Planar broadband oval-C antenna for LTE700 and GSM850/900 applications

Abstract

This paper presents a broadband antenna presently being used in LTE700/GSM850/900 systems for smart phone applications. The proposed CPW-fed monopole antenna consists of oval-C and dual-L-shaped strips. The impedance bandwidth defined by return loss S ₁₁   −10 dB is from 660 to 975 MHz. The antenna bandwidth includes LTE700 (698–806 MHz), GSM 850 (824–894 MHz), and GSM900 (880–960 MHz) GSM850/900 bands. Long-term evolution (LTE) is one of the mobile communication technologies that target the 700 MHz band (LTE bands 13 and 17: 698–806 MHz). The LTE service is expected to provide better communication quality than the existing services, such as GSM850 (824–894 MHz) and GSM900 (880–960 MHz). However, mobile phones are desired to be able to cover at least a few of the existing service bands and LTE bands at the same time especially before the wide spread of the LTE services. The measured peak gains are 1.72–3.12 dBi with sufficient bandwidths to cover modern portable communication devices. The radiation efficiencies are all larger than 75% for an entire band. The simulated and measured results show a good agreement. This proposed antenna with multiband, broadband matched impedance, stable radiation patterns, constant antenna gains, and compact size is suitable for multimode applications.

Acknowledgment

This work was sponsored by the National Science Council under the contract number of NSC 100-2221-E-024-002.