• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.1
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• pp.8-13
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• 2016

A pattern-switchable origami antenna is designed with paper using inkjet-printing technology. The proposed antenna can be switched between loop and dipole antenna modes by folding and unfolding the paper, respectively. The proposed antenna is designed for the resonant frequencies of both modes to be 1.85 GHz. Eutectic gallium-indium liquid metal is introduced in order to avoid cracks in the conductive ink when the paper is folded. The performance of the proposed antenna is demonstrated through simulation and measurement results and antenna gain of dipole-mode and loop-mode are -4 dBi and -5 dBi, respectively. Also, the nulls of both dipole and loop modes compensate nulls from each mode.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.25-31
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• 2014

In this paper, a modified Alford loop antenna for on-body communication system is proposed. The proposed antenna operating in the ISM band is designed with consideration of human body effect. One of advantages of the Alford loop antenna structure is low-profile, however the Alford loop antenna is not suitable for on-body devices since it does not have a ground plane for other electronic part of on-body system and requires balanced feeding structure. To be embedded on on-body devices, the proposed antenna is design with the unbalanced feed structure and ground. The performance of the proposed antenna is simulated and measured when it is placed on the human body phantom to consider the effect of the human body. The proposed antenna a 10 dB return loss bandwidth over the ISM band and monopole-like radiation pattern with low-profile. The antenna has the surface of appropriate for on-body communication environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.12
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• pp.1053-1058
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• 2016

The eLoran(enhanced Long Range Navigation) transmitting antenna is analyzed for co-location with an AM transmitting antenna in an MF transmitting site. To compensate for the loading effect, the umbrella-type loading is applied for eLoran antenna. The validity of the co-location between the MF antenna and the eLoran antenna is verified through the simulation results of the radiation pattern and the return loss. Also, coupling including antenna matching circuit is analyzed to verify the effect of the transmitting circuit. The coupling between the LF and eLoran antenna is -53.3 dB at 100 kHz and -64.8 dB at 1,053 kHz, respectively.

• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.59-65
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• 2022

In this paper, a digital active phased array antenna is briefly introduced and beam forming method for a dual-channel side-lobe blanking applied to blank the side-lobe of the main beam is described. Next, the antenna performance was verified from results of design and antenna near-field measurement for the antenna main beam and side-lobe blanking beam. Then, a single-channel side-lobe blanking beam forming method was proposed to reduce the number of channels than the existing system operating dual-channel side-lobe blanking beam and weight distribution for each element of the side-lobe blanking antenna was designed with the proposed method. Finally, the designed single-channel side-lobe blanking beam pattern and blanking ability were verified and compared with the dual-channel side-lobe blanking beam. In addition, by comparing/verifying the conventional dual-channel and the proposed single-channel side-lobe blanking beam patterns measured through the receiving near-field test of the digital active phased array antenna and their ability to blank side-lobe of the main beam, validity of the proposed method for forming single-channel side-lobe blanking beam was confirmed.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.523-529
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• 2021

This paper shows the design and fabrication of antenna embedded in marine buoy for marine IoT service, especially automatic identification system of fishing gears. Frequency band of proposed antenna has dual band of 433 MHz and 920 MHz considering marine IoT extension. Dual pattern monopole type for 920 MHz and meander type for 433 MHz are adopted in the proposed antenna. Voltage standing wave ratio is obtained 1.548 at 433 MHz and obtained 1.5 of mean value at 920 MHz band by measuring the fabricated antenna. The maximum antenna gain of 3.83 dBi is measured at 902 MHz among 920 MHz band, while antenna gain of 433 MHz is obtained 1.18 dBi. Although antenna gain of 433 MHz is low than 920 MHz band, this gain is larger than desired value of -5 dBi. And, it is confirmed that other measured values meet the performance criteria for archiving communication distance of 10 km between marine buoy and fishing ship in automatic identification system of fishing gears.

• Journal of Advanced Navigation Technology
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• v.19 no.1
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• pp.60-65
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• 2015

In the present study, compact $0^{th}$ order resonant antenna for 2.4 GHz ISM frequency band is newly proposed. In case of wireless communication systems such as wi-fi, bluetooth and Zigbee, antennas with omni-directional radiation pattern are necessary because of the demands for uniformly received electric field strength without variation for direction. It is well-known that $0^{th}$ order resonant antennas are not only advantageous for miniaturization but also have advantage of maintaining omni-directional radiation pattern. The proposed antenna is composed of two-element array in which the size of unit element should be smaller than ${\lambda}/4$ correspondent to the resonant length of typical monopole antennas The proposed antenna which is placed at middle and upper side of PCB with $50{\times}50mm^2$ size is designed and fabricated within limited space of $8{\times}5mm^2$. The measured impedance bandwidth ($S_{11}{\leq}-10dB$) is about 100 MHz (2.4~2.5 GHz) which corresponds to quite wide bandwidth in comparison with the antenna size, and also the measured peak gain over the passband is more than 3 dBi which is thought to be slightly wider than the other $0^{th}$ order resonant antenna.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.4
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• pp.61-70
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• 2008

This paper designed the antenna for collecting and servicing the traffic information that apply to freeway Traffic Management System, as using DSRC (Dedicated Short Range Communication). Active DSRC is the technology that is using 5.8GHz Radio Frequency to a mean Sequency and there are a lot of the case occurring a physical electric wave shadowing because of the traveling straight of a electric wave. In such inferior communication environment, it constructed the stabilized communication link that can do collecting and servicing the correct traffic information and designed the beam pattern considering the establishment position of the antenna that can apply to various road environments and a communication area. By considering the communication link environment, this paper designed and manufacture the mean frequency of 5.8GHz, the input loss of -17dB in 75MHz bandwidth, the Axial ratio of 1.5:1, and $2{\times}4$ array microstrip antenna which beam pattern have the characteristic of $55^{\circ}$ horizontal half power beam width and $26^{\circ}$elevation half power beam width and the minimum establishment height of the antenna was designed as 14m for avoiding electric wave shadowing on a physical condition between vehicles

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.5 s.96
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• pp.534-540
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• 2005

This paper analyzes the correlations between the impedance matching of the antenna and the radiation characteristics of the mobile handset body. Using two kinds of mobile handset which has retractable and fixed antenna the impedance and radiation pattern is measured under totally 16 conditions. By measured results, it has been identified that the radiation energy into human head can be reduced by attaining the better impedance matching when the radiation pattern out of the mobile handset is like the ideal monopole antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.3
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• pp.253-259
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• 2003

This paper presents the basic characteristics of a 5 element dipole array antenna which has a four parastic element and one driving element at the center of the circular array. The coupled integral equations for the unknown current distributions on dipole elements are derived and solved by applying Galerkin's method of moments. The numerical results show that the highest power gain of 7.8 dBi is obtained at radius of d = 0.3lλ when two short circuited parastic element neighbors. In order to verify the theoretical analysis, the radiation pattern is compared with Preston's results.