Antenna having a cable grounding area

1. An antenna, comprising:

a substrate having a first surface and a first width;

a feed-in terminal;

a radiating portion extended from the feed-in terminal along a first direction to form a first hook portion;

a connecting conductor extended from the feed-in terminal to a ground terminal along a second direction opposite to the first direction; and

a ground portion extended from the ground terminal and having a cable grounding area; wherein:

the ground portion and the connecting conductor form a second hook portion opposite to the first hook portion;

the cable grounding area has a longitudinal center line and is located under a coaxial cable;

the first direction and the longitudinal center line form therebetween a specific angle ranging from 49-59 degrees;

the first surface is rectangular and has a first corner area, a second corner area, a third corner area and a fourth corner area;

the second hook portion is located on the first and the fourth corner areas; and

the ground portion is disposed on the first surface, and includes:

a main ground portion disposed on the fourth corner area, being rectangular, and including a first edge, a second edge adjacent to the first edge, a third edge opposite to the first edge, and a fourth edge opposite to the second edge;

a first sub-ground portion extended from the first edge, disposed on the first corner area, and being a rectangular conductor having a second width; and

a second sub-ground portion extended from the second edge toward the third corner area, and being a rectangular conductor having a first inner edge, a first outer edge opposite to the first inner edge, a second length and a third width.

2. The antenna as claimed in claim 1 , wherein:

the radiating portion is disposed on the first surface, and includes:

a first radiating conductor extended from the feed-in terminal, and having a second inner edge, a second outer edge opposite to the second inner edge, a first length and a fourth width;

a second radiating conductor extended from the first radiating conductor, and having a third outer edge and a fifth width; and

a third radiating conductor extended from the second radiating conductor, and having a third inner edge, a fourth outer edge, a fifth outer edge, a third length and a six width; and

the first inner edge is parallel to and adjacent to the fifth outer edge.

3. The antenna as claimed in claim 2 , wherein:

the second width is two-fifths of the first width;

the third width is one-fifth of the first width;

the fourth width is one-fifth of the first width;

the fifth width is one-fifth of the first width;

the sixth width is one-fifth of the first width;

the first length is larger than the second length; and

the second length is larger than the third length.

4. The antenna as claimed in claim 2 , wherein:

the radiating portion, the connecting conductor and the ground portion form thereamong a gap; and

the third radiating conductor is extended to the cable grounding area along a direction opposite to the first direction.

5. The antenna as claimed in claim 2 , wherein:

the antenna has an operating frequency band determined by a total length being the sum of the first length, the fourth width and the third length;

a length from the feed-in terminal, through the connecting conductor and the first sub-ground portion, to the cable grounding area is equal to the total length; and

the total length is equal to one-fourth of an operating wavelength of the antenna.

6. The antenna as claimed in claim 2 , wherein:

the substrate has a left edge and a lower edge;

the fourth edge overlaps the left edge; and

the third edge overlaps the lower edge.

7. The antenna as claimed in claim 6 , wherein:

the first sub-ground portion has a left edge overlapping the left edge of the substrate having an upper edge; and

the first sub-ground portion has an upper edge overlapping the upper edge of the substrate.

8. The antenna as claimed in claim 7 , wherein the second sub-ground portion has a first outer edge overlapping the lower edge of the substrate.

9. The antenna as claimed in claim 8 , wherein the second outer edge overlaps the upper edge of the substrate.

10. The antenna as claimed in claim 6 , wherein the substrate further comprises a right edge, and the third outer edge overlaps the right edge of the substrate.

11. The antenna as claimed in claim 1 , wherein:

the fifth outer edge and the first inner edge of the second sub ground portion form therebetween a specific distance; and

the specific distance determines an impedance matching of the antenna.

12. The antenna as claimed in claim 1 , wherein the coaxial cable has a central conductor coupled to the feed-in terminal and a shielded conductor surrounding the central conductor.

13. The antenna as claimed in claim 12 , wherein:

the cable grounding area further has a first terminal, and a second terminal opposite to the first terminal; and

the longitudinal center line passes through the feed-in terminal, the first terminal and the second terminal.

14. The antenna as claimed in claim 13 , wherein the shielded conductor is electrically connected to the cable grounding area.

15. An antenna, comprising:

a substrate having a first surface and a first width;

a radiating portion extended along a first direction; and

a cable grounding area extended along a second direction, and located under a coaxial cable, wherein:

the first direction and the second direction form therebetween a specific angle ranging from 49-59 degrees;

the first surface is rectangular and has a first corner area, a second corner area, a third corner area and a fourth corner area; and

the antenna further includes a ground portion disposed on the first surface, and including:

a main ground portion disposed on the fourth corner area, being rectangular, and including a first edge, a second edge adjacent to the first edge, a third edge opposite to the first edge, and a fourth edge opposite to the second edge,

a first sub-ground portion extended from the first edge, disposed on the first corner area, and being a rectangular conductor having a second width; and

a second sub-ground portion extended from the second edge toward the third corner area and being a rectangular conductor having a first inner edge a first outer edge opposite to the first inner edge, a second length and a third width.

16. The antenna as claimed in claim 15 , wherein:

the radiating portion is extended to a first turning point to form a first radiating conductor;

the first radiating conductor is extended from the first turning point to a second turning point to form a second radiating conductor; and

the second radiating conductor is extended from the second turning point to form a third radiating conductor.

17. An antenna, comprising:

a substrate having a first surface and a first width;

a feed-in terminal;

a radiating portion extended from the feed-in terminal along a first direction; and

a ground portion having a cable grounding area extended along a second direction and located under a coaxial cable, wherein:

the first direction and the second direction form therebetween a specific angle ranging from 49-59 degrees;

the first surface is rectangular and has a first corner area, a second corner area a third corner area and a fourth corner area; and

the ground portion is disposed on the first surface, and includes:

a main ground portion disposed on the fourth corner area, being rectangular, and including a first edge, a second edge adjacent to the first edge, a third edge opposite to the first edge, and a fourth edge opposite to the second edge;

a first sub-ground portion extended from the first edge, disposed on the first corner area, and being a rectangular conductor having a second width; and

a second sub-ground portion extended from the second edge toward the third corner area, and being a rectangular conductor having a first inner edge, a first outer edge opposite to the first inner edge, a second length and a third width.

18. The antenna as claimed in claim 17 , further comprising a surface and an insulating layer, wherein:

a length from the feed-in terminal, through the ground portion, to the cable grounding area equals one-fourth of the operating wavelength of the antenna; and

the surface of the antenna is covered by the insulating layer except for the feed-in terminal and the cable grounding area;

the feed-in terminal is electrically connected to a central conductor of the coaxial cable; and

the cable grounding area under the coaxial cable is electrically connected to a shielding conductor of the coaxial cable.