• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.61-62
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• 2018

In this paper, we studied a wideband double-sided dipole antenna operating at 3.5 GHz (WiMAX) band. The each printed dipoles are placed on the both sides of the substrate. It can be easily implemented and is suitable for connection with an active circuit. In order to obtain wideband printed dipole characteristics, thick rectangular shaped dipole is adopted. Feeding Circuit for dipole array and balun were designed for impedance matching with a $50{\Omega}$ microstrip feed line. The antenna is designed by simulation for an operation in the frequency range of 3.4~3.7 GHz Simulation results show that the maximum gain in the 3.5 GHz band is 5.5 dBi and the bandwidth with VSWR less than 2 is about 1 GHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.849-852
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• 2007

In this paper, the high gain and the broadband microstrip patch antenna, which is applicable to 5 GHz band wireless LAN, is designed in order to integrate IEEE 802.11a's detailed standards($a:5.15{\sim}5.25$, $b:5.25{\sim}5.35$, $c:5.725{\sim}5.875$ [GHz]). Designed patch antenna has settled resonance frequency by insert substance(polyurethane: ${\varepsilon}_r=6.5$) between the separated parasitic patch and radiation patch for the purpose of miniaturize. And the form (${\varepsilon}_r=1.03$) were to fix the separated radiation patch and ground plans by air. Designed frequency bandwidth(VSWR 2:1) of the antenna showed broadband characteristic of $4.9[GHz]{\sim}6.1[GHz]$ to about 1.2[GHz]. Also the E-plan and H-plan profit 12[dBi] above, the 3[dB] beamwidth showed the characteristic over the E-plan $30^{\circ}$ and H-plan $60^{\circ}$ to be improved.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.517-521
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• 2018

In this paper, we designed a microstrip antenna for LTE / WLAN for wireless mobile communication high - speed communication network. The substrate of the proposed antenna is FR-4 (er = 4.3), the size is $20[mm]{\times}40[mm]$ and can be used in the frequency band of 2.77 [GHz] and 5 [GHz] Respectively. The simulation was performed using CST Microwave Studio 2014. The simulation result shows that the gain is 2.034 [dBi] at 2.77 [GHz] and 4.95 [dBi] at 5 [GHz]. The S-parameter was also found to be less than -10 [dB] (WSWR 2: 1) in the desired frequency band. The frequency bands of LTE and WLAN are widely used around the world, and the usage of the frequency is also increasing. For this reason, the dual-band antenna of LTE / WLAN is designed to help many users in a good way to use both technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2227-2235
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• 2009

This paper describes the system configuration and measured performances of a wireless power transmission system which utilizes microwave. The technically final target of this system is to provide DC power to various mobile terminals within limited spaces such as buildings, conference rooms, and so on. The prototype system is built using in-house designed and fabricated circuits such as microwave oscillator, high power amplifier, microstrip patch antenna, low pass filter, and detector/rectifier. The fixed RF power of 29.3dBm at 2.4GHz is produced from the high power amplifier and transmitted through the transmitting antenna, while the received RF power at the receiving antenna is transformed into DC power through the detector/rectifier. The measured change of DC voltage according to the distance between transmitting and receiving antenna is described.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.979-983
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• 2008

Planar antennas are very efficient for the use of the out-door data transmission applications due to their low-profile characteristics. But the size of the antenna in UHF band blocks the practical usage. In this paper, a miniaturized planar antenna is investigated for the application of AMR system in UHF band. The designed antenna is fabricated in the form of the microstrip patch on the FR-4 substrate. The miniaturization is achieved by slot-loading on the patch. First, effects of simple slots on the size reduction are analyzed, followed by the design using more complex slots resulting in the reduction ratio of 37.9% in 425.6 MHz and bandwidth of 3.8 MHz. The effort of epoxy coating for the protection is also investigated.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.4 s.346
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• pp.44-51
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• 2006

In this paper, the resonance characteristics of zigzag wire dipole antennas are first analyzed by the method of moment(MOM) for shortening the space occupation length of straight wire dipole antenna Considering the shortening effect the integrated zigzag dipole antennas with the simplified microstrip feed are designed. Since the integration gives rise to discontinuities due to antenna line width with abrupt bend angles, the compensation by the chamfer is applied. Futhermore the integrated parasitic zigzag lines are properly attached to both sides of substrate for compensation of the effect of the dielectric substrate, hence improving the resonance characteristic. The design results at UHF and ISM band are verified with experiments.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.546-549
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• 2003

본 논문에서는 GPS용 안테나의 소형화를 위해 패치 길이 방향으로 T자형 슬릿 구조를 이용하여 GPS 중심 주파수인 1.575 GHz로 안테나를 설계, 제작하였다. 선형편파의 경우, 설계 주파수에서 패치 높이 3 mm 일 때, 패치 길이 $48 mm{\times}$폭 90 mm로 평면형($84 mm{\times}90 mm$)에 비해 42.9 %의 길이 단축 효과를 얻었으며, 반사손실 -20.3 dB, -10dB 대역폭 9 MHz (0.5 %), E-면 -3dB 빔폭 $77.7^{\circ}$, H-면 -3dB 빔폭 $66.2^{\circ}$, 이득 5.3 dBd의 특성을 나타내었다. 원형편파의 경우, 설계 주파수에서 패치 크기는 $57 mm{\times}57 mm$의 정방형으로서 T자형 슬릿 길이만을 조절하여 $90^{\circ}$의 위상차를 야기시켰으며 평면형 원형편파($82 mm{\times}86.5 mm$)에 비해 54.2 %의 면적 축소 효과 및 이득 3.89 dBd, 반사손실 -28.9 dB, 축비 1.96 dB, 2dB 축비 유지 대역폭 18 MHz로 양호한 원형편파 특성을 얻었다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.3
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• pp.31-37
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• 2015

In this paper, newly proposed dual-band microstrip antennas using stacked inverted-L-shaped parasitic elements are presented for GPS $L_1(1.575GHz)$ and $L_2(1.227GHz)$ bands. For making dual band which has large interval, ${\lambda}/4$($L_1$ band) inverted-L-shaped parasitic elements were stacked at both side of radiation apertures on the half-wavelength($L_2$ band) patch antennas. The resonance in the parasitic elements occurs through coupling to the patch. Next, due to using circular polarization at GPS, ${\lambda}/4$($L_1$ band) inverted-L-shaped parasitic elements was stacked using sequential rotation technique on the patch and both side of the diagonal corners of the antenna were eliminated to make dual-band circular polarization. The designed circular polarized antenna's dimensions are $0.43{\lambda}L{\times}0.43{\lambda}L{\times}0.06{\lambda}L$ (${\lambda}L$ is the free-space wavelength at 1.227 GHz). Measured -10 dB bandwidths was 120 MHz(7.6%) and 82.5 MHz(6.7%) at GPS $L_1$ and $L_2$ bands. and 3 dB axial ration bandwidths are 172 MHz(10.9%) and 25 MHz(2.03%), respectively. All of these cover the respective required system bandwidths. Within each of the designed bands, broadside radiation patterns were observed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.9 s.112
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• pp.900-912
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• 2006

A GPS receiving antenna installed in the missile's warhead is designed and fabricated at a center frequency 1.575 GHz. The circular shaped antenna is installed in the middle of the warhead where the antenna's patch and the ground plane are connected with a hollow cylindrical shaped short pin. Using the dual feeding and phase difference method, an omni-directional radiation pattern which direction is normal to the missile's axis(H-plane) is obtained. The optimized diameters of the circular patch and the cylindrical ring typed shorting pin of the GPS receiving antenna which use the FR4.material(dielectric constant $\varepsilon_r=4.6$) are 59.5 mm and 14 mm, respectively. The cylindrical body with diameter 100 mm and height 500 mm is attached to the lower part of the warhead in order to complete the missile figure. The radiation patterns are measured by changing the angle and phase between the dual feeding points. When the phase difference of dual feeding is $100^{\circ}$ and the angle between the dual feeding points is $100^{\circ}$, the nearly omni-directional radiation pattern in the H-plane is obtained. In this case, the antenna gain is -5.55 dBd and the relative level difference between the maximum and the minimum radiation intensity is 3.98 dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.12
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• pp.1340-1350
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• 2009

The design and implementation of planar Active Phased Array Antenna System are described in this paper. This Antenna system operates at X-band with its bandwidth 10 % and dual polarization is realized using dual slot feeding microstrip patch antenna and SPDT(Single Pole Double Through) switch. Array Structure is $16\times16$ triangular lattice structure and each array is composed of TR(Transmit & Receive) module with more than 40 dBm power. Each TR module includes digital attenuator and phase shifter so that antenna beam can be electronically steered over a scan angle$({\pm}60^{\circ})$. Measurement of antenna pattern is conducted using a near field chamber and the results coincide with the expected beam pattern. From these results, it can be convinced that this antenna can be used with control of beam steering and beam shaping.