LENS, ELECTROMAGNETIC LENS ASSEMBLY HAVING THE LENS, AND WIRELESS COMMUNICATION DEVICE HAVING THE ELECTROMAGNETIC LENS ASSEMBLY

A wireless communication device includes a casing having a wireless signal penetrating area, an antenna sending a wireless signal through the wireless signal penetrating area, and an electromagnetic lens assembly including a lens barrel and a lens. The lens barrel has a first end and a second end. The first end is closer to the wireless signal penetrating area than the second end. The lens disposed in the lens barrel has an incident surface and an emission surface on an axis of the lens. The incident surface is a flat surface facing the first end. The emission surface is a convex surface and has a curvature, which is not equal to 0, from a perspective of a first axis perpendicular to the axis of the lens, and has a curvature of 0 from a perspective of a second axis perpendicular to the axis of the lens and the first axis.

BACKGROUND OF THE INVENTION

Technical Field

The present disclosure relates generally to a wireless communication, and more particularly to a lens, an electromagnetic lens assembly having the lens, and a wireless communication device having the electromagnetic lens assembly.

Description of Related Art

With advantages in wireless communication, the demand for wireless signal bandwidth and data transmission rate is increasing day by day, and therefore, there is a need for the manufacturers to develop an antenna module with high peak gain and high wireless transmission rates.

Typically, conventional wireless signal accesses points are used for the transmission of wireless signals on a wireless network, and the coverage of the wireless signals sent by the wireless signal accesses points are usually relatively wide. However, in certain cases, the wireless signal needs to be concentrated in a specific direction, so that the general accesses point is not applicable. In such cases, a wireless signal accesses point with an electromagnetic lens is needed to concentrate the wireless signals in a specific direction.

The conventional wireless signal accesses point with an electromagnetic lens usually embeds the electromagnetic lens in a casing of the wireless signal accesses point, and the structure of the casing is different from the casing of a general wireless signal accesses point. The manufacturers of the wireless signal accesses point have to prepare two types of casing s at the same time to meet different requirements, one is for the general wireless signal accesses point, and the other is for the wireless signal accesses point with electromagnetic lens, which may cause unnecessary inventory pressure.

BRIEF SUMMARY OF THE INVENTION

In view of the above, the primary objective of the present disclosure is to provide a lens, an electromagnetic lens assembly having the lens, and a wireless communication device having the electromagnetic lens assembly, which could bring down inventory and stocking cost of the casing for manufacturers.

The present disclosure provides a wireless communication device, including a casing, an antenna, and an electromagnetic lens assembly, wherein the casing has a wireless signal penetrating area. The antenna is located in the casing and corresponds to the wireless signal penetrating area and sends a wireless signal through the wireless signal penetrating area. The electromagnetic lens assembly includes a lens barrel and a lens, wherein the lens barrel has a first end and a second end opposite to the first end on an axis of the lens barrel. The first end is closer to the wireless signal penetrating area than the second end. The lens is disposed in the lens barrel for concentrating an electromagnetic wave. The lens has an incident surface and an emission surface on an axis of the lens, wherein the incident surface of the lens is a flat surface and faces the first end, and the emission surface is a convex surface. The emission surface has a curvature, which is not equal to 0, from a perspective of a first axis perpendicular to the axis of the lens, and has a curvature of 0 from a perspective of a second axis perpendicular to the axis of the lens and the first axis. The lens satisfies 0.50≤R/Rc≤0.6 and 0.4≤R/D≤0.5, wherein a radius of a projection circle that the emission surface projects along the axis of the lens is defined as R; a curvature radius of the emission surface on the second axis is defined as Rc; a distance between the incident surface and the antenna on the axis of the lens is defined as D.

The present disclosure further provides an electromagnetic lens assembly, including a lens barrel and a lens disposed in the lens barrel for concentrating an electromagnetic wave, wherein the lens barrel has a first end and a second end opposite to the first end on an axial direction of the lens barrel. The lens has an incident surface and an emission surface on an axis of the lens, wherein the incident surface is a flat surface facing the first end; the emission surface is a convex surface, and has a curvature, which is not equal to 0, from a perspective of a first axis perpendicular to the axis of the lens, and has a curvature of 0 from a perspective of a second axis perpendicular to the axis of the lens and the first axis. The lens satisfies 0.50≤R/Rc≤0.6, wherein a radius of a projection circle that the emission surface projects along the axis of the lens is defined as R; a curvature radius of the emission surface on the second axis is defined as Rc.

The present disclosure further provides a lens for concentrating an electromagnetic wave, wherein the lens has an incident surface and an emission surface on an axis of the lens. The emission surface is a convex surface, and has a curvature, which is not equal to 0, from a perspective of a first axis perpendicular to the axis of the lens, and has a curvature of 0 from a perspective of a second axis perpendicular to the axis of the lens and the first axis. The incident surface is a flat surface. The lens satisfies 0.50≤R/Rc≤0.6, wherein a radius of a projection circle that the emission surface projects along the axis of the lens is defined as R; a curvature radius of the emission surface on the second axis is defined as Rc.

With the aforementioned design, the electromagnetic lens assembly could facilitate directional gain on the wireless signals emitted by the antenna, without increasing the thickness of the casing of the host. When the electromagnetic lens assembly is removed, the host could transmit wireless signals without the electromagnetic lens assembly, which effectively brings down inventory and stocking cost of the casing for manufacturers.

DETAILED DESCRIPTION OF THE INVENTION

A wireless communication device1according to a first embodiment of the present disclosure is illustrated inFIG.1toFIG.12, wherein the wireless communication device1is an accesses point as an example. The wireless communication device1includes a host10and an electromagnetic lens assembly16. A first axis X, a second axis Y, and a third axis Z that are perpendicular to one another are defined for explanation purpose.

The host10is adapted to send and receive wireless signals such as Wi-Fi signals, wherein the host10includes a casing12and an antenna14. The casing12is made of plastic, such as Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), etc. A side plate122of the casing12has an opening122athat constitutes a wireless signal penetrating area. The antenna14is located in the casing12and corresponds to the opening122a. In the current embodiment, the antenna14is an array antenna that is a 3×5 array antenna as an example. However, the antenna14could be a 2×4, 4×8, 4×4, 8×8, or higher-order array antennas in other embodiments. A center of the antenna14and a center of the opening122aare located at the same axis (i.e., the third axis Z), and a longitudinal direction of the antenna14extends along the first axis X, while a latitudinal direction of the antenna14extends along the second axis Y, wherein the antenna14sends a wireless signal via the opening122a.

The electromagnetic lens assembly16is detachably engaged with the casing12and corresponds to the opening122aand includes a lens barrel18and a lens42, wherein an axial direction of the lens barrel18extends along the third axis Z, and the lens barrel18has a first end18aand a second end18bopposite to the first end18ain the axial direction of the lens barrel18. The first end18ais closer to the opening122athan the second end18b. The lens42is disposed in the lens barrel18for concentrating an electromagnetic wave of the wireless signal sent by the antenna14. The lens42is made of a material that could be passed through by the electromagnetic wave. In the embodiment, the material can be a high-frequency microwave plastic (Rexolite1422), which has a dielectric constant of 2.53, a refractive index of 1.59, a dissipation factor of 0.00066 in 10 GHz, or other materials with low loss tangent such as teflon.

In the current embodiment, the lens barrel18includes a tube body20and a protective cover34, wherein the tube body20and the protective cover34are made of plastic, such as Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), etc., for preventing UV penetration. The tube body20is tapered in shape, wherein two ends of the tube body20are open, and one of the two ends of the tube body20is the first end18a. The first end18ahas an engaging portion22, wherein the engaging portion22is detachably engaged with a periphery around the opening122avia a plurality of bolts S. An outer periphery of the tube body20has a plurality of strengthening ribs24. The electromagnetic lens assembly16could selectively include a sealing ring32disposed between the engaging portion22and the side plate122of the casing12, thereby sealing the periphery around the engaging portion22and the opening122a. The other end of the tube body20is a first engaging end26adapted to be engaged with the protective cover34. A side of the protective cover34is a second engaging end36, wherein the second engaging end is open, while another side of the protective cover34is the second end18band is closed.

Referring toFIG.3toFIG.12, an inner wall of the tube body20adjacent to the first engaging end26has a plurality of supporting ribs28and a plurality of first positioning ribs30, wherein the supporting ribs28and the first positioning ribs30are arranged radially. In the current embodiment, a number of the first positioning ribs30is four as an example, wherein the first positioning ribs30slightly protrude out of the first engaging end26. The supporting ribs28constitute a shoulder portion of the tube body20. An inner wall of the protective cover34has a plurality of abutting ribs38and a plurality of second positioning ribs40, wherein the abutting ribs38are arranged radially and constitute an abutting portion. In the current embodiment, a number of the second positioning ribs40is four as an example, and the second positioning ribs40slightly protrude out of the second engaging end36.

The lens42is a cylinder and has a flange portion44protruding in a radial direction of the lens42. Referring toFIG.6toFIG.8, a side of the flange portion44in an axial direction of the lens42(i.e., the third axis Z) abuts against the supporting ribs28of the tube body20, and the abutting ribs38of the protective cover34abut against another side of the flange portion44in the axial direction of the lens42, thereby fixing the lens42. The flange portion44has a plurality of notches442. In the current embodiment, each of two sides of the lens42in the radial direction of the lens42has a notch442as an example, wherein two of the first positioning ribs30enters one of the notches442, and the two first positioning ribs30respectively abut against two sides of the notches442in a circumference of the lens42, thereby restricting the lens42from rotating. Two of the second positioning ribs40of the protective cover34correspondingly enter between the two first positioning ribs30and respectively abut against the corresponding two first positioning ribs30, thereby restricting the protective cover34from rotating. The second engaging end36of the protective cover34could be engaged with the first engaging end26of the tube body20(e.g. via a glue).

Referring toFIG.9toFIG.12, an axis i of the lens42extends along the third axis Z, wherein the lens42has an incident surface46and an emission surface48in the axis i. The incident surface46is a flat surface facing the first end18aand is perpendicular to the axis i. The emission surface48is a convex surface and has a curvature from the perspective of the first axis X, wherein the curvature is not equal to 0. The emission surface48has a curvature of 0 from the perspective of the second axis Y. Referring toFIG.12, a radius of a projection circle that the emission surface48projects along the axis i is defined as R. Referring toFIG.11, a curvature radius of the emission surface48on the second axis Y is defined as Rc. Referring toFIG.6, a distance between the incident surface46and the antenna14on the axis i is defined as D. The lens42satisfies 0.50≤R/Rc≤0.6 and 0.4≤R/D≤0.5.

When the lens42satisfies the abovementioned conditions, a wireless signal emitted through the emission surface48could have a good directivity gain.

In the current embodiment, a radius R1of the cylinder of the lens42is 34.7 mm, and a periphery of the emission surface48has a round angle50. The radius R of the projection circle of the emission surface48is 34.15 mm. The curvature radius Rc of the emission surface48is 62 mm. A height H between a lowest point and a highest point of the emission surface48on the axis i is about 10.4 mm, wherein H=Rc−√{square root over (Rc2−R2)}. A thickness H1of the lens42on the axis i is 12.6 mm. A thickness H2of the flange portion44on the axis i is 1.5 mm. The distance D between the incident surface46and the antenna14on the axis i is 76.7 mm. R/Rc is about 0.55. R/D is about 0.45. R/D is related to a coverage area of a wave beam of the antenna14(or a scanning angle of an array antenna), wherein R/D=tan(a); 2 times a is the coverage area of the wave beam (or the scanning angle of the array antennas).

In an embodiment that a periphery of the emission surface48does not have the round angle50, the radius R1of the cylinder (e.g. 34.7 mm) is equal to a radius R of a projection circle of the emission surface48along the axis i, wherein at this time, a height H between the lowest point and the highest point of the emission surface48on the axis i is about 10.6 mm.

Referring toFIG.13andFIG.16, compare a field pattern with the electromagnetic lens assembly16of the current embodiment and a field pattern without the electromagnetic lens assembly16In the current embodiment, a peak gain of the electromagnetic lens assembly16on the Z-X plane and on the Z-Y plane is about 22.2 dBi; a beamwidth on the Z-X plane is 6.2 degrees; a beamwidth on the Z-Y plane is 29.3 degrees. When the electromagnetic lens assembly16is not installed, a peak gain on the Z-X plane and on the Z-Y plane is about 17.9 dBi; a beamwidth on the Z-X plane is 16.9 degrees; a beamwidth on the Z-Y plane is 29.1. In other words, the lens42increases the peak gain by 4.3 dB.

In this way, the electromagnetic lens assembly16could facilitate directional gain on the wireless signals emitted by the antenna14. When the electromagnetic lens assembly16is removed, the host10still has the function of the wireless signal accesses point and could be used alone. In addition, a cover (not shown) could be installed at the opening122aof the casing12of the host10to prevent moisture, dust, foreign objects, etc. from entering the interior of the casing12.

In an embodiment, the lens42could have at least one notch442; the tube body20could have two first positioning ribs30for entering the notch442of the lens42; the protective cover34could have two second positioning ribs40for entering between the two first positioning ribs30to respectively abut against the two first positioning ribs30.

In an embodiment, the lens42could have at least one notch442, and the tube body20could have at least one first positioning rib30, wherein a width of the notch442matches with a width of the first positioning rib30, allowing the first positioning rib30to enter the notch442to restrict the lens42from rotating.

In an embodiment, a flat lens (not shown) could be disposed on the casing12to close the opening122a, wherein the flat lens is made of a material that could be passed through by the electromagnetic wave, for example, a high-frequency microwave plastic (Rexolite1422), teflon, etc., thereby the flat lens constitutes the wireless signal penetrating area.

A wireless communication device2according to a second embodiment of the present disclosure is illustrated inFIG.17toFIG.20, which has almost the same structures as the first embodiment, except that a casing54of the second embodiment includes a body542and a flat lens544, wherein the body542has an opening542a, and the flat lens544is disposed on the body542and is located at the opening542a; a material of the flat lens544and the material of the lens42are the same; the flat lens544constitutes the wireless signal penetrating area. Additionally, in the current embodiment, a first end60aand a second end60bof a lens barrel60of an electromagnetic lens assembly58are respectively an open end, and an outer peripheral surface of the lens barrel60has an engaging portion62that could be detachably fixed to the casing54through a support66, making the first end60abe spaced apart from the flat lens544by a space. The lens42is located between the first end60aand the second end60b, and the emission surface48of the lens42faces the second end60b. A body of the lens42could selectively be coated with an anti-ultraviolet coating (not shown), wherein the anti-ultraviolet coating could be, for example, Acrylate Resin. The anti-ultraviolet coating could be at least provided on the emission surface48, or covers a surface of the entire body of the lens42, preventing the lens42from being irradiated by the ultraviolet rays for a long time and deteriorating to affect the convergence of the electromagnetic wave.

An inside of the lens barrel60also has a shoulder portion64for abutting against the flange portion44of the lens42, wherein the flange portion44of the lens42could be engaged with the shoulder portion64(e.g. through a glue).

In this way, the electromagnetic lens assembly58could facilitate directional gain on the wireless signals emitted by the antenna56. When the electromagnetic lens assembly58is removed, the host52still has the function of the wireless signal accesses point and could be used alone.

A wireless communication device3and a lens68according to a third embodiment of the present disclosure is illustrated inFIG.21toFIG.23, wherein in the current embodiment, an antenna76is a 2×4 array antennas as an example, and the wireless communication device3also satisfies 0.50≤R/Rc≤0.6 and 0.4≤R/D≤0.5.

In the current embodiment, a radius R1of a cylinder of the lens68is 30 mm; a periphery of an emission surface72of the lens68does not have the round angle, so that a radius R of a projection circle of the emission surface72along the axis i is also 30 mm; a curvature radius Rc of the emission surface72is 53.6 mm; a height H between a lowest point and a highest point of the emission surface72on the axis i is about 9.17 mm, wherein H=√{square root over (Rc2−R2)}; a thickness H1of the lens68on the axis i is 11.17 mm; a thickness H2of a flange portion74of the lens68on the axis i is 1.5 mm; a distance D between an incident surface70of the lens68and the antenna76on the axis i is 66.1 mm; R/Rc is about 0.55; R/D is about 0.45.

Since a coverage area of a wave beam of the 2×4 array antennas76(or a scanning angle of an array antenna) is smaller, the curvature radius Rc of the emission surface72is smaller, the radius R of the projection circle is smaller, and the distance D between the incident surface70and the antenna76on the axis i is shorter.

In the current embodiment, the lens barrel (not shown) adopts the structure of the lens barrel18of the first embodiment and adjusts the size of the lens barrel to correspond to the size of the lens68. In an embodiment, the lens barrel could also adopt the structure of the lens barrel60of the second embodiment.

Referring toFIG.24andFIG.27, compare a field pattern with the electromagnetic lens assembly of the current embodiment and field pattern without the electromagnetic lens assembly. In the current embodiment, a peak gain of the electromagnetic lens assembly on the Z-X plane and on the Z-Y plane is about 21.5 dBi; a beamwidth on the Z-X plane is 5.2 degrees; a beamwidth on the Z-Y plane is 32 degrees. When the electromagnetic lens assembly is not installed, a peak gain on the Z-X plane and on the Z-Y plane is about 15.6 dBi; a beamwidth on the Z-X plane is 20.9 degrees; a beamwidth on the Z-Y plane is 44.3 degrees. In other words, the lens68increases the peak gain by 5.9 dB.

With the aforementioned design, the electromagnetic lens assembly could facilitate directional gain on the wireless signals emitted by the antenna, without increasing a thickness of the casing of the host. It is worth mentioning that, when the electromagnetic lens assembly is removed, the host could be used alone to transmit wireless signals, thereby effectively bringing down inventory and stocking cost of the casing for manufacturers.

It must be pointed out that the embodiments described above are only some preferred embodiments of the present disclosure. All equivalent structures which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present disclosure.