Title :
A low-profile spiral antenna array above an EBG reflector
Author :
Nakano, H. ; Hitosugi, K. ; Huang, P. ; Mimaki, H. ; Yamauchi, J.
Author_Institution :
Coll. of Eng., Hosei Univ., Tokyo, Japan
Abstract :
A spiral antenna array with an EBG reflector is analyzed using the FDTD method and the radiation characteristics are discussed, where the number of array elements is chosen to be four. It is emphasized that the antenna height above the surface of the EBG reflector is smaller (0.06 wavelength) than the antenna height for conventional spiral arrays above a PEC reflector (0.25 wavelength). The spiral arms are optimized to obtain CP wave radiation, taking into account mutual coupling among the four spirals. It is found that the array shows a frequency bandwidth of approximately 17% for a 3-dB axial ratio criterion. Within this axial ratio bandwidth, the impedance shows a relatively constant value and the gain reaches a maximum value of 16.1 dBi.
Keywords :
antenna arrays; antenna radiation patterns; electric impedance; electromagnetic coupling; electromagnetic wave polarisation; finite difference time-domain analysis; photonic band gap; reflector antennas; spiral antennas; EBG reflector; FDTD method; PEC reflector; antenna height; axial ratio; axial ratio bandwidth; circular polarisation; frequency bandwidth; gain; impedance; mutual coupling; radiation characteristics; radiation pattern; spiral antenna array; Antenna arrays; Arm; Bandwidth; Finite difference methods; Frequency; Impedance; Mutual coupling; Reflector antennas; Spirals; Surface waves;
Conference_Titel :
Antennas and Propagation Society International Symposium, 2005 IEEE
Print_ISBN :
0-7803-8883-6
DOI :
10.1109/APS.2005.1552162
