• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.2
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• pp.145-149
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• 2006

UHF band omnidirectional antennas for RFID tag were designed. Crossed loaded dipole and bended dipole were applied to be designed for both miniaturization and omnidirectional radiation pattern. By suppling 90 degrees phase difference between crossed dipoles, omnidirectional E-plane patterns can be obtained. -10 dB reflection coefficients of 3 types dipole antenna which have designed under conjugate matched with input impedance of chip were shown as 670-1,050 MHz, 700-1,250 MHz and 600-1,020 MHz, respectively, and also shown that all antenna have omnidirectional radiation pattern both E and H plane.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.43-49
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• 2008

Motivated by the Communication Broadcasting Convergence service, various technical approaches are being used to develop more efficient antenna models. This paper proposes a compact mobile antenna which is attachable to a cell phone and is applicable for Communication Broadcasting Convergence. In the design of the antennas for mobile handsets, size reduction is a crucial factor. In this paper, the compactness of a loop antenna is realized by bending a folded-dipole. A short planar dipole is transformed to a twice folded dipole and a loop antenna to produce a larger input resistance. The current distribution of the antenna is the same as a loop antenna, and its radiation patterns are omni-directional. We also analyze the performance of the RFID antenna by exploring the current-induced near field radiation patterns using a electro-optic field mapping system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.159-160
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• 2014

In this paper, a design method for a broadband planar dipole antenna for the terrestrial digital television (DTV) reception is studied. The proposed antenna is an asymmetrical planar dipole consists of a rectangular patch with an embedded t-shaped slit, and the antenna shape is printed on a side of an FR4 substrate. The effects of geometrical parameters on the antenna performance are examined, and the parameters are adjusted to operate in the DTV frequency band of 470-806 MHz. The prototype antenna is fabricated on an FR4 substrate with a size of $260mm{\times}30mm$. The performance of the antenna is tested experimentally to verify the results of this study.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.8
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• pp.880-885
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• 2010

In this paper, we propose a reconfigurable beam steering antenna using a dipole and a loop. The radiation patterns of the two antennas were cancelled or compensated, and head for the specific direction when a dipole and a loop antenna are combined at the reasonable ratio. The structure of the antenna is very simple and planar. By changing on/ off states of switches, the proposed antenna can steer the beam direction in the x-y plane. Simulation results confirmed the steering characteristic by using two imaginary switches. The proposed antenna can change the direction of the maximum gain in the x-y plane($0^{\circ}$, ${\pm}50^{\circ}$). The proposed antenna operates in 2.5~2.56 GHz(VSWR<2). It showed that peak gain of the antenna is 1.96~2.48 dBi and overall beam width of the reconfigurable antenna covers about $125^{\circ}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2003-2008
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• 2013

In this paper, a design method for a ultra-wideband printed semi-circular-shaped dipole antenna operating in the band of 1-15 GHz is studied. The effects of the gap between the two arms of the semi-circular-shaped dipole and the radius of the semi-circle on the input reflection coefficient and gain characteristics are examined to obtain the optimal design parameters. The optimized printed semi-circular-shaped dipole antenna is fabricated on an FR4 substrate and the experimental results show that the antenna has a desired extremely wideband characteristic with a frequency band of 1-15 GHz (175%) for a VSWR < 2.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.1
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• pp.109-121
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• 1999

In this paper, HF band LPDA(Log-periodic Dipole Antenna) and MLPDA(Modified Log-periodic Dipole Antenna) above lossy grounds were analyzed using moment method by considering the practical media parameter of lossy grounds, not assuming free space or perfect ground approximation. The radiation pattern and gain of LPDA and MLPDA as functions of frequency, antenna height from ground, and antenna tilt angle are presented, and the lossy ground effect on antennas characteristics are described. MLPDA was found to exhibit a smaller variation for gain and radiation pattern and a higher maximum beam direction relative to LPDA. It was shown that media parameter of lossy grounds and antenna height have a direct influence on the antenna gain of both LPDA and MLPDA.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.219-220
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• 2006

In this paper, we designed and implemented the Dual Band Dipole Antenna with Tapered Microstrip Balun for WLAN Access Point. Two dipole antennas with different resonant frequency and the antenna structure combined additional line were implemented for dual band performance. In order to feed the balun current, the tapered microstrip balun was used. Produced the Dual Band Antenna shows a special quality. The quality is that all VSWR is less than 1.5 in the 2.4GHz and 5GHz frequency bands in 802.11 standards, and it profits not less than 1.7dBi having typical Dipole Antenna pattern the very "a form of 8"pattern and Omni-directional pattern.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.207-211
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• 2015

In this paper, we proposed a broadband planar Yagi-Uda dipole antenna with dual tapered balance and unblance (balun) by CPW-fed to CPS. This antenna consisted of driver, three directors, dual tapered balun and CPS-fed to CPS. The fed structure of CPW-fed to CPS had a benefit points much simpler than other planar Yagi-Uda antennas and provided design more flexibility in arranging the reflector. The proposed antenna is introduced dual tapered balun to improve the impedance matching. It balun is inserted between the CPW-ground and the CPS. The proposed antenna is exhibited the bandwidth of 4.78 GHz (1.94~6.72 GHz) (S11 < -10 dB) and the gain of 4.9~7.2 dBi within that bandwidth. This antenna will applicate wireless communication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2245-2251
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• 2013

In this paper, a design of a compact series-fed dipole pair(SDP) antenna with end-loaded rectangular patches is presented. In order to reduce the lateral size of a conventional SDP antenna, rectangular patches are end-loaded to the two dipole elements of the SDP antenna and a grooved ground plane is used by adding a patch at both ends of the ground plane. The effects of varying the length and width of the rectangular patches on the antenna performance such as input reflection coefficient are investigated. An optimized compact SDP antenna covering a frequency band ranging from 1.7 GHz to 2.7 GHz is designed and fabricated on an FR4 substrate. The total width of the fabricated prototype of the proposed antenna is reduced by approximately 14.3% compared to the conventional SDP antenna. Experimental results show that the antenna presents a 48.7% bandwidth in the range of 1.68-2.76 GHz and a stable gain of 5.6-6.0 dBi with minimal degradation. Moreover, a front-to-back ratio is improved by about 0.7 to 7.4 dB.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.5
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• pp.251-258
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• 2002

In this paper, the dipole-fed planar array antenna applied Yagi-Uda antenna away theory to microstrip antenna is designed and fabricated at X-band. The design procedure of the dipole-fed planar array antenna with the wide bandwidth is presented to be easily practiced to a wireless communication system. The radiation pattern, return loss and bandwidth of the antenna are improved by the finite differential time domain(FDTD) numerical method. The propriety of analysis of planar dipole antenna is proved from the measured data. From the measured results, the antenna maximum gain is 4.9dBi at center frequency of 10GHz and frequency bandwidth is about 40%. Front-to-back ratio is 16dB, and half-power beam-width of E-plane and H-plane are 117$^{\circ}$and 156$^{\circ}$, respectively. When VSWR of antenna is less than 2, the measured results are agreed well with the theoretical values in the frequency range from 7.4GHz to 11.88GHz.