Wireless communication device and antenna

1. A wireless communication device comprising:

a case that includes a dielectric member made of a first dielectric material, and a cover layer made of a second dielectric material which covers an outer surface of the dielectric member;

a wireless communication circuit that is housed in the case;

an antenna element that is electrically connected to the wireless communication circuit, the antenna element being made of a conductive material and provided on an inner surface of the dielectric member; and

an adhesive layer that is disposed between the antenna element and the dielectric member to adhere the antenna element onto the dielectric member, the adhesive layer being made of a third dielectric material.

2. The device according to claim 1 , wherein the third dielectric material has a relative permittivity that is not more than seven.

3. The device according to claim 2 , wherein the second dielectric material has a relative permittivity that is not more than seven.

4. The device according to claim 1 , further comprising:

an additional antenna element that is electrically connected to the wireless communication circuit, the additional antenna element being made of a conductive material and provided on the outer surface of the dielectric member to be at least partially covered by the cover layer; and

an additional adhesive layer that is disposed between the additional antenna element and the dielectric member to adhere the additional antenna element onto the dielectric member, the additional adhesive layer being made of a fourth dielectric material,

wherein the third dielectric material has a relative permittivity that is not more than seven, and

wherein the fourth dielectric material has a relative permittivity that is not more than seven.

5. The device according to claim 4 , wherein the second dielectric material has a relative permittivity that is not more than seven.

6. The device according to claim 1 ,

wherein the dielectric member has a thickness that is in a range from 0.5 mm to 1 mm,

wherein the antenna element has a thickness that is not less than 10 μm,

wherein the adhesive layer has a thickness that is in a range from 5 μm to 20 μm, and

wherein the cover layer has a thickness that is in a range from 5 μm to 20 μm.

7. The device according to claim 6 , further comprising:

an additional antenna element that is electrically connected to the wireless communication circuit, the additional antenna element being made of a conductive material and provided on the outer surface of the dielectric member to be at least partially covered by the cover layer; and

an additional adhesive layer that is disposed between the additional antenna element and the dielectric member to adhere the additional antenna element onto the dielectric member, the additional adhesive layer being made of a fourth dielectric material,

wherein the additional antenna element has a thickness that is not less than 10 μm, and

wherein the additional adhesive layer has a thickness that is in a range from 5 μm to 20 μm.

8. The device according to claim 1 , further comprising:

an additional antenna element that is electrically connected to the wireless communication circuit, the additional antenna element being made of a conductive material and provided on the outer surface of the dielectric member to be at least partially covered by the cover layer; and

an additional adhesive layer that is disposed between the additional antenna element and the dielectric member to adhere the additional antenna element onto the dielectric member, the additional adhesive layer being made of a fourth dielectric material,

wherein at least one of the antenna element and the additional antenna element is in close contact with the respective one of the adhesive layer and the additional adhesive layer by being interposed with an ink layer therebetween, the ink layer having a characteristic to grow plating.

9. An antenna comprising:

a case that includes a dielectric member made of a first dielectric material, and a cover layer made of a second dielectric material which covers an outer surface of the dielectric member;

an antenna element that is made of a conductive material and provided on an inner surface of the dielectric member; and

an adhesive layer that is disposed between the antenna element and the dielectric member to adhere the antenna element onto the dielectric member, the adhesive layer being made of a third dielectric material.

10. The antenna according to claim 9 , wherein the third dielectric material has a relative permittivity that is not more than seven.

11. The antenna according to claim 10 , wherein the second dielectric material has a relative permittivity that is not more than seven.

12. The antenna according to claim 9 , further comprising:

an additional antenna element that is made of a conductive material and provided on the outer surface of the dielectric member to be at least partially covered by the cover layer; and

an additional adhesive layer that is disposed between the additional antenna element and the dielectric member to adhere the additional antenna element onto the dielectric member, the additional adhesive layer being made of a fourth dielectric material,

wherein the third dielectric material has a relative permittivity that is not more than seven, and

wherein the fourth dielectric material has a relative permittivity that is not more than seven.

13. The antenna according to claim 12 , wherein the second dielectric material has a relative permittivity that is not more than seven.

14. The antenna according to claim 9 ,

wherein the dielectric member has a thickness that is in a range from 0.5 mm to 1 mm,

wherein the antenna element has a thickness that is not less than 10 μm,

wherein the adhesive layer has a thickness that is in a range from 5 μm to 20 μm, and

wherein the cover layer has a thickness that is in a range from 5 μm to 20 μm.

15. The antenna according to claim 12 , further comprising:

an additional antenna element that is made of a conductive material and provided on the outer surface of the dielectric member to be at least partially covered by the cover layer; and

an additional adhesive layer that is disposed between the additional antenna element and the dielectric member to adhere the additional antenna element onto the dielectric member, the additional adhesive layer being made of a fourth dielectric material,

wherein the additional antenna element has a thickness that is not less than 10 μm, and

wherein the additional adhesive layer has a thickness that is in a range from 5 μm to 20 μm.

16. The antenna according to claim 9 , further comprising:

an additional antenna element that is made of a conductive material and provided on the outer surface of the dielectric member to be at least partially covered by the cover layer; and

an additional adhesive layer that is disposed between the additional antenna element and the dielectric member to adhere the additional antenna element onto the dielectric member, the additional adhesive layer being made of a fourth dielectric material,

wherein at least one of the antenna element and the additional antenna element is in close contact with the respective one of the adhesive layer and the additional adhesive layer by being interposed with an ink layer therebetween, the ink layer having a characteristic to grow plating.

17. A wireless communication device comprising:

casing means for accommodating electronic components, the casing means including a dielectric member made of a first dielectric material, and a cover layer made of a second dielectric material which covers an outer surface of the dielectric member;

wireless communication means for performing wireless communication, the wireless communication means being housed in the casing means;

antenna means for transmitting and receiving radio waves, the antenna means being electrically connected to the wireless communication means, the antenna means being made of a conductive material and provided on an inner surface of the dielectric member; and

adhesive means for adhering the antenna means onto the dielectric member by being disposed between the antenna means and the dielectric member, the adhesive means being made of a third dielectric material.

18. An antenna comprising:

casing means for accommodating electronic components, the casing means including a dielectric member made of a first dielectric material, and a cover layer made of a second dielectric material which covers an outer surface of the dielectric member;

antenna means for transmitting and receiving radio waves, the antenna means being made of a conductive material and provided on an inner surface of the dielectric member; and

adhesive means for adhering the antenna means onto the dielectric member by being disposed between the antenna means and the dielectric member, the adhesive means being made of a third dielectric material.

19. A wireless communication device comprising:

a case that includes a dielectric member made of a first dielectric material, and a cover layer made of a second dielectric material which covers an outer surface of the dielectric member;

a wireless communication circuit that is housed in the case;

an antenna element made of a conductive material and provided on the outer surface of the dielectric member between the dielectric member and the cover layer, the antenna element being electrically connected to the wireless communication circuit by a connection member that penetrates the case; and

an adhesive layer that is disposed between the antenna element and the dielectric member to adhere the antenna element onto the dielectric member, the adhesive layer being made of a third dielectric material.