Design of an all-textile circular patch antenna with corrugated ground for guided wave along the body surface for WBAN applications

Abstract

An all-textile circular patch antenna with corrugated ground for guided wave along the body surface is proposed. The proposed antenna consists of center-coupled-fed circular patch and thread-corrugated ground. The thread-corrugated ground, made of conductive sewing threads, acts as an inductively reactive surface to support a body surface TM mode wave. The proposed antenna with a thickness of 7mm (0.14 lambda(0) at 6GHz) operates in the 6-GHz band. Considering a practical on-body application, the proposed antenna is fabricated using all-textile materials, such as conductive fabric, conductive threads, fabric substrate, and conductive epoxy. To evaluate the human body effect, a two-thirds muscle-equivalent semi-solid phantom is utilized. The measured 10-dB return loss bandwidth of the antenna on the phantom is 9.5%, which ranges from 5.77 to 6.34GHz. The gain enhancement on the phantom surface (theta=90 degrees) is 8.65dB from -8.1 dBi for the antenna without a corrugated ground to 0.55 dBi for the antenna with a thread-corrugated ground.