-selective Rayleigh fading, a perfect/imperfect power control, a single cell, and a multicell.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.811-816
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• 2011

In this paper, we propose a optimal design using the Evolution Strategy of a high gain $4\times4$ array antenna that have the resonant frequency of a 19.05GHz with 18.86GHz~19.26GHz bandwidth. The proposed array antenna structure is designed to be allocated equally electric power by microstrip patch power splitter. Thus the optimal array antenna with power splitter are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The simulation result of $4\times4$ array antenna is confirmed that the Gain is 19.36 dBi at resonance frequency 19.05GHz.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.2
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• pp.69-77
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• 2009

Small size and low profile antenna for mobile vehicular-top-mounted is needed in satellite communication services such as DBS, Satellite Internet and VSAT. In middle latitudes, the development of an array antenna which has the conformal, low profile and 45 degree beam tilted configuration, and has the high gain with sharp beamwidth, low sidelobe and low loss is required for Ka band satellite communication. In this paper, in order to meet with these performances, an array antenna consisting of the vertical polarized waveguide longitudinal slots based on the leaky-wave mode of traveling wave antenna is proposed. Especially, for the lower sidelobe level the radiation power control using a design method of the different slot width is proposed. An array antenna consisting of 32 leakywave elements is showing 34.4 dBi of gain, 3.6 degree of beamwidth, below than -25 dB of sidelobe level, 43 degree of beam tilt angle in center frequency 20.0 GHz. Feed network designed by waveguide cooperated feed shows good performance of wideband and low loss.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.11
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• pp.1672-1678
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• 2022

In this paper, the relay antenna was designed in consideration of the performance of the 28GHz band 5G mobile communication relay horn antenna, such as radiation pattern and return loss. A horn array for 5G mobile communication repeater was designed by arranging the antenna elements in phase, and the performance was analyzed. Unlike conventional WCDMA (3G) and LTE (4G), in millimeter wave band communication, high path loss occurs between transmission and reception. In the design of a 5G millimeter wave horn antenna, antenna performance such as isolation and gain between antenna elements as well as gain and bandwidth of the antenna must be additionally considered. The antenna gain of the single horn antenna (1×1) and the array horn antenna (2×4) in the 28GHz band is about 10.44d Bi and 19.58dBi, respectively, and the return loss is designed to be less than -18dB. It has proven its validity and has been shown to be suitable for application to 5G mobile communication relay system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.3
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• pp.59-65
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• 2013

This paper presents a novel calibration method for a base station system adopting an antenna array. The proposed technique utilizes Zadoff-Chu sequence, which is included in the LTE pilot signal periodically, in order to compute the phase characteristic of each antenna channel. As the Zadoff-Chu sequence exhibits an excellent autocorrelation characteristic, it is possible for the receiving base station to retrieve the Zadoff-Chu sequence transmitted from each mobile terminal. In addition, we can obtain the phase characteristic of each antenna channel, which is the ultimate goal of the calibration procedure. The proposed calibration algorithm has been implemented using an FPGA (Field Programmable Gate Array). We have applied the proposed algorithm to an array consisting of 2 antenna elements for simplicity. the phase value implied to the first and second antenna path is very accurately calculated from the proposed procedure. From the experimental test, the proposed method provides accurate calibration results.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.211-214
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• 2004

Microstrip slot array antenna fed by microstrip line is introduced. Slot antenna is designed to operate at 10 GHz for using in radar systems. Antenna have dielectric constant of the substrate is 2.17 (PTFE). In fact, it is study to analyze slot array antenna including feeding line with wide bandwidth. The characteristics of antenna is proposed and analyzed for instance input impedance, $S_{11}$ parameter and far field radiation patterns which these characteristics can also be calculated efficiently and accurately by using FDTD Method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.117-124
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• 2001

In this paper, the design of a U-slot array antenna for PCS base station has been implemented and studied. The U-slot antenna is a single layer type with an antenna volume smaller but a bandwidth lager than the designs utilizing parasitic patches, which exceed 17 % bandwidth, for the probe fed case. Designed U-slot array antenna has stable radiation patterns and an average gain above 12 dB across the PCS frequency band. In this paper, through the designing of a U-slot array antenna, we have presented the availability for PCS base station antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.4
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• pp.359-365
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• 2002

In this work, a new type of the active array antenna for IMT-2000 base stations by using dual-polarization diversity is proposed and developed. As an element of array antenna, a single micorstrip patch antenna of ${\pm}$ 45$^{\circ}$slanted is designed by obtaining the bandwidth of 1,885 ㎒ to 22,000 ㎒. The polarization isolation between two linearly polarized waves is less than 16 ㏈. The gain of element antenna is more than 7 ㏈i. finally, 2${\times}$8 dual-polarization active array antenna is developed with ElRP of 1,200 W and polarization isolation of 20 ㏈ by placing a low power amplifier at each antenna element.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.549-554
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• 2017

In this paper, we studied the design and fabrication of $2{\times}2$ microstrip array antenna at around 5 GHz band.. To improve of frequency properties of antenna, feed microstrip patch antenna was simulated by HFSS(High Frequency Structure Simulator). A $2{\times}2$ array antenna was designed and fabricated by photolithograph on an FR4 substrate (dielectric constant of 4.4 and thickness of 1.6 mm). The fabricated $2{\times}2$ array antenna showed a center frequency, the minimum return loss and bandwidth were 5.3 GHz, -24dB, and 390MHz, respectively.