Asymmetric ridge waveguide radiating element for a scanned planar array

A brief description is given of a linear array radiating element for use in a large low-sidelobe scanned X-band planar slot array. The planar array is comprised of many vertical resonant linear array elements (waveguides with broad wall shunt slots) each fed from a phase shifter for electronic scan. The authors emphasis is on a technique for placing all slots of the linear arrays precisely on a common centerline. The design used results in an all-metal design. That is simple to fabricate, and eliminates the secondary grating lobes of the staggered slot array design which appear when the array is scanned.<>