Patent ID: 8810471

Claim:
A circularly polarized ceramic patch antenna having an extended ground for a vehicle, which is disposed on a board having a feeder circuit and a ground plane of a vehicle antenna, comprising: the patch antenna having a dielectric through which a first feeder hole is bored and which is formed of a ceramic, a radiator that is formed of a quadrilateral metal thin film, diagonally opposite corners of which are partly chamfered for circular polarization, and that is formed on the dielectric, a main ground through which a second feeder hole is bored at a position corresponding to the first feeder hole so as to be greater in diameter than the first feeder hole and which is formed of a metal thin film placed under the dielectric, and a feeder that connects the radiator and the feeder circuit on the board through the first and second feeder holes; and the extended ground, through which a third feeder hole is bored so as to correspond to the second feeder hole, which is formed under the patch antenna, which has a predetermined thickness, which is formed of a metal conductor having a shape which is the same as a shape of the patch antenna, and which is electrically connected to the ground plane formed on the board.