• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1993-1995
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• 2003

In this paper, a Dolph-Tschebyscheff type Microstrip array patch Antenna was designed and simulated with a commercial tools. Then we fabricated an Antenna and took a measurement of the radiation pattern of the Antenna in the Anechoic Chamber room. Despite of the same case, each simulation using commercial tools showed some different results. The simulation using the Microwave Studio gave more desirable result than the ADS. We found the error of the progress of production.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.4
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• pp.92-98
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• 2008

A beam steering system of X-band 2-D phased array antenna for radar application is developed. The beam steering system consists of real-time command generator, beam steering unit, control PCB of array module and power supply. It plays a role of beam steering and on-line check of phased array antenna. The performance of beam steering system is verified with pulse timing of current control in phase shifters and measurement of far-field of phased array antenna. The developed beam steering system offers basic technology to develop full-scale beam steering system of multi-function radar.

• Journal of Advanced Information Technology and Convergence
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• v.9 no.2
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• pp.99-105
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• 2019

In this paper, we describe the procedure of simulation design and measured results of a compact planar antenna for handset applications. The broad bandwidth covering the interested frequency band for mobile handset is achieved by introduction of an open ended L-shaped slot which is newly proposed and corresponds to the monopole slot. In order to minimize the impact on circuit part placement, the proposed antenna is placed on the ground plane edge of PCB with size of 60×65 mm². The measurement result for 10dB impedance bandwidths is 640 MHz (1.7~2.34 GHz), covering the required bandwidths for DCS (Digital Cellular System)-1800 (1710 ~ 1880 MHz) / IMT (International Mobile Telecommunication)-2000 (1885 ~ 2200 MHz) bands. In particular, we would like to emphasize the proposed antenna has an omnidirectional radiation pattern suitable for commercial wireless communication.

• Journal of Advanced Navigation Technology
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• v.20 no.3
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• pp.246-251
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• 2016

This paper has optimized WPT (wireless power transfer) antenna, and compared EM (electromagnetic) simulation result with measurement for the magnetic resonant type standard of A4WP (alliance for wireless power) using 6.78MHz frequency and 1m distance. Power transmission distance is affected by various factors such as system shape, antenna size, and resonator coil pitch etc, which were confirmed by the EM simulation. By simulation an optimized WPT antenna was designed for a fixed distance, and the transmission loss ${\mid}S_{21}{\mid}$ has been calculated with changing distance. Measurement was carried for the fabricated antenna, and the measured transmission loss is 1.5dB with 70% efficiency at maximum 1.3m distance compared to the simulated loss of 1.6dB with 69% efficiency

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.4 s.107
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• pp.317-323
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• 2006

The conventional Wheeler cap method can extract the reliable efficiency of the antenna when the antenna operates as a simple series or parallel RLC circuit model. This method, however, may give an unreliable efficiency when the antenna under test has a complicated operating principle. In this paper, we revisit the conventional Wheeler cap method and propose a modified Wheeler cap method basedon the high-order circuit model. The proposed method can provide an accurate efficiency even for the antenna with a more complicated operating principle. Then we calculate efficiencies of other antennas with different operating principles and compare the results with the simulations.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.78-86
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• 2013

A hybrid MIMO(Multi Input Multi Output) antenna which is operating both a monopole and a IFA(Inverted F Antenna) is designed. It's applied Vlade(Vertical lade) technique to reduce antenna space, and a diagonally fed MIMO antenna is designed on the bare board for the data communication. Return losses due to variables of antenna length are simulated for the design. Antenna for the hexa-frequency band of LTE700, CDMA, GSM, DCS, PCS and WCDMA is designed and implemented. This antenna is satisfied 3:1 VSWR over the whole design band by the measurement of return loss. And average gains and efficiencies were -3.67 ~ -2.53dBi and 42.06 ~ 55.84% for LTE700/CDMA/GSM frequency band, -3.27 ~ -1.21dBi and 47.08 ~ 75.6% for DCS/PCS/WCDMA frequency band. The isolation between 2 antenna that is one of important factors for the MIMO system was measured good performance as -8.14 ~ -25.77dB over the whole service band.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.623-627
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• 2014

In recent years, wireless communication technologies in human body have received an increasing attention and the research on an antenna that can be worn also has been actively conducted. In this paper, an wearable antenna that can receive GPS signal frequency is proposed. The antenna was manufactured by using a copper polyester fabric with thickness of 0.08mm as a radiator and a ground plate, and a goatskin with thickness of 0.7mm as dielectric substrate. Cutting edges placed in diagonal direction of square patch in order to obtain a circular polarization characteristic, and the conductive cloth and leather was laminated by using a conductive epoxy. First, goatskin dielectric constant was obtained through the simulation and measurement of resonance frequency of the three square patch antennas with different size. On the basis of the results, an antenna operating in the GPS band was designed and the performance of the antenna was validated by making the experiment. The change of the characteristic of the antenna that is located on the shoulder parts of the clothing and wearing person were measured. And it was confirmed that the reception sensitivity has a similar level as compared to the commercially produced ceramic GPS antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.1 s.116
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• pp.44-52
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• 2007

In this paper, An active antenna of T-DMB was developed to equip to handhold gadgets by using LNA and a parasitic element allowing to miniature. The size of the fabricated active antenna is $80{\times}6{\times}0.4\;mm$ and FR4 is used for the substrate. The size of the proposed antenna is reduced by 38.8% at the operating frequency compared to one without a parasitic element, and a short stub. The proposed antenna shows improved performance at the measurement especially in the ratio of S/N compared with conventional monopole of 300 mm. The proposed antenna is well able to adapt into handhold gadgets for receiving T-DMB.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.2
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• pp.41-50
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• 2010

In this paper, a multi-band antenna with novel structure for mobile communications is designed and fabricated. The proposed antenna has the Multi-band antenna characteristics by two common-grounded slots with different size and angle. In order to reduce size and to enhance the gain of the antenna, a reflector is consisted of chokes on the three sides. It is optimized by using the CST Microwave Studio commercial software based on the FIA(Finite Integration Algorithm) and PBA(Perfect Boundary Approximation), and then the fabricating and measuring is practiced. As a result of measurement, the reflection coefficient is less than -11 dB(VSWR < 1.8) and the gain of antenna is more than 6dBi at 824~894MHz and 1885-2500MHz.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1611-1618
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• 2017

This paper presents a compact reconfigurable printed monopole antenna, operating in three different frequency bands (2.45 GHz, 3 GHz and 5.2 GHz), depending upon the state of the lumped element switch. The proposed multiband reconfigurable antenna is designed and fabricated on a 1.6 mm thicker FR-4 substrate having a relative permittivity of 4.4. When the switch is turned ON, the antenna operates in a dual band frequency mode, i.e. WiFi at 2.45 GHz (2.06-3.14 GHz) and WLAN at 5.4 GHz (5.11-5.66 GHz). When the switch is turned OFF, it operates only at 3 GHz (2.44-3.66 GHz). The antenna radiates omni-directionally in these bands with an adequate, bandwidth (>10 %), efficiency (>90 %), gain (>1.2 dB), directivity (>1.7 dBi) and VSWR (<2). The fabricated antenna is tested in the laboratory to validate the simulated results. The antenna, due to its reasonably compact size ($39{\times}37mm^2$), can be used in portable devices such as laptops and iPads.