Patent ID: 7994999

Claim:
A microstrip antenna comprising: a ground plane; a dielectric material having a predetermined thickness disposed on the ground plane; an inner radiating element disposed on the dielectric material, the inner radiating element having a predetermined outer perimeter and a first resonating frequency; an outer radiating element disposed on the dielectric material, co-planar with and at least partially surrounding the inner radiating element, the outer radiating element being spaced from the predetermined outer perimeter of the inner radiating element by a predetermined distance, the outer radiating element having a predetermined inner perimeter, a predetermined outer perimeter and a second resonating frequency different from the first resonating frequency of the inner radiating element; a first plurality of radiating apertures between a top edge of the predetermined outer perimeter of the inner radiating element and the ground plane; a second plurality of radiating apertures between a top edge of the predetermined inner and outer perimeters of the outer radiating element and the ground plane; a cross-shaped microstrip feed network disposed between and coplanar with the inner and outer radiating elements, the cross-shaped microstrip feed network being separated from the inner and outer radiating elements by a predetermined distance, the cross-shaped microstrip feed network being capacitively coupled to the inner and outer radiating elements and having a coupling capacitance between the feed network and the inner and outer radiating elements that is proportional to the predetermined distance between the cross-shaped microstrip feed network and the inner and outer radiating elements.