Circuit Modeling and Analysis of Wearable Antennas on the Effect of Bending for Various Feeds

The promising utilization of wearable antennas has experienced gigantic growth during the last decade. An antenna is one of the most significant and crucial components of wireless wearable devices. They need to be particularly designed to work while worn on and off the body. The wearable antenna embedded into clothing finds its use in wireless communications including tracking and navigation, mobile and wearable computing, and public safety and security. For user accessibility, there is a growing requirement for incorporating antennas on or in clothing. Determining the dielectric characteristics of the flexible substrates utilized in the design of the wearable antenna is also essential. In this paper, a Microstrip Ring Resonator (MRR) is employed to determine the dielectric properties of fabric substrates followed by state-of-the-art designs of wearable antennas and their bending effects at ISM band frequencies. An electrical equivalent model is designed to realize the potentials inside the geometry of an antenna under bending environment. This is followed by observing the effect of bending for different feeding methods on the wearable antenna's parameters when bending on a certain radius. The robustness of the proposed wearable antenna is examined by measuring the antenna under various bending curvatures for return loss, gain, and efficiencies. This will disclose the various contemplations for designing a wearable antenna from different feeding mechanisms with different materials and exemplifying the antenna's outcomes to dynamic moments of the human body. The performance of the proposed wearable antenna is acceptable even in a deformation environment, and there is a good agreement between the measured and the simulation results.