FOLDED TRIPLE-FREQUENCY QUASI-YAGI-TYPE ANTENNA WITH MODIFIED CPW-TO-CPS TRANSITION

A novel side-feed quasi-Yagi type antenna capable of triple-frequency operation at about 1900, 2400 and 3600MHz is presented in this paper. The antenna is composed of a folded quasi- Yagi element and a modifled CPW-to-CPS transition. The proposed antenna can be mounted perpendicularly to the feed circuit board of an array antenna so that it ofiers a novel design with a free degree of feed point so as to save device space, and its folded quasi-Yagi element can result in a low proflle to the system. The experimental results demonstrate that the proposed antenna can operate over three frequency bands, with i10dB re∞ection coe-cient bandwidths of 200MHz, 200MHz, and 400MHz at the central frequencies of 1.9, 2.4, and 3.6GHz, respectively. Moreover, in the whole working bands, the antenna basically keeps the same radiation pattern and the gain is over 2.6dBi.