New Compact Antenna Array for MIMO Internet of Things Applications

Abstract

A communication system is proposed for the Internet of Things (IoT) applications in desert areas with extended coverage of regional area network requirements. The system implements a developed six-element array that operates at a 2.45 GHz frequency band and is optimized to reduce the size and limit element coupling to less than −20 dB. Analysis of the proposed system involves a multiple-input multiple-output (MIMO) operation to obtain the diversity gain and spectral efficiency. In addition, the radiation efficiency of the proposed antenna is greater than 65% in the operation bandwidth (more than 30 MHz) with a peak of 73% at 2.45 GHz. Moreover, an adaptive beamforming system is presented based on monitoring the direction of arrival (DOA) of various signals using the root MUSIC algorithm and utilizing the DOA data in a minimum variance distortionless response (MVDR) technique beamformer. The developed array is found to have an envelope correlation coefficient (ECC) value of less than 0.013, mean effective gain (MEG) of more than 1 dB, diversity gain of more than 9.9 dB, and channel capacity loss (CCL) of less than 0.4 bits/s/Hz over the operation bandwidth. Adaptive beamforming is used to suppress interference and enhance the signal-to-interference noise ratio (SINR) and is found to achieve a data rate of more than 50 kbps for a coverage distance of up to 100 km with limited power signals.

Characteristics mode analysis based wideband Sub-6 GHz flexible MIMO antenna using a unique hybrid decoupling structure for wearable applications

“…Any on-body communication scenario needs the antenna to be placed less than 5 mm from the surface of the skin. Therefore, the proposed MIMO antenna is kept at 5 mm from the skin layer imitating the real-time scenario of placing the antenna over the clothes that have a thickness of approximately 1-6 mm [17]. SAR is calculated for 1 g and 10 g of tissue at the resonant frequency of 4.1 GHz.…”

“…Numerous approaches are seen in the literature for improving the isolation between the inter-elements such as incorporating slots [9,10], stubs [11,12], metamaterial [13], defected ground plane (DGS) [2,14], electromagnetic band gap structures (EBG) [15], neutralization lines (NL) [16] or hybrid (combination of any two of the specified techniques) [7]. Even though the above-mentioned techniques help provide the isolation, optimizing the MIMO antenna decoupling structures maintaining the operating bandwidth, stable gain, radiation efficiency, and desired directional radiation patterns with a low antenna volume is challenging [17,18].…”

Co‐designed radome with parasitic patches for the profile reduction and gain enhancement of antennas

“…[1][2][3][4][5] However, these technologies suffer from large feed losses and element mutual coupling which substantially deteriorates the gain and aperture efficiency (AE). In Abdulkawi et al, 6 an antenna obtains a high efficiency in a very compact configuration by etching four slots on a square patch; however, the gain is still not so high for high-performance applications. Meanwhile, most of the antennas require radomes against external hostile environmental conditions which significantly influence the radiation distances and the signal qualities of the underlying antennas.…”

Filtenna with Frequency Reconfigurable Operation for Cognitive Radio and Wireless Applications

“…The internet of things (IoT) is considered one of the most technological innovations that pave the way for human-machine interconnectivity which aims to communication devices within their environment through the internet with a high level of intelligence [ 16 , 17 ]. IoT operates in the frequency range from lower frequencies up to 5.8 GHz and microstrip antennae can be easily integrated into IoT devices, so the size miniaturization is considered an important factor in selecting the appropriate antenna model for IoT applications [ 18 , 19 ].…”