Patent attributes
A millimeter-wave antenna includes a slit which is provided in a GND conductor formed in a first surface of a circuit board, a horn antenna which is provided with a first opening and a second opening, and an impedance matching device which is provided in a slot shape between the slit and the first opening of the horn antenna. The impedance matching device is formed in the slot shape which is filled with a dielectric having a dielectric constant different from that of the circuit board. The impedance matching device is configured such that a length of the slot shape in a propagation direction is less than ¼ of a wavelength of a use frequency upper limit. The impedance matching device is configured such that a size of a rectangular shape of the slot shape in a magnetic field direction is larger than the first opening of the horn antenna.
