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Special Techniques of Printed Antenna
Published in Binod Kumar Kanaujia, Surendra Kumar Gupta, Jugul Kishor, Deepak Gangwar, Printed Antennas, 2020
Dinesh Kumar Singh, Ganga Prasad Pandey
A small deviation in the impedance bandwidth is observed because of the fabrication imperfection and the irregular surface of the metal sheet. The proposed antenna gives an impedance bandwidth of 60.37% from 3.71 to 6.91 GHz, confirming the wideband characteristics of the MED antenna. Furthermore, the antenna has achieved CP characteristics due to the insertion of I-shaped slots in an extended manner on both sides of the semicircular patches. The axial ratio is the ratio of two orthogonal components of the E-field in a given direction and is often used for the antennas in which the desired polarization is circular. The circularly polarized waves can be generated when two orthogonal E-field components with equal amplitude but with in-phase quadrature are radiated. The acceptable value of the axial ratio is less than 3 dB for the patch antennas [39]. Figure 8.35 presents the variation of the measured and simulated AR values with the frequency. It is seen from the figure that a 3 dB AR bandwidth of 20.60% in the frequency range of 3.71 and 4.55 GHz is achieved in the simulation.
A Low-Profile and Compact Multi-Functional ENG-TL Inspired Antenna with Hybrid Polarizations for LTE/UMTS, WiMAX, and WLAN Applications
Published in IETE Journal of Research, 2022
Raghvenda Kumar Singh, Ashish Gupta
After optimizing every geometrical parameter, the prototype of the proposed antenna is fabricated using standard printed circuit board technology. Consequently, its reflection and far-field attributes are measured by connecting 50Ω SMA connector to it. Reflection measurements are conducted using S820E (1 MHz–30 GHz) Anritsu handheld vector network analyzer. The snapshot of the developed antenna prototype along with the testing setup is portrayed in Figure 8. Figure 9(a) shows that this antenna is working over 2.42–2.50 GHz, 3.29–3.59 GHz and 5.43–5.55 GHz exhibiting −10 dB bandwidth of 3.25% at 2.46 GHz, 8.72% at 3.44 GHz and 2.18% at 5.49 GHz. It can be noted that the experimental curve of the input reflection coefficient is following well with the simulated one; however, the measured resonant frequencies are found slightly on the lower side. The reason for this inconsistency could be permittivity tolerance, imperfect fabrication or manual soldering of SMA connector to the feed line. The axial ratio is measured using the rotating-source method [24]. The measured axial ratio is compared with the simulated one in Figure 9(b). It can be observed that the 3-dB AR band expands from 3.26 to 3.54 GHz (8.28% at 3.38) with an axial ratio of 1.12 dB at 3.38 GHz. The measured CP bandwidth is obtained as 250 MHz (3.29–3.54 GHz), which corresponds to 7.26% at 3.44 GHz.
Micro-strip antenna with high bandwidth, cone pattern, circular polarization, and slit
Published in Electromagnetics, 2019
Jafar Khalilpour, Milad Nosrati
In the antennas with circular polarization, an axial ratio which indicates the circularity of polarization in the frequency range is quite significant and plays an important role in practical use. The simulation and measurement results of the axial ratio are shown in Figure 7. According to this figure, the amount of AR is 0 dB in central frequency. Therefore, the two perpendicular components of the electric field have the same amplitude. In other words, polarization is circular because there are two perpendicular electric field components with equal amplitude and 90º phase difference between them. This figure also shows that the maximum 3 dB bandwidth of axial ratio is obtained in angle θ = 40°. This maximum value of bandwidth is about 17.6% at the frequency of 2.2 GHz. Also, this figure shows a good agreement between simulation and measurement results.
Circularly Polarized Dual Band Dual Slot Antenna for WLAN, Wi-MAX and Wi-Fi Applications
Published in IETE Journal of Research, 2023
Penchala Reddy Sura, M. Sekhar
The acceptable values of the axial ratio are below 3 dB value. The plot of the axial ratio of the proposed dual slotted dual band CP antenna is displayed in Figure 4. The measured axial ratio value of the intended antenna over the dual bands is below 3 dB. The performance of the given antenna is good in the point of view of axial ratio.