Design and Performance Analysis of MIMO Patch Antenna using

Superstrate for Minimization of Mutual Coupling

Abstract: - Antennas play a critical role in wireless communications. Where the existing design focuses only on

frequency reconfiguration, but it does not take advantage of the entire frequency and power spectrum.

Therefore, the honeycomb-shaped Metamaterial cells used in the suggested antenna design serve as a

superstrate for microstrip patch antennas with an extensive range of actual negative permittivity and

permeability, as well as a refractive index feature. Also, to reduce mutual coupling in current printed and other

antennas. The superstrate microstrip antenna which is based on metamaterial through RF MEMS Varactor

suggested antenna was designed to reduce mutual coupling and improve system performance in 5G technology,

specifically in mm-wave applications. The obtained results for metamaterial superstrate designs demonstrate

high bandwidth and gain behaviour.

Key-Words: - Metamaterial, Superstrate, Patch, Gain, Bandwidth, Frequency, Mutual coupling

Received: July 9, 2021. Revised: May 13, 2022. Accepted: June 8, 2022. Published: July 4, 2022.

1 Introduction

telecommunications technology that will enable the

rate at which the packet transmits in the range of

10Mbps to 10Bbps [1, 2]. Microwave refers to ultra-

high frequency (UHF) frequencies ranging from 300

MHz to 3000 MHz as well as extremely high

frequency (EHF) frequencies ranging between 30

GHz to 300 GHz. In general, both licensed

authorized and unauthorized microwave bands are

frequently operating in both bands such as super-

high frequency (SHF) and extra-high frequency

groups of more cells and covering more distances to

more number of cells that are small that provide

increased bandwidth and channel capacity while

reducing power transmitted as they change to

millimeter waves. The mm-Wave is an important

feature of 5G systems and its role in systems that are

related to cellular services for users [3][4]. [5] [6]

propose mm-Wave for 5G cellular communication,

whereas [7] [8] provide propagation models for 5G

these high frequencies will place limits on this

standards because they allow broadcast signal

characteristics to be adjusted to match millimeter-

wave[9]. 5G is a cutting-edge wireless system that

was widely used in or before the 2020 years. The

MIMO antenna system, which can give 9-99 times

more than 4G and LTE systems in terms of

bandwidth [10], is a critical component of 5G

technology. High-speed data transmission that is

combined through spectrum management via many

antennas on a single physical substrate is a relatively

SIMO or MISO, but it has some drawbacks in terms

of antenna correlation and space efficiency [12].

One of the most promising 5G technologies is multi-

input and multi-output (MIMO). MIMO technology,

which has been extensively investigated, can

improve data transmission speed and give resistance

to multiple paths fading. In a MIMO system, the

transmitter or receiver must have two or more

antenna elements [13]. The planned MIMO antenna,

like certain designs [15], must inevitably produce

procedures are studied and reported in the latest

survey to minimize any effect of reciprocal

coupling. Some parameters like parasitic which are

etched, rings which are split resonators, bandgap

electromagnetic strut, ure, and defective structures

can all be employed to lessen mutual coupling in 5G

antenna are designed using MIMO technology. To

minimize mutual coupling, metamaterials are

utilized and discussed in [17].

[27], optimization of topology [28], array-antenna

decoupling surface (ADS) [29], decoupling ground

[30], near-field resonator [31], polarization diversity

[32], split ring resonator (SRR)All of the above-

mentioned measures can successfully reduce mutual

antenna. To overcome the limitation of massive

antenna coupling, a novel design must be

developed.

The contribution of this paper,

 To reduce mutual coupling, Metamaterial

Superstrate-based Micro Strip Patch Antenna is

used.

 To limit wave propagation, circular or hexagonal

shape metamaterial cells are designed.

 Adding varactor diode switches to the metamaterial

description of the suggested methodology; Section 4

reviews implementation outcomes; and Section 5

ends the article. Finally, all simulations were carried

out using ANSYS HFSS.

2 Literature Survey

T. S. Rappaport, et al. [42] Recent advancements in

millimeter-wave frequencies are being driven by

increased demand for more throughput rate of data

transmission over short distances multimedia users.

used in high throughput systems in wireless.

In [43] The antenna structure is physically modest

because of the 60 GHz frequency and 5 mm free-

space wavelength. High data rates can be achieved

while avoiding co-channel interference thanks to the

availability of 9 GHz bandwidth in the 60 GHz

range. Although there are huge free-space losses at

this frequency, big free-space losses 2 can be

compensated for by using a high-gain antenna array.

In the case of indoor radio communications, a

[45] showed that a CLL-MTM superstrate is a

suitable instrument for attenuating surface waves in

antennae which are used in patch arrays the

superstrates are based on CLCLL-MTM’she ability

to build autonomously arrays its is based on the

planar antenna is a key advantage. This method,

however, is ineffective for larger patch array

antennas. Jiang, et al [46] offers a new meta-surface

superstrate for decoupling massive antenna arrays It

should be emphasized that achieving high isolation

4G architectures which are designed using array-

based multi-band slot antenna. The proposed design

has a square ring that double-element slot radiators

and is subjected to microstrip structures and allows

for easy integration of RF and microwave circuits.

Yang, et. Ojaroudi al [48] proposed FR4 based

printed substrate of a thickness of 0.8mm which is

connected by a coaxial wire, which can provide

three-wide operational bandwidths for 5G

technologies uses: 3288–3613 MHz and 1596–2837

microstrip-based patch multiband antenna is

proposed and it uses metamaterial and

metamaterials have qualitatively new

electromagnetic response functionalities are not

exiting in present communication networks. The

integration of antennae is easily present

simultaneously at different frequencies. Chouhan,

et al [51] Proposes a MIMO system that is based on

a spider-shaped fractal that is used WLAN,

WiMAX, Wi-Fi, C, and Bluetooth technologies. It

MHz used in WLAN, 3.1-10.6 GHz used in UWB,

and X band used for 8-12 GHz. Gao, et al. [53] The

antenna is composed of two modified coplanar

waveguides (CPWs) that feed staircase-shaped

radiating components for orthogonal radiation

[54] The Metamaterial Superstrate Antenna

considerably contributes to the antenna's gain. The

primary purpose of this research is to improve the

gain and directivity of the Metamaterial Microstrip

Patch Antenna used in Wireless Point-to-Point

Communication applications like Dedicated Short-

Range Communications (DSRC). Nazl, et al. [55]

For 5G applications, a novel patch antenna for

wideband antenna design in the sub-6 GHz range is

being developed. The CST software was used to

Lee, et al. [56] In a MIMO-based antenna, the

characters are separated into two radiating features

and these are magnified using an SRR array

structure. Where the designed antenna met under

return loss of 10 dB condition in the Mobile-

WiMAX frequency band. Two antenna elements are

separated by 0.1mm. However, the antenna's

performance has not been precisely assessed [42]

The antenna [44] covers the 1.34–3.92 GHz and

series stub for matching, both of which are

impractical [46]. It is difficult to obtain high

isolation for larger arrays because mutual

interactions between inner and outer array members

make overall decoupling difficult [47], hence a

novel method is required to deal with massive

MIMO patch antenna arrays for 5G technology.

work that has been suggested for the MIMO antenna

arrays is not focused on the MIMO microstrip patch

antenna system. To solve the aforementioned

difficulties, a novel Metamaterial Superstrate-based

Micro Strip Patch Antenna with reduced mutual

coupling has been created to improve the antenna

system's performance, as shown in figure 1.

The metamaterial cells employed in the suggested

antenna design have the cell shape of a honeycomb

and are used as a superstrate based on microstrip

addition, the MIMO antenna includes a 2 mm

separation between antenna parts, which provides

excellent isolation. As a result, the suggested

antenna was developed to reduce mutual coupling

and thereby improve system performance in 5G

technology, particularly in mm-wave applications.



Fig. 1. Schematic representation of the suggested framework

considered using the equation provided below.

 

Based on the known equation, the subsequent values

are calculated.

Table 1. MIMO Patch antenna parameters

3.1.1 MIMO Antenna Performance and

Proposed Meta-Material

The proposed MIMO-based antenna array based on

feeding and a 2mm edge-to-edge antenna element

distance comprise the MIMO antenna array. For

minimization of mutual coupling, the metamaterial

is integrated with the MIMO antenna and originates

to be composed of four identical antennae which are

based on the patch design edged by coaxial lines,

with two metamaterial cells implanted in the FR-4

substrate to increase the MIMO antenna which is

isolated. As a result, the slots are cut into the

metamaterial's surface and their performance is

suggested meta-material cells. Currents flow from

one antenna patch to the next. Whenever presented

3-D metamaterial structure is integrated, the antenna

induces very small surface currents. As a result, of a

significant current flow on the 3-D structure of

Metamaterial, the surface current is limited and

Fig. 2: Circular and hexagonal slot antennas are

printed on an FR4 substrate.

metamaterial is used to compute the split-ring

resonator.

antenna structure metamaterial property (S-

Parameter). The reflectance (S11) and transmittance

(S21) characteristics are used to compute the

refractive index (n) and impedance (z), as shown in



Fig. 3: Depicts a side view of the proposed antenna

structure.

Fig.3 illustrates the proposed antenna from the side.

Consequently, the projected antenna is powered via

coaxial feed. ROGERS RT Duroid 5880 creates 1.6

mm thick substrates and metamaterial are positioned

at the top of each superstrate. The circle

metamaterial element has a diameter of 2 mm.

microstrip patch antenna, on the additional hand,

increases gain and bandwidth as shown in Fig.4.

use of a reconfigurable antenna. Consequently, the

varactor diode is used in the reconfigurable antenna

to accelerate the speed of frequency tuning. This

diode is critical in a reconfigurable antenna. Where

variable capacitor formation is based on its varying

capacitance value, the reverse bias voltage changes,

and so does the antenna's frequency at which it is

operating, junction capacitance, and current

distribution. Figure 5 depicts the varactor diode

equivalent circuit. Tuning the varactor diode in the

and beam width, a novel foraging, and navigation

optimization algorithm has been given. Hence, the

antenna parameters are optimized by altering the

metamaterial superstrate permeability and

permittivity values.

suggested framework outperforms the existing

approaches in the metamaterial superstrate.

Fig. 7: HFSS software is utilized to design.

antenna, and the length and width of the antenna are

this instance millimeter-wave frequency.

Fig. 8: A return loss of -19.2dB is measured at a

of the metamaterial layer property, which allows us

to reduce the antenna size are shown in Fig 8. It is

also a measure of the mismatch between the load

and the transmission line. As the impedance

mismatch rises. VSWR in a standing wave is

formulated between the ratio of the maximum

Fig. 11: MIMO antenna impedance bandwidth and

mutual coupling

The 3-D metamaterial cells anticipated are then

integrated into the manufactured element MIMO

antenna array. The HFSS is used to compare the

simulation results of the MIMO antenna with and

without the recommended meta-material in Fig. 11.

The proposed MIMO antenna has a bandwidth of

enhances isolation while reducing mutual coupling.

4.3 Comparison Analysis

This section describes the simulation outputs of the

proposed framework as well as the comparative

analysis.

Fig. 12: Different iteration Vs Permittivity

Permittivity is a measure of how easily charges

Fig.13. and Table 2 depict the comparative study of

the return loss with the existing techniques [54-56].

The return loss of the suggested technique achieves

-19.2 dB, which is -9.2dB higher than the [55] and -

6 dB higher than the [54].

Table 2. Comparison of Return loss (dB)

Fig. 14: Gain(dB) Vs Proposed Gain

Fig.14 and Table 3 provide a comparison of the gain

(dB) with known approaches [47-50]. The proposed

Where the proposed technique achieves reduced

mutual coupling of -18 dB using metamaterial

superstrate.

Table 4. Comparison of mutual coupling (dB)