CN214336921U - Differential feed network and antenna - Google Patents

Abstract

The utility model provides a differential feed network for produce two routes output signal with 180 degrees phase differences, including parallel double-line, public metal boundary and shielding part, the three forms altogether boundary shielding double-line structure: the common metal boundary is located between the parallel double lines, the shielding part is connected with the common metal boundary to form two shielding cavities, and the parallel double lines are respectively located in the two shielding cavities. The present disclosure also provides an antenna, including a dual-polarized radiation unit and the differential feed network. The differential feed network disclosed by the invention realizes mode conversion of TEM waves by a common boundary shielding double-wire structure, can realize stable and undisturbed two paths of signals with 180-degree phase difference in a wider frequency band, can expand the working bandwidth of an antenna, effectively reduces the cross polarization of radiation, and improves the symmetry and stability of an antenna directional diagram.

Description

Differential feed network and antenna

Technical Field

The utility model relates to the field of communication technology, especially, relate to a differential feed network and an antenna.

Background

The feeding network of the antenna is one of the important components in the antenna, and in the radio frequency circuit for wireless communication, feeding the antenna by using a differential feeding technology has become a common feeding mode. The differential feed adopts two feed ports, and two paths of differential mode signals with equal size and 180-degree phase difference are respectively input to the two feed ports to serve as excitation signals. The differential feed plays a key role in realizing low cross polarization and differential mode beams for the antenna. With the development of antenna technology, higher and higher broadband requirements are put on the application of antennas. One of the key techniques for differential feeding is whether it can keep the transmission signals of the differential ports in anti-phase over a wide frequency band.

SUMMERY OF THE UTILITY MODEL

The present disclosure describes a differential feed network and an antenna.

According to a first aspect of embodiments of the present disclosure, there is provided a differential feed network for generating two output signals with a phase difference of 180 degrees, comprising parallel twin wires, a common metal boundary and a shielding part, which together form a common boundary shielded twin wire structure: the common metal boundary is located between the parallel double lines, the shielding part is connected with the common metal boundary to form two shielding cavities, and the parallel double lines are respectively located in the two shielding cavities.

According to one embodiment of the differential feeding network, the shielding section comprises a metallic shielding layer and a metallic connection section for connecting the metallic shielding layer with the common metallic boundary.

According to one embodiment of the differential feed network, the parallel twin lines are first converted into a transition structure and then into a common boundary shielded twin line structure.

According to one embodiment of the differential feed network, the transition structure is a shielded two-wire structure formed by parallel two wires and a shielding part, wherein the shielding part forms a shielding cavity and the parallel two wires are located in the shielding cavity.

According to one embodiment of the differential feed network, the transition structure is a common-boundary dual microstrip structure formed by parallel double lines and a common metal boundary, wherein the common metal boundary is located between the parallel double lines.

According to one embodiment of the differential feed network, the parallel two lines are converted from microstrip lines.

According to one embodiment of the differential feed network, the differential feed network is disposed on a PCB board, the PCB board includes a plurality of metal layers, wherein the parallel twin lines are disposed on two metal layers, the common metal boundary is disposed on the metal layer between the parallel twin lines, the metal shielding layer is disposed on the two metal layers outside the parallel twin lines, and the metal connecting portion penetrates through the metal shielding layer and the common metal boundary.

According to a second aspect of embodiments of the present disclosure, there is provided an antenna comprising: a dual-polarized radiation unit for radiating or receiving electromagnetic waves to or from a space; and the differential feed network is used for carrying out differential feed on the dual-polarized radiation unit.

The differential feed technology disclosed by the invention realizes mode conversion of TEM waves through a common boundary shielding double-wire structure, can realize stable and undisturbed two paths of signals with 180-degree phase difference in a wider frequency band, and can expand the working bandwidth of an antenna, effectively reduce the cross polarization of radiation and improve the symmetry and stability of an antenna directional diagram by using the differential feed network disclosed by the invention.

Drawings

Fig. 1 is a schematic structural diagram of a differential feed network shown in the present disclosure according to an embodiment.

Fig. 2 is a schematic diagram of the electric field around a differential feed network shown in the present disclosure according to one embodiment.

Fig. 3 is a graph illustrating electric field simulations around a differential feed network according to one embodiment of the present disclosure.

Fig. 4 is a schematic structural diagram of a differential feed network shown in the present disclosure according to an embodiment.

Fig. 5 is a schematic structural diagram of a differential feed network shown in the present disclosure according to an embodiment.

Detailed Description

Embodiments of the present disclosure are described below with reference to the drawings. It should be understood that the drawings are not necessarily to scale. The described embodiments are exemplary and not intended to limit the present disclosure, which features may be combined with or substituted for those of the embodiments in the same or similar manner. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

In a radio frequency circuit for wireless communication, feeding an antenna by using a differential feeding technology has become a common feeding method. The differential feed adopts two feed ports, and two paths of differential mode signals with equal size and 180-degree phase difference are respectively input to the two feed ports to serve as excitation signals. The differential feed plays a key role in achieving low cross polarization and differential mode beam for the antenna. With the development of antenna technology, higher and higher broadband requirements are put on the application of antennas. In the related art, currently, 5G NR needs to cover a 700MHz-5GHz frequency band. In addition, the recent LTE newly expands the frequency band of 400MHz, and the Wi-Fi dual frequency requires the frequency bands of 2.4GHz and 5 GHz. In order to meet the application scenario of a wide frequency band, a requirement is made for inverting the transmission signal of a differential port in which differential feeding is stable in a wide frequency band.

In view of this, an embodiment of an aspect of the present disclosure provides a differential feed network for generating two output signals with a phase difference of 180 degrees, and referring to fig. 1, the differential feed network includes parallel twin wires 100, a common metal boundary 200 and a shielding part 300, which together form a common-boundary shielded twin-wire structure, where the common-boundary shielded twin-wire structure is: the common metal border 200 is located between two parallel double lines 100 which are parallel up and down, the shielding part 300 is connected with the common metal border 200 to form two shielding cavities, and the two parallel double lines 100 are respectively located in the two shielding cavities.

The differential feed technology disclosed by the invention realizes mode conversion of TEM waves through a common boundary shielding double-wire structure, and can realize stable and undisturbed two paths of signals with 180-degree phase difference in a wider frequency band, referring to FIG. 2, wherein the left diagram shows an open parallel double-wire transmission line, the right diagram shows a common boundary shielding double-wire structure, and an arrow in the diagram represents an electric field direction; and referring to fig. 3, wherein the left diagram illustrates an electric field simulation diagram around an open parallel twin line and the right diagram illustrates an electric field simulation diagram around a common border shielded twin line structure. By using the differential feed technology disclosed by the invention, the working bandwidth of the antenna can be expanded, the cross polarization of radiation is effectively reduced, and the symmetry and stability of an antenna directional diagram are improved. The common metal boundary divides the TEM wave main mode into two sub-modes, and the two sub-modes form stable differential phase and equal common ratio according to current distribution and phase on the double lines. The shield contributes to a shielded strip-line TEM mode by connecting to the common metal boundary, which has the benefit of noise electromagnetic shielding and improves the system signal-to-noise ratio. If the shield is not connected to the common metal boundary, it can cause resonance problems in the bandwidth and reduce system performance. The setting of shielding part can avoid thereby open feed arouses the whole cross polarization of high-order mode radiation deterioration antenna on the one hand, thereby on the other hand avoids introducing the signal to noise ratio of external electromagnetic interference influence system.

In some embodiments, the shield portion includes a metal shield layer and a metal connection portion for connecting the metal shield layer and the common metal boundary. As an example, as shown in fig. 1, the shielding part 300 includes a metal shielding layer 301 and a metal connecting part 302, wherein the metal shielding layer 301 is two flat plate-type metal structures disposed up and down, and the metal connecting part 302 is a metal structure connecting the metal shielding layer 301 and the common metal boundary 200.

Optionally, the parallel twinax is first converted to a transition structure and then to a common boundary shielded twinax structure. Referring to fig. 2, it can be seen that the electric field distribution of the parallel double-line structure is very different from that of the common-boundary shielding double-line structure, and the introduction of the transition structure can avoid signal distortion caused by different structure conversion, and simultaneously avoid the problem of common-mode current interference caused by mode mismatch. Specifically, referring to fig. 4, in some embodiments, the parallel twinax 100 is first converted into a transition structure, which is a shielded twinax structure formed by the parallel twinax 100 and the shielding portion 300, wherein the shielding portion 300 encloses to form a shielded cavity, the parallel twinax 100 is located in the shielded cavity, and then converted into a common boundary shielded twinax structure after the transition structure. Referring to fig. 5, in other embodiments, the parallel twinax 100 is first converted to a transition structure, which is a common boundary dual microstrip structure formed by the parallel twinax 100 and a common metal boundary 200, wherein the common metal boundary 200 is located between the parallel twinax 100, and then converted to a common boundary shield twinax structure after the transition structure.

Alternatively, the parallel double lines are converted from microstrip lines. And differential feed is adopted on the basis of the microstrip line, so that the cross polarization of the antenna can be further improved, and meanwhile, the connection with an external circuit is facilitated.

Optionally, the differential feeding network is disposed on a PCB, the PCB includes a plurality of metal layers, wherein the parallel twin lines are disposed on two metal layers respectively, the common metal boundary is disposed on the metal layer between the parallel twin lines, the metal shielding layer is disposed on the two metal layers outside the parallel twin lines, and the metal connecting portion penetrates through the metal shielding layer and the common metal boundary.

Another aspect of the present disclosure provides an antenna, including: a dual-polarized radiation unit for radiating or receiving electromagnetic waves to or from a space; and the differential feed network is used for carrying out differential feed on the dual-polarized radiating elements. The dual-polarized antenna adopting differential feed can reduce the multipath loss of the antenna, so that the antenna can receive more energy.

It should be noted that the drawings in the present disclosure are simplified schematic drawings, and are only used for schematically illustrating the positional relationship and the connection relationship between the parts in the embodiments.

In the description above, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In the present disclosure, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present disclosure, "a plurality" means at least two, e.g., two, three, etc., unless explicitly specifically limited otherwise.

Although embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure, and that changes, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present disclosure.

Claims (8)

1. A differential feed network is used for generating two paths of output signals with 180-degree phase difference and is characterized by comprising parallel double lines, a common metal boundary and a shielding part, wherein the parallel double lines, the common metal boundary and the shielding part form a common boundary shielding double-line structure: the common metal boundary is located between the parallel double lines, the shielding part is connected with the common metal boundary to form two shielding cavities, and the parallel double lines are located in the two shielding cavities respectively.

2. The differential feed network of claim 1, wherein said shield portion comprises a metallic shield layer and a metallic connection portion for connecting said metallic shield layer to said common metallic boundary.

3. The differential feed network of claim 1, wherein said parallel twinax is first converted to a transition structure and then to said common boundary shielded twinax structure.

4. The differential feed network of claim 3, wherein the transition structure is a shielded two-wire structure formed by the parallel twin wires and the shield, wherein the shield forms a shielded cavity and the parallel twin wires are located within the shielded cavity.

5. The differential feed network of claim 3, wherein said transition structure is a common-boundary dual microstrip structure formed by said parallel twin lines and said common metal boundary, wherein said common metal boundary is located between said parallel twin lines.

6. The differential feed network of claim 1, wherein said parallel dual lines are converted from microstrip lines.

7. The differential feed network of claim 2, wherein said differential feed network is disposed on a PCB board, said PCB board comprising a plurality of metal layers, wherein said parallel twin wires are disposed on two of said metal layers, respectively, said common metal boundary is disposed on said metal layer between said parallel twin wires, said metal shielding layer is disposed on two of said metal layers outside said parallel twin wires, and said metal connecting portion penetrates said metal shielding layer and said common metal boundary.

8. An antenna, comprising:

a dual-polarized radiation unit for radiating or receiving electromagnetic waves to or from a space; and

a differential feed network according to any of claims 1-7, for differential feeding of said dual polarized radiating elements.

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