Design of W-Band Dual Polarized Slotted Waveguide Array Antenna on an Annular Disk

This paper describes the design of a W-band dual polarized slotted waveguide (WG) array antenna. The slotted WG array is arranged on an annular disk, and so the feeding technique for this annular slotted WG array is more complicated than a regular array such as rectangular array. Broad wall longitudinal offset slot WG and edge wall inclined slot WG are staggered in turn to form the dual polarized array. In order to reduce the spacing between two adjacent WGs, ridged WG is adopted for designing broad wall longitudinal offset slot array. For making the beam width equal in two orthogonal principal planes, parameters of the WGs are carefully selected to ensure that the spacing between longitudinal adjacent slots is equal to that between transverse adjacent slots. The feeding networks for the annular disk WG array are carefully designed in irregular shapes, which can split electromagnetic waves to each WG (of the array) in phase. Finally, the antenna is processed and tested. Simulated results and measured results are presented. Measured gains of the horizontal polarization (HP) and vertical polarization (VP) are 35 dBi and 31.5 dBi, respectively, and efficiencies of the HP and VP are 56% and 28%, respectively, estimated from the measured gains and the calculated directivities.