Beam switched antenna design for jamming mitigation of legacy GPS receivers

We propose a low-cost solution for jamming mitigation of GPS by electronically switching antenna beam. Jamming signals are assumed to be directed from low elevation angles so that antenna rejection from zenith to low elevation must be improved by switching from wide angle half power beam width to a narrow one. Using low-cost, commercially available ceramic patches, four-element antenna array and its feed network are designed and one of the elements is designated as the normal (default) mode operation of the antenna. Proposed system can easily be replaced with existing active antenna to improve anti-jam capability of the receiver.