Frequency Reconfigurable Dual Narrow Band Antenna matched on the Low Band LTE FDD Physical Layer

Abstract

The upcoming widening of the LTE frequency Low Band (LB) towards 600 MHz imposes a strong miniaturization effort to the smartphone antenna which can no more maintain its radiation efficiency performance over the full 600-960 MHz range. To overcome this issue, the design strategy consists in matching the antenna only where it is instantaneously used. Thus, based on the FDD spectrum usage, the proposed antenna presents two narrow bands that can be reconfigured independently anywhere in the whole LTE LB. The proposed design takes into account current limitations of the tunable capacitor (low Q factor). The measured total efficiency increases with frequency from 11% at 617 MHz to 60% at 960 MHz.