A waveguide broad-wall transverse slot linear array with reflection- canceling inductive posts and grating-lobe suppressing parasitic dipoles

A design of a linearly-polarized non-resonant waveguide broad-wall transverse slot linear array with suppressed grating lobes is presented. Each unit element in the array consists of a transverse slot, an inductive post and a parasitic dipole-pair at a height of half of the free space wavelength. It is designed as an isolated unit without considering mutual coupling by using the Method of Moments (MoM) for radiation suppression in grating beam direction and reflection cancellation at the input. The elements thus designed are used in a travelling wave array environment. It is predicted that the reflection is less than -20 dB at 11.95 GHz while the grating lobes are suppressed by more than 15 dB. The design and the characteristics of the array are confirmed by measurements.