Microstrip antenna

Claim 1

A microstrip antenna for radiating or detecting electromagnetic signals having a wavelength λo comprising: a dielectric sheet of relative dielectric constant ε r , relative permeability μ r and uniform thickness t having a. on a first broad surface 1. at least three thin conductive resonant dipole radiator elements, each radiator element having two orthogonal coordinates that respectively define E and H planes of electromagnetic radiation for said radiator element, with the E plane coordinate dimension of each radiator element being approximately one-half the dielectric wavelength λo/√ε r μ r ; 2. said radiator elements conductively joined by thin conductive strips into an array or arrays of at least two radiator elements; and 3. a terminal for connecting each array to a transmission line, b. on the other broad surface an essentially continuous thin conductive ground element more than coextensive with the radiator elements which defines a radiation aperture; wherein the improvement comprises: a. said conductive strips comprise one or more bridge elements, each bridge element having a length providing approximately a phase reversal from end to end at the operating wavelength λo, each bridge element conductively joining two adjacent radiator elements in the same array at edges of approximately opposite phase, the width of each bridge element being less than the H coordinate dimension of one of the radiator elements it joins and less than one-half the H coordinate dimension of the other radiator element it joins, and in each array a bridge element is conductively joined to the periphery of a radiator element at a location that is opposite in phase to a location on said radiator element where said terminal or another bridge element is connected; and b. said terminal for connecting each array to a transmission line is located on a radiator element off the element's H coordinate.