A circularly polarized multimode patch antenna with full hemispherical null steering for GPS applications

A novel multimode element was proposed based on concentric circular patch antenna elements supporting TM₁₁ and TM₂₁ modes. Using shorting vias, the need for symmetric feed arrangements are eliminated. This antenna maintains excellent CP within the main beam while supporting a null that can be scanned anywhere in the upper hemisphere. We are currently researching wideband implementations of this antenna and the use of additional patch modes. Additional results and related work will be presented during the symposium.