Cross dipole antenna and composite antenna
AssigneeNippon Antena Kabushiki Kaisha
InventorJinichi Inoue
Life of this patent
Estimating the term…
Abstract
A first dipole antenna consisting of dipole antennae 2a, 2b and a second dipole antenna consisting of dipole antennae 2c, 2d are disposed so as to be approximately orthogonal at approximately λ/4 intervals on a reflecting plate 6 having a diameter of approximately λ/2 or more. By disposing a plurality of non-feeding elements 3a to 3h around the first dipole antenna and second dipole antenna and isolating them by approximately λ/4, the transmission gain and axial ratio in a low elevation angle can be improved.
Claims14
A cross dipole antenna, comprising:
- a reflecting plate;
- a first dipole antenna disposed at a prescribed interval on said reflecting plate;
- a second dipole antenna disposed at a prescribed interval on said reflecting plate so as to be approximately orthogonal to said first dipole antenna;
- and
- a plurality of non-feeding elements disposed around said first dipole antenna and said second dipole antenna and uprising from said reflecting plate.
A cross dipole antenna, comprising:
- a reflecting plate formed in which the reflecting face is inclined such that the center portion protrudes further than the peripheral portion;
- a first dipole antenna disposed at a prescribed interval on said reflecting plate;
- and
- a second dipole antenna disposed at a prescribed interval on said reflecting plate so as to be approximately orthogonal to said first dipole antenna.
A composite antenna in which a cross dipole antenna capable of receiving circularly polarized waves and a whip antenna capable of receiving linearly polarized waves of an identical or adjacent frequency band to said circularly polarized waves are provided on a reflecting plate;
- wherein said cross dipole antenna comprises a first dipole antenna disposed at a prescribed interval on said reflecting plate and a second dipole antenna disposed at a prescribed interval on said reflecting plate so as to be approximately orthogonal to said first dipole antenna;
- said whip antenna is fixated on said reflecting plate by being isolated from said cross dipole antenna by a distance corresponding more than approximately ¼ wavelength of the wavelength in the center frequency of the used frequency band;
- and
- said cross dipole antenna is capable of receiving broadcast signals of circularly polarized waves transmitted from a satellite and saidwhip antenna is capable of receiving broadcast signals of linearly polarized waves of identical contents as with said broadcast signals transmitted from the ground.
A composite antenna in which a cross dipole antenna capable of receiving circularly polarized waves and a whip antenna capable of receiving linearly polarized waves of an identical or adjacent frequency band to said circularly polarized waves are provided on a reflecting plate;
- wherein said cross dipole antenna comprises a first dipole antenna disposed at a prescribed interval on said reflecting plate, a second dipole antenna disposed at a prescribed interval on said reflecting plate so as to be approximately orthogonal to said first dipole antenna, and a plurality of non-feeding elements disposed around said first dipole antenna and said second dipole antenna and uprising from said reflecting plate;
- said whip antenna is fixated on said reflecting plate by being isolated from said cross dipole antenna by a distance corresponding to more than approximately ¼ wavelength of the wavelength in the center frequency of the used frequency band;
- and
- said whip antenna is also used as said non-feeding elements.
Dependencies are inferred from the claim text.