Patent Description:
Embodiments of the present disclosure relate to the technical field of communications, and in particular, to a microstrip radiation unit and an array antenna.

With the rapid development of mobile communication technology, the 5th-Generation (<NUM>) mobile communication technology applies large-scale antenna technology, and dozens or even hundreds of antenna arrays are deployed at a base station to increase network capacity. The large-scale antenna technology in the <NUM> era turns the antenna into an integrated active antenna unit (AAU). AAU integrates the antenna and the radio remote unit (RRU), resulting in the significant increase in the total weight of the AAU, which brings great troubles to the load-bearing and antenna installation of a tower, and thus the lightweight of the antenna becomes the most intuitive and most important goal to be achieved.

The traditional radiation unit is mainly made by the following three solutions. A first solution is to adopt an aluminum alloy integral die-casting structure, in which due to the use of a metal base material with a higher density, a vibrator has a heavier weight, which does not meet a demand for lightweight of large-scale antennas. Moreover, the radiation portion and the feeding portion are separated, and the assembly is complicated, so it is not suitable for large-scale automated production. A second solution is to adopt a PCB structure, in which the radiation portion and the feeding portion are etched on different flat substrate PCBs, and then the various parts are welded together to generate electrical contact. Although this implementation greatly reduces the weight of the radiation unit, due to the large number of parts, complex assembly and low reliability, it is very adverse to large-scale automated production. A third solution is an improvement on the basis of the first solution, in which the radiation portion is made of engineering plastic by injection molding, and then the whole is electroplated. Although the weight of the radiation unit is reduced, the radiation portion and the feeding portion are still separate structures, which leads to complex assembly.

Therefore, how to meet the requirements of simplified assembly while realizing the lightweight of the radiation unit to facilitate large-scale automated production is still a pressing problem for those skilled in the art.

The Chinese patent with publication No. <CIT>, entitled "an antenna radiation unit for <NUM> system" discloses an antenna radiation unit for <NUM> system, relating to <NUM> technology field, including: the antenna comprises an upper-layer dielectric body, a lower-layer dielectric body, a radiation patch, a parasitic patch, a plurality of feed probes, a metal ground plate and a feed network; the upper-layer dielectric body is coaxially arranged at the upper end of the lower-layer dielectric body, the lower end of the lower-layer dielectric body is connected with the metal grounding plate, a plurality of feed probes are axially symmetrically arranged at the outer side of the lower-layer dielectric body, and the feed probes are positioned between the metal grounding plate and the radiation patch and keep direct current disconnection with the metal grounding plate; the feed network is arranged at the lower end of the metal grounding plate and feeds the feed probe through the pin; the parasitic patch is arranged on the upper surface of the upper-layer dielectric body, and the radiation patch is arranged on the upper surface of the lower-layer dielectric body; the radiation unit body can be integrally formed, has high processing precision and a simple structure, and is easy for later-stage array assembly; meanwhile, the electric characteristics such as dual polarization, broadband, high gain, high cross polarization discrimination and the like can be realized.

The Chinese patent publication No. <CIT>, entitled "integrated four-point differential feed low-profile dual-polarized oscillator unit and base station antenna" provides an integrated four-point differential feed low-profile dual-polarized oscillator unit and a base station antenna comprising the dual-polarized oscillator unit, wherein the dual-polarized oscillator unit comprises a dielectric substrate and a <NUM>-degree phase difference division plate which are arranged in parallel up and down, and the dielectric substrate is connected with the <NUM>-degree phase difference division plate through a dielectric support in a supporting way; one surface of the dielectric substrate, which faces away from the <NUM>-degree phase difference plate, is provided with a metal radiation surface, the metal radiation surface is provided with four feeding parts, the four feeding parts are combined into a group in pairs, the two feeding parts in the same group are symmetrically arranged relative to the center of the metal radiation surface, and the two groups of feeding parts are orthogonally arranged at an angle of plus or minus <NUM> degrees; the <NUM>-degree phase difference plate is provided with a feed connection point corresponding to the four feed parts respectively, and the feed parts are connected with the corresponding feed connection points through feed pins; two feeding connection points connected with the same group of feeding parts are connected with each other and then connected with the antenna feeding network.

patent with publication No. <CIT> entitled "antenna element for a base station antenna" discloses an antenna element preferably for a base station antenna. The antenna element comprises: a support structure being a single part and comprising a foot, a top and a wall connecting the foot to the top, the wall surrounding a hollow area; a first metallization arranged on a first surface area of the support structure, the first metallization forming at least a first radiating element extending along the wall from the foot to the top; and a second metallization arranged on a second surface area of the support structure, the second metallization forming at least a first feeding circuit for the first radiating element.

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the drawings needed to be used in the descriptions of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description show some embodiments of the present application, and other drawings may be obtained according to these drawings without any creative work for those skilled in the art.

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure are clearly and completely described below in conjunction with the accompanying drawings in the present disclosure. Obviously, the described embodiments are a part of the embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without any creative work belong to the scope of the present disclosure.

In order to solve the problems that the traditional radiation unit is generally heavy, does not meet the lightweight requirements of large-scale antennas, is relatively complicated in assembly, and is not suitable for large-scale automated production, an embodiment of the present disclosure provides a microstrip radiation unit capable of realizing the light weight of the radiation unit while meeting the requirements of simplification in assembly. <FIG> is a schematic structural diagram of a microstrip radiation unit according to an embodiment of the present disclosure. As shown in <FIG>, the microstrip radiation unit includes a dielectric substrate <NUM>, a radiation circuit <NUM>, and a feed circuit <NUM>; wherein the dielectric substrate <NUM> is integrally formed by injection molding and includes a top portion <NUM>, a support portion <NUM>, and a welding portion <NUM>. The support portion <NUM> is connected to the top portion <NUM> and the welding portion <NUM>, respectively; the radiation circuit <NUM> is arranged on an upper surface of the top portion <NUM>, and the feed circuit <NUM> is arranged on a lower surface of the top portion <NUM> and extends along the support portion <NUM> to the welding portion <NUM>.

In an embodiment, the dielectric substrate <NUM> is an integrally injection-molded single part including the top portion <NUM>, the support portion <NUM>, and the welding portion <NUM> from top to bottom, wherein the support portion <NUM> is a connecting part between the top portion <NUM> and the welding portion <NUM>. Although the support portion <NUM> may be a single column structure as shown in <FIG>, it may also be composed of a plurality of support components. Here, a surface of the top portion <NUM> in contact with the support portion <NUM> is confirmed as a lower surface of the top portion <NUM>, and accordingly a surface of the top portion <NUM> not in contact with the support portion <NUM> is confirmed as an upper surface of the top portion <NUM>. The radiation circuit <NUM> is arranged on the upper surface of the top portion <NUM>. The radiation circuit <NUM> may completely cover the upper surface of the top portion <NUM>, or may be arranged on the upper surface of the top portion <NUM> in a shape consistent with the upper surface of the top portion <NUM>, or may be arranged at a preset position of the upper surface on the top portion <NUM> based on a preset shape, which is not limited in the embodiment of the present disclosure. Correspondingly, the feed circuit <NUM> is arranged on the back of a surface for arranging the radiation circuit <NUM>, that is, the lower surface of the top portion <NUM>, and the support portion <NUM> in contact with the lower surface of the top portion <NUM> finally extends to the welding portion <NUM>, so as to facilitate the electric connection between the feed circuit <NUM> and the feed network through the welding portion <NUM> in the state that the welding portion <NUM> is connected to the feed network when the microstrip radiation unit is installed. It should be noted that the radiation circuit <NUM> is arranged on the upper surface of the top portion <NUM>, the feed circuit <NUM> is arranged on the lower surface of the top portion <NUM>, and a specific arrangement position of the radiation circuit <NUM> on the upper surface of the top portion <NUM> corresponds to a specific arrangement position of the feed circuit <NUM> on the lower surface of the top portion <NUM> such that the radiation circuit <NUM> arranged on the upper surface of the top portion <NUM> and the feed circuit <NUM> arranged on the lower surface of the top portion <NUM> form a coupled feeding of the radiation unit.

In addition, the radiation circuit <NUM> and the feed circuit <NUM> may be arranged on the dielectric substrate <NUM> by 3D-MID (3D molded interconnect device) technology.

In the microstrip radiation unit according to the embodiment of the present disclosure, the weight of the radiation unit is reduced by an integrally injection-molded dielectric substrate <NUM>, and the radiation circuit <NUM> and the feed circuit <NUM> are both arranged on the dielectric substrate <NUM> to realize the integration of the radiation unit, thus simple structure is provided, no assembly is required, reliability and consistency of the radiation units are improved, and it is more suitable for large-scale manufacturing. In addition, the single-layer radiation circuit is adopted to implement the microstrip radiation unit, which has good low profile characteristics, effectively reduces the height of the radiation unit, further reduces the weight of the radiation unit, and provides the lightweight of the radiation unit.

Based on the above embodiments, <FIG> is a schematic structural diagram of a microstrip radiation unit according to another embodiment of the present disclosure. As shown in <FIG>, in the microstrip radiation unit, an extension hole <NUM> is opened in the center of the top portion <NUM>, and extends towards the direction of the welding portion in the support portion; and the radiation circuit is extended to and arranged on a wall of the extension hole <NUM>.

In an embodiment, an extension hole <NUM> is provided in the center of the top portion <NUM>, and extends towards the direction of the welding portion. Here, the extension hole <NUM> may be a through hole, that is, both the support portion and the welding portion of the dielectric substrate are designed as hollow structures. Alternatively, the extension hole <NUM> may also be a blind hole, that is, the extension hole <NUM> extends in but does not pass through the support portion, which is not specifically limited in the embodiment of the present disclosure. By making the extension hole <NUM> in the dielectric substrate, the materials used may be further reduced, and thus the weight of the microstrip radiation unit may be decreased.

On this basis, the radiation circuit arranged on the upper surface of the top portion <NUM> is extended to and arranged on the wall of the extension hole <NUM>. In <FIG>, the radiation circuit is divided into two parts, one part is a radiation circuit arranged on the upper surface of the top portion <NUM>, that is, a top radiation circuit <NUM>, and the other is a radiation circuit extending to the wall of the extension hole <NUM>, that is, the extension radiation circuit <NUM>. Since the extension hole <NUM> is a hole provided in the center of the support portion, the support portion may be regarded as a hollow structure, the wall of the extension hole <NUM> is regarded as the inner wall of the support portion, and the surface of the support portion on which the feed circuit is arranged is regarded as an outer wall of the support portion. By extending and arranging the radiation circuit on the inner wall of the support portion, the cross-polarization index of the microstrip radiation unit may be greatly improved.

Based on any of the above embodiments, in the microstrip radiation unit, a non-conductive area is also arranged on the radiation circuit.

In an embodiment, in order to improve the polarized isolation, a non-conductive area is also arranged on the upper surface of the top portion, and the embodiments of the present disclosure do not limit the shape, number, and specific location of the non-conductive area. <FIG> is a top view of a microstrip radiation unit according to an embodiment of the present disclosure. As shown in <FIG>, the top portion <NUM> of the dielectric substrate is circular, the top portion <NUM> is provided with a radiation circuit <NUM>, and the center of the top portion <NUM> is provided with an extension hole <NUM>. Four groups of demetallized non-conductive areas <NUM>, each of which is a staight-line shape, are evenly distributed on the upper surface with the center of the top portion <NUM> as a center of symmetry. <FIG> is a top view of a microstrip radiation unit according to another embodiment of the present disclosure. As shown in <FIG>, the top portion <NUM> of the dielectric substrate is octagonal, the top portion <NUM> is provided with a radiation circuit <NUM>, and the center of the top portion <NUM> is provided with an extension hole <NUM>. Four groups of demetallized non-conductive areas <NUM>, each of which is splayed, are evenly distributed on the upper surface with the center of the top portion <NUM> as a center of symmetry.

Based on any of the above embodiments, in the microstrip radiation unit, reinforcing ribs are also arranged on the top portion.

In an embodiment, by additionally arranging reinforcing ribs on the top portion of the dielectric substrate, the structural strength of the integrated dielectric substrate and the flatness of the top planar structure may be improved. Square-shaped reinforcing ribs with skirt may be disposed at the peripheral edges of the top portion, or cross-shaped reinforcing ribs may be disposed on the surface of the top portion based on the center of the top portion, which is not specifically limited in the embodiments of the present disclosure.

Based on any of the above embodiments, in the microstrip radiation unit, the radiation circuit and the feed circuit are symmetrically arranged about a central axis of the dielectric substrate. Therefore, when the microstrip radiation unit is subject to the complete machine assembly as a single component, the electrical connection assembly of the radiation unit and the feed network does not require additional identification, which is very suitable for automated production in large-scale array antenna applications.

Based on any of the above embodiments, <FIG> is a bottom view of the microstrip radiation unit according to an embodiment of the present disclosure. As shown in <FIG>, the microstrip radiation unit includes four groups of feed circuits <NUM> uniformly distributed with a central axis of the dielectric substrate <NUM> as an axis of symmetry.

In an embodiment, each group of feed circuits <NUM> has the same structure, and is distributed along the central axis by a <NUM>° rotation in sequence. Here, the microstrip radiation unit containing four groups of feed circuits <NUM> is referred to as a dual-polarized radiation unit. Each polarization of the dual-polarized radiation unit is fed differentially (with a <NUM>° phase difference) by two groups of feed circuits <NUM> arranged oppositely and symmetrically so as to suppress high-order modes, further reduce the coupling between two ports, and improve the pattern consistency and isolation of +<NUM>° polarization and -<NUM>° polarization of a dual-polarized oscillator.

Based on any of the above embodiments, in the microstrip radiation unit, the welding portion <NUM> includes four plug pins <NUM> evenly distributed with the central axis of the dielectric substrate <NUM> as an axis of symmetry, and each feed circuit <NUM> wraps a plug pin <NUM>.

In an embodiment, referring to <FIG>, each feed circuit <NUM> includes a top feed circuit <NUM>, an intermediate connecting portion <NUM> and a bottom welding portion <NUM>. The top feed circuit <NUM> is a portion of said feed circuit <NUM> arranged on the top portion <NUM> of the dielectric substrate, the intermediate connecting portion <NUM> is a portion of said feed circuit <NUM> arranged on the support portion <NUM> of the dielectric substrate for connecting the top feed circuit <NUM> and the bottom welding portion <NUM>, and the bottom welding portion <NUM> is a portion of said feed circuit <NUM> arranged on the welding portion <NUM> of the dielectric substrate for wrapping one plug pin <NUM> corresponding to the welding portion <NUM>. Here, the bottom welding portion <NUM> for wrapping the plug pin <NUM> is configured to electrically connect with a port of the feed network to provide signal excitation.

Based on any of the foregoing embodiments, referring to <FIG>, in the microstrip radiation unit, a slot <NUM> is provided between any two adjacent plug pins <NUM> of the welding portion <NUM>. Through the arrangement of the slot <NUM>, the weight of the integrated dielectric substrate <NUM> is further decreased. Here, the slot <NUM> may be a slot of various shapes such as U-shaped slot and V-shaped slot.

Based on any of the above embodiments, the microstrip radiation unit is a three-dimensional molded interconnect device, and the entire microstrip radiation unit is a single component, which simplifies a supply chain, has a simple structure, improves the reliability and consistency of the radiation units, and is suitable for large-scale manufacture.

Based on any of the above embodiments, <FIG> is a schematic structural diagram of an array antenna according to an embodiment of the present disclosure. As shown in <FIG>, the array antenna includes several microstrip radiation units <NUM>, and a feed network <NUM> configured to install each microstrip radiation unit <NUM>.

In an embodiment, each microstrip radiation unit <NUM> is welded to the feed network <NUM> through the welding portion of the dielectric substrate to provide the electrical connection between the feed circuit and the feed network <NUM>. The welding portion may be a pin-type welding structure, or may be a patch-type welding structure, and the installation method between the microstrip radiation unit <NUM> and the feed network <NUM> is not specifically limited in the embodiments of the present disclosure.

<FIG> is a schematic structural diagram of a feed network according to an embodiment of the present disclosure. Referring to <FIG>, several feed ports <NUM> are provided on the feed network <NUM> for electrical connection with the welding portion of the microstrip radiation unit. In <FIG>, four feed ports <NUM> are provided for the microstrip radiation unit whose welding portion includes four plug pins. Each plug pin corresponds to one feed port <NUM>. In the case that four plug pins have rotational center symmetry, the four plug pins only need to be directly connected to the four feed ports <NUM> without additional identification during assembly, and thus blind mating assembly may be realized, which may significantly shorten the assembly time in antenna production and increase the assembly efficiency. Therefore, it is very suitable for implementing automated production in large-scale array antenna applications.

<FIG> is a schematic diagram of differential feeding of an integrated microstrip radiation unit according to an embodiment of the present disclosure, including an integrated microstrip radiation unit <NUM> and a differential feed network <NUM> thereof. Referring to <FIG> and <FIG>, the four plug pins of the integrated radiation unit are blindly plugged into the four feed ports of the differential feed network <NUM> without additional identification. In the differential feed network <NUM>, two feed ports of the same polarization are arranged oppositely with a <NUM>° phase difference.

Referring to <FIG>, the microstrip radiation unit <NUM> includes a dielectric substrate <NUM>, a radiation circuit <NUM> and a feed circuit <NUM>. The dielectric substrate <NUM> is an integrated structure and is integrally formed by injection molding with high-temperature-resistant engineering plastics. The dielectric substrate <NUM> includes a top portion <NUM>, a support portion <NUM>, a welding portion <NUM>, and reinforcing ribs <NUM>. An extension hole <NUM> is provided at the center of the top portion <NUM> to form a smooth transition structure with the support portion <NUM>, which is unobstructed from the top view. The radiation circuit <NUM> includes a top radiation circuit <NUM> arranged on the upper surface of the top portion <NUM> of the dielectric substrate and an extension radiation circuit <NUM> arranged on the wall surface of the extension hole <NUM>. In addition, the top radiation circuit <NUM> is provided with a demetallized gap, that is, a non-conductive area <NUM>. The feed circuit <NUM> includes a top feed circuit <NUM> arranged on the bottom surface of the top portion <NUM> of the dielectric substrate, an intermediate connecting portion <NUM> arranged on the outer wall surface of the support portion <NUM> of the dielectric substrate, and a bottom welding portion <NUM> arranged on the welding portion of the dielectric substrate and wrapping one of the four plug pins of the welding portion <NUM> of the entire dielectric substrate.

Here, the top portion <NUM> of the dielectric substrate has a square planar structure, and may also has a round or other polygonal structure. Through the arrangement of the extension hole <NUM> at the center of the top portion <NUM>, materials used may be reduced and the weight of the integrated dielectric substrate <NUM> is also decreased. The top radiation circuit <NUM> arranged on the top portion <NUM> of the dielectric substrate has a circuit shape consistent with the planar shape of the top portion <NUM> of the dielectric substrate <NUM>. On the top radiation circuit <NUM>, four groups of non-conductive regions <NUM> having the same structures with the central axis of the dielectric substrate <NUM> as the axis of symmetry are provided, whose shapes are linear or inversed V-shaped or other deformed shapes, so as to improve the polarization isolation. Through the arrangement of the extension radiation circuit <NUM> extending downwardly from a connection part between the extension hole <NUM> on the top portion <NUM> of the dielectric substrate and the support portion <NUM> of the dielectric substrate toward the inner surface of the support portion <NUM> of the dielectric substrate, that is, along the wall of the extension hole <NUM>, the cross-polarization ratio index of the microstrip radiation unit <NUM> may be greatly improved.

The reinforcing ribs <NUM> are respectively arranged on the peripheral edges of the top portion <NUM> of the dielectric substrate, forming a square skirt, and a cross shape on the center of the bottom surface of the top portion <NUM>, so as to improve the structural strength of the integrated dielectric substrate <NUM> and the flatness of the planar structure of the top portion <NUM>. In addition, the support portion <NUM> forms a hollow closed structure to enhance the structural strength of the integrated dielectric substrate <NUM>. The support portion <NUM> may be in a barrel shape or other closed shapes. The welding portion <NUM> includes four surrounding plug pins <NUM> that rotate by <NUM>°. A U-shaped slot <NUM> is provided in an area of two adjacent plug pins <NUM> to further reduce the weight of the integrated dielectric substrate <NUM>.

The microstrip radiation unit <NUM> includes four groups of feed circuits <NUM>, each of which has the same structure and is distributed along the central axis in a <NUM>° rotation in turn. For a single feed circuit <NUM>, the top feed circuit <NUM>, arranged on the bottom surface of the top portion <NUM>, in the feed circuit <NUM> and the radiation circuit <NUM> form a radiation unit coupling feed, and the intermediate connecting portion <NUM> is configured to connect with the top feed circuit <NUM> and the bottom welding portion <NUM>, so as to provide the continuous electrical connection of the entire feed circuit <NUM>. The bottom welding portion <NUM> for wrapping the plug pin <NUM> is configured to electrically connect with a feed port of the feed network <NUM> to provide signal excitation. Here, the bottom welding portion <NUM> may be configured as a pin-type plug-welding type structure, or may be configured as a disc-shaped patch type welding structure, which is not specifically limited in the embodiments of the present disclosure. The four groups of feed circuits <NUM> based on the above structure jointly provide the feed excitation of the dual-polarized microstrip radiation unit <NUM>, so as to suppress high-order modes, further reduce the coupling between two ports, and improve the pattern consistency and isolation of +<NUM>° polarization and -<NUM>° polarization of a dual-polarized oscillator. It should be noted that in the embodiments of the present disclosure, the coupling feed mode may be adopted to effectively increase the matching bandwidth of the oscillator.

Claim 1:
A microstrip radiation unit (<NUM>), comprising
a dielectric substrate (<NUM>),
a radiation circuit (<NUM>) and a feed circuit (<NUM>);
wherein the dielectric substrate (<NUM>) is integrally formed by injection molding, and comprises a top portion (<NUM>), a support portion (<NUM>) and a welding portion (<NUM>), and the support portion (<NUM>) is connected to the top portion (<NUM>) and the welding portion (<NUM>) respectively;
the support portion (<NUM>) is a single column structure or is composed of a plurality of support components, and
the welding portion (<NUM>) is used for providing the electrical connection between the feed circuit (<NUM>) and a feed network (<NUM>) when being connected with the feed network;
the radiation circuit (<NUM>) is arranged on an upper surface of the top portion (<NUM>), and the feed circuit (<NUM>) comprises an intermediate connecting portion (<NUM>) that extends along an outer surface of the support portion (<NUM>), and a bottom welding portion (<NUM>) arranged on the welding portion (<NUM>) and connected to the intermediate connecting portion (<NUM>); and
an extension hole (<NUM>) is provided in the center of the top portion (<NUM>), and extends towards the direction of the welding portion (<NUM>) in the support portion (<NUM>); and the radiation circuit (<NUM>) is extended to and arranged on a wall of the extension hole (<NUM>),
characterized in that,
the feed circuit (<NUM>) comprises a top feed circuit (<NUM>) arranged on a lower surface of the top portion (<NUM>) and connected to the intermediate connecting portion (<NUM>), wherein the feed circuit (<NUM>) has an elongated shape with a first end being the bottom welding portion and a second end being the top feed circuit (<NUM>).