Research On The Miniaturized Broadband And Multi-band Planar Inverted-F Antenna

Nowadays, the requirements of miniaturized, broadband and multi-band on antennas used for communication terminals have been proposed, due to the rapid development of mobile and personal communication technologies. Planar inverted-F antenna coming out during these years has been rapidly and widely adopted because it has the outstanding structural properties of small size, light weight, low profile, internally equipped, easily fabricated and easily mounted on the carrier. Besides, it can implement the properties of broadband and multi-band.Based on the basic principles of the PIFA antenna, a compact internal wideband PIFA and a novel dual ISM-band PIFA are presented respectively with the help of the commercial electromagnetic simulation software. Good agreement between the measurement and simulation results can be observed, which indicates that the antennas reported in this thesis are practical.The main work and creative points of this thesis can be summarized as follows:1. Make a detailed description on many configurations of different kinds of PIFA antennas based on every part of the PIFA antenna. The principal characteristics and analysis methods are introduced. Meanwhile, the miniaturized, broadband and multi-band technologies about the microstrip antenna are analyzed and summarized.2. A single-layer single-patch wideband PIFA with a very low profile for mobile terminals is proposed. The relative bandwidth is obviously larger than those of the existing similar structural antennas and reaches 85%. The presented PIFA can cover the frequency bands of DCS,PCS,WCDMA,UMTS,WiBro,Bluetooth and DMB, simultaneously. The return loss, voltage standing wave ratio, radiation patterns, peak gain and current distribution of the presented wideband PIFA are analyzed and discussed. In addition, the antenna is fabricated and tested. The measured results agree well with the simulated results..3. A novel compact dual-band PIFA for WLAN terminals is proposed. The antenna can cover the frequency bands of WLAN applications defined by IEEE802.11a/b/g and HiperLAN2 protocols simultaneously. The return loss, voltage standing wave ratio, radiation patterns, peak gain and current distribution of the presented dual-band PIFA are analyzed and discussed. In addition, the antenna is fabricated and tested. Good agreement between the measurement and simulation can be obtained.4. The effects of the dimensions of the radiating element, the shorting method, the width of the shorting plate, the location of the feeding point, the feeding method and the ground plane are analyzed combining with the antennas presented in this thesis.