DESIGN AND INVESTIGATION OF A WHEEL AND PLUS-CONFIGURED METAMATERIAL ANTENNA FOR X-BAND FREQUENCIES

Abstract

This patent presents a novel design and investigation of an X-band antenna optimized for enhanced performance in radar and communication applications. The proposed antenna utilizes a microstrip patch configuration, incorporating easily available . materials and geometric modifications to achieve a compact form factor while maintaining high gain and efficient radiation patterns. Key features include novel design techniques of wheel shaped and plus shaped patterns within the less area that minimizes reflection losses and enhances bandwidth. The antenna's performance is evaluated through extensive simulations and empirical testing, demonstrating superior characteristics such as low sidelobe levels and improved directionality. This design offers significant advantages for applications in satellite communications, weather radar, and military systems, paving the way for more efficient and effective deployment in real-world scenarios. This can work well with operating frequency of 70Hz to 140Hz from this the obtained gain is 23.6dB. which can be used for 60 wireless communication.

Specification

Field of Invc.ntion:
This invention relates to the development of a metamaterial array for obtaining
enhanced bandwidth, and rcconfigurability of antennas which can adapt to different
communication environments. The directional pattern and gain of an antenna should be
increased. When considering these parameters of antenna, antenna size may be increased.
which has to be fit, and portable with loT applications. Even though the system with radiation
characteristics arc designed well, the system has to manipulate electromagnetic signals as
well as with source signals. By taking into account all of these parameters, metamaterials are
designed in this patcni.
The designed antenna has moderate to high gain of up to 5.6 dBi, with I 0 elements
used in this design, with 77% efficiency. This antenna can be used for the frequency ranges
upto 4.5GHz.
Background of an invention:
• (0001] Mctamaterial structure : Metamaterials are fascinating materials engineered to
have properties not found in naturally occurring materials. They achieve this through their
structure rather than their composition. By arranging small, repeating units in specific
patterns, metamaterials can exhibit unusual electromagnetic properties, like negative
refraction or perfect absorption.Metamaterials are vast, spanning from improved
communication technologies to advanced medical imaging and even stealth technology.
Their ability to control and manipulate waves opens up a world of possibilities in both
science and engineering.
• [0002) Metamatcrial based enhancement of antenna parameters:Metamaterials can be
engineered to reduce the physical size of antennas while maintaining or even improving
their perforrnance.By incorporating metamaterial structures, antennas can achieve higher
gain. Metamaterials ·can be designed to concentrate electromagnetic fields, which
enhances the radiated power and improves signal reception.Metamaterials can increase the
bandwidth of antennas, allowing them to operate over a wider range of frequencies. This is
beneficial for applications requiring multi-band or wideband operation. Metamatcrials can
help reduce losses in antennas, leading to higher efficiency. By minimizing scattering and
absorption losses, antennas can transmit and receive signals more
effectively.Metamaterials can focus the radiation pattern of an antenna, improving its
directivity. This is useful for applications requiring precise signal transmission and
reception in specific directions.Metamaterials offer unique design opportunities that allow
for unconventional antenna shapes and configurations, which can lead to innovative
solutions tailored for specific applications.
•
•
(0003] Metamaterial array: Using metamaterials in antenna arrays can enhance
beamforrning capabilities and improve the performance of phased array
systems.Metamaterial arrays are structured collections of metamaterial units arranged in a
periodic or semi-periodic fashion. These arrays leverage the unique properties of
metamaterials to achieve advanced electromagnetic functionalities that go beyond what
can be achieved with conventional materials. Many metamaterial arrays have periodic
structures, meaning the unit cells are repeated in a regular pattern. This periodicity can
lead to phenomena such as band gaps, where certain frequencies are blocked, and can
enable control over wave propagation.Metamaterial arrays can be designed to be selective
to certain frequencies, making them useful for applications in filters and frequencyselective
surfaces.This can also be employed in devices operating at microwave and
terahertz frequencies
[0004] Different metamaterial structures : Metamaterials can have different shapes and
structures based on the desired effects. Some types of metamaterial structures are listed
below:
I. Split-Ring Resonators (SRRs) to change the magnetic resonance property
Commonly used in designs that require magnetic response, such as
metamaterial antennas and filters .
2. Complementary Split-Ring Resonators (CSRRs) which exhibit electric
resonance with negative permittivity.
3. Fishnet metamaterials which are constructed with overlapping of metals
and dielectrics. These kinds of structures are used for optical devices.
4. Negative index metamaterial : These metamaterials exhibit negative
permittivity and negative permeability enabling negative refraction.
• (0005] Different feeding systems for metamaterials: Feeding systems should transfer
the full electromagnetic energy into a metamaterial-based device.
Regular microstrip feedlines can provide a convenient and compact way to feed
signals. This can feed a number of microstrip antenna arrays.
Coaxial feed structures can also be used where the inner conductor is connected
to the metamaterial structure at the same time the outer· conductor is grounded .This kind of
feeding structure is applicable in resonators and where precise feeding is required.
A small pin or probe can make a connection with metamaterial structure known
as probe feeding. This method of direct coupling is required for localized coupling.
Some slots can couple energy from a source into the metamaterial structure via
the slots called slot coupling. This method gives selective coupling. Proximity coupling also
works in the same way.
For large scale antenna metamaterial antenna arrays, or multi element devices,
distribution of energy across large or complex metamaterial structures is required. Hence
complex networks of antennas or feeding elements. Between the antenna elements, capacitive
and inductive coupling cases are also possible. This leads to the different non contact type
feeding.
• [0006] Design procedure : Designing starts with the fixation of operating
frequency and then for metamaterials,
• Design of the innovative meta material cells/curves
• Iteration of the metamaterial cells within the structure of patch antenna
• Coupling of the cell with a microstrip feed line
• Parametric analysis of the feed width & length, ground height, and slot width
to achieve the best results using simulation softwares like CST, ANSYS, to
simulate the antenna parameters like reflection coefficient and gain.
• Based on the parametric analysis, length, width and position of the
metamaterial elements are fixed and other compatible parameters are
checked.
• [0007) Materials used for antenna fabrication: Metals such as Copper, Gold, Silver,
Aluminium, Dielectrics such as polymers dielectrics and semiconductors composites such
as metal dielectric composites and polymer based composites plastics can be used. These
materials are selected based on their conductivity, pennittivity and permeability. Due to
the insertion of metamaterial structures its frequency characteristics also changed.
• [0008) Key factors to be considered for metamaterial : Materials should have certain
permittivity with permeability related to specific applications. Materials have to be
selected with low loss tangents, for high. efficiency in case of sensor applications.
Fabrication materials should be compatible with existing fabrication methods like
photolithography, 3D printing, or chemical vapor deposition.
Objective of the invention:
A primary objective of the invention is to use the antenna for X band frequencies
Another objective of the invention is to surpass conventional antenna limitations by
exploiting the extraordinary electromagnetic characteristics of metamaterials.
Brief description of the prior art:
There are several different designs of metamaterial antennas and methods for various
parameters enhancements either within the plane or different planes. Some of the designs are
explained below.
• [0009] Bandwidth enhancement structures are proposed in ref[!] with metamaterial
structure at the backside to enhance the bandwidth with Roger material. This MTM
structure has four slots in each ring.This structure enhances bandwidth by 13.5 %, and
gain attains pencil beam pattern, (i.e.) focussed towards particular direction with
reduced side lobes. A simple mesh like pattern in of MTM structure [2]creates a wide
band gain from 3.06 GHz -36.4 GHz at the same time the gain by 8.02 dB.
• ]0010] Gain enhancement Chen et al.[3] proposed the MTM cell which enhances
the gain at the specified frequency by 4.1 dB and increases the aperture efficiency by
38% -95%. A circular rubylith metamaterial structure inserted as superstates increases
the gain by 3 dB in the work proposed by Saravanan et al [ 4]. This MTM cell
provides good results in both FR4 superstrate and photonic superstates.
• ]0011] Isolation enhancement In between the main radiating patches, more
metamaterial isolating structures have been proposed.More authors proposed their
structures to enhance isolation ·either as substrate or superstate. Suneetha et al.[5],
Ameen et al. [6], Singh et al. [7],Yujun et al.[8].
• [0012] Frequency selective surface (FSS): FSS consists of a periodic
arrangement of metallic or dielectric elements that define its frequency response,
resonant behaviour and filtering capabilities which are discussed by Wang et al.[9], or
it can be implemented with a separate surface as substrate and superstrate.
Superstrate [I 0] will suppress all the surface waves which are interrupting the
propagation waves. Superstates may have different structures as described in [0004] .
Brief Descriptions of accompanying drawings:
FlG.l(a): 100 shows the top view of wheel and plus-configured metamaterial antenna
FIG.l(b): 100 shows"the side view of wheel and plus-configured metamaterial antenna
FIG 2(a): 200 shows the top view of wheel and plus -configured metamaterial antenna patch
antenna highlighting the wheeled patterns
FIG 2(b): 200 shows the top view of wheel and plus -configured metamaterial antenna patch
:!:: antem1a highlighting the "plus" patterns
Detailed Description:
' • [0013) An antenna has a central patch with a corresponding centre frequency f, that is
sized to transmit or receive a radio signal. a feed line emanating from central patch;
wavelength embedded over the substrate;
The present invention consists of a novel, multi-element bi-directional antenna with
hexagonal shape. The antenna is a log periodic-type antenna configuration that is formed in
one piece of microstrip conductive material. The antenna design forms an array of hexagonal
elements and feeds at the centre point. Size of the antenna is increased from the centre where
line feed is given.
(0014( Specification with drawings: Referring to Figures I ,100 (a) and 100 (b), the top and
side view of wheel and plus configured metamaterial antenna is given., Thickness of the
substrate is given as 1.6mm in FR-4 lossy metal sheet. The dimension is 54mmx54mm.
In Figure 2(a):200, the top view is given, highlighting the wheel pattern made using
metamaterial. We provide the indications 10, 12, 13, and 14 to indicate the group of wheel
patterns on the antenna with dimension 18mmx 18mm. In Figure 2(b ):200, the top view is
given, highlighting the plus pattern made using metamaterial with dimension 18mmx 18mm ..
We give the indications 20, 21, 22, and 23 to indicate the group of plus patterns on the
antenna. Each individual group of wheel/plus pattern has four unit cells within it. Figure
2(c):200 the label 30 is given to highlight the patch feed location. The size of the patch feed
is 9mmx9mm. The label 40 in Figure 2(d):200 is the coaxial feed at the centre having coaxial
feed radius of 0.8 mm and length 5mm ..
Figure 3(a):300 represents the metamaterial unit cell of plus shaped design containing labels
"51, 52, 53, 54, 55, 56". In that label '51' represents the width of an individual longer arm, its
dimension is 0.8mm. Similarly '52' represents the width of the end projection of the arm; its
dimension is 0.8mm. '56' represents the length of the small gap present in the end of the arm;
its dimensions is 0.3mm. "53 and 55" represent the length of the longer arm; its dimensions
are 5.6mm and 8.1 mm respectively. "54" represents the length span of the shorter arm at the
end of each arm; its dimension is 2.4mm.
We claim:
l. A patch antenna comprising:
• A FR4 dielectric substrate;
• A radiating patch element superimposed on the dielectric substrate;
• A metamaterial structure superimposed on the dielectric substrate, the
metamaterial structure comprising a plurality of wheel-shaped and plus-shaped
unit cells;
• Wherein the wheel-shaped and plus-shaped unit cells are configured to
enhance the antenna's perfom1ance in a 11-12 GHz frequency band.
2. The antenna of claim I, wherein the patch feeding element located at the center of the
antenna structure.
3. The antenna of claim I, wherein the wheel-shaped "metamaterial cells comprises six
radiating arms extending radially outward from the central element. Each arm is of the
same width.
4 .. The antenna of claim I, wherein the plus-shaped metamaterial cells comprise four
radiating arms extending radially outward from the central element. Each arm is of
the same width.
5. The wheel-shaped metamaterial of claim 3, are arranged in groups four. There are
four such groups presented in the comers of the main patch.
6. The plus-shaped metamaterials of claim 4 are arranged in 4 groups .. Four such
groups arc presented in-between spaces in the main patch left over by the wheelshaped
metamaterial.
7. The arrangements mentioned in claims 5 and 6 are entailed in any such arrangements
of wheel and plus shaped metamaterial patterns within the patch antenna structure .

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