Embedded 3D multi‐band antenna with ETS process technology covering LTE/WCDMA/ISM band operations in a smart wrist wearable wireless mobile communication device design

Abstract

An internal etching for three-dimensional structures (ETS) antenna capable of operating in the 810-960, 1370-1450 and 1710-2630 MHz bands, respectively, for long-term evolution (LTE)/wideband code division multiple access (WCDMA)/2.4 GHz industrial, scientific and medical (ISM) band operations suitable for being embedded within a smart wrist wearable wireless mobile communication device is proposed. The proposed antenna radiation efficiency can achieve 37.8-55.3% from 810-960 MHz, 53.1-92.63% from 1370-1450 MHz and 52.9-93.1% from 1710-1630 MHz for LTE/WCDMA bands and 87.4% for ISM band without the hand phantom in the free space condition. The antenna radiation efficiency of the LTE/WCDMA and ISM bands is reduced by half because of the hand phantom with lossy material properties. Furthermore, the health risk related to exposure to electromagnetic radiation, the specific absorption rates of the device are evaluated and the results were far below the limits required by the Federal Communications Commission (FCC) organisation. The embedded three-dimensional (3D) multi-band antenna can be adapted for the smart wrist wearable wireless mobile communication device. This study breaks the pattern that wearable devices must work with mobile phones. The wearable device proposed herein can directly communicate with the carrier base station independently.