宽带等角螺旋天线设计Log-Spiral antenna from 2 to 40 GHz with impedance matching Petr Piksa Department of Electromagnetic Field, Faculty of Electrical Engineering, Czech Technical University in Prague, Technick a 2, 166 27, Prague 6, Czech Republic Phone: +420 2 2435 2275, Fax: +420 2 3333 9958, E-mail: piksap@fel.cvut.cz Abstract The designed antenna consists of the logarithmically spiral stripline antenna and wideband transformer from 50 to 150 . This antenna is suitable as a wideband iluminator for a parabolic reector working in the range 2 to 40 GHz. INTRODUCTION The spiral consists of two identical arms which are shifted about 180 with respect to each other. The curves of the arms are described by the function r = r0 ea(φ+) (1) where r0 is the distance at φ = 0, a determines the increasing rate of r and ……