Array antenna apparatus capable of switching direction attaining low gain

摘要

An array antenna apparatus includes a dielectric substrate, a feeder element, a parasitic element, and a directivity control unit. The feeder element and the parasitic element have an equal length. The feeder element and the parasitic element are arranged such that they intersect with each other at a substantially central portion of the parasitic element and a feeder unit of the feeder element and such that the parasitic elements are arranged symmetrically around the feeder element. An interval between the feeder element and the parasitic element is not larger than half wavelength of a radio wave. The parasitic element has a varactor diode serving as a variable capacitance element loaded. The directivity control unit supplies a control voltage to the varactor diode, and switches directivity of the array antenna apparatus.