A differential-fed cross-polarized high-gain antenna

Abstract

The present invention discloses a differential-fed cross-polarized high-gain antenna, which includes a radiation surface, a reflecting surface, and a feeding network disposed between the radiation surface and the reflecting surface. The feeding network is set to be one group or two orthogonal groups; the feeding network includes a one-to-two differential power divider. The differential power divider includes two branches, and each of the two branches includes two double-strip lines. The two groups of double-strip lines are symmetrically arranged along the horizontal direction, and a feeding probe coupled to the radiation surface is respectively provided at the ends of the two groups of double-strip lines. The two feeding probes are respectively connected to the front and back sides of the two groups of double-strip lines, and the phases of the two feeding probes differ by 180 degrees. The radiation surface is set to be an axisymmetric surface, and the two feeding probes are symmetrically disposed on both sides of the radiation surface. The technical solution of the present invention realizes high gain and ultra-wideband of the antenna.

Description

Technical Field

[0001] The present invention relates to the technical field of antenna communication, and particularly to a differentially-fed cross-polarized high-gain antenna. Background Art

[0002] With the development of mobile 5G Internet and vehicle-to-everything (V2X), whether it is an array antenna or a MIMO antenna, they all tend to develop towards miniaturization and ultra-wideband. Cross-polarized antennas utilize spatial multiplexing and save a great deal of space to a large extent; while ultra-wideband technology not only requires the radiation surface of the antenna to be ultra-wideband, but also the feeding network to support ultra-wideband. Differentially-fed antennas can improve the antenna gain and are widely used in array antennas. However, the bandwidth of traditional differentially-fed network is narrow, thus affecting the bandwidth of the entire antenna. Therefore, there are deficiencies in the prior art and improvements are needed. Summary of the Invention

[0003] The main object of the present invention is to propose a differentially-fed cross-polarized high-gain antenna, aiming to achieve high gain, narrow beamwidth, and ultra-wideband of the antenna.

[0004] To achieve the above object, a differentially-fed cross-polarized high-gain antenna proposed by the present invention includes a radiation surface, a reflecting surface, and a feeding network disposed between the radiation surface and the reflecting surface. The feeding network is set as one group or two orthogonal groups; the feeding network includes a one-to-two differential power divider. The differential power divider includes two branches, and each branch includes two double-strip lines. The two groups of double-strip lines are symmetrically arranged along the horizontal direction, and a feeding probe coupled to the radiation surface is respectively provided at the end of each group of double-strip lines. The two feeding probes are respectively connected to the front and back sides of the two groups of double-strip lines, and the phases of the two feeding probes differ by 180 degrees. The radiation surface is set as an axisymmetric surface, and the two feeding probes are symmetrically disposed on both sides of the radiation surface.

[0005] Preferably, the radiation surface is set as a rectangular, circular, or octagonal patch.

[0006] Preferably, the radiation surface is set as a rectangular patch, and the two feeding probes are respectively disposed at the two diagonals or the centers of the two symmetric sides of the rectangular patch.

[0007] Preferably, the feeding network is set as two groups, and the two groups of feeding networks are arranged vertically and orthogonally along the horizontal direction.

[0008] Preferably, the two feeding probes are set as feeding probes for diagonal coupling feeding on the radiation surface.

[0009] Preferably, the 3dB beamwidths of the E-plane and H-plane of the antenna are 48 degrees at the resonant frequency of 3.7 - 3.9 GHz.

[0010] Preferably, the isolation between the two ports of the antenna is less than -22 dB at a resonant frequency of 3.7 - 3.9 GHz.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: The feeding network adopts two coupled feeding probes, which are respectively coupled and fed at the diagonal or opposite center of the radiation surface, and has a wider bandwidth than direct feeding. At the same time, a one-to-two differential power divider is adopted, and a pair of strip lines are respectively installed at both ends. With a double-strip line structure, the phases on the two conductors of the double-strip line differ by 180 degrees itself. Electromagnetic waves with equal energy and a phase difference of 180 degrees are respectively fed to the two ports of the antenna from the diagonal of the radiation surface. Combined with the diagonal feeding of the radiation surface, the phase also differs by 180 degrees, and the overall difference is an integer multiple of 360 degrees, so that the exciting currents are superimposed in the same direction, improving the gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0013] Figure 1 It is a schematic diagram of the overall structure of the antenna of the present invention;

[0014] Figure 2 It is a schematic diagram of a set of feeding network structures of the present invention;

[0015] Figure 3 It is a schematic diagram of two sets of feeding network structures of the present invention;

[0016] Figure 4 It is a schematic diagram of the SWR of the antenna of the present invention;

[0017] Figure 5 It is a schematic diagram of the E-plane of the antenna of the present invention;

[0018] Figure 6 It is a schematic diagram of the H-plane of the antenna of the present invention;

[0019] The realization, functional characteristics and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] A differential-fed cross-polarized high-gain antenna proposed in this embodiment refers to Figure 1 and Figure 2, comprising a radiation surface 1, a reflecting surface 2, and a feeding network 3 disposed between the radiation surface 1 and the reflecting surface 2, the feeding network 3 being provided as one set or two orthogonal sets; the feeding network 3 includes a one-to-two differential power divider 31, the differential power divider 31 includes two branches, and the two branches respectively include two double-strip lines 32, the two sets of double-strip lines 32 are symmetrically arranged in the horizontal direction, and a feeding probe 33 coupled to the radiation surface 1 is respectively provided at the ends of the two sets of double-strip lines 32, the two feeding probes 33 are respectively connected to the front and back sides of the two sets of double-strip lines 32, and the phases of the two feeding probes 33 differ by 180 degrees, the radiation surface 1 is provided as an axisymmetric surface, and the two feeding probes 33 are symmetrically disposed on both sides of the radiation surface 1.

[0021] It should be noted that the radiation surface 1 can be provided as a rectangular, circular or octagonal patch. In this embodiment, the radiation surface 1 is provided as a rectangular patch, and the two feeding probes 33 are respectively disposed at the two diagonals or the centers of the two symmetric sides of the rectangular patch. The two feeding probes 33 are provided as feeding probes 33 for diagonal coupling feeding on the radiation surface 1. The incident wave enters from the incident port and passes through the one-to-two differential power divider 31, dividing the energy into two equal parts. Then it is transmitted to the feeding probes 33 through the two double-strip line branches. The two feeding probes 33 are respectively connected to the upper and lower sides of the double-strip line, so the phases differ by 180 degrees. The probes feed the antenna at two positions at the diagonals or the centers of the two opposite sides of the radiation patch respectively. When feeding at the two diagonals, the two excited currents are equal in magnitude and opposite in direction, and the phases differ by 180 degrees. If there is no differential feeding, the radiated electromagnetic waves cancel each other out in the normal direction; the phases of the two ports of the differential feeding network 3 itself differ by 180 degrees, so the currents excited by the two diagonal feedings on the antenna differ by 360 degrees, that is, 0 degrees, and the radiated electromagnetic waves are enhanced in the normal direction, and the gain will increase. Diagonal feeding or feeding on opposite sides can theoretically be regarded as two radiation surfaces 1. If the excited currents are in the same direction, they will be superimposed, and the gain will be higher than that of single-corner or single-side feeding.

[0022] It should be noted that in order to superimpose the electromagnetic waves fed diagonally, the phases of the two feeds must differ by 180 degrees. The traditional power divider uses a lengthened microstrip line with a length equal to half of the wavelength of the center frequency, causing a phase lag of 180 degrees, and a 180-degree phase difference is generated between the two ports. Then, for frequencies lower than the center frequency, increasing this length results in a phase lag of less than 180 degrees; for frequencies higher than the center frequency, increasing this length results in a phase lag exceeding 180 degrees. Therefore, theoretically, only at the center frequency can the phases of the two feeds differ by 180 degrees, and the electromagnetic waves radiated through the patch can be superimposed. Deviating from the center frequency will result in poor effects. Therefore, the bandwidth of traditional differential feeding is limited. In the differential network of this embodiment, the phases of the two conductors of the double strip line always differ by 180 degrees regardless of the frequency. Therefore, it is a broadband differential power divider 31, and the lengths of the two groups of double strip lines 32 are equal, and no additional compensation is required.

[0023] Further, referring to Figure 3 . The feeding network 3 is set to two groups, and the two groups of feeding networks 3 are arranged vertically and orthogonally along the horizontal direction.

[0024] Further, the 3dB beamwidth of the antenna is narrow, about 10 degrees narrower than that in the case of single feeding. When the resonant frequency is 3.7 - 3.9 GHz, the 3dB beamwidths of the E-plane and H-plane of the antenna are 48 degrees, and the isolation degree between the two ports of the antenna is lower than -22 dB.

[0025] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A differential-fed cross-polarized high-gain antenna, characterized in that, It includes a radiation surface, a reflection surface and a feeding network disposed between the radiation surface and the reflection surface, and the feeding network is arranged in one group or two orthogonal groups; the feeding network includes a one-to-two differential power divider, the differential power divider includes two branches, and each of the two branches includes two double-strip lines. The two groups of double-strip lines are symmetrically arranged in the horizontal direction, and a feeding probe coupled to the radiation surface is respectively provided at the end of each of the two groups of double-strip lines. The two feeding probes are respectively connected to the front and back sides of the two groups of double-strip lines, and the phases of the two feeding probes differ by 180 degrees. The radiation surface is arranged as an axisymmetric surface, and the two feeding probes are symmetrically disposed on both sides of the radiation surface; The two feeding probes are arranged as feeding probes for diagonal coupling feeding on the radiation surface; The radiation surface is arranged as a rectangular, circular or octagonal patch.

2. The differential-fed cross-polarized high-gain antenna according to claim 1, characterized in that, The radiation surface is arranged as a rectangular patch, and the two feeding probes are respectively disposed at the two diagonals or the centers of the two symmetric sides of the rectangular patch.

3. The differential-fed cross-polarized high-gain antenna according to claim 1, characterized in that, The feeding network is arranged in two groups, and the two groups of feeding networks are vertically orthogonally arranged in the horizontal direction.

4. The differential-fed cross-polarized high-gain antenna according to claim 1, characterized in that, The 3dB beam widths of the E-plane and H-plane of the antenna at the resonance frequency of 3.7 - 3.9 GHz are 48 degrees.

5. The differential-fed cross-polarized high-gain antenna according to claim 1, characterized in that, The isolation degree between the two ports of the antenna at the resonance frequency of 3.7 - 3.9 GHz is lower than -22 dB.

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