Cylindrical Luneburg Lens Antenna Loaded with Printed Loops for Side lobe Level Reduction

A 26-GHz cylindrical Luneburg lens antenna loaded with printed metal loops for low side lobe level is proposed in this paper. The microwave generated by the feeding waveguide is focused in the E-plane. 6-shell technology is utilized for the lens design. In the H-plane, the lens functioned as a loading dielectric and thus a radiation pattern with high side lobe level occurs. Proposed printed loops affect the H-field distribution of the antenna and through the loops, radiation pattern in H-plane could be adjusted in certain degree. With suitable size for the loading loops, the side lobe level reduction of approximate −8.5 dB will be realized in the H-plane radiation pattern at 26 GHz for the cylindrical lens antenna.