Archimedean spiral antenna loaded with dielectric plates

This work presents the design and simulation of a 6 GHz to 13 GHz Archimedean spiral antenna loaded with dielectric plates. Two dielectric plates separated by an air gap placed precisely on the Archimedean spiral antenna. The dielectric plates are made up of FR-4 dielectric material (dielectric constant 4.3 and loss tangent 0.025). It is found that, after the placement of the dielectric plates, directivity of the Archimedean spiral antenna has been increased in the entire operating bandwidth, especially in the high frequency range without 3dB axial ratio disturbance. The analysis of the radius and air gap between Dielectric plates is also given.