阅读说明：本技术 基于罗特曼透镜的圆极化扫描阵列天线 (Circular polarization scanning array antenna based on Rotman lens ) 是由 金荣洪 李建平 耿军平 梁仙灵 王堃 于 2020-04-10 设计创作，主要内容包括：本发明提供了一种基于罗特曼透镜的圆极化扫描阵列天线,包括：相移网络层、馈电网络层和天线阵列层。所述相移网络层包括：馈电SMA接头10和罗特曼透镜网络,所述馈电SMA接头10与所述罗特曼透镜网络电连接；所述馈电网络层包括：馈电网络5,对所述天线阵列层进行馈电；所述天线阵列层包括：多个贴片天线单元1,呈阵列结构排列。本发明可在波束扫描方向形成较好的圆极化,实现了阵列天线的圆极化波束扫描。(The invention provides a circular polarization scanning array antenna based on a Rotman lens, which comprises: phase shift network layer, feed network layer and antenna array layer. The phase shift network layer includes: a power feed SMA connector 10 and a Rotman lens network, wherein the power feed SMA connector 10 is electrically connected with the Rotman lens network; the feed network layer includes: a feed network 5 for feeding the antenna array layer; the antenna array layer includes: the patch antenna units 1 are arranged in an array structure. The invention can form better circular polarization in the beam scanning direction, and realizes circular polarization beam scanning of the array antenna.)

1. A circularly polarized scanning array antenna based on a rotman lens, comprising: the antenna comprises a phase shift network layer, a feed network layer and an antenna array layer;

the phase shift network layer includes: a power feed SMA connector (10) and a Rotman lens network, wherein the power feed SMA connector (10) is electrically connected with the Rotman lens network;

the feed network layer includes: a feed network (5) for feeding the antenna array layer;

the antenna array layer includes: a plurality of patch antenna units (1) arranged in an array structure;

the feed network (5) connects the patch antenna units (1) of each row or each column to form a sub-array;

in the subarray, the odd-number patch antenna units (1) have the same rotation angle and the same feed phase, the even-number patch antenna units (1) have the same rotation angle and the same feed phase, and the phase difference of the odd-number patch antenna units (1) is 90 degrees;

the phase difference between adjacent sub-arrays is 180 degrees.

2. The circularly polarized scanning array antenna based on a rotman lens according to claim 1, characterized in that the feeding network (5) connects together the odd-numbered patch antenna elements (1) of the patch antenna elements (1) of each row or each column and connects together the even-numbered patch antenna elements (1) of the patch antenna elements (1) of each row or each column, respectively.

3. The circularly polarized scanning array antenna based on the rotman lens as claimed in claim 2, wherein the feeding network (5) connects two adjacent odd-numbered patch antenna units (1) in a tree structure, and the feeding network (5) connects two adjacent even-numbered patch antenna units (1) in a tree structure.

4. The circularly polarized scanning array antenna based on the rotman lens as claimed in claim 1, wherein every four patch antenna units (1) in the rectangular arrangement are a small matrix, the rotation angles of the four patch antenna units (1) in the small matrix are different, and each patch antenna unit (1) is rotated 90 degrees, 270 degrees, 180 degrees, 90 degrees and 0 degrees, respectively, relative to the adjacent patch antenna unit (1) in the small matrix.

5. The rotman lens based circularly polarized scanning array antenna of claim 1, wherein the rotman lens network comprises:

a Rotman lens floor (7);

rotman lens dielectric plate (8): is arranged on the upper surface of the Rotman lens floor (7);

and the Rotman lens (9) is arranged on the upper surface of the Rotman lens dielectric plate (8).

6. The rotman lens based circularly polarized scanning array antenna of claim 1, wherein the feed network layer further comprises:

upper dielectric sheet (4): the power supply network is arranged on the upper side of the feed network (5);

lower dielectric plate (6): the power supply network is arranged at the lower side of the feed network (5);

the feed network is formed by pressing the upper dielectric plate (4), the feed network (5) and the lower dielectric plate (6).

7. The circularly polarized scan array antenna based on a rotman lens of claim 6, wherein the upper dielectric plate (4) and the lower dielectric plate (6) comprise a prepreg.

8. The rotman lens based circularly polarized scanning array antenna of claim 1, wherein the antenna array layer further comprises:

antenna dielectric plate (2): the patch antenna unit (1) is arranged on the antenna dielectric plate (2).

9. The circularly polarized scan array antenna based on a rotman lens of claim 1, wherein the output terminals of the rotman lens network are respectively connected to the sub-arrays through equal phase transmission lines.

10. The circularly polarized scan array antenna based on a rotman lens of claim 1, wherein the rotman lens network is a microstrip structure.

Technical Field

The invention relates to the field of antennas, in particular to a circular polarization scanning array antenna based on a Rotman lens.

Background

With the rapid development of wireless communication technology, communication with mobile satellites as a common communication situation is becoming more and more common. The relative position of a satellite and a vehicle, a ship, or the like with which the satellite communicates is often changed from moment to moment, and for this reason, a communication antenna is required to have a beam scanning capability. Meanwhile, the characteristic that the circularly polarized antenna can receive any polarized wave is of great importance to the communication occasion with frequent position change, such as mobile satellite communication, and the influence of multipath effect can be overcome to a certain extent by circular polarization.

Through literature search, John Huang published in the IEEE Transactions on Antennas and Propagat journal of 1986 article "A Technique for an Array to Generation circular polarization with Linear Polarized Elements", which proposes a method for obtaining circular polarization by using rotation of a Linearly Polarized antenna, and designs a corresponding feed network for experimental verification. The method is commonly used to improve the axial ratio and the directional diagram symmetry of the antenna Array, and is widely used in the design of Circularly Polarized Antennas, such as the article "a wide band Sequential-Phase fed Polarized Patch Array" published in the journal of IEEE Transactions on Antennas and propague, the "circular-Polarized Focused antenna Array" published in the journal of IEEE Antennas and wireless propagation Antennas, and the like, all apply the rotation technology to obtain better circular polarization performance and more symmetric directional diagram based on the Circularly Polarized antenna unit. However, in all the above documents, only the phase distribution of the rotation formed in the normal direction of the array is considered, and the adopted feed network is not suitable for the case of beam scanning. In a common array for realizing circular polarization beam scanning, the antenna units are required to have a wider axial ratio beam width so as to ensure the axial ratio of the main lobe direction when the array scans at a large angle. In addition, in the antenna array, the axial ratio of the antenna element is inevitably narrower than the beam width due to the influence of coupling. The variation of the axial ratio of the Beam width of the Antenna elements in the Array was analyzed by the article "Wide-Beam circulation polarized Microtrip Magnetic-Electric Dipole Antenna for Wide-Angle scanning phased Array", published in the journal of IEEEantennas and Wireless Propagation Letters. It can be seen that the axis of the antenna element in the array is narrower than the beam width, and large-angle circular polarization beam scanning is difficult to realize.

Disclosure of Invention

In view of the defects in the prior art, the present invention aims to provide a circular polarization scanning array antenna based on a rotman lens.

According to the invention, the circularly polarized scanning array antenna based on the Rotman lens comprises: the antenna comprises a phase shift network layer, a feed network layer and an antenna array layer;

the phase shift network layer includes: a power feed SMA connector 10 and a Rotman lens network, wherein the power feed SMA connector 10 is electrically connected with the Rotman lens network;

the feed network layer includes: a feed network 5 for feeding the antenna array layer;

the antenna array layer includes: a plurality of patch antenna units 1 arranged in an array structure;

the feed network 5 connects the patch antenna units 1 in each row or each column to form a sub-array;

in the subarray, the odd-numbered patch antenna units 1 have the same rotation angle and the same feed phase, the even-numbered patch antenna units 1 have the same rotation angle and the same feed phase, and the phase difference of the odd-numbered patch antenna units 1 is 90 degrees;

the phase difference between adjacent sub-arrays is 180 degrees.

Preferably, the feeding network 5 connects the odd-numbered patch antenna units 1 of the patch antenna units 1 of each row or each column together, and connects the even-numbered patch antenna units 1 of the patch antenna units 1 of each row or each column together, respectively.

Preferably, the feeding network 5 connects two adjacent odd-numbered patch antenna units 1 in a tree structure, and the feeding network 5 connects two adjacent even-numbered patch antenna units 1 in a tree structure.

Preferably, every four patch antenna units 1 arranged in a rectangular shape are a small matrix, the rotation angles of the four patch antenna units 1 in the small matrix are different, and each patch antenna unit 1 rotates 90 degrees, namely 270 degrees, 180 degrees, 90 degrees and 0 degrees, relative to the adjacent patch antenna unit 1 in the small matrix.

Preferably, the rotman lens network comprises:

a Rotman lens floor 7;

rotman lens dielectric plate 8: is arranged on the upper surface of the Rotman lens floor 7;

and the Rotman lens 9 is arranged on the upper surface of the Rotman lens dielectric plate 8.

Preferably, the feeding network layer further includes:

upper dielectric plate 4: the power supply network is arranged on the upper side of the feed network 5;

lower dielectric plate 6: the power supply network 5 is arranged at the lower side;

the feed network is formed by pressing the upper dielectric plate 4, the feed network 5 and the lower dielectric plate 6.

Preferably, the upper dielectric plate 4 and the lower dielectric plate 6 include prepregs.

Preferably, the antenna array layer further comprises:

antenna dielectric plate 2: the patch antenna unit 1 is arranged on the antenna dielectric plate 2.

Preferably, the output ends of the rotman lens network are respectively connected with the sub-arrays through equal-phase transmission lines.

Preferably, the rotman lens network is a microstrip structure.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention can realize the rotation phase distribution (270 degrees, 180 degrees, 90 degrees and 0 degrees) in the beam scanning direction, namely, the circularly polarized beam scanning is realized.

2. The invention designs a novel feed network to realize the rotation phase.

3. The low profile of the Rotman lens antenna is realized by a multilayer board pressing technology.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic view of the overall structure of the present invention;

fig. 2 is a top view of the antenna array of the present invention;

FIG. 3 is a top view of the stripline feed network of the present invention;

FIG. 4 is a top view of the Rotman lens network of the present invention;

FIGS. 5-8 are schematic diagrams of the rotational phase of the present invention;

FIG. 9 is a graph of the output amplitude and phase profile of a Rotman lens in accordance with the present invention;

FIG. 10 is a graph of the lens feed end reflection coefficient and isolation of the present invention;

FIG. 11 is a directional diagram of a Rotman lens of the present invention fed at different ports;

fig. 12 shows the axial ratio and gain of the beam scanned to different directions according to the present invention.

In the figure: the antenna comprises 1-patch antenna unit, 2-antenna dielectric plate, 3-antenna floor, 4-upper dielectric plate, 5-feed network, 6-lower dielectric plate, 7-Rotman lens floor, 8-Rotman lens dielectric plate, 9-Rotman lens and 10-feed SMA joint.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

The invention is applied to the technical field of communication, such as vehicle-mounted satellite communication and the like. The whole antenna is of a planar structure, and is convenient to conform to the carrier. Different wave ports of the Rotman lens correspond to different beam directions, and the beam directions can be switched by switching a feed port of the Rotman lens.

As shown in fig. 1 to 4, the circularly polarized scanning array antenna based on the rotman lens provided by the present invention has a planar multilayer structure, and sequentially includes an antenna array layer, a feeding network layer and a phase shifting network layer from top to bottom, which adopt a rotation technology. And each layer is pressed through a prepreg, and the thickness of the whole antenna is 3.2 mm. Antenna Array rotation techniques reference is made to John Huang article "A Technique for an Array to Generator Circuit Polarized Elements" which shows the rotation rules of the antenna Elements and sub-arrays. Feed network design referring to fig. 3 and 5-8, the feed phase for each element in each row (or column) sub-array is derived from fig. 5-8. Referring to fig. 3, a feed network may be designed that meets the requirements of the rotational phase, and is not limited to a stripline structure. Reference is made to the paper "Wide-Angle Microwave Lens for Line Source Applications" in w.rotman, which gives the design principle and implementation method of the Lens.

The phase shift network layer includes: a power feed SMA connector 10 and a Rotman lens network, wherein the power feed SMA connector 10 is electrically connected with the Rotman (Rotman) lens network. The rotman lens network includes: a rotman lens floor 7, a rotman lens dielectric plate 8 and a rotman lens 9. The rotman lens dielectric plate 8 is disposed on the upper surface of the rotman lens floor 7, and the rotman lens 9 is disposed on the upper surface of the rotman lens dielectric plate 8.

The feed network layer includes: a feed network 5, an upper dielectric plate 4 and a lower dielectric plate 6. The feed network 5 feeds the antenna array layer, the upper dielectric plate 4 is arranged on the upper side of the feed network 5, the lower dielectric plate 6 is arranged on the lower side of the feed network 5, and the feed network is formed by pressing the upper dielectric plate 4, the feed network 5 and the lower dielectric plate 6.

The antenna array layer includes: a plurality of paster antenna element 1 and antenna dielectric plate 2, paster antenna element 1 sets up on antenna dielectric plate 2. The patch antenna units 1 are arranged in an array structure. The patch antenna unit 1 may be either a linear or a circular polarized unit.

The feeding network 5 connects the patch antenna units 1 of each row or each column to form a sub-array. In the subarray, the odd-numbered patch antenna elements 1 have the same rotation angle and the same feed phase, the even-numbered patch antenna elements 1 have the same rotation angle and the same feed phase, and the phase difference between the odd-numbered patch antenna elements 1 is 90 degrees. The phase difference between adjacent sub-arrays is 180 degrees. The Rotman lens network is in a micro-strip structure, and the output end of the Rotman lens network is respectively connected with the sub-arrays through equal-phase transmission lines.

The feed network 5 connects the odd-numbered patch antenna units 1 of the patch antenna units 1 of each row or each column together, and connects the even-numbered patch antenna units 1 of the patch antenna units 1 of each row or each column together. The feeding network 5 connects every two adjacent odd-numbered patch antenna units 1 together in a tree structure, and the feeding network 5 connects every two adjacent even-numbered patch antenna units 1 together in a tree structure. Every four patch antenna units 1 arranged in a rectangular shape are a small matrix, the rotation angles of the four patch antenna units 1 in the small matrix are different, and each patch antenna unit 1 rotates 90 degrees relative to the adjacent patch antenna unit 1 in the small matrix, namely 270 degrees, 180 degrees, 90 degrees and 0 degree respectively.

The working principle of the invention for realizing circular polarized beam scanning is as follows:

fig. 5 shows a circularly Polarized antenna Array using the rotation Technique, which was first proposed in the article "a Technique for an Array to a generalized antenna Polarization with linear Polarized Elements" published in ieee trains. In the rotation technology, each 4 units form a sub-array, each unit rotates 90 degrees relative to the previous unit, and the sub-array also rotates 90 degrees relative to the previous sub-array. The array obtained by the method can obtain better circular polarization performance, and the corresponding common feed networks are shown in figure 6. The two networks can form rotating phase distribution in the normal direction of the antenna array, so that better circular polarization performance can be obtained in the normal direction. But is not suitable for the case of beam scanning because the phase between the antenna elements is not adjustable.

Fig. 7 shows a circular polarized antenna array feeding network suitable for beam scanning proposed by the present invention, and the feeding phases in fig. 5(b) are obtained by adding the feeding phases of the elements and the feeding phases of the sub-arrays in fig. 5 (a). It can be seen that for a single row (or column), the handedness of the odd (or even) numbered elements is uniform and the feeding phase is the same. Therefore, a new feeding network in fig. 7 is proposed. The network takes a single row (or column) as a subarray, connects odd-numbered cells and even-numbered cells respectively, and adds 90-degree phase difference between the odd-numbered cells and the even-numbered cells, so that the subarray forms circular polarization. In order to meet the phase distribution of the rotation technology, a phase difference of 180 degrees needs to be added between the sub-arrays. Fig. 8 shows the phase distribution on the equiphase plane at the time of beam scanning. It can be seen that, after the proposed feed network is adopted, the phase difference between the sub-arrays can be adjusted at will, so that the beam can point to any direction. Meanwhile, on the equiphase surface, the phase still meets the requirement of the rotation phase. Thus, the network is suitable for circular polarized beam scanning.

To achieve beam scanning, the present invention employs a Rotman lens to provide the phase differences required for beam scanning. As shown in fig. 1, the Rotman lens produces the phase difference required for the subarray scan, and the designed subarray provides a rotated phase distribution. The formation of the rotational phase distribution on the scanned beam equiphase plane is realized.

The output amplitude and phase of the Rotman lens are shown in fig. 9, and it can be seen that the Rotman lens can provide the amplitude and phase differences required for beam scanning.

The reflection coefficient of the input port of the Rotman lens and the isolation of wave port 1 from other wave ports are shown in fig. 10. The reflection coefficient and the isolation are both less than-10 dB.

The simulation results of the beam sweep are shown in fig. 11. It can be seen that the beam sweep range reaches ± 44 °.

The axial ratio and gain during beam scanning are shown in fig. 12. It can be seen that the axial ratios are all less than 3dB in the beam scan direction.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.