radiating element and feeding technique

Microstrip patch antenna has a radiating patch which is made by conductive materials like copper. On the other side there is a ground plane and between two planes we have dielectric. Radiating element and feed line are photo etched on the dielectric. In this paper rectangular shape was chosen. The length of element for rectangular form should be 0.3333λ0 < L <0.5λ0, and the thickness should be very thin t<< λ0 (λ0 is the free-space-wavelength).