• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.8
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• pp.15-27
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• 2008

In this paper, an EBG(Electromagnetic BandGap) resonator antenna with a stripline type FSS(Frequency Selective Surface) superstrate for PCS-band base station antennas is proposed. The characteristics of resonant frequency and -3dB bandwidth of a unit cell of a superstrate are first analyzed by varing several design parameters such as a strip width and a unit cell width in order to design an EBG resonator antenna satisfying the required antenna gain and bandwidth for PCS-band base station antennas. Among various unit cell shapes, strip dipole and stripline are considered and their characteristics are compared. It was found that a resonant length of the EBG resonator antenna becomes smaller when the stripline shape is used and the control of the bandwidth is also much easier. By using the unit cell simulation results, planar and cylindrical EBG resonator antennas at PCS-band are designed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.5
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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 Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1445-1450
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• 2013

In this paper, a broadband series-fed bow-tie dipole pair (SBDP) antenna operating in the band of 1.7-2.7 GHz for mobile communication base station applications is proposed. The proposed antenna uses bow-tie-shaped dipole elements instead of straight strip dipole ones used in a conventional series-fed dipole pair (SDP) antenna. The simulation results show that the lowest operating frequency is shifted toward lower frequency as the flare angle increases, and so the lengths of the bow-tie dipole elements can be reduced in proportion to the frequency shift toward lower frequency. An SBDP antenna with a flare angle of 10 degrees is fabricated on an FR4 substrate (dielectric constant = 4.4 and thickness = 1.6 mm) and total width of the fabricated antenna is reduced by 10% compared to that of the conventional SDP antenna. The measured impedance bandwidth for voltage standing wave ratio (VSWR) < 2 is 48.8% (1.69-2.78 GHz), gain is 5.8-6.3 dBi, and the front-to-back ratio (FBR) is 14-17 dB.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.689-695
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• 2007

Wireline relay stations(RS's) are connected to cellular base stations(BS's) via radio-over-fiber(RoF) to enhance system capacity and to reduce shadow areas. Unlike wireless multi-hop systems, BS-to-RS signaling is transmitted out-of-band, thus reducing the effect of interference caused by frequency reuse. In this paper, antenna arrays used in addition to the wireline RS's are considered to evaluate the transmission capacity gain and performance variations according to the may structures. In particular, RS locations to maximize the gain, may distribution patterns for a given number of antenna elements, performance enhancement for a varying number of elements are experimentally determined to suggest a proper utilization of antenna ways in conjunction with wireline RS's.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.601-609
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• 2010

This paper measured EMF strength of the duty measurement radio station(77 station) and the non-duty measurement radio station(41 station) of mobile communication base station in Jeonbuk region. As the result of measurement, it generally reveals that EMF is highly low level compare to the human protection guideline. And It is regarded as level that the national people who live close to the mobile communication base station don't have to worry about electromagnetic wave. This paper provides comparative analyses categorized by the duty measurement station and the non-duty measurement station. The results reveals that the average value and the maximum value of the non-duty measurement station preferably was higher than all the duty measurement station. It is thought that the EMF exposure strength of the national people is caused by approach of station antenna rather than antenna power. Consequently this paper suggests that standard of the antenna power(exceed 30 W), standard of antenna height(exceed 10 m) specified by Radio Regulation Act enforcement ordinance, legal basis for mobile communication base station have to be changed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.572-579
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• 2008

To predict the system coverage in the middle frequency(MF) band, it is required to know the antenna efficiency at a base station. However, calculating the accurate efficiency is difficult since the efficiency may change according to the area where the antenna is installed. Thus, this paper proposes a method to obtain the antenna efficiency of a base station in the MF band from the measurement. This method uses the measured field strengths and the attenuation model in the MF band. Therefore, an attenuation model which is used in the proposed method is presented at first. Then, the process of the proposed method is followed using detailed explanations. Finally, antenna efficiencies of base stations which are currently operating are obtained by applying the proposed method and the usefulness of the obtained results are verified by comparing with ideal efficiencies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.8
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• pp.781-787
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• 2004

In this paper, a novel dual and wide band aperture stacked patch antenna for Cellular/PCS/IMT-2000 base station is presented. It consists of single microstrip patch having notches along the radiating patch, two dielectric substrates and a form material. To achieve wide band characteristic, we utilize the coupling effect between the notched patch and the resonant aperture in the ground plane and by properly cutting notches on the patch, an aperture stacked patch antenna could be designed to yield dual frequency operation. By the proper choice of resonant aperture size and height of a foam material, dual and wide band characteristic could be realized the measured impedance bandwidth(1:1.5 VSWR) of designed antenna at lower band(860 MHz) reaches 77 MHz and covers the Cellular CDMA band(824∼894 MHz). The measured impedance bandwidth(1:1.5 VSMR) of the designed antenna at upper band(1,960 MHz) is about 550 MHz and covers both the PCS band(1,750∼l,870 MHz) and the for-2000 band(1,920∼2,170 MHz). Good broadside radiation with high gain(5.65∼7.4 dBi) characteristics have also been observed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.1018-1024
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• 2001

In this paper, an array antenna is designed far base station of a street micro-cell in urban areas. It has a rectangular radiation pattern. The current distribution of the array is decided by using a modified Woodward-Lawson sampling pattern synthesis method. To confirm the realization of the array antenna with rectangular pattern, 12 array antenna with a planar type monopole fed by stripline is fabricated and measured. In the results of the measured values, H-plane pattern of the antenna nearly yields a rectangular radiation pattern.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.551-557
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• 1997

In mobile radio environment, it is well known that the base station antenna height gain factor is 6 dB / octave. But the mobile radio environment is not simple and affected by the terrain contour or the man-made structures, so the antenna height gain factor varies due to the propagation conditions. This paper represents the received signal power gain due to the base station antenna height in the microcell environment on the basis of the flat terrain and sloping terrain model. The gain point which shows the antenna height gain is derived in this paper.