• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.3
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• pp.329-335
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• 2008

This paper proposes a miniaturized half-circular-slot UWB antenna. Using an analysis of the neld patterns, we show that the original circular-slot UWB antenna operates on a series of multi-pole radiation based on $TE_n$ modes, and a perfect magnetic wall exists along an axis of symmetry on the antenna. Using the perfect magnetic wall we designed and fabricated the miniaturized UWB antenna on RF-60A substrate with t=0.64mm, ${\varepsilon}_r=6.15\;and\;tan\;{\delta}=0.0025$, which not only has the half size of the original but also maintains UWB characteristics. The measured gain of the miniaturized antenna is $-2.1{\sim}4.3dBi$, which is comparable with the gain, $-2.7{\sim}3.1dBi$, of the original circular-slot UWB antenna. The radiation pattern is also similar to that of the original antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.11
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• pp.1194-1200
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• 2009

An internal antenna which has 1 cc volume was implemented on the FPCB(Flexible Printed Circuit Board) for the mobile phone. We increased antenna gain and efficiency by the applying of current direction concept on the antenna pattern for this small antenna. Short antenna length for the GSM band was compensated by the spiral inductor on the FPCB. For broadening bandwidth on GSM band, it's applied 2 spiral inductors. A conductor pattern for the DCS band was positioned perpendicular with the FPCB. Antenna was implemented on FPCB that is dielectric constant 4.4 and thickness 0.05 mm, and FPCB was attached on a carrier dimensioned $L{\times}W{\times}H=30{\times}7{\times}5\;mm$. Measurements showed that max. VSWR 2:1, efficiency 42.49~60.95 % and 47.95~73.21 %, average gain -3.72~-2.15 dBi and -3.19~-1.35 dBi on the GSM and DCS band, respectively. These results are good performances among the small antenna. And the radiation patterns are omnidirectional on the H-plane to both band.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.125-129
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• 2010

This paper introduces an X-band microstrip patch array antenna that can be suitable for an energy saving system. The presented patch antenna comprises with 2-element linear array. The antenna is simulated using CST MWS and manufactured using FR-4(h=1.0mm, ${\varepsilon}r=4.4$). The estimated bandwidth, gain and beamwidth are 4%(VSWR$\leq$2), 6.3dBi and about 60o in elevation and 15o in azimuth, respectively. The antenna is fabricated and optimized based on the simulation result and installed on the backside of the sensor circuit and measured. The measured bandwidth, gain and beamwidth are 7%(VSWR$\leq$2), 4.8dBi and about 55o(El)/15o(Az), respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.121-126
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• 2022

This study is about an antenna implemented in the form of a monopole having a hexagonal symmetric pattern by simplifying the modified Hilbert curve fractal monopole structure. The modified Hilbert curve fractal monopole structure was simplified and miniaturized, and the radiator was implemented in a hexagonal symmetrical pattern to improve performance. The dielectric constant of substrate is 4.7, and the total line length with a meander-shaped symmetrical structure is 59 mm. The size of the antenna is 10 mm × 10 mm × 0.8 mm, and the line width is 0.4 mm. The size of the antenna measuring jig is 64 mm × 21 mm × 1 mm. The resonant frequency is 1.57 GHz, and the frequency range is 1.51 to 1.615 GHz. The frequency bandwidth is 105 MHz. As for the antenna gain, the measurement gain of the YZ-plane was 2.32 dBi, and that of the XZ-plane was -1.03 dBi. As a result, we confirmed that antenna miniaturization is possible using a hexagonal symmetric pattern fractal structure. In addition, we confirmed that the antenna performance can be easily improved by changing the structure of the radiator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2615-2618
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• 2009

Double rectangular patch with 4-bridges is investigated for solution of IEEE 802.11b/g (2.4 GHz) and 802.11a (5.5 GHz). Rectangular patch for 5.5 GHz frequency band is printed on the PCB substrate and connected to another rectangular patch for 2.4 GHz frequency band with 4-bridges to obtain dual band operation in an antenna element. 4-bridges can modify the desired frequency band from its original frequency band by changing its width. Gain of 2.4 GHz patch is 5 dBi and 5.5 GHz patch is 3.7 dBi at ${\theta}=0^{\circ}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1414-1418
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• 2013

In this paper, analyzed of UAVs operation altitude and range from the point of view of the data link. UAVs operation altitude is determined by the specification of the mission equipment and operational purposes. The link-of-sight analysis of data link equipment before deciding the unmanned aircraft operation altitude conditions should be considered. If GDT=0m installation then 32dBi antenna apply 15,779 meter is operation altitude. 44dBi antenna 7,927 meters. Operating altitude perspective, high-gain antenna is recommended of the long range communication.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.12
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• pp.1445-1454
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• 2008

In this paper, small UWB antenna with band-stop function for mobile handsets is proposed. A gap between radiator and under and side ground is adjusted for small size and broadband. A radiator is folded to the back side of PCB for miniaturization and tapered feeding structure is used to enhance matching characteristic. A antenna clearance has a size of $14{\times}14\;mm^2$ and a size of radiator is $10{\times}7\;mm^2$. It covers all UWB band from 3.15 GHz to 4.75 GHz and from 7.2 GHz to 10.2 GHz for VSWR<2 and has band stop characteristic at 5.8 GHz. A maximum gain is measured as 5.85 GHz. In case conventional handset case is considered, it also covers all UWB and a maximum gain is measured from -2 dBi to -2 dBi.

• Journal of electromagnetic engineering and science
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• v.14 no.3
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• pp.306-313
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• 2014

A Fabry-Perot resonator cavity antenna for Ku-band application is presented in this paper. The Fabry-Perot cavity is formed by a ground plane and a frequency selective surface (FSS) made of a circular hole array. The cavity resonance is excited by a single-feed microstrip patch located inside the cavity. The measured results show that the proposed antenna has an impedance bandwidth of approximately 13% ($VSWR{\leq}2$) and a 3-dB gain bandwidth of approximately 7%. The antenna produces a maximum gain of 18.5 dBi and good radiation patterns over the entire 3-dB gain bandwidth. The antenna's very thin profile, high directivity, and single excitation feed make it promising for use in wireless and satellite communication applications in a Ku-band frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.167-173
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• 2009

This paper proposes an electronically beam steering array antenna, consisting of single fed active element and 4 parasitic elements, operating in 5.8 GHz ISM band. Beam steering can be achieved by controlling the reactance of the variable reactance control circuit connected to the load of the parasitic elements without using the high cost phase shifters. The proposed antenna realizes ${\pm}30^{\circ}$ beam scanning of E-plane and H-plane with the below -10 dB return loss in ISM band. The gain of the $6.18{\sim}7.53\;dBi$ in E-plane and $7.022{\sim}7.779\;dBi$ in H-plane is shown in the scanning range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.983-993
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• 2001

This paper proposed a novel chip type ceramic dielectric antenna by using the advanced meander line technique that the radiational metals are formed on the face of ceramic dielectric(8$\times$4$\times$1.5 mm, alumina) and both faces of substrate(1.0 mm thickness, FR-4). The performance of the antenna model has a good agreements between measurements and computed results. Resultly, it has a 10 dB return-loss bandwidth(2.4∼2.4835 GHz) and 1.7 dBi measured radiation gain for Bluetooth application. The proposed antenna model can overcome the limited radiation of the small-sized antenna.