Low-Profile Strip-Loaded Textile Antenna With Enhanced Bandwidth and Isolation for Full-Duplex Wearable Applications

A novel dual-port textile antenna with a low profile and enhanced bandwidth is proposed for 2.45 GHz IMS-band full-duplex wearable applications. The antenna is developed on a textile material by using an advanced screen-printing technology and, thus, exhibits a very good structural flexibility and a high manufacturing accuracy. To improve the bandwidths at the two input ports, an innovative method is introduced for the first time where two additional strips are incorporated into the antenna design. These additional strips are placed perpendicularly to the feed lines to generate another resonant frequency, which is then combined with the fundamental mode of the patch antenna, producing the second-order resonant properties with enhanced bandwidths. The proposed strips are also beneficial to significantly improve the isolation between the two channels/ports. To maintain a robust linkage, a study of structural deformation is carried out by bending the antenna along both the 0° and 45° directions. The experimental results also show that the antenna is robust to the human tissue loading, where the specific absorption rate (SAR) is lower than 0.37 W/kg when the antenna is fully attached. The measured results agree reasonably well with the simulations providing experimental verification of the design concept. The antenna is believed to be the first dual-mode textile antenna of its type which features a low profile, improved bandwidth, high isolation, and low cost, making it a good candidate for potential full-duplex wearable applications.