Design of multi‐band antenna for LTE wearable device with shared slots and radiators for smart watch

Abstract

In this study, multi-band antenna for LTE wearable device with shared slots and radiators for smart watch was present. This study incorporated 4G communication frequency bands, a GPS positioning system, and BT/Wi-Fi in a 43.6 × 43.6 × 5.8 mm 3 metal case to achieve satisfactory radiation fields and performance efficiency within a small space. This article presents an overview of the theory. There are four ports in the system. Frist, Port 1 is a lowfrequency antenna offering LTE 700 and GSM 850/900. The maximal gain and efficiency are respectively 3.9 dBi and 82%. Second, Port 2 is a high-frequency monopole with a winding long path on the side of the frame to achieve a reflection loss bandwidth that fully encompasses GSM 1800/1900/UMTS and LTE 2300/2500. The maximal gain and efficiency of this port are respectively 5.3 dBi and 92%. There are also have GPS (Port 3) and Wi-Fi (Port 4) antenna implement IFA and loop excitation mechanisms, respectively. This antenna system can fulfill the market demand. As confirmed through both simulation and measurement, the antenna can cover LTE bands. Increasing the path capacity of a MIMO system to increase the transmission speed is a crucial focus in mobile communication research and development.

A Multi-Frequency Omnidirectional Antenna Based on a Ring-Shaped Structure

“…In recent years, various approaches have been developed to design and produce multi-frequency antennas. The main methods include the multilayer method [ 22 , 23 , 24 ], slot method [ 25 , 26 ], branch method [ 27 , 28 ], the reconfigurable method [ 29 , 30 , 31 ], the metamaterial loading method [ 32 , 33 , 34 , 35 , 36 ], and Dipole multifrequency antenna [ 37 , 38 , 39 , 40 ]. For example, in 2010, Chen et al [ 22 ] proposed a dual-frequency microstrip antenna using low-temperature co-fired ceramic (LTCC) technology by adopting a multi-layer method, which can be used for GPS positioning.…”

“…In 2019, Zhang et al [ 34 ] achieved dual-frequency operation by loading a transmission line-inspired structure onto the antenna. In 2020, a four-port four-frequency antenna available at high-low frequencies was presented by Chen et al [ 37 ]. In 2021, Wan, S.Y.…”

Design of Miniaturized Tri-band Wearable Antenna Based on Characteristic Mode Theory

“…In the era of increasingly diverse communication methods, the vast majority of smartwatches realize the function of communication through the Operating System (OS), connecting to Wi-Fi or inserting a Subscriber Identity Module (SIM) card to access the Internet, also interconnecting with other smart terminals using Bluetooth. Hence, smartwatches need multiple antennas or multi-band antennas to support these functions [35][36][37][38][39][40][41].…”