Abstract: An object of the present invention is to provide a miniaturized plane antenna having good axial ratio characteristics over a broad frequency range. An antenna equipped with feeding points at two axial directional impedance matching points of a radiation electrode formed on a surface of a dielectric substrate is mounted on a two-layer wiring board equipped with a 90° hybrid and ports. In the wiring board, the 90° hybrid by means of a closed conductor pattern is configured to have ports drawn out toward an inside of the closed conductor pattern to be connected with the antenna and another port to be connected to a coaxial line, and an earth conductor is arranged outside the closed conductor pattern so as to surround it or inside the closed conductor pattern. The 90° hybrid is adapted to be accommodated in a back face of the antenna.

Abstract: An object of the present invention is to provide a miniaturized plane antenna having good axial ratio characteristics over a broad frequency range. An antenna equipped with feeding points at two axial directional impedance matching points of a radiation electrode formed on a surface of a dielectric substrate is mounted on a two-layer wiring board equipped with a 90° hybrid and ports. In the wiring board, the 90° hybrid by means of a closed conductor pattern is configured to have ports drawn out toward an inside of the closed conductor pattern to be connected with the antenna and another port to be connected to a coaxial line, and an earth conductor is arranged outside the closed conductor pattern so as to surround it or inside the closed conductor pattern. The 90° hybrid is adapted to be accommodated in a back face of the antenna.