• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.906-912
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• 2008

We designed and implemented a 3-dimensional structure internal antenna which has volume less than 1.5 cc for mobile phone to improve efficiency and gain. Multiple bending for the resonance of small internal antenna derives reduction of gain due to cancellation of antenna current. In this study, the current cancelation was reduced by the minimization of antenna bending. And the helix element was applied for the purpose both compensation of short antenna length and action of radiation element. For the verification of this study, a 1.5 cc volume 3D antenna which was fabricated by the press method applied to the dual band mobile phone. Measurement showed that efficiencies and gains under the slide down and up were 27.73 %, 0.29 dBi for the GSM band and 46.84 %, 2.27 dBi for the USPCS band, and had good performance under the small antenna volume. H-plane radiation pattern showed omnidirectional for the both band.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1032-1037
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• 2016

In this paper, the method of isolation enhancement for the mobile phone MIMO antenna of LTE class 40(2300~2400MHz) was studied. Design of MIMO antenna was based on the hybrid antenna that operates both a monopole and an IFA(Inverted F Antenna). A structure for the isolation enhancement which controls induced electric field on the ground plane is located between MIMO antenna, and was not connected with the ground but apart 0.3mm. A MIMO antenna that operates on class 3~40(1710~2400MHz) of LTE service bands and a structure for the isolation enhancement at the class 10 band were designed. VSWR measurement of implemented antenna on the FR4 board showed within 3:1 at entire design bands, and isolation between antennas at the class 40 band was less than -30dB. Isolation was enhanced more than 20dB by the studied structure. ECC(Envelope Correlation Coefficient) for MIMO performance was under 0.1, and antenna average gain and efficiency measured in the anechoic chamber were -4.28~-1.40dBi and 37.32~72.36% respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.171-174
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• 2011

In this paper, transformed IFA design is proposed to improve the antenna gain of GSM/DCS/PCS band. New antenna structure has been approved to be more convenient matching in the mobile phone terminal and increase gains and expansion bandwidth through the simulation and real measurement. According to measurement, it's shown 1.57dB higher average gain than conventional IFA.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.41-47
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• 2013

This letter describes a dual-band compact monopole antenna with two branches for Wi-Fi applications. The proposed antenna is based on a planar monopole design, and composed of two branches of radiating patches for dual-band operation. The ground size of the antenna matches the ground size of a typical hand-held cellular phone for improved compatibility with mobile phone printed circuit boards. The antenna is designed using a simulator and fabricated with optimized parameters. The fabricated antenna is measured at the lower and higher operating frequencies, and the return loss coefficient, gain, and radiation patterns are determined.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.4
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• pp.395-398
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• 2016

In this paper, a hybrid MIMO antenna for the mobile communication metal phone with auxiliary letter slot is designed and implemented. Auxiliary letter slot locates on the rear metal cover of the phone, and operates on LTE class 40 band. The slots of two letters are designed and operated with monopole+IFA hybrid antenna. Antenna satisfies under VSWR 3: 1 for LTE class 13 / LTE class 14 / CDMA / GSM / DCS / PCS / W-CDMA / LTE class 40 bands. Average gains and antenna efficiencies measured by the anechoic chamber were -5.57~-1.45 dBi and 27.75~71.6 %, respectively.

• ETRI Journal
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• v.41 no.3
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• pp.337-347
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• 2019

The specific anthropomorphic mannequin (SAM) phantom was designed to provide a conservative estimation of the actual peak spatial specific absorption rate (SAR) of the electromagnetic field radiated from mobile phones. However, most researches on the SAM phantom have been based on early phone models. Therefore, we numerically analyze the SAM phantom to determine whether it is sufficiently conservative for various types of mobile phone models. The peak spatial 1- and 10-g averaged SAR values of the SAM phantom are numerically compared with those of four anatomical head models at different ages for 12 different mobile phone models (a total of 240 different configurations of mobile phones, head models, frequencies, positions, and sides of the head). The results demonstrate that the SAM phantom provides a conservative estimation of the SAR for only mobile phones with an antenna on top of the phone body and does not ensure such estimation for other types of phones, including those equipped with integrated antennas in the microphone position, which currently occupy the largest market share.

• Journal of IKEEE
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• v.19 no.2
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• pp.124-132
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• 2015

In this paper, we proposed a multiband internal antenna for LTE mobile handset that could be used for mobile devices. The proposed antenna has a volume of $50mm(W){\times}21mm(L){\times}5mm(H)$, ground plane size is $60mm(W){\times}100mm(L)$, and covers 9 service frequency bands including LTE(Long Term Evolution) band with VSWR(Vlotage Standing Wave Ratio) less than 3. With rapid change of technologies, people wants to include more function into one device. In addition, each country uses different frequency band for traffic service, it is necessary to design multiband antenna for mobile phone since traveling foreign country needs roaming. And if we can cover several services with one antenna, cost and volume needed for antennas are minimized. A HFSS (High Frequency Structure Simulator) of the Ansoft Corporation based on a finite element method is employed to analyze the proposed antenna in the design process and to compare the simulation and experimental results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1541-1547
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• 2005

In this paper, Dualband internal antenna for GSM/DSC handset is proposed. The antenna has a size of about $38mm{\times}90mm{\times}1mm$, giving a total mobile phone PCB for support and fold type patch of about $30mm{\times}8mm{\times}3.2mm$. This antenna characteriatic facilitates the fine-tuning of the two operating frequencies of 909MHz and 1762MHz in the dualband design. The measured radiation pattern in the E-plane and H-plane for operating frequencies of 909MHz and 1762MHz is compared and analyzed. The designed and fabricated two band internal antenna for GSM/DSC handset have a gain between 0dBi and 2.0dBi at all bands. Also, the electric firld distribution and directivity on human head caused by portable phone is analyzed. An analysis model is composed of a human head model and the antenna mounted on the same ground plane as portable telephone size.

• Journal of IKEEE
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• v.15 no.4
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• pp.339-344
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• 2011

In this paper, we proposed an internal multi-band monopole antenna for mobile phone that can be used for smart phones. The proposed antenna has a small volume of $38{\times}8.5{\times}5\;mm^3$, ground size is $100{\times}60\;mm^2$, and covers the GSM900 (Global System for Mobile communications : 880-960 MHz), DCS (Digital Communications System : 1710-1880 MHz), K-PCS (Korea-Personal Communications Service : 1750-1870 MHz), US-PCS (US Personal Communications Service : 1850-1990 MHz), Bluetooth (2400-2483 MHz), Wibro (2300-2390 MHz) and WLAN (Wireless Local Area Network : 2400-2483.5 MHz) bands. The measured peak gains of the implemented antenna are 1.15 dBi at 920 MHz, 3.58 dBi at 1795 MHz, 3.46 dBi at 1810 MHz, 2.91 dBi at 1920 MHz, 5.18 dBi at 2345 MHz, 3.37 dBi at 2442 MHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.3
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• pp.315-320
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• 2010

In this paper, an internal TDMB(Terrestrial Digital Multimedia Broadcasting) antenna for mobile phone is proposed. The overall dimension of designed antenna with substrate is 30 mm$\times$5 mm$\times$0.6 mm. The proposed antenna consists of a meander type radiator which is connected front- and back-plane of Kapton substrate by via hole and parasitic element for tuning the resonant frequency. And to compensate the electric length of desired frequency, passive inductor is used for matching element. Measured gain of the implemented antenna -17.6 dBi at 174 MHz, -13.01 dBi at 195 MHz, and -14.9 dBi at 216 MHz.