Design and Validation of Loop-Based Ultraminiature Low-Profile Ultrawideband Capsule Antenna Inside Wistar Rat
Rakesh N. Tiwari, Deepti Sharma, Prabhakar Singh, Vikrant Kaim, Taimoor Khan, Binod Kumar Kanaujia
Abstract
In this communication, a modified loop-based ingestible capsule antenna is presented with a small footprint of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi \times (3.5)^{2} \times 17$ </tex-math></inline-formula> mm3 for a wireless ultrawideband (UWB) endoscopy system. In a homogeneous muscle phantom, the proposed capsule antenna exhibits a frequency band ranging from 0.560 to 10.6 GHz. The in vivo measurement is carried out by implanting the capsule antenna inside the stomach of the Wistar rat. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert \text {S}_{11} \vert $ </tex-math></inline-formula> results are compared when the capsule antenna is placed in a homogeneous phantom model and inside minced pork. The capsule antenna performance in the different organs of the digestive tract is studied using a 3-D human body voxel using CST Microwave studio simulator. The omnidirectional radiation patterns of the proposed design ensure that it is a suitable candidate for endoscopy communication. This antenna is applicable for industrial, scientific, and medical (ISM) 0.915 GHz, wireless medical telemetry services (WMTS) 1.4 GHz, ISM 2.45 GHz, and 3.1–10.6 GHz (UWB) frequency range.