Antenna device with choke sleeve structures
View Patent ↗An unbalanced antenna includes a non-conductive substrate having one short edge, and two long edges connected respectively to two opposite ends of the short edge and parallel to each other, and an unbalanced antenna disposed proximate to the short edge of the non-conductive substrate and having a ground portion. A ground plane has side edges extending along the long edges of the non-conductive substrate, and is electrically coupled with the ground portion. The length of the ground plane is longer than a quarter of an equivalent wavelength corresponding to an operating frequency of the unbalanced antenna. A pair of choke sleeve structures are symmetrically disposed at opposite sides of the ground plane and spaced apart from the unbalanced antenna by a quarter of an equivalent wavelength corresponding to the operating frequency. Each choke sleeve structure has one end connected to the ground plane, and the other end extending in a direction away from the unbalanced antenna.
1. An antenna device comprising:
a non-conductive substrate having a short edge, and two long edges connected respectively to two opposite ends of said short edge and substantially parallel to each other;
an unbalanced antenna being disposed on said non-conductive substrate proximate to said short edge of said non-conductive substrate and having a ground portion;
a ground plane disposed on said non-conductive substrate, located at one side of said unbalanced antenna, and electrically coupled to said ground portion, said ground plane having two opposite side edges that extend along said two long edges of said non-conductive substrate, said ground plane having a length longer than a quarter of an equivalent wavelength corresponding to an operating frequency of said unbalanced antenna; and
a pair of choke sleeve structures symmetrically disposed on said ground plane at locations which are inwardly of said two opposite side edges of said ground plane and which are spaced apart from said unbalanced antenna by about a quarter of the equivalent wavelength corresponding to the operating frequency, each of said choke sleeve structures having a first end connected to said ground plane, and a second end extending in a direction away from said unbalanced antenna.
2. The antenna device according to claim 1 , wherein each of said choke sleeve structures is an elongated metal line section, wherein there is a first gap between said second end of each of said choke sleeve structures and said ground plane, wherein each of said choke sleeve structures further has an inner side edge, and there is a second gap between said inner side edge and said ground plane.
3. The antenna device according to claim 1 , wherein said choke sleeve structures separate said ground plane into a current active region located at one side of said choke sleeve structures proximate to said unbalanced antenna, a current restricting region where said choke sleeve structures are located, and a current suppressing region located at another side of said choke sleeve structures distal from said unbalanced antenna.
4. An antenna device comprising:
a non-conductive substrate having a short edge, and two long edges connected respectively to two opposite ends of said short edge and substantially parallel to each other;
an unbalanced antenna being disposed on said non-conductive substrate proximate to said short edge of said non-conductive substrate and having a ground portion;
a ground plane disposed on said non-conductive substrate, located at one side of said unbalanced antenna, and electrically coupled to said ground portion, said ground plane having two opposite side edges that extend along said two long edges of said non-conductive substrate, said ground plane having a length longer than a quarter of an equivalent wavelength corresponding to an operating frequency of said unbalanced antenna; and
a pair of choke sleeve structures symmetrically disposed on said ground plane at locations which are outwardly of said two opposite side edges of said ground plane and which are spaced apart from said unbalanced antenna by about a quarter of the equivalent wavelength corresponding to the operating frequency, each of said choke sleeve structures having a first end connected to said ground plane, and a second end extending in a direction away from said unbalanced antenna.
5. The antenna device according to claim 4 , wherein each of said choke sleeve structures is an elongated metal line section, and further has an inner side edge forming a gap with an adjacent one of said opposite side edges of said ground plane.
6. The antenna device according to claim 4 , wherein said choke sleeve structures separate said ground plane into a current active region located at one side of said choke sleeve structures proximate to said unbalanced antenna, a current restricting region where said choke sleeve structures are located, and a current suppressing region located at another side of said choke sleeve structures distal from said unbalanced antenna.