Abstract: An antenna assembly includes a conducting ground plane, a single dielectric substrate layer or a plurality of dielectric substrate layers each with different dielectric constants mounted to the conducting ground plane. A central patch element is mounted to the dielectric substrate layer or layers and configured to radiate within a first frequency band. A plurality of probes (i) extend through the conducting ground plane and the dielectric substrate and (ii) are physically connected to the central patch element. A parasitic ring is disposed around the central patch element and reactively coupled thereto. The parasitic ring is configured to radiate within a second frequency band.

Abstract: A spatial null steering microstrip antenna array comprising two concentric microstrip patch antenna elements. An inner circular antenna is used as an auxiliary element in nulling interference received by an outer annular ring antenna disposed around the inner antenna. The outer annular antenna is resonant in a higher order mode but forced to generate a right hand circularly polarized lower order (TM11) far field radiation pattern, thereby allowing co-modal phase tracking between the two antenna elements for adaptive cancellation. Each antenna element is appropriately excited by symmetrically spaced probes. Other applications of the antenna array include GPS multipath suppression, simultaneous satellite and terrestrial communications, and co-site interference suppression. Dual frequency band applications are achieved by stacked array configurations.

Abstract: A spatial null steering microstrip antenna array comprising two concentric microstrip patch antenna elements. An inner circular antenna is used as an auxiliary element in nulling interference received by an outer annular ring antenna disposed around the inner antenna. The outer annular antenna is resonant in a higher order mode but forced to generate a right hand circularly polarized lower order (TM11) far field radiation pattern, thereby allowing co-modal phase tracking between the two antenna elements for adaptive cancellation. Each antenna element is appropriately excited by symmetrically spaced probes. Other applications of the antenna array include GPS multipath suppression, simultaneous satellite and terrestrial communications, and co-site interference suppression. Dual frequency band applications are achieved by stacked array configurations.