Page 116 - IJEEE-2023-Vol19-ISSUE-1

112 | Neamah, Al Sabbagh, & Al-Rizzo

to improve the isolations between and decrease the mutual by co-linear their centers. To obtain bandwidth enhancement
coupling among the components of UWB MIMO antennas. for UWB applications, a SSM is rotated with angle (RO) as
Suppressing mutual coupling and offering an alternative parametric study to get better impedance bandwidth. The
current path are broad categories into which all methods may CST program is used for computer simulation design. A 50
be conducted. When antennas are placed in an orthogonal ? subminiature version A (SMA) connection is added to the
configuration, there is a lot of space between each antenna simulated model for coupling matching to improve
element, which prevents interference [14], [15]. If the size of simulation precision. Table 1 shows the antenna's final
the antenna is not a major consideration in the design, this optimized dimensions.
method can be used successfully. Also, the mutual coupling
can be minimize by ground plane modifications, such as 50 ? SMA
engraving slits, slots, and adding stubs, which promote Connector
isolation between elements by altering the distribution of
surface currents [16]–[18]. Slits, slots, and stubs are Fig.1: Schematic representation of proposed sector-shape
examples of parasitic decoupling components whose form is monopole (SSM) UWB antenna element. The 50 ?
crucial because of the frequency dependence of the subminiature version A (SMA) connector is included for
structures [19]–[22]. coupling matching. The values of dimensions can be found
in Table I.
The aim of this paper is to design a 1×2 super UWB
MIMO antenna based on orthogonal polarization diversity. Figure 2 shows the rotating a sector-shaped patch across
The proposed structure consists of two rotated orthogonal various degrees allowed us to examine its effect on
single-shape monopole antenna for optimal performance impedance bandwidth. Figure 3 shows reflection coefficient
within a bandwidth of 3.6 to 40 GHz. In addition, the antenna across different angles of (RO). An optimal value is obtained
is equipped to L-shape common ground for efficient at (RO) of 46 degrees to achieve a bandwidth of around 36.5
coupling. The designed antenna is simulated by using CST GHz (3.5- 40) GHz.
software. The antenna's performance is determined in terms
of main quantities, such as loss and gain, also MIMO
metrics, such as ECC, MEG, and TARC. This paper is
organized as follows. Section 2 describes the design
procedure of a single patch, whereas the configuration of
MIMO components is discussed in its subsection. In Section
3, the MIMO antenna analysis is presented in detail, while in
Section 4, the findings are compared to earlier work in the
field. Section 5 concludes with a summary of the noteworthy
results.

II. ANTENNA CONFIGURATION TABLE I
PROPOSED ANTENNA DIMENSIONS
A. Design Procedure
Parameter W L FW R2 GW1 Gt GW2
Figure 1 shows the geometry of the UWB sector like
shape monopole antenna. The overall size of UWB antenna Unit(mm) 18 23 2.5 7.5 50 0.035 7.5
is 20×27 mm printed on a !! 4.4, 0.0025 lost tangent and a
1.6 mm thick FR4 low cost substrate. The element proposed Parameter LP1 LP2 SR SL1 ST SW R1
antenna consists of sector shape feed by coplanar
waveguide. The primary design is started by calculating a
radius of a circular patch antenna, as described by Equations
(1,2) [23].

Unit(mm) 12.75 12.75 0.4 0.25 1.6 19 1

R = 2H æ A ö (1)
pAer çè pA ÷ø (2)
1+ [ln 2H + 1.7726]1/ 2

A = 8.791*109
f r er

where

e r : Dielectric constant of the substrate (a) (b)
Fig. 2: UWB sector shape monopole (SSM) antenna (a)
f r : Resonant frequency, GHz primary shape (b) final shape view.

H: Thickness of the substrate, cm
However, the idea of merge large and tiny sectors of circles
is to stimulate all resonance modes for various frequencies