Comparison of three series fed microstrip array geometries

The authors describe three different design approaches for series-fed broadside microstrip arrays having a center feed point. The first array uses a standard standing-wave feed design, but with the novel feature that the patch width is varied in order to obtain the desired amplitude taper. The second design also uses patches of varying widths, but the main feed line is designed to be matched at each patch tap point. The third array uses a center-fed feed network with each half of the array designed as a traveling-wave array with a main beam angle slightly off broadside. As a comparative example, the authors have designed and tested a 16-element array with a 22-dB sidelobe level for each of the above designs. Patterns, bandwidth, gain, and directivity have been compared for the three designs.<>