Quad-port electromagnetic band gap (EBG)—backed non-isomorphic multiple-input-multiple-output (MIMO) antenna for wearable applications

Abstract

This paper presents the design of a quad-port orthogonal Ultra-Wideband (UWB) monopole antenna backed with an EBG structure. The EBG structure provides band stop / band reject characteristics in the entire UWB range. The overall dimension of the diversity antenna is 70 × 70 × 1〖 mm〗^3 (0.68λ_0× 0.68λ_0×〖0.01λ〗_0), where λ_0 corresponds to the lowest resonating frequency. The proposed monopole antenna offers good impedance bandwidth of 8.67 GHz (2.93-11.6 GHz). The estimated diversity characterization metrics observed over the obtained frequency range are Envelope Correlation Coefficient (ECC) < 0.11, Mean Effective Gain (MEG) < 1 dB, Effective Diversity Gain (EDG) < 9.88 dB, Apparent Diversity Gain (ADG) < 9.99 dB, Channel Capacity Loss (CCL) < 0.19 bits/s/Hz, and Total Active Reflection Coefficient (TARC) < -20.95 dB. Also, SAR analysis is realized for the antenna in seven different tissues of the body (forehead, forearm, upper arm, chest, abdomen, thigh and lower leg) to check radiation exposure towards the human body.

Enhancing Gain and Isolation of a Quad-Element MIMO Antenna Array Design for 5G Sub-6 GHz Applications Assisted with Characteristic Mode Analysis

“…researchers have reported various techniques to address inter-element coupling, including the use of decoupling elements 4 , shielding walls 5 , electromagnetic band gap (EBG) structures 6 , and meta-surfaces 7 . Decoupling elements are employed to prevent surface currents from flowing between energized ports.…”

Enhancing gain and isolation of a quad-element MIMO antenna array design for 5G sub-6 GHz applications assisted with characteristic mode analysis

“…One of the primary concerns for researchers is the inter-element coupling effect between MIMO elements, which arises from the proximity of multiple radiating elements within a confined space. In recent years, researchers have reported various techniques to address inter-element coupling, including the use of decoupling elements 4 , shielding walls 5 , electromagnetic band gap (EBG) structures 6 , and meta-surfaces 7 . Decoupling elements are employed to prevent surface currents from flowing between energized ports.…”

Dual-Band Metamaterial-Based EBG Antenna for Wearable Wireless Devices

“…To overcome these limitations, metamaterial-based EBG layers were used to isolate the body and the antenna 2 International Journal of RF and Microwave Computer-Aided Engineering in [21], which reduces the SAR values from 2.57 W/kg to 0.68 W/kg. Different structures of the EBG elements were studied such as mushroom structure in [22] and some complex structures in [23], proving the potential function of EBG [24][25][26][27][28] to reduce the interference between the body and the antenna. Unfortunately, the proposed EBG antennas have complex designs and strongly sensitive electromagnetic behavior, which are not suitable for wearable devices.…”