• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1057-1062
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• 2016

In this paper, a design method for a compact log-perio dic half-bow-tie dipole array antenna for an operation in a UWB band(3.1-10.6 GHz) is studied. The proposed antenna is miniaturized by using half-bow-tie shaped dipole elements instead of strip-type dipole elements, which are commonly used in a general log-periodic dipole array(LPDA) antenna, and by reducing the element spacing. The effects of the flare angle of the half-bow-tie elements and the spacing factor on input reflection coefficient and realized gain characteristics of the proposed log-periodic antenna are analyzed. The optimized antenna is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 2.95-11.31 GHz for a VSWR < 2, which assures the operation in the UWB band. In addition, the length and width of the proposed antenna are reduced to 32.1 % and 18.3 %, respectively, compared to the LPDA antenna.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.2
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• pp.182-191
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• 1988

A log periodic microstrip array antenna using direct coupling feeder is designed at the frequency 7.2-12.4GHz. Transmission line analysis method was used for the design of each antenna element in consideration of the effects of dielectric and conductor loss and the discontinuity, also the optimized feeding points were obtained for the impedance matching between a main transmission line and each antenna element. It is shown that the measured VSWR was less that 2.4 at the frequency 7.2-12.4GHz, and 53% bandwidth was achived.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7A
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• pp.678-682
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• 2011

In this paper, a compact log periodic dipole array (LPDA) antenna operating from 1 to 6 GHz is studied. Inverted-L shaped dipole elements are used to miniaturize the lateral size of an LPDA antenna and the spacing factor is also decreased to reduce the total length of the LPDA antenna. As the top-loading length of the inverted-L shaped dipole elements is increased, the width of the LPDA antenna is decreased but the bandwidth and the gain of the antenna are decreased. The fabricated compact LPDA antenna is printed on FR4 substrate With a dielectric constant of 4.4 and a thickness of 1.6 mm, and its size is reduced to 32% in width and 49% in length compared to a standard LPDA antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.3
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• pp.170-176
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• 2017

In this paper, we proposed the miniaturized structure of the Log-Periodic Dipole Array(LPDA) antenna for PS-LTE(Pubic Safety-Long Term Evolution) service. The length of array dipole was shortened by adding a fractal tree element with iteration to the array dipole to miniaturize the LPDA antenna. As the result, the proposed LPDA antenna was reduced up to 25 %, compared a typical LPDA antenna. To validation of the proposed LPDA antenna specification, the proposed LPDA antenna is fabricated using aluminum with 1.5 mm thickness and performances are measured. Comparison between simulation result and experiment shows good agreement.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.5 no.3
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• pp.48-58
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• 1994

In this paper, a CLPDA (Crossed Log-Periodic Dipole Antenna) for EMI / EMC Measurement is presented, and is analyzed by Combining the moment method and the transmission line theory. The CLPDA has a broaddband characteristic. It is so important to achieve a impedance matching over op- erating frequency range that Twin-boom method is used at feed point. Here, the current distribution, input admittance, radiation pattern and gain are calculated. In practice CLPDA is fabricated. Calculated result for radiation pattern and gain are very closed to measured result.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.5
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• pp.444-452
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• 1988

The LP(Log-periodic) type antenna composed of the cross fed and parasitic loop elements has been proposed for a high gain and broadband characteristics. This antenna has been analyzed by using moment method, and current distribution, input impedence, power gain, and radiation patterns has been calculated and compared with LPDA. It was found to have high gain, broadband characteristics, and similiar patterns for E and H plane against LPDA.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1353-1355
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• 2003

Genetic algorithms (GA) is a well known technique that is capable of handling multiobjective functions and discrete constraints in the process of numerical optimization. Together with the Pareto ranking scheme, more than one possible solution can be obtained despite the imposed constraints and multi-criteria design functions. In view of this unique capability, the design of the log-periodic dipole antenna array (LPDA) using this special feature is proposed in this paper. This method also provides gain, front-back level and S parameter design tradeoff for the LPDA design in broadband application at no extra computational cost.

• ETRI Journal
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• v.34 no.1
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• pp.118-121
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• 2012

In this letter, a miniaturized log-periodic dipole array (LPDA) antenna operating from 1 GHz to 6 GHz is proposed for portable direction finding applications. To reduce the lateral size of an LPDA antenna, bow-tie elements and a top-loading technique are utilized and spacing factor is decreased to reduce the spacing between the LPDA elements. The proposed miniaturized LPDA antenna has the measured gain and front-to-back ratio ranging from 1.2 dBi to 3 dBi and from 7 dB to 22 dB, respectively.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.344-349
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• 2022

A compact LPDA antenna consisting of right triangle-shaped dipole elements appended with strips is proposed for UWB applications. First, right triangle-shaped dipole elements are used instead of conventional strip dipole elements to reduce the width of the LPDA antenna. Second, the spacing between the LPDA elements is decreased to reduce the length of the LPDA antenna. Finally, strips are appended at the ends of the right triangle-shaped dipole elements in order to further reduce the width of the antenna. A prototype of the proposed antenna with 16 elements and gain > 4 dBi is fabricated on an FR4 substrate with dimensions of 44 mm×30 mm. Measured frequency band of the fabricated antenna is 2.99-14.76 GHz for a VSWR < 2, which ensures UWB operation, and measured gain range is 4.0-5.5 dBi with a front-to-back ratio larger than 10 dB. The length and width of the proposed compact LPDA antenna are reduced by 40.9% and 20.6%, respectively, compared to the conventional LPDA.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.7 no.3
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• pp.142-146
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• 2014

In this paper, an antenna which has quad band in GSM/DCS/PCS/Bluetooth is proposed. This structure is designed with miniaturization for wide band characteristic based on monopole antenna and log-periodic toothed trapezoid patch antenna which has slots. To achieve multi-bandwidth is used the microstrip line on the substrate. An antenna size is $35mm{\times}20mm$ on FR-4(${\varepsilon}r=4.4$) ground substrate of $35mm{\times}75mm{\times}1mm$ size. And proposed antenna is satisfied with impedance bandwidth(VSWR ${\leq}$ 3). The simulated maximum radiation gain is 1.92 dBi, 3.26 dBi, 3.97 dBi at the center frequency of 0.92 GHz, 1.97 GHz, 2.45 GHz, respectively.