• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.248-256
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• 2015

In this paper, a hybrid MIMO antenna for the metal phone with auxiliary slot for 4th generation mobile communication is designed and implemented. Auxiliary slot locates on the rear metal cover of the phone, and handles for LTE class 40 band. The auxiliary slot operates hybrid with a monopole antenna. Studied antenna satisfies under VSWR 3:1 for LTE class 13/ LTE class 14/ CDMA/ GSM/ DCS/ PCS/ W-CDMA/ LTE class 40 bands. ECC(Envelope Correlation Coefficient) value for MIMO characteristic is less than 0.2 over the whole design bands. Average gains and antenna efficiencies measured by MTG 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.15 no.4
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• pp.397-405
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• 2004

In this paper, performance analysis of mobile phone with internal antenna for PCS band was carried out. The radiation patterns for antenna and mobile phone with internal antenna were simulated by using 3D simulation program, HFSS and SEMCAD. Radiation pattern variation was observed according to installation of LED circuit and ground pattern and by using simulation radiation pattern was improved. And radiation patterns of mobile phones with internal and external antennas were measured by using for field measurement system and chamber. Measured radiation pattern for mobile phone with internal antenna shows good agreement with simulation result. And the radio sensitivities of mobile phones with internal and external antennas were measured by using Agilent E5515C and chamber and compared. The measured radio sensitivity of mobile phone with internal antenna shows proper performances comparable to other model with external antenna. Measured result shows that the difference on averaged co-polar radio sensitivity is 0.12 ㏈.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.78-81
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• 2015

This paper investigates the performance of phone case with different permittivities like plastic, urethane and silicone. Then, we put an electromagnetic band gap (EBG) structure in phone case to reduce the specific absorption rate (SAR). In order to design the phone case, a loop antenna for PCS 1900 band was used. The phone case consists of a hairpin-like EBG structure that is more compact than other EBG structures. The SEMCAD X fdtd simulation results showed that, this proposed phone case can reduce SAR by 13 - 30% at similar power that is radiated by the antenna. This phone case can be used in future to reduce the SAR from mobile phones.

• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.197-203
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• 2011

A triple-band antenna which can be used at GSM900, PCS1900 and Bluetooth(or Wi-Fi) frequency band is proposed. The proposed antenna is designed based upon switching between IFA(Inverted F Antenna) that has a resonant length of ${\lambda}/4$ and loop antenna that has a resonant length of ${\lambda}/2$. It can be applied to triple-band only by use of single printed pattern due to the switching characteristic. It is designed by use of the IFA for the application to the GSM900, while it is designed by use of the loop antenna for the application to the PCS1900 and by use of additional pattern of IFA for the application to the Bluetooth(or Wi-Fi) respectively. As a result, it has been observed that the proposed antenna satisfies the required return loss(${\leq}10dB$) and also has efficiency(${\geq}80%$) over the whole band. Moreover the proposed antenna has omni-directional radiation pattern which is suitable to apply to the mobile phone.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1602-1609
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• 1998

In this paper, the design and implementation of the novel RF front end circuit for CDMA based PCS phone is described. This novel scheme is realized by building the power amplifier module combined with duplexer. The dielectric filters which are parts of duplexer are broken up and relocated into the module. Electromagnetic analysis for via holes and coupling between narrow transmissio lines is icluded to design a circuit. The combined moule has been minimaturized to be as small as 1.5CC. It has satisfied IS-95 requirements for linearity performances of CDMA signal at 24-dBm output power as well as played apart as a duplexer. The operating current of about 95mA has been saved owing to both rearranging dielectric filters and limiting operating point to class-B by considering real working power range of CDMA phones.

• 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 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.15 no.4
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• pp.327-334
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• 2004

In this paper, a triplexer for Advanced Mobile Phone Service(AMPS), United States-Personal Communication Services(US-PCS), and Global Positioning System(CPS) is designed using L and C lumped elements. The triplexer shows the insertion loss of 0.6 ㏈, 1.1 ㏈, and 1.6 ㏈ for AMPS, US-PCS, and GPS bands, respectively. Also, it shows the attenuation characteristic of less than 18 ㏈, and the VSWR of less than 2.0 through the all pass-band.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2212-2215
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• 2001

Nowadays, environmental protection is increasingly concerned more than ever before. Therefore, it is prerequisite both to monitor some data and control them on-line for reducing the environmental pollution. In this paper, internet-based 3-dimensional monitoring system which utilizes PCS phones for wireless data communication with server computer is presented and its feasibility is tested by physical installation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.1
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• pp.90-97
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• 2010

In this paper, we propose antenna topology and ground plane shape to improve the performance of PIFA (Planar Inverted F Antenna) which is built-in mobile phone. First, we designed the PIFA antenna consists of multiple radiators to provide multi-current paths. Then we designed U-shaped ground plane on the PCB under the antenna. The proposed antenna structure shows TRP/TIS improvement of 2.0 dB/3.7 dB for GSM and 2.2 dB/ 2.0 dB for DCS and 0.8 dB/1.5 dB for PCS and 1.3 dB/0.7 dB for WCDMA at the free space.