A Ground-Plane-Truncated, Broadly Steerable Yagi–Uda Patch Array Antenna

A low-profile, broadly steerable, and reconfigurable array antenna with parasitic patches is proposed and investigated in this work. For patch-type antenna arrays, improvement of the beam-scanning range using parasitic patches is very limited. The typically achieved scanning range is between -30° and +30° from the broadside. Increasing the number of parasitic elements generally will only provide a mere 3 °-5 ° improvement in terms of the beam-scanning range. In this work, the scanning range is improved by approximately 57% via a novel approach combining the additional parasitic elements and ground plane reduction techniques. Numerical and experimental results have validated that the array is capable of producing five different beam patterns directed towards -50°, -30°, 0°, +30°, and +50° steerable at the xz-plane using an optimized switching method and careful switch location selection on the parasitic elements.