An Ultrawideband Capsule Antenna for Biomedical Applications

This letter presents a symmetrical dual-loop antenna with ultrawideband performance and operating in the Industrial Scientific, and Medical (ISM, 2.4-2.4835 GHz) band for use in wireless endoscopy applications. The antenna is composed of two identical loops located symmetrically around the center, a feeding patch at the center of the feeding loop, and a parasitic patch connected to another loop. A simulated ultrawideband of 143%, ranging from 1.11 to 6.03 GHz, can be achieved in the ISM band by adding two rectangular patches at the center of these two loops and rotating the feeding direction by 90°. Finally, the proposed antenna is measured in pork, and a measurement bandwidth of 124% is obtained.