Radiation characteristics of small slot antenna for wristwatch-type pager worn on human body

✍ Scribed by Yoshinobu Okano; Koichi Ito

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 195 KB
• Volume: 83
• Category: Article
• ISSN: 8756-6621
• DOI: 10.1002/(sici)1520-6424(200009)83:9<93::aid-ecja10>3.0.co;2-g

✦ Synopsis

In recent years, the demand for compactness in portable radios has become increasingly stronger. This trend is more significant in pagers, and wristwatch-type pagers have been commercialized. In this article, a small slot antenna to be installed in the watchband is investigated. Since the present antenna is used in close proximity to the human body, human models for both theoretical and experimental studies are created taking into account the human body as part of the antenna structure, and the radiation characteristics of the small slot antenna actually worn on the human body are measured and calculated. It is found that a gain of about 15 dBd can be obtained even when the antenna is worn on the human body, and this is enough compared to the gain of 30 dBd required in the antenna for pagers. The radiation pattern variation due to the position change of the user is also investigated, and the radiation patterns are measured and calculated for various positions. It is found that good radiation characteristics as an antenna for pagers can be obtained even considering the arm position variation of users.