Performance analysis of an all-dielectric planar Mikaelian lens antenna for 1-D beam-steering application

This paper investigates the performance of an all-dielectric planar Mikaelian lens based on ray transfer matrices and full-wave analysis for 1-D beam-steering application. This new lens concept has its intrinsic flat shape characteristic allowing for a simple low-cost planar feed technology. To verify the design concept, a lens prototype excited by five rectangular microstrip patch antennas with perforated structure (21×24 holes) is fabricated using stereolithography (SLA) 3-D printing. The simulated and measured results of the proposed lens prototype, operating at 10 GHz, shows that the switched-beam coverage over a certain range of beam-steering angles can be obtained. The intrinsic phase error of lens resulting from comatic aberration exhibits obvious increase as the off-axis angle of beam increases, which leads to further deterioration of the corresponding radiated beam. The beam-steering capabilities from -20° to +20° with around 13.2 dBi of realized gain and side-lobe level (less than -11.5dB), and up to potential steering angles (±30°) with around 10 dBi of realized gain can be steadily achieved. Moreover, the realized gain, efficiency and side-lobe level can be further improved to get better radiation performances by using other materials with lower loss tangent. Due to its intrinsic flat shape characteristic, this lens concept could be a potential alternative to develop a low-cost, low-profile and easy-to-fabricate beam-switching array antenna for microwave communication applications.