Patch antenna

Microstrip antenna for transmitting or receiving waves of wave-length λ comprising:

• a first insulating plate and a first metallization effected on one face of said plate covering a part of said first plate to form a ground plane,
• a second insulating plate and at least a second metallization effected on one face of said second plate and presenting dimensions smaller than those of the first metallization, said second plate comprising a peripheral zone surrounding said second metallization over a width substantially equal to λ/10, corresponding to a region where the amplitude of the electromagnetic field created by the periphery of said second metallization is maximum, said second plate being provided with recesses in at least a part of said peripheral zone, solid portions separating said recesses in order to ensure a mechanical connection between that portion of said second plate bearing the second metallization and the rest of said second plate;
• at least one feedline connected to said first and second metallizations, and
• spacer means fastened with the two plates in order to maintain the two plates in a predetermined relative position so that the two metallizations face each other and the second metallization is opposite the first.