THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. 2014 May; 25(5), 491 503. http://dx.doi.org/10.5515/KJKIEES.2014.25.5.491 ISSN 1226-3133 (Print) ISSN 2288-226X (Online) 491 TM 31 - Design of a TM 31 Higher Order Mode Half Circular-Ring Microstrip Patch Antenna for On-Body Communications 탁진필 전재성 김선우 최재훈 Jinpil Tak Jaesung Jeon Sunwoo Kim Jaehoon Choi 요 약 TM 31 - . TM 31 , . TM 31 C- , half mode . . ISM(Industrial, Scientific, and Medical) 2.45 GHz (2.4 2.485 GHz) 0.25 λ 0 ×0.46 λ 0 ×0.025 λ 0 , 2.38 2.49 GHz 4.24 % 10-dB . 2/3 - , , . , . Abstract In this paper, a TM 31 higher order mode half circular-ring microstrip antenna with monopole-like radiation characteristic for on-body communication is proposed. By using shorting vias, TM 31 resonance mode was excited, while achieving compact low-profile antenna with monopole-like radiation characteristics. To overcome the narrow bandwidth of a patch antenna, a C-shape half ring patch with shorting vias having TM 31 mode is closely located around a half circular patch. For size reduction, half mode is adopted. The proposed antenna has the overall dimensions of 0.25 λ 0 ×0.46 λ 0 ×0.025 λ 0 at the industrial, scientific, and medical(ISM) 2.45 GHz band(2.4 2.485 GHz) and the 10-dB return loss is 4.24 % ranging from 2.38 to 2.49 GHz. To verify body effect, two-thirds muscle equivalent semi solid phantom was fabricated and used to measure the antenna performance. A communication link is analysed to investigate the effect of human-body movements and antenna locations. Key words: Circular-Ring Microstrip Patch, On-Body, TM 31 Mode, Monopole-Like Radiation Pattern  2013 (ICT) . (Department of Electronics and Computer Engineering, Hanyang University) Manuscript received December 26, 2013 ; Revised February 5, 2014 ; Accepted February 10, 2014. (ID No. 20131226-131) Corresponding Author: Jaehoon Choi (e-mail: choijh@hanyang.ac.kr) . 서 론 , WBAN(Wireless Body Area Network) . ⓒ Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved.