Fig. 10

Bending analysis of proposed antenna at different diameters. The flexible nature of the proposed antenna is presented in a, b. The proposed antenna weighs 3.36 g only as shown in c, demonstrating both the lightweight and low-profile characteristics of the fabricated antenna. To understand the bending feasibility, the antenna is wrapped over the hollow cylindrical PVC pipe of diameter 22 mm and 48 mm as shown in d, e, respectively. The return loss characteristic (S₁₁) plotted in f represents the comparison of results obtained for bending over the hollow PVC pipe of diameter 22 mm and 48 mm. The result shows a maximum value of S₁₁ as − 39.22 dB for bending with a small diameter; however, it gives the bandwidth of 8.47 GHz below − 10 dB with a slight shift in starting frequency, whereas in the case of large diameter, it is observed that the proposed antenna has functioned very well with a maximum value of S₁₁ as − 37.03 dB around 3.365 GHz and maintained the frequency response below − 10 dB in the range of 2.65 GHz to 12 GHz. The response of the antenna for a smaller diameter in terms of S₁₁ value is degraded to some extent when it is compared with a large diameter