square planar loop antenna design.

hi.i have to design a square planar loop antenna.however, i dont know what is the mathematical equation used to design it.the antenna dont have a ground plane. what i know is the design is like a folded dipole.i also confused how to feed the the antenna with 50 ohm line impedance.please help me.thank you.

Size matters. Large loops (circumference ≈ λ) act like dipols, small loops are pure magnetical antennas with low radiation resistance. See http://en.wikipedia.org/wiki/Loop_antenna for the differentiation. A impedance matching network will be required to connect to a 50 ohms line.

thanks a lot.i want to know,for microstrip patch antenna,there are specific formula to find the width and length of the patch.so how about the loop antenna?is there any specific formula to find the width of the line?i mean for the feeding.also hor to calculate the gap between each feeding line?