Systems, apparatus and methods for transmitting and receiving electromagnetic radiation

A dual mode patch antenna is described herein. The dual mode patch antenna includes an active patch mounted on a first substrate, the active patch having two orthogonal ports located on corresponding X, Y axes of symmetry intersecting at an axis zero located at a center of the active patch, the two orthogonal ports creating a dual mode coupling vector. The dual mode patch antenna also includes a passive patch positioned on top of the active patch, the passive patch mounted on a second substrate, a ground plane positioned below the first substrate, and a conductive boundary wall defining a boundary around the patch antenna, the conductive boundary wall contacting the ground plane below the active patch. The conductive boundary wall includes a compensating dual mode discontinuity that creates a cancelling vector equal in amplitude to the intrinsic, built-in dual mode coupling vector to improve cross-pol attenuation and/or port-to-port isolation of the antenna.