A four spiral slots microstrip patch antenna for radiotelemetry capsules based on FDTD

作     者：HUANG Biao YAN Guo-zheng LI Qian-ru 

作者机构：Department of Instrument Shanghai Jiao Tong University Shanghai 200240 China 

出 版 物：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 (浙江大学学报（英文版）A辑（应用物理与工程）)

年 卷 期：2007年第8卷第10期

页      面：1560-1567页

核心收录：

学科分类：080904[工学-电磁场与微波技术] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

基　　金：Project (No. 2006AA04Z368) supported by the Hi-Tech Researchand Development Program (863) of China 

主　　题：Finite-difference time-domain (FDTD) Microstrip patch antenna Specific absorption rate (SAR) Radiotelemetry capsule 

摘      要：Antenna is very crucial to radiotelemetry capsules which can measure the physiological parameters of the gastroin- testinal (GI) tract. The objective of this paper is to design a novel spiral slots microstrip patch antenna for the radiotelemetry capsules communicating with external recorder at 915 MHz located in ISM (Industry, Science, and Medical) bands. The microstrip patch antenna is designed and evaluated using the finite-difference time-domain (FDTD) method. Return loss characteristics and the effect of the human body on resonant frequency are analyzed, and the performances of radiation patterns at different positions of the human alimentary tract are also estimated. Finally, specific absorption rate (SAR) computations are performed, and the peak 1-g and 10-g SAR values are calculated. According to the peak SAR values, the maximum delivered power for the designed antenna was found so that the SAR values of the antenna satisfy the ANSI (American National Standards Institute) limitations.