Communication device and antenna structure
A communication device includes a nonconductive housing, a cable, an antenna structure, and a signal source. The nonconductive housing has a hollow structure. The cable is coupled to the signal source. The cable includes a signaling conductor and a grounding conductor. The antenna structure includes an antenna body and an enclosed radiation element. The antenna body is coupled to the signaling conductor. The antenna body is disposed outside the nonconductive housing. The enclosed radiation element is coupled to the grounding conductor. The enclosed radiation element is disposed inside the nonconductive housing.
1. A communication device, comprising:
a nonconductive housing, having a hollow structure;
a signal source;
a cable, coupled to the signal source, and comprising a signaling conductor and a grounding conductor; and
an antenna structure, comprising:
an antenna body, coupled to the signaling conductor, wherein the antenna body is disposed outside the nonconductive housing;
an enclosed radiation element, coupled to the grounding conductor, wherein the enclosed radiation element is disposed inside the nonconductive housing.
2. The communication device as claimed in claim 1 , wherein the enclosed radiation element substantially has a straight-line shape.
3. The communication device as claimed in claim 1 , wherein an angle between the antenna body and the enclosed radiation element is from 0 to 180 degrees.
4. The communication device as claimed in claim 1 , wherein the antenna structure covers a low-frequency band and a high-frequency band, the low-frequency band is from 700 MHz to 960 MHz, and the high-frequency band is from 1700 MHz to 2700 MHz.
5. The communication device as claimed in claim 4 , wherein a distance between the antenna body and the enclosed radiation element is shorter than or equal to 3 wavelengths of the low-frequency band.
6. The communication device as claimed in claim 4 , wherein the antenna body comprises:
a connection radiation element, coupled to a positive feeding point;
a main radiation element, coupled to the connection radiation element;
a first meandering radiation element, coupled to a negative feeding point; and
a second meandering radiation element, coupled to the negative feeding point;
wherein the connection radiation element is positioned between the first meandering radiation element and the second meandering radiation element.
7. The communication device as claimed in claim 6 , wherein the connection radiation element, the first meandering radiation element, and the second meandering radiation element have a symmetrical pattern.
8. The communication device as claimed in claim 6 , wherein the connection radiation element has a variable-width straight-line shape.
9. The communication device as claimed in claim 6 , wherein the first meandering radiation element surrounds a first nonconductive region, and the second meandering radiation element surrounds a second nonconductive region.
10. The communication device as claimed in claim 6 , wherein the main radiation element has an asymmetrical pattern.
11. The communication device as claimed in claim 6 , wherein the main radiation element has a rectangular notch.
12. The communication device as claimed in claim 6 , wherein a length of the antenna body is substantially equal to 0.25 wavelength of the low-frequency band.
13. The communication device as claimed in claim 6 , wherein a length of the enclosed radiation element is greater than 3 times a width of the antenna body.
14. The communication device as claimed in claim 6 , wherein a length of the antenna body is greater than 7 times a width of the antenna body.
15. The communication device as claimed in claim 6 , wherein a sum of a length of the antenna body and a length of the enclosed radiation element is substantially equal to 0.4 wavelength of the low-frequency band.
16. The communication device as claimed in claim 6 , wherein a sum of a length of the main radiation element and a length of the enclosed radiation element is substantially equal to 0.6 wavelength of the high-frequency band.
17. The communication device as claimed in claim 1 , wherein the antenna body is classified as a folded dipole antenna.
18. The communication device as claimed in claim 1 , wherein the antenna structure further comprises:
a connector, wherein the cable is coupled through the connector to the antenna body and the enclosed radiation element.
19. The communication device as claimed in claim 1 , wherein the antenna structure further comprises:
a nonconductive antenna cover, wherein the antenna body is disposed inside the nonconductive antenna cover.
20. An antenna structure, comprising:
an antenna body, coupled to a positive electrode of a signal source; and
an enclosed radiation element, coupled to a negative electrode of the signal source;
wherein the antenna structure covers a low-frequency band and a high-frequency band;
wherein a sum of a length of the antenna body and a length of the enclosed radiation element is substantially equal to 0.4 wavelength of the low-frequency band.