antenna-theory.com

[bacurrie45]

Hi I am new to the site but find it very useful. I am currently doing a master's project where i have to make a number of designs for a log spiral antenna and an archimdean spiral antenna. My upper frequency is 1 GHz and my lower frequency is 300 MHz and the antenna will have two arms once designed the antennas will be put on to a printed circuit board. In the following two equations what confuses me is what is phi? what does it start at and how do i calculate it? is it the winding angle?. i then understand this angle is rotated through pi/2 to be self complementary. Also in some text books it states r is a polar coordinate so once i calculate r do i need to convert it Any help would be appreciated.

r=Roe^aᶲ
r=aθ