Patent Description:
With the rapid development of the mobile communication industry, consumers' requirements for mobile network are gradually increasing. Moreover, in the present environment where <NUM>, <NUM>, <NUM> and <NUM> networks coexist and tower resources are rare, base station antennas are required to develop in the direction of multi-frequency and miniaturization. Therefore, multi-port broadband base station antennas are increasingly favored by the market.

The multi-port broadband base station antenna can form more antenna arrays without increasing the antenna width, which will reduce the distance between the antenna arrays and increase the mutual influence between the antenna arrays. In this case, it is required to have a consistent and stable radiation pattern within the operating frequency band. A good choice is to add a director above the radiating unit. Use of the parasitic effect between the director and the radiating unit can make the antenna radiation wave radiate in the normal radiation direction, thereby realizing the reduction of the antenna width by increasing the height of the array. However, when the number of directors is increased or the size there of is large, resonance will occur during operation of the antenna, hence affecting the performance of the antenna itself.

Patent (application) references like <CIT> , <CIT> , <CIT>, and <CIT> and <CIT> disclose similar technical features therein.

The object of the present invention is to at least solve one of the drawbacks in the prior art proposed in the background technology, and to realize the object of the present invention, the following technical solution is proposed:.

In a first aspect, the present invention proposes a double-layered director which is configured to be arranged directly above a corresponding high-frequency radiation unit, the double-layered director includes a first director (<NUM>) and a second director (<NUM>) installed above the first director (<NUM>), the second director (<NUM>) includes a dielectric substrate (<NUM>) and a split copper foil (<NUM>) installed on the dielectric substrate (<NUM>); the split copper foil (<NUM>) includes a plurality of small copper foils (<NUM>), and the plurality of small copper foils (<NUM>) are circumferentially arranged at intervals around a center of the second director (<NUM>); the small copper foils (<NUM>) are of an annular sectoral shape; the double-layered director is configured to weaken the influence of the resonant current of the director on the high-frequency radiation unit due to arrangement of the split copper on the electric substrate; and the first director (<NUM>) is made of a whole piece of a metal sheet.

Preferably, the number of the small copper foils is at least <NUM>.

Preferably, the length of the small copper foils is less than <NUM>. 25λ, where λ is the wavelength of the center frequency of the high-frequency radiation unit.

Preferably, the shape of the metal sheet is circular or polygonal.

A second aspect of the present invention proposes a multi-frequency base station antenna array. It includes a reflector and a high-frequency array and a low-frequency array arranged on the reflector, the high-frequency array includes several high-frequency radiation units (<NUM>), and the low-frequency array includes several low-frequency radiation units (<NUM>), each high-frequency radiation unit is distributed below a corresponding low-frequency radiation unit, wherein a double-layered director as mentioned above is also arranged directly above a corresponding high-frequency radiation unit.

Preferably, the high-frequency array and the low-frequency array are a two-row array each.

The present invention brings the following good effects.

The present invention arranges a split copper foil on the dielectric substrate. This not only weakens the influence of the resonant current of the director on the high-frequency radiation unit itself, but also simplifies the boundary of the radiation unit, and reduces the coupling and mutual interference between the high-frequency and low-frequency radiation units, and avoids the superposition of scattered waves which otherwise will cause the pattern distortion. This in turn enables the multi-frequency base station antenna to have consistent and stable horizontal half-power beamwidth and gain within the operating frequency band.

It should be noted that the inventions illustrated in <FIG> are not covered by the appended claims.

First director; <NUM>. Second director; <NUM>. High-frequency radiation unit; <NUM>. Low-frequency radiation unit; <NUM>. Split copper foil; <NUM>. Dielectric substrate; <NUM>. Small copper foil.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, embodiments of the present invention. These drawings are all simplified schematic diagrams, and only illustrate the basic structure of the present invention in a schematic manner, so the drawings only show the configurations related to the present invention. Based on the embodiments of the present invention, all other embodiments obtained by person of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that when an element is referred to as being "mounted on" another element, it can be directly on the other element or there can also be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or an intervening element may also be present.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. Herein, the terms used in the description of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. As used herein, the term "and" includes any and all combinations of one or more of the associated listed items.

Please refer to <FIG>. A first aspect of the embodiment of the present invention proposes a double-layered director, which is mainly applied to a multi-frequency base station antenna array. As shown in <FIG>, the double-layered director includes a first director <NUM> and a second director <NUM>, and the second director <NUM> is installed directly above the first director <NUM>. Specifically, the first director <NUM> and the second director <NUM> may be connected and fixed through an insulating support post.

Preferably, the first director <NUM> is constructed of a whole piece of circular metal sheet, and its diameter is between <NUM>. 5λ, where λ is the wavelength of the center frequency of the antenna. In addition, the metal sheet can also be a square or polygonal metal sheet. It is not limited to a circular shape, and those skilled in the art can set it according to actual need.

In this embodiment, the second director <NUM> is a split director, which is made of a PCB. The second director <NUM> includes a dielectric substrate <NUM> and a split copper foil <NUM> installed on the dielectric substrate <NUM>. Here, the dielectric substrate <NUM> plays a role of supporting the split copper foil <NUM>.

The split copper foil <NUM> includes a plurality of small copper foils <NUM>, each of which is a lobe, and the plurality of small copper foils <NUM> are arranged circumferentially around a center of the second director <NUM> at intervals.

In this embodiment, the number of the small copper foils <NUM> is at least <NUM>, for example, it may be <NUM>, <NUM>, <NUM> and so on. As shown in <FIG>, it is a schematic top view of four small copper foils in a double-layered director of the present invention.

In this embodiment, the shape of the small copper foil <NUM> may be a sectoral shape or annular sector.

As shown in <FIG>, in one embodiment, the split copper foil <NUM> is formed by <NUM> sectoral small copper foils <NUM> circumferentially arranged around the center of the second director <NUM> at intervals. In some other embodiments, the small copper foil <NUM> may also be other polygons, such as an annular sector. As shown in <FIG>, the split copper foil <NUM> is constructed of <NUM> small copper foils <NUM> of sectoral shape arranged circumferentially around the center of the second director <NUM> at intervals. Of course, the split copper foil <NUM> may also be formed by circumferentially arranging <NUM> small copper foils <NUM> of a sectoral shape around the center of the second director <NUM> at intervals. Here, the radius of each small sectoral copper foil <NUM> is smaller than <NUM>. 25λ, where λ is the wavelength of the center frequency of the antenna.

As shown in <FIG>, a second aspect of this embodiment proposes a multi-frequency base station antenna array. The multi-frequency base station antenna array includes a reflector and a high-frequency array and a low-frequency array arranged on the reflector. The high-frequency array includes several high-frequency radiation units <NUM>, and the low-frequency array includes several low-frequency radiation units <NUM>. Here, two rows of the high-frequency arrays and low-frequency arrays are provided, and a corresponding high-frequency radiation unit <NUM> is distributed below a corresponding low-frequency radiation unit <NUM>. The multi-frequency base station antenna array also includes a double-layered director described in the above embodiments, and the double-layered director is arranged directly above a corresponding high-frequency radiation unit <NUM>.

In order to fully demonstrate the effectiveness of the split director of the present invention, <FIG> shows comparison width change curves of the horizontal plane half-power beamwidth of the array antenna that adds two layers of prior art metal directors of the same size and the double-layered director of the present invention. It can be seen from <FIG> that after adding the split director of the present invention, the half-power beamwidth in the working frequency band of the antenna is more convergent, and the more the number of lobes, the more convergent the half-power beamwidth in the working frequency band. This is due to the introduction of the split director, which not only avoids the influence of the resonance of the director on the antenna high-frequency array itself, but also reduces the coupling and mutual interference between the high and low frequency radiation units, thus avoiding the superposition of scattered waves which otherwise will cause the pattern distortion.

The beneficial effects of the embodiments of the present invention are: the present invention produces multiple effects simultaneously by disposing the split copper foils <NUM> on the dielectric substrate <NUM>. This not only weakens the influence of the resonant current of the director on the high-frequency radiation unit <NUM> itself, but also simplifies the boundary of the radiation unit, and reduces the coupling and mutual interference between the high-frequency and low-frequency radiation units, and avoids the superposition of scattered waves which otherwise will cause the pattern distortion. This in turn enables the multi-frequency base station antenna to have consistent and stable horizontal half-power lobe width and gain within the operating frequency band.

The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the range described in this specification.

Claim 1:
A double-layered director, configured to be arranged directly above a corresponding high-frequency radiation unit,
the double-layered director includes a first director (<NUM>) and a second director (<NUM>) installed above the first director (<NUM>),
wherein the second director (<NUM>) includes a dielectric substrate (<NUM>) and a split copper foil (<NUM>) installed on the dielectric substrate (<NUM>);
the split copper foil (<NUM>) includes a plurality of small copper foils (<NUM>), and
the plurality of small copper foils (<NUM>) are circumferentially arranged at intervals around a center of the second director (<NUM>);
the small copper foils (<NUM>) are of an annular sectoral shape;
wherein the double-layered director is configured to weaken the influence of the resonant current of the director on the high-frequency radiation unit due to arrangement of the split copper on the electric substrate; and the first director (<NUM>) is made of a whole piece of a metal sheet.