We present a 4-port Multiple-Input-Multiple-Output (MIMO) antenna array operating in the mm-wave band for 5G applications. An identical two-element array excited by the feed network based on a T-junction power combiner/divider is introduced in the reported paper. The array elements are rectangular-shaped slotted patch antennas, while the ground plane is made defected with rectangular, circular, and a zigzag-shaped slotted structure to enhance the radiation characteristics of the antenna. To validate the performance, the MIMO structure is fabricated and measured. The simulated and measured results are in good coherence. The proposed structure can operate in a 25.5–29.6 GHz frequency band supporting the impending mm-wave 5G applications. Moreover, the peak gain attained for the operating frequency band is 8.3 dBi. Additionally, to obtain high isolation between antenna elements, the polarization diversity is employed between the adjacent radiators, resulting in a low Envelope Correlation Coefficient (ECC). Other MIMO performance metrics such as the Channel Capacity Loss (CCL), Mean Effective Gain (MEG), and Diversity gain (DG) of the proposed structure are analyzed, and the results indicate the suitability of the design as a potential contender for imminent mm-wave 5G MIMO applications.

This work presents a 4-element multiple-input multiple-output (MIMO) antenna with a single layered metasurface array for fifth generation (5G) millimeter-Wave (mm-Wave) communication systems. Each MIMO antenna element is composed of a 1×2 array with a corporate feed network. Moreover, a metasurface array structure consisting of 9×6 Circular Split Ring (CSR) shaped cells is employed to improve the gain and isolation between the MIMO antenna elements. The proposed antenna system is realized using 0.787 mm thick Rogers RT Duroid 5880 substrate. The performance of the antenna is investigated in terms of s-parameters, radiation characteristics, and MIMO parameters. The antenna operates at the mm-Wave frequency band ranging from 24.55 to 26.5 GHz. The incorporation of the metasurface layer enhanced the gain thus attaining a peak measured gain of 10.27 dBi. Additionally, isolation is also improved by 5dB after the employment of metasurface. The investigation of MIMO performance metrics such as Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Channel Capacity Loss (CCL), and Mean Effective Gain (MEG) exhibits good antenna characteristics. The demonstrated radiation properties of the proposed antenna ascertain its suitability for the forthcoming 5G communication systems.

This work demonstrates an integrated multiple-input multiple-output (MIMO) antenna solution for Long Term Evolution (LTE) and Millimeter-Wave (mm-wave) 5G wireless communication services. The proposed structure is comprised of a two-element LTE MIMO antenna, and a four-element 5G MIMO configuration with rectangular and circular defects in the ground plane. For experimental validation, the proposed structure is fabricated on a Rogers RO4350B substrate with 0.76 mm thickness. The overall substrate dimensions are 75 mm × 110 mm. The proposed structure is capable of operating at 5.29–6.12 GHz (LTE 46 and 47 bands) and 26–29.5 GHz (5G mm-wave) frequency bands. Additionally, the measured peak gain of 5.13 and 9.53 dB is attained respectively for the microwave and mm-wave antennas. Furthermore, the analysis of the MIMO performance metrics demonstrates good characteristics, and excellent field correlation performance across the operating bands. Furthermore, the analysis of the Specific Absorption Rate (SAR) and Power Density (PD) at the lower frequency band (5.9 GHz) and PD only at mm-Wave frequency band (28 GHz) verifies that the proposed antenna system satisfies the international human safety standards. Therefore, the proposed integrated MIMO antenna configuration ascertains to be a potential contender for the forthcoming communication applications.

In this study, a biotelemetry device for scalp implantation is proposed with an ultra-miniaturized and simple-structured implantable antenna that exhibits dual-band characteristics in the industrial, scientific, and medical bands (915 MHz and 2.45 GHz). The proposed system incorporates two batteries and microelectronic components in a total volume of 434.72 mm3. The recommended antenna has a reduced volume of 9.8 mm3 (7 mm × 7 mm × 0.2 mm), which is the smallest antenna presented so far. In homogeneous and heterogeneous environments, the designed antenna system has peak gain values of -28.04 and -28.94 dBi, respectively, at 915 MHz, and -23.01 and -23.06 dBi, respectively, at 2.45 GHz. For validation, the prototype of the antenna and corresponding system are immersed in a 3D head phantom (saline solution), and the measured results are found in close agreement with the simulation results. Additionally, the data communication range is analyzed through a link budget calculation at several data rates and an input power of -16 dBm. The radiation of the antenna system in the two principal planes (E and H) are similar to being omni-directional and directed away from the anatomical human body model as mandatory for the telemetry applications. Hence, the proposed antenna system can be employed in scalp implantation, especially for intracranial pressure monitoring.

The work in this article presents the design and realization of a low-profile, four-port MIMO antenna supporting fifth-generation (5G) wireless applications operating at a millimeter-Wave (mm-Wave) band. Each MIMO antenna is a 2-element array fed with a corporate feeding network, whereas the single antenna is a patch with a bow-tie slot at the center and slits at the edges. The vertical and horizontal slots are incorporated as a Defected Ground Structure (DGS) to optimize the antenna performance. In addition, a slotted zig-zag decoupling structure is etched from edge to edge on the top side to enhance the isolation. Significant isolation (>−40 dB) is achieved between antenna elements by employing spatial and polarization diversity techniques. The proposed antenna covers the 5G mm-Wave band with a −10 dB bandwidth ranging from 27.6–28.6 GHz, whereas the maximum gain attained for the proposed structure is 12.02 dBi. Moreover, the lower correlation values, higher diversity gain, and lower channel capacity loss make it a suitable contender for 5G MIMO applications at the mm-Wave range.