A tapered loop antenna with broadband characteristics for ultra-wideband radio

In recent years, radio communication using ultrawideband (UWB) technology has shown great promise for healthcare and medical applications. Although many UWB antennas have been investigated and developed by several research institutes so far, it is difficult to find a loop type of antenna with broadband characteristics covering UWB frequency band. A loop antenna can be useful and effective component used in wristwatch and bracelet typed devices for the healthcare, because it is easy to build in them. In this paper, a loop type of the UWB antenna was proposed and investigated. The Finite Difference Time Domain method was used for the electromagnetic analyses of the antenna characteristics. As a result, the VSWR characteristics of the proposed antenna were less than 2.0 over the UWB frequency band enough in practical use.