Fig. 13 Simulated and measured E-plane and H-plane radiation
pattern of the proposed antenna (a, b) 3.5 GHz, (c, d) 4.4 GHz, (e, f)
8.8 GHz, (g, h) 12.0 GHz.
Figure 13 (a), (c), (e), (g) shows the simulated (red solid line) and
measured (red dotted line) normalized co-polar, simulated (black solid
line) and measured (black dotted line) cross-polar E-plane (xy-plane)
radiation pattern of the proposed antenna at 3.5, 4.4, 8.8, and 12 GHz
respectively. Similarly figure 13 (b), (d), (f), (h) shows the simulated
(black solid line) and measured (black dotted line) normalized co-polar,
simulated (red solid line) and measured (red dotted line) cross-polar
H-plane (xz-plane) radiation pattern of the proposed antenna at 3.5,
4.4, 8.8, and 12 GHz respectively From the simulated as well as measured
co-polar H-plane radiation patterns of the proposed antenna at 3.5, 4.4,
8.8, and 12 GHz shown in figure 13 (b), (d), (f) and (h) it is clear
that there is purely Omni-directional radiation pattern of co-polar
H-plane at all the simulated and measured operating frequencies and it
is highly consistent in all the operating frequencies. H-plane
cross-polar radiation pattern at the operating frequencies of 3.5, 4.4,
8.8, and 12 GHz reveal that there is significant increase of the level
of average simulated H-plane cross-polar radiation from -35 dB at 3.5
GHz to -20 dB at 12 GHz. This increase of the level of H-plane
cross-polar radiation as the frequency increases is due to the
destructive scattering of the radiation from the different edges of the
constituent structures such as open-ended slit ring, SRR etc. On the
other hand, the co-polar E-plane radiation patterns of the proposed
antenna shown in figure 13 (a), (c), (e), (g) are directional along
00 and 1800, respectively. The
co-polar E-plane radiation pattern at the operating frequencies of 3.5,
4.4, 8.8, and 12 GHz are roughly a dumbbell-shape or of the shape of
English letter “8”. This shape of co-polar E-plane radiation pattern
is highly consistent with all the operating frequencies of 3.5, 4.4,
8.8, and 12 GHz which shows that the proposed UWB notch antenna is well
suitable for application in entire UWB system except in the operating
band of WLAN. Regarding the simulated cross-polar radiation pattern of
the E-plane radiation pattern, the level of average E-plane cross-polar
radiation varies from -45 dB at 3.5 GHz to -30 dB at 12 GHz. The
measured E-plane and H-plane radiation patterns of all the aspects such
as co-polar and cross-polar radiation, the measured radiation patterns
of E–plane and H-plane are in accordance with their simulated
counterpart signifies accurate fabrication of the proposed antenna
prototype.