This section premeditates the made-up model of the proposed antenna together with the comparison of simulated and measured results of various operational indicators. The fabricated structure of the antenna has been delineated in Fig. 6 and the assessment of simulated and measured coefficient of reflection is depicted in Fig. 7. It can be seen in Fig. 7, that the measured antenna exhibit all the frequency bands almost similar to the resonant points revealed by the simulated antenna. So, we can say that both the results (simulated and measured) are in a good match with each other. But, small discrepancies have been reported among the simulated and measured results which may have arisen as a result of the manufacturing tolerance such as soldering bumps of SMA connector as well as inappropriate etching of copper and some variations in the physical dimension of the fabricated structure.
The measured proposed antenna displays the operational frequency ranges from 1.10–3.24GHz, 3.93–5.24GHz, 6.57–7.29GHz, and 8.12–9.72GHz with corresponding impedance BW of 2.14, 1.31, 0.72, 1.60GHz. From, these measured results it is evident that proposed HFA can be used for distinct wireless standards such 1800 MHz 2G spectrum of GSM band (1.71–1.88GHz), Aircraft Surveillance (1.09GHz), 3G Cellular Communication Mobile Uplink (1.90–1.98GHz), Advance Wireless Services (2.11–2.15GHz), LTE 2300/LTE 2500 (2.3–2.4GHz/2.5–2.69GHz), RFID (2.4GHz), Wi-Fi (2.4–2.485GHz), Bluetooth (2.4GHz), WiMAX (3.3–3.7GHz), mobile/fixed satellite navigation (6.61–7.04GHz, 8.175–8.215GHz) and aeronautical and radio navigation (9.0–9.5GHz).
Graphical illustration of the variation in the field strength of radio waves in 2D and 3D space has been specified by using the radiation pattern of the antenna. As the patch antennas are radiate normally to the surface of the metallic radiating element, so these patterns are shown in the rectilinear or polar form with a decibel (dB) strength scale. The simulated and measured radiation patterns in E and H-plane at distinct resonant frequency points are delineated in Fig. 8. Proposed HFA reveals nearly bidirectional in E-plane and completely Omni-directional pattern in H-plane at operative frequency bands, which clearly postulates that the proposed antenna is an appropriate candidate for multiband wireless applications. Peak realized gain and radiation versus frequency are represented in Fig. 9 in the anticipated frequency ranges. This evidently displays that the measured and simulated gain responses are in reasonable congruent with each other. It can also be reported that the gain of the proposed antenna varies between 1.0 to 4.87dB, 4.62 to 5.28dB, 4.98 to 6.85dB, and 4.75 to 6.28dB in the attained operative frequency ranges. Also, the radiation efficiency of the proposed antenna varies from 0.87 to 0.79% in the first frequency range and almost constant between 0.78 to 0.80% in the other three operational frequency ranges.
Table 2
A Comparison of proposed HFA with existing antennas of same category
Reference
|
Fractal curves
|
Size of antenna (mm2)
|
Resonant frequencies (GHz)
|
Maximum gain
(dB)
|
[36]
|
Sierpinski and Meander
|
700×400
|
0.89/1.85/2.04
|
2.1
|
[37]
[38]
[39]
[40]
[41]
[42]
This work
|
Koch and Cantor
Koch and Minkowski
Koch and Minkowski
Sierpinski Carpet and Gasket
Sierpinski gasket and Meander
Giuseppe Peano and Cantor
Meander and Koch
|
25×66
45×38.92
39.4×48.4
59×29
400×400
34×34
20×40
|
1.9/3.15
4.46/8.78
2.45/3.85/4.45
2.36/4.7
0.925/1.85/2.045
2.44/5.81
1.6/4.8/6.9/8.8
|
4.78
5.73
6.8
6.1
---
10.19
6.85
|
The comparison of the proposed HFA has been made with the existing antennas of the same category and illustrated in Table 2 for better understanding. It is evident from Table 2, that the proposed HFA is compact in size and exhibits more frequency bands as compared to the other reported antennas. It has also been observed that HFA deliberated in [42] exhibits more gain as demonstrated by proposed HFA, but it projects less number of frequency bands as well as larger in size, in comparison to it. Thus, giving reliable vision to the above conversation, it can be anticipated that the proposed HFA is best amongst the existing HFAs represented in state of art of literature.