Wireless module
View Patent ↗A wireless device that suppresses deterioration of antenna characteristics and can be made thin is provided. The wireless device is provided with a substrate, a wireless module that is mounted on the substrate and has an antenna unit, and a casing that accommodates the substrate and the wireless module. The wireless device has a gap of a length that is an approximate multiple of a half-wavelength of a radio wave corresponding to a communication frequency of the antenna unit, from the antenna unit toward the casing.
1. A wireless device comprising:
a substrate;
a wireless module that is mounted on the substrate and includes an antenna unit; and
a casing that accommodates the substrate and the wireless module and has a recessed section in a region that opposes the antenna unit,
wherein a distance between the antenna unit and the recessed section is a length that is an approximate multiple of a half-wavelength of a radio wave corresponding to the communication frequency of the antenna unit, and
a distance between the antenna unit and a first side surface of the recessed section that corresponds to a radiation direction of the radio wave is longer than a distance between the antenna unit and a second side surface of the recessed section that corresponds to a direction opposite to the radiation direction of the radio wave.
2. The wireless device according to claim 1 ,
wherein the casing includes an antenna-opposing region that opposes the antenna unit, and a non-antenna-opposing region that is a region other than the antenna-opposing region,
and the antenna-opposing region is formed from a material that has a lower relative permittivity, or a smaller dielectric loss tangent, than the non-antenna-opposing region.
3. The wireless device according to claim 1 , further comprising,
a first member provided between the antenna unit and the casing such that a gap is provided between the antenna unit and the first member, the gap having a length that is an approximate multiple of a half-wavelength of the radio wave.
4. The wireless device according to claim 1 , further comprising,
a first member provided between the antenna unit and the casing,
wherein a distance between the antenna unit and the first member is less than a half-wavelength of the radio wave, and the first member has an opening in a region, which opposes the antenna unit.
5. The wireless device according to claim 1 ,
wherein a distance between the antenna unit and a bottom surface of the recessed section is a length that is an approximate multiple of a half-wavelength of the radio wave.
6. The wireless device according to claim 1 ,
wherein a distance between the antenna unit and a side surface of the recessed section is a length that is an approximate multiple of a half-wavelength of the radio wave.
7. The wireless device according to claim 1 ,
wherein a bottom surface of the recessed section of the casing has a tapered surface that is substantially orthogonal to a radiation direction of the radio wave.
8. The wireless device according to claim 7 ,
wherein the antenna unit includes a plurality of antenna elements,
and a bottom surface of the recessed section of the casing has a tapered surface that is substantially orthogonal to a radiation direction of a radio wave from each of the antenna elements.
9. The wireless device according to claim 7 ,
wherein an outer peripheral surface of the casing has a tapered surface along the bottom surface of the recessed section.
10. A wireless device comprising:
a substrate;
a wireless module that is mounted on the substrate and includes an antenna unit; and
a casing that accommodates the substrate and the wireless module and has a recessed section in a region that opposes the antenna unit,
wherein a distance between the antenna unit and the recessed section is a length that is an approximate multiple of a half-wavelength of a radio wave corresponding to the communication frequency of the antenna unit, and
an area of a first side surface of the recessed section that corresponds to the radiation direction of the radio wave is larger than an area of a second side surface of the recessed section that corresponds to a direction opposite to the radiation direction of the radio wave.
11. The wireless device according to claim 10 ,
wherein the casing includes an antenna-opposing region that opposes the antenna unit, and a non-antenna-opposing region that is a region other than the antenna-opposing region,
and the antenna-opposing region is formed from a material that has a lower relative permittivity, or a smaller dielectric loss tangent, than the non-antenna-opposing region.
12. The wireless device according to claim 10 , further comprising,
a first member provided between the antenna unit and the casing such that a gap is provided between the antenna unit and the first member, the gap having a length that is an approximate multiple of a half-wavelength of the radio wave.
13. The wireless device according to claim 10 , further comprising,
a first member provided between the antenna unit and the casing,
wherein a distance between the antenna unit and the first member is less than a half-wavelength of the radio wave, and the first member has an opening in a region, which opposes the antenna unit.
14. The wireless device according to claim 10 ,
wherein a distance between the antenna unit and a bottom surface of the recessed section is a length that is an approximate multiple of a half-wavelength of the radio wave.
15. The wireless device according to claim 10 ,
wherein a distance between the antenna unit and a side surface of the recessed section is a length that is an approximate multiple of a half-wavelength of the radio wave.
16. The wireless device according to claim 10 ,
wherein a bottom surface of the recessed section of the casing has a tapered surface that is substantially orthogonal to a radiation direction of the radio wave.
17. The wireless device according to claim 16 ,
wherein the antenna unit includes a plurality of antenna elements,
and a bottom surface of the recessed section of the casing has a tapered surface that is substantially orthogonal to a radiation direction of a radio wave from each of the antenna elements.
18. The wireless device according to claim 16 ,
wherein an outer peripheral surface of the casing has a tapered surface along the bottom surface of the recessed section.