Antenna device
Linear elements 101 a to 101 d are conductors, which have the element length equivalent to half a wavelength, have been placed so that they may draw a diamond shape. Delay elements 102 a and 102 b are bent conductors, which have a total length equivalent to one fourth wavelength and a length L 2 equivalent to one eighth. The linear elements 101 a and 101 c are connected one another via the delay element 102 a , while the linear elements 101 b and 101 d are connected one another via the delay element 102 b . A feeding section 103 is connected to each of the ends of the linear elements 101 a and 101 b for feeding power to them. Between the tips of the linear elements 101 c and 101 d , a gap with a length L 3 is left. A reflector 104 has been placed at a distance h from a diamond-shape antenna with delay elements along the −Z axis, the distance h being equivalent to 0.42 wavelength. This achieves the antenna device, which may be suitably mounted on any of small wireless apparatuses and form a primary beam, of which horizontally-polarized wave or vertically-polarized wave tilts toward the horizontal direction.
1. An antenna device having an open end, the antenna device comprising:
four linear elements, each of which has a length equivalent to a half wavelength of an operating frequency, the elements being placed in a diamond shape on a plane,
a feeding section that feeds power to one end of a first linear element and one end of a second linear element, the feeding section being put at one of the apexes of the diamond shape,
a first delay section connected to the other end of the first linear element and one end of a third linear element for delaying the phase of an antenna current by a given phase,
a second delay section connected to the other end of the second linear element and one end of a fourth linear element for delaying the phase of an antenna current by the same phase as that of the first delay section, and
a reflector placed at a given distance in parallel to the plane, on which the linear elements have been placed.
2. The antenna device according to claim 1 , wherein the first delay section and the second delay section have a length within a given range and the first and second delay sections being linear elements having a bent form.
3. The antenna device according to claim 1 , wherein the first delay section and the second delay section are lumped constant parts.
4. The antenna device according to claim 1 , further comprising at least one director element having a length equivalent to a half wavelength of an operating frequency or less, the director element being placed at a given distance from the open end.
5. A sector antenna device, wherein a plurality of antenna devices according to claim 1 are used, the antenna devices being placed on a plane while being shifted at equal angles from each other.
6. The antenna device according to claim 5 , wherein six antenna devices have been placed in a row on a given rectangular plane, the six antenna devices being shifted by 60° from each other.
7. An antenna device comprising:
a dielectric substrate with a given dielectric constant,
a conductor layer formed on the dielectric substrate,
a diamond-shape slot elements formed on the conductor substrate, of which each side of the diamond shape has a length equivalent to a half wavelength of an operating frequency,
a first delay section and a second delay section disposed at each of opposite apex pairs of the diamond shape to delay the phase of an antenna current,
a feeding section disposed on either of another one of the opposite apex pairs of the diamond shape for feeding power to the slot elements,
a termination part formed at the other of another one of the opposite apex pairs of the diamond shape, for terminating the slot elements, and
a reflector placed beyond the substrate at a given distance from and in parallel to the conductor layer.
8. The antenna device according to claim 7 , wherein the first delay section and the second delay section are slot elements, having a bent form with a length within a given range, which are formed on the conductor layer.
9. The antenna device according to claim 7 , wherein the feeding section feeds power using a micro strip line laid on a rear plane of the substrate, on which the conductor layer has been formed.
10. The antenna device according to claim 7 comprising at least one director slot element, with a length equivalent to a half wavelength of an operating frequency or less, which has been formed at a given distance from the termination part.