Page 118 - IJEEE-2023-Vol19-ISSUE-1

114 | Neamah, Al Sabbagh, & Al-Rizzo

S-Parameters (dB) 0 Antennas with a (left-right) layout can provide Super-UWB
(3.6-40) GHz and achieve high isolation of more than 20 dB.
-10 To make the antenna applicable, we proposed an L-shaped
common ground. However, in most cases, a common ground
-20 structure causes the resonance between this structure and the
radiation elements, which causes rejects in its response.
-30 Figure 7 shows the S-parameters of the final shape of the 1×2
S11 orthogonal MIMO antenna with L common ground by
considering the left-right layout. Good results can be seen
-40 S21 shown in figure 7, where the reflection coefficients of S11
S12 and S22 are less than -10 dB for a frequency range of 3.6 to
40 GHz, with an isolation of less than 20 dB.
-50 S22
Figure 8 shows the simulated gain versus frequency. The
3 6 9 12 15 18 21 24 27 30 33 36 39 42 minimum value recorded of the gain is about 1.6 dBi by CST
Frequency (GHz) software at 3.6 GHz, while the maximum value is obtained at
40 GHz, which equals 5.9 dBi. This gain is acceptable for
0 (a) most modern telecommunication applications.

-10

S-Parameters (dB) -20

-30 S-parameters (dB) 0 With L common ground S11
-10 S12
S11 -20 S21
-40 S21 S22

S12 -30
S22
-50 -40
3 6 9 12 15 18 21 24 27 30 33 36 39 42
Frequency (GHz) -50

S-parameters (dB) 0 (b) -60

-10 5 10 15 20 25 30 35 40
Frequency (GHz)
-20
Fig. 7: S-parameters with L common ground of MIMO
-30 antenna versus frequency by using CST.
S11

-40 S21
S12

-50 S22

3 6 9 12 15 18 21 24 27 30 33 36 39 42
Frequency (GHz)

(c)

0

-10

S-Parameteres -20

-30

S11

-40 S21
S12

S22

-50 Fig. 8: Simulated gain of MIMO antenna versus frequency
3 6 9 12 15 18 21 24 27 30 33 36 39 42 by using CST.

Frequency (GHz) Figure 9 shows the simulated surface current versus different
frequencies along the response band when port 1 is excited.
(d) As shown in figure 9, the current is concentrated around the
patch's neck. Most of the current is along the arc and the
Fig. 6: Orthogonal two element MIMO antenna (a) (Right – angle side edge.
Right) (b) (Right-left) (c) (Left –Left) (d) (Left –Right).