Analysis of frequency behavior of slot arrays

While slot arrays are usually designed at midband frequency, it is often useful to evaluate the input match bandwidth, beam deflection, and pattern distortion occuring when frequency changes. A perturbation method is presented here for analysing the frequency behavior of arrays of longitudinal slots fed by an air-filled or dielectric-filled rectangular waveguide. The two examples discussed, a resonant array and a traveling wave array show good agreement between experimental and theoretical results, and give an insight into the severe frequency limitations on slot arrays.