volume | PIER Journals

Abstract

Growing demand for conformal, on-body communication systems has driven the development of compact, mechanically flexible, and conformal antennas. However, the reported literature on flexible dielectric resonator antennas with systematic conformal analysis is limited. This research gap has motivated the present investigations. The study aims to assess the comprehensive conformal analysis of a flexible cylindrical dielectric resonator antenna (CDRA) designed for X-band (operating near 10 GHz). The proposed antenna is bent over cylindrical and conical surfaces with radii of 40 mm and 30 mm, respectively. The conformal configurations are analyzed to evaluate performance and subsequently validated through experiments. The planar antenna resonates at 10.5 GHz, with a measured gain of approximately 5.2 dBi and a bandwidth of 450 MHz (10.27-10.72 GHz). The simulated results showed a downward frequency shift for both cylindrical and conical bending environments compared to the planar configuration. At the same time, the prototype measurements demonstrated an upward shift in the frequency of cylindrical bending of the antenna with increasing curvature, due to material-dependent properties. In contrast, the antenna undergoes non-uniform geometric deformation and strain-dependent permittivity behavior during conical bending. This leads to a downward shift in frequency and significant variations in radiation characteristics. Despite deformations, a stable broadside radiation performance and practically viable gain levels were achieved, with an overall bandwidth of 10.26-11.2 GHz. In addition, a specific absorption rate (SAR) analysis confirms the antenna's compliance with general public exposure safety limits, with a maximum SAR peak of 1.26 W/kg for 10 g averaged mass, in accordance with safety standards. The conformal analyses, along with the SAR validation for compact (less than 2 mm) and fully flexible CDRA, substantiate the novelty of the present study. Hence, the proposed antenna maintains a reliable performance under various bending conditions, highlighting its suitability for flexible, conformal, and wearable X-band applications.

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Ms. Amera Anjum

Dr. Jagadish Chandra Mudiganti