Mario wrote:
"I have to write a seminar which subject is Patch Antenna."

The 3rd edition of "Antennas For All Applications" by Kraus et al is
available in paperback from Mc Graw-Hill.

It has dimensions, construction, action, impedance. drawings, diagrams,
directivity, effective height, bandwidth (attributed to Jackson and
Alexopolus), matching to microstrip, arrays of patches, bibliography of
microstrip antennas, directional patterns of some arrays, and a
comparison of a 4-patch CP array with the axial-mode helix (a Kraus
invention) (see page 328).

Best regards, Richard Harrison, KB5WZI