Title :
A broadband plate antenna with slits
Author :
Noguchi, Keisuke ; Mizusawa, M. ; Matsutani, Hiroshi ; Betsudan, S.
Author_Institution :
Div. of Electr. Eng. & Electron., Kanazawa Inst. of Technol., Ishikawa, Japan
Abstract :
As a small antenna of handsets for personal communication systems, a two-strip meander-line antenna and a normal mode helical antenna have been suggested. The values of quality factors of both antennas are from 20 to 30 when the size of the antennas are smaller than 0.1 wavelength. The quality factor Q is really important to evaluate the bandwidth of an antenna. The bandwidth is in inverse proportion to Q. Therefore, if the quality factor can be small, the bandwidth becomes broadband. A plate antenna whose quality factor is smaller than those of the meander line antenna and the normal mode helical antenna can be obtained with broadband characteristics. In order to realise the impedance matching, the antenna consists of two plates, and the currents of the two plates are produced in imbalance and balance modes. In this paper, the small plate antenna with slits is treated. The impedance characteristics of the antenna is made clear and increasing the bandwidth by using two plates is also discussed.
Keywords :
Q-factor; helical antennas; impedance matching; mobile antennas; personal communication networks; telephone sets; VSWR; antenna size; bandwidth; broadband plate antenna; handsets; impedance characteristics; impedance matching; input impedance; normal mode helical antenna; personal communication systems; quality factor; slits; two-strip meander-line antenna; wavelength; Bandwidth; Broadband antennas; Equations; Equivalent circuits; Helical antennas; Impedance; Q factor; Resonance; Resonant frequency; Surface resistance;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1999. IEEE
Conference_Location :
Orlando, FL, USA
Print_ISBN :
0-7803-5639-x
DOI :
10.1109/APS.1999.789297
