Optimization of Beam-Tilted Linearly Polarized Radial-Line Slot-Array Antennas

This letter investigates the performance of beam-tilting technique when applied to improve matching of linearly polarized radial-line slot-array antennas. The application of a full-wave analysis reveals a severe deterioration of radiation patterns even for small tilt angles. An iterative optimization procedure is proposed in order to restore the radiation performance in conjunction with the desired matching enhancement. Performance and limitations of the correction procedure are discussed in terms of the beam pointing direction. One prototype is fabricated, and measurements are reported to validate the conclusions of this letter.