Patent ID: 6992635

Claim:
A planar array antenna comprising: a substrate made of a dielectric material; a powered antenna element of a microstrip-line type disposed on one principal surface of said substrate; a ground conductor disposed on the other principal surface of said substrate; a feeding system for feeding high frequency power to the powered antenna element; an adjacent passive element disposed on the one principal surface of said substrate; a first passive element disposed ahead of said powered antenna element with space therebetween; and a second passive element disposed ahead of said adjacent passive element with space therebetween; wherein said powered antenna element and a first passive element corresponding to the powered antenna element constitute a powered element pair, said adjacent passive element and a second passive element corresponding to the adjacent passive element constitute a passive element pair, and said passive element pair is disposed so that it adjoins said powered element pair in an electric field direction or a magnetic field direction of radio wave emitted from said powered antenna element.