• Journal of Advanced Navigation Technology
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• v.11 no.1
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• pp.72-78
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• 2007

In this paper, the wide-band monopole antenna with a parasitic element on the ground plane for application in Cellular, GSM and RFID mobile terminals such as the mobile phone or Personal Digital Assistant(PDA) phone is presented. The VSWR of the designed antenna is 2:1 over the frequency range of 820 MHz to 1040 MHz(bandwidth of 23.6 %). Therefore, the designed antenna can provide wide bandwidth covering the Cellular(824 MHz~894 MHz), RFID(908.5 MHz~914 MHz) and GSM(Tx:880 MHz~915 MHz, Rx:925 MHz~960 MHz). The radiation characteristics of the fabricated antenna were also studied. According to the measured radiation patterns, the maximum gains at 859 MHz and 911.25 MHz(center frequencies of the Cellualr and RFID bands) are -0.7 dBi and 0.16 dBi, respectively. The measured maximum gains of GSM bands are -0.48 dBi(897.5 MHz, the center frequency of Tx) and 1.69 dBi(942.5 MHz, the center frequency of Rx).

• Journal of Korea Game Society
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• v.8 no.4
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• pp.87-93
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• 2008

The game engine has executed an application after making a mobile 3D game engine which is based on mobile 3D standard graphic API using openGL-ES so far. But, We could not do it satisfactorily that contents compatibility of various types as a various low-level's function is supported. At this point, This study introduce a mobile 3D game engine which is based on mobile 3D standard graphic API using JSR-184 that supporting a high-level's API more than openGL-ES and optimizing to Java environment on J2ME in the center of GSM phone. Also, We shows that the proposed skinned-mesh scheme for enhancing the process speed of a 3D object on JSR-184 engine. The experimental results are shown.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.1
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• pp.60-67
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• 2002

In this paper, the dual band VCO of mobile communication terminal using oscillation part switching circuit is proposed. In order to model the VCO accurately, the resonator is converted the equivalent circuit which is analyzed to use numerical method and designed optimal the dual band VCO operating GSM and DCS band. In order to demonstrate the objective theory of the proposed VCO, the dual band VCO is designed and experimented. The results of experiment, it is conformed that the VCO can be used mobile communication hand phone and components of three generation mobile communication systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1876-1882
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• 1999

In this paper, we have proposed a FCB detection algorithm for the GSM system which is european cellular standard. The detection algorithm can be implemented using received signal sampler, correlator, and post detection combiner. GSM mobile phone can use the proposed algorithm for detection of the Broadcasting Channel, and to obtain the initial timing estimate. The proposed algorithm has a architecture which is suitable for DSP or ASIC implementation, and required memory size is small. The performance of the algorithm is a function of the processing data window size and the threshold values. Proper window size and the threshold values can be determined by analyzing the correlator and combiner. The proposed algorithm has been implemented using DSP, and the performance was verified using baseband simulation. The simulation assumed frequency offset values of 0ppm and 15ppm with the receiver filter bandwidth set at both minimum and maximum. It is shown that the algorithm is robust under various assumptions, and suitable for real implementations.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.294-296
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• 2008

본 논문에서는 변형된 Monopole 안테나에 의한 GSM 900, 1800, 1900 3중 대역 BAR TYPE 형 휴대폰내장형 안테나를 설계 및 제작 하였다. 본 논문은 실제 상용화된 휴대 단말기의 내장형 안테나를 Monopole 타입으로 설계하여 현재 상용 중인 안테나에 부합하는 특징을 가지도록 하였다. 설계된 안테나를 제작 측정한 결과 기존의 안테나 보다 약 5.51% 1.39dB 특성이 개선되었다.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.100-105
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• 2006

Many corporations will get much mote benefits if they investigate the model deciding to purchasing mobile phone in that cell phone of our country has about 20% of market share in the world market. Considering this situation to divide cell phone market between CDMA and GSM in world market, it is not easy to make cell phone to satisfy the suitable method which each country wants. Through this study, we anticipate that it will offer the measuring method about consumer purchasing decision of each country. The research is to study how it is Effected by any factor when comsumer selects product and make research model. Based on the research model, we is to make a question. The research Is to complete the theoretical system on the basis of records about the cell phone and to study the improvement strategic using AHP and Conjoint Analysis which analyzes the consuming trend to customer's cell phone.

• 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 Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.706-713
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• 2010

In this paper, the small loop antenna with a parasitic loop structure for penta-band mobile phone application is proposed. This antenna is composed of a feed monopole, a radiating loop antenna with a parasitic loop structure and an additional radiating element. The antenna is printed on the very thin flexible substrate to mount on the dielectric carrier with a volume of 40 mm$\times$11 mm$\times$3 mm. The bandwidth of the proposed antenna is 402 MHz(773~1,175 MHz) for low band and 583 MHz(1,622~2,205 MHz) for high band. As a result, the proposed antenna covers the five bands of GSM850, GSM900, DCS1800, PCS1,900 and WCDMA for a 3:1 VSWR. Moreover, the radiation pattern, gain and efficiency are appropriate for mobile handset. Therefore, this antenna is suitable for small sized multi-band mobile handset applications.

• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.9
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• pp.881-887
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• 2011

In this paper, we proposed vertically structured radiator for increasing bandwidth and gain of mobile phone internal antenna. The proposed antenna has vertically structured radiator instead of planar structured radiator to improve the antenna characteristics for GSM850/900 and DCS1800/PCS1900 bands. The antenna improve bandwidth of low band with 28 % than planar structured radiator. and also, improve bandwidth of high band with 14 %, efficiency 31.80~86.36 %, average gain -4.956~-0.617 dBi on the GSM850/900 and DCS1800/PCS1900 bands. These results are good performance among the small antenna with vertically structured radiator for increasing bandwidth and gain.