Title :
Realization of wideband characteristics for a spiral antenna backed by a conducting plane reflector
Author :
Nakano, H. ; Soga, H.
Author_Institution :
Coll. Eng., Hosei Univ., Tokyo, Japan
Abstract :
It is shown that backing a spiral antenna with a conducting plane reflector narrows the inherent wideband radiation characteristics of the spiral by distorting the current distribution. When a small, circular conducting plane is inserted between the spiral and the plane reflector, the distorted current distribution can be changed to a traveling wave. This traveling-wave current has a decaying amplitude, leading to a desirable radiation beam of good circular polarization. The frequency band for CPW (circularly polarized wave) radiation can be extended from 1:1.18 without the small disk 1:1.42 with the disk.<>
Keywords :
antenna radiation patterns; antenna reflectors; electromagnetic wave polarisation; microwave antennas; EM wave polarization; circular polarization; conducting plane reflector; decaying amplitude; distorted current distribution; small disk; spiral antenna; traveling-wave current; wideband radiation characteristics; Arm; Broadband antennas; Current distribution; Frequency; Image analysis; Image restoration; Moment methods; Polarization; Reflector antennas; Spirals;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1989. AP-S. Digest
Conference_Location :
San Jose, CA, USA
DOI :
10.1109/APS.1989.134953
