Effects of tolerances on sidelobe levels in slotted waveguide arrays

Fabrication tolerances are known to affect the electrical performance of slotted waveguide arrays. The effects on sidelobe level, pointing angle and gain is studied by introducing systematic and random errors in slot offsets, slot lengths and waveguide dimensions in the radiating layer of the array. A similar study was done by introducing errors in slot inclination angle, slot lengths and waveguide dimension in the coupling layer. The study was also extended for analyzing the patterns away from resonance. The analysis helps to quantify the tolerance requirements on the critical dimensions of the slotted waveguide arrays. The results of analysis for Ku-band and Ka-band designs are presented as examples to support our conclusion.