• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.5
• /
• pp.568-575
• /
• 2011

In this paper, we propose a small broadband antenna for mobile device. The proposed antenna consists of a printed rectangular monopole antenna and a parastic element connected to ground using narrow meander line and it is designed on a FR-4 substrate that has a thickness of 0.8 mm and a dielectric constant of 4.4. The FR-4 substrate's size is 50 mm${\times}$90 mm comparable to the real mobile device. The fabricated antenna's size is 12.5 mm${\times}$10.5 mm${\times}$0.8 mm and the measurement shows -10 dB return loss bandwidth of 2,200~6,000 MHz and gains of 2.86~4.01 dBi. Accordingly, the proposed antenna can support mobile device for WiBro(2,300~2,380 MHz), WLAN(IEEE 802.11b/g/n: 2,400~2,480 MHz, IEEE 802.11a: 5,150~5,825 MHz), and mobile WiMAX(IEEE 802.16e : 2,500~2,690 MHz, 3,400~3,600 MHz) service bands.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.158-158
• /
• 2008

In general, a wireless communication device has employed a whip antenna or a stubby antenna. Recently, wireless communication device is increasingly employing an embedded antenna, Intenna, for the sake of miniaturization. Further, it may employ both external and embedded antennas. Examples of the embedded antenna include a multi-band monopole antenna, which radiates uniformly in all directions when viewed from above, and a planar inverted F antenna (PIFA), which is a variation of the monopole antenna. However, since the conventional antenna is mounted in a finished state on the mobile communication terminal, there is a limitation of space required for providing the antenna. According to the present study, there is provided an Intenna that is deposited on a front or back case of the mobile communication terminal by a sputtering method. Accordingly, it is possible to overcome a limitation of space required for providing the Intenna and to improve the performance of the Intenna formed on the front or back case of the mobile communication terminal.

• Journal of Communications and Networks
• /
• v.18 no.3
• /
• pp.429-438
• /
• 2016

In this paper, we investigate an interference mitigation scheme by antenna selection in device-to-device (D2D) communication underlaying downlink cellular networks. We first present the closed-form expression of the system achievable rate and its asymptotic behaviors at high signal-to-noise ratio (SNR) and the large antenna number scenarios. It is shown that the high SNR approximation increases with more antennas and higher ratio between the transmit SNR at the base station (BS) and the D2D transmitter. In addition, a tight approximation is derived for the rate and we reveal two thresholds for both the distance of the D2D link and the transmit SNR at the BS above which the underlaid D2D communication will degrade the system rate. We then particularize on the small cell setting where all users are closely located. In the small cell scenario, we show that the relationship between the distance of the D2D transmitting link and that of the D2D interfering link to the cellular user determines whether the D2D communication can enhance the system achievable rate. Numerical results are provided to verify these results.

• Journal of Satellite, Information and Communications
• /
• v.9 no.1
• /
• pp.102-106
• /
• 2014

In this paper, we investigate the realistic environment influence on the Hearing-Aid Compatibility(HAC) of the body-held device mock-up with a dual-band antenna. In detail, first, a dual-band internal antenna is designed considering the neighboring objects essential to a real attachable mobile device. This comes to reality by making its mock-up version. Second, the HAC of this device is simulated and measured for 'stand alone', and 'hand-held' cases. Particularly, the electromagnetic simulation of the designed antenna in the real device is verified by the standard measurement. Finally, the evaluated HAC is analyzed in terms of the relations with the bands, the mock-up environment and the hand effect.

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

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.2
• /
• pp.161-166
• /
• 2009

In this paper, we propose the internal mobile antenna for TDMB and KPCS. The proposed antenna is made of different dielectric substrate and it has small size ($45{\times}8{\times}8\;mm$, about 2.8 cc) for mobile device. TDMB antenna is designed spiral structure that makes maximum current for each cell and KPCS antenna is PIFA that is usually used for internal antenna. In order to compensate length of resonance TDMB antenna has a large inductor above 100 nH. In this case, the inductor isolate KPCS signal at TDMB by cutting high frequency. Also the antenna has good isolation because TDMB radiator is parasitic element in KPCS band. We simulated the antenna by using CST microwave studio and measured performance of the antenna in anechoic chamber Proposed antenna has $-6{\sim}-14\;dBi$ gain for TDMB and $-3.5{\sim}-5\;dBi$ gain for KPCS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.11
• /
• pp.951-959
• /
• 2015

Ground radiation antenna in mobile devices is becoming an issue for satisfying both miniaturization and high performance. Ground radiation antenna controls the characteristic mode of the ground plane and couples this mode with the ground radiation antenna, thereby having good radiation performance. In this paper, the characteristic mode theory and applications of ground radiation antenna will be introduced. The operating mechanism of single band, wideband and dual-band ground radiation antennas are studied.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.1
• /
• pp.16-23
• /
• 2015

In this paper, a bent microstrip patch antenna, which is suitable for band-type wearable devices and RF configuration, to be used in the WCDMA2100 mobile network is proposed. The proposed antenna using RF configuration which is consisted of separated Tx and Rx frequency band is designed to operate or function in WCDMA2100 Tx frequency band only and it is not strongly affected by the human body because of the conductor at the bottom side. At both flat case and bent case, the proposed antenna's maximum gain satisfies at least 5.3 dBi, and its -6 dB return loss bandwidth is wider than 20 MHz. The simulated surface absorption rate($SAR_{1g}$) result is under 0.7 [W/kg]. The proposed antenna suits in band-type wearable devices which is worn on wrists or arms.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.42 no.9 s.339
• /
• pp.65-70
• /
• 2005

For the base station or repeater which is in operation as part of a mobile communication system, any kind of degradation in antenna performance such as lowered gam or increased VSWR which maybe due to aging of antenna, connector corrosion or other environmental factors, is difficult to detect and react to immediately. In this paper, a VSWR measurement device which is capable of detecting the VSWR of a PCS forward path ($1,840\~1,870$MHz) antenna in operation in real time without any interruption in service is developed. Such regular measurement will allow the prediction of any serious failures and insure reliable operation of the antenna. All components of the antenna VSWR measurement device was researched so that the whole system could be produced and shown to be accurate in measuring the YSWR of an actual RF repeater in operation, proving it's effectiveness.

• Journal of electromagnetic engineering and science
• /
• v.14 no.3
• /
• pp.317-319
• /
• 2014

In this letter, a small-loop antenna for a mobile UHF RFID device is proposed. To achieve size reduction, a ferrite sheet optimized for a 900 MHz band is applied. The overall dimensions of the antenna are $46mm{\times}35mm{\times}0.24mm$, and it has a bandwidth of 45 MHz with a return loss of less than -6 dB. The proposed antenna satisfies near and far field UHF EPC global frequency band communications (902-928 MHz).