Design of Internal Multi-band Mobile Antenna for LTE700/WCDMA/UMTS/WiMAX/WLAN Operation

摘要

In this paper, an internal multi-band antenna is proposed for use with the LTE700/-WCDMA/UMTS/WiMAX/WLAN bands. The proposed antenna was configured to have three radiating elements. These elements were the folded loop line, rectangular patch inserting meandered slit, and L-shaped ground branch closely coupled to the feeding line. The antenna was constructed on a substrate FR4 with a relative permittivity of 4.5. The antenna operated at a lower band to cover the LTE700 operations and at a wide upper band to cover the WCDMA/ UMTS/WLAN operations. In addition, this antenna could also provide another upper band at about 3.5 GHz to cover WiMAX operations. By inserting the folded loop line and L-shaped ground branch, the LTE700 operations had VSWR ≤ 2.5 and RL ≤ -8dB, while the WiMAX operations had VSWR < 2 and RL < -10dB. By adding the rectangular patch with a meander slit, WCDMA/UMTS/WLAN band operations had VSWR < 2 and RL < -10dB. The return loss and radiation patterns of the suggested antenna were simulated by commercial EM tool software by SEMCAD X. The computed results show both a good omni-directional radiation pattern and a moderate amount of radiation gain. According to the results mentioned, the proposed antenna can be applied to mobile handset using the LTE700/WCDMA/UMTS/WiMAX/WLAN bands.