A Flat Low-Cost Slotted Waveguide Antenna Array

Slotted waveguide array antennas find application in many microwave communication and radar systems which require narrow-beam or shaped-beam patterns. They are particularly useful in airborne applications where a light weight and small volume are important. These antennas may be either resonant or nonresonant arrays of various narrow-wall and broadwall slot types /1/. Generally, for a broadside array with uniform phase a resonant array is selected as the standard solution. However, such a standing-wave array must be carefully matched and has a very limited bandwidth. To avoid these problems of standing-wave arrays a new solution is presented, which provides broadside radiadion in spite of a series-fed traveling-wave array. This technique is based on a special choice of the phase difference between adjacent elements and related modifications of slot positions for the considered fixed-beam application.