Title :
Spiral antenna with frequency-independent coplanar feed for mobile communication systems
Author :
Gschwendtner, E. ; Parlebas, J. ; Wiesbeck, W.
Author_Institution :
Inst. fur Hochstfrequenztech. & Elektron., Karlsruhe Univ., Germany
Abstract :
The spiral antenna investigated in this contribution is a four-arm spiral antenna, that is fed with a coplanar transmission line. The frequency independent characteristics of the structure are maintained and the feeding structure itself, that does not need any kind of balun, is also frequency independent. The radiation pattern is not that of a conventional two-arm spiral with differential feed but an omnidirectional pattern with a null in the zenith. The measured bandwidth is more than 5:1, therefore it is suitable for a mobile terminal for the coverage of several communication services at one time such as GSM, DCS1800, DECT and UMTS.
Keywords :
UHF antennas; antenna feeds; antenna radiation patterns; coplanar transmission lines; land mobile radio; microwave antennas; mobile antennas; spiral antennas; 1.5 to 10 GHz; DCS1800; DECT; GSM; UMTS; bandwidth; coplanar transmission line; four-arm spiral antenna; frequency-independent coplanar feed; mobile communication systems; mobile terminal; omnidirectional pattern; radiation pattern; spiral antenna; Antenna feeds; Antenna radiation patterns; Bandwidth; Coplanar transmission lines; Frequency; Impedance matching; Mobile antennas; Spirals; Time measurement; Transmission line antennas;
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.1999.789201
