Ultra-wideband dual-circularly-polarized horn antenna

Abstract

The invention relates to the technical field of wireless communication, and particularly discloses an ultra-wideband dual-circularly-polarized horn antenna, which comprises a horn body, a feed cavity and a circular polarizer which are connected in sequence, the horn body is of a square-circle transformation structure, one end, close to the feed cavity, of the horn body is of a square structure, and one end, away from the feed cavity, of the horn body is of a circular structure. According to the invention, ultra-wideband dual-circularly-polarized radiation and reception of the antenna can be effectively realized, and the antenna has the advantages of high structural integration level, light weight, wide working frequency band (relative bandwidth 117%), high radiation efficiency, low axial ratio and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communications, and more particularly to an ultra-wideband dual circular polarization horn antenna. Background Art

[0002] Complex climate conditions and geographical environment factors can have adverse effects on linear polarization communication systems. Compared with linear polarization antennas, circular polarization antennas can overcome polarization mismatch, multipath effects, channel crosstalk and other problems that occur during signal transmission. Therefore, in many scenarios, circular polarization antennas have gradually replaced linear polarization antennas and have been widely used. With the development of satellite communications, remote control, and telemetry technology, the application scope of radar has expanded, and a single polarization method can no longer meet system requirements. The application of dual circular polarization antennas has become more and more widespread.

[0003] The Chinese patent with publication number CN113097740A discloses a dual-frequency transceiver sharing dual circular polarization feed source, and its relative working bandwidth is only 17%;

[0004] Chinese patent publication number CN115241643A discloses a high-isolation dual circularly polarized antenna based on K and Ka bands, with a relative bandwidth of 50%; however, both dual circularly polarized antennas cannot meet the requirements of ultra-wideband (relative bandwidth of more than 100%) systems.

[0005] Publication number CN219226616U mentions a dual circularly polarized ultra-wideband conical horn antenna, which integrates three independent components: a dual-linear polarization horn antenna, a circular polarizer, and an adapter frame through cables and fasteners; although the antenna ultra-wideband dual circular polarization operation is achieved, the cable introduces insertion loss, which reduces the antenna radiation efficiency and the gain; the adapter frame structure brings extra weight, and the traditional exponential curve ridge structure used accounts for too large a volume, which cannot meet the use requirements of lightweight systems.

[0006] In summary, the existing dual circularly polarized horn antenna technology cannot achieve ultra-wideband, high efficiency, and low axial ratio operation of the antenna; and cannot meet the use requirements of a lightweight ultra-wideband dual circularly polarized system. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide an ultra-wideband dual circular polarization horn antenna; to realize the ultra-wideband dual circular polarization radiation and reception of the antenna, and to have the advantages of high structural integration, light weight, wide working frequency band (relative bandwidth 117%), high radiation efficiency, low axial ratio, etc.;

[0008] The solution adopted by the present invention to solve the technical problem is:

[0009] An ultra-wideband dual circularly polarized horn antenna comprises a horn body, a feed cavity and a circular polarizer connected in sequence; the horn body is a square-circle transformation structure, wherein the end of the horn body close to the feed cavity is a square structure, and the end of the horn body away from the feed cavity is a circular structure; the square-circle transformation structure is conducive to broadband matching of the antenna and can effectively suppress the generation of high-order modes.

[0010] In some possible implementations, ridges are disposed in the speaker body; the ridges are in four groups and are arranged at equal intervals around the circumference of the circular structure; two adjacent groups of ridges are perpendicular to each other, and the projections of the four groups of ridges are located on the midline of the square structure;

[0011] The edge of the ridge away from the speaker body is in a curve; the curve is a quarter sine curve.

[0012] In some possible implementations, a gap is formed between one end of the ridge close to the feeding cavity and the inner side of the speaker body, and the gap is triangular. The setting of the gap makes the volume of the ridge smaller, which can effectively reduce the weight of the speaker body.

[0013] In some possible implementations, the feeding cavity includes a feeding body mounted on a horn body, a cable mounted on the body and performing feeding, and a pressing block for fixing the cable on the body; the other end of the cable is connected to a circular polarizer.

[0014] In some possible implementations, the circular polarizer includes a polarization body installed on a feeding body and connected to a cable, and a circuit board installed in the polarization body; two interfaces serving as external input and output of the antenna, and two ports for cable plugging are provided on the polarization body.

[0015] In some possible implementations, the cables are semi-steel cables with an arc-shaped structure, and the planes where the two groups of cables are located are perpendicular to each other.

[0016] In some possible implementations, the circuit board includes three layers of dielectric plates stacked and pressed in sequence; a C-shaped strip line is printed on both sides of a dielectric plate in the middle of the three layers; the two strip lines are relatively staggered along the opening direction; the two ends of one strip line are respectively connected to an interface and a port, and the two ends of another strip line are respectively connected to another interface and another port.

[0017] In some possible implementations, the dielectric plate is circular and has a diameter of 0.51λ. max The total thickness of the three dielectric plates is 0.0155λ max .

[0018] In some possible implementations, the size of the ultra-wideband dual circularly polarized horn antenna is Φ0.68λ max×2.35λ max The size of the speaker is Φ0.68λ max ×1.92λ max , the wall thickness of the speaker is 0.0083λ max ; The size of the feed cavity is 0.54λ max ×0.54λ max ×0.1λ max , the size of the circular polarizer is Φ0.63λ max ×0.26λ max ; Among them, λ max is the maximum working wavelength.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The circuit board in the present invention can be processed by using mature printed circuit technology, and other structures can be realized by machining, so that the present invention has the advantages of high structural integration and good consistency;

[0021] The invention has ultra-wideband characteristics, with a relative bandwidth of 117%; a standing wave of less than 1.64; a port isolation of more than 12 decibels; a gain of 7.2 to 16.4 decibels, which increases linearly with frequency; and an axial ratio of less than 1.14 decibels. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the speaker body in the present invention;

[0024] Figure 3 It is a schematic diagram of the cross-sectional structure of the ridge in the present invention;

[0025] Figure 4 It is a schematic diagram of the structure of the feeding cavity in the present invention;

[0026] Figure 5 It is a schematic diagram of the circular polarizer and interface structure in the present invention;

[0027] Figure 6 It is a schematic diagram of the circular polarizer and port structure in the present invention;

[0028] Figure 7 It is a schematic diagram of the structure of the circuit board in the present invention;

[0029] Figure 8 It is the actual measurement result of the standing wave of the present invention;

[0030] Fig. 9 It is the measured result of port isolation of the present invention;

[0031] Fig.10 For the present invention in F min The lowest frequency, measured results of 0° and 90° sections;

[0032] Fig.11 For the present invention in F 0 Center frequency, measured results of 0° and 90° sections;

[0033] Fig.12 For the present invention in F max The highest frequency, 0° and 90° cross-section measured results;

[0034] Fig.13 The measured curve of gain changing with frequency of the present invention;

[0035] Fig.14 It is the measured result of the axial ratio of the present invention;

[0036] Among them: 1. speaker body; 2. feeding cavity; 3. circular polarizer; 4. ridge; 5. cable; 6. pressure block; 7. port; 8. interface; 9. circuit board; 10. strip line. DETAILED DESCRIPTION

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. The "first", "second" and similar words mentioned in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one" or "one" and other similar words do not indicate a quantity restriction, but indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more. For example, multiple positioning columns refer to two or more positioning columns. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The present invention is described in detail below.

[0039] like Figure 1-Figure 7 As shown, the present invention discloses an ultra-wideband dual circular polarization horn antenna, comprising a horn body 1, a feeding cavity 2 and a circular polarizer 3;

[0040] The speaker body 1 adopts a square-circle transformation structure, and two pairs of ridge 4 structures are integrated inside the speaker body 1, that is, the four ridges 4 are symmetrically distributed; due to the existence of the ridges 4, the flange end of the speaker body 1 (the end close to the feeding cavity 2) is a square ridge waveguide structure, and the radiation end (the end away from the feeding cavity 2) is a circular ridge waveguide structure. The speaker body 1 will gradually transition from the flange end of the square ridge waveguide structure to the radiation end along its radial direction to the circular ridge waveguide structure;

[0041] The overall size of the ultra-wideband dual circularly polarized horn antenna is Φ0.68λ max ×2.35λ max , 0.68λ max is the outer diameter of the circular ridge waveguide structure, 2.35λ max is the length of the entire antenna;

[0042] The size of the speaker body 1 is Φ0.68λ max ×1.92λ max , 1.92λ max is the length of the speaker body 1; the wall thickness of the speaker body 1 is 0.0083λ max ;

[0043] The cross section of the feeding cavity 2 is a square structure, and its specific size is 0.54λ max ×0.54λ max ×0.1λ max , 0.54λ ma is the side length, 0.1λ max is the thickness;

[0044] The size of the circular polarizer 3 is Φ0.63λ max ×0.26λ max， 0.63λ max is the outer diameter of the circular polarizer 3, 0.26λ max is the length of the circular polarizer 3; where λ max is the maximum working wavelength.

[0045] The circular polarizer 3 is a dual circular polarizer, which has two interfaces 8 and two ports 7. Both interfaces 8 are SMA-50K ports, which respectively realize left-hand circular polarization and right-hand circular polarization of the antenna; the two ports 7 are arranged on the side close to the speaker body 1, and the interface 8 is arranged on the side close to the circular polarizer 3.

[0046] Compared with the traditional square speaker and round speaker structure, the speaker body 1 in the present invention is beneficial to the broadband matching of the antenna and can effectively suppress the generation of high-order modes.

[0047] The edge of the ridge 4 away from the speaker body 1 is curved; the curve is a quarter sine curve, that is, the edge of the ridge 4 away from the speaker body 1 is a quarter sine curve, and a triangular notch 41 is provided at its end (the end close to the feeding cavity 2). Compared with the traditional exponential curve ridge structure, the ridge 4 in the present invention is smaller in size and can effectively reduce the weight of the speaker body 1.

[0048] The feeding cavity 2 includes two arc-shaped cables 5, and the cables 5 are semi-steel cables;

[0049] One end of the semi-steel cable 5 feeds the feeding cavity 2 and is fixed in the feeding cavity by means of a pressing block 6 and glue injection; the other ends of the two groups of semi-steel cables 5 are respectively connected to the two groups of ports 7 provided on the dual circular polarizer 3 by "plugging".

[0050] The circuit board 9 is formed by laminating three layers of dielectric plates stacked in sequence, and a C-shaped strip line 10 is printed on both sides of the middle dielectric plate in the middle, and the two strip lines 10 are relatively staggered along the opening direction; the two ends of one strip line 10 are respectively connected to a group of interfaces 8 and a group of ports 7 of the circular polarizer 3; the two ends of another strip line 10 are respectively connected to another group of interfaces 8 and another group of ports 7 of the circular polarizer 3;

[0051] Furthermore, the dielectric plate is ROGERS Duriod 6002 plate, the thickness of the middle dielectric plate is 0.127 mm, and the thickness of the other two groups of dielectric plates is 0.762 mm.

[0052] The circuit board 9 also includes a metal ground arranged on the side of the two outer groups of dielectric plates away from the middle dielectric plate; the two groups of ports 7 and the two groups of interfaces 8 are respectively connected to the two groups of strip lines 10 through the inner core passing through the circuit board 9, and the inner core is four groups; the two ends of one group of strip lines 10 are respectively connected to a group of ports 7 and a group of interfaces 8, and the other group of strip lines 10 is connected to another group of ports 7 and another group of interfaces 8.

[0053] The above scheme was tested and the test results are as follows:

[0054] Figure 8 This is the measured standing wave result of the present invention; the ultra-wideband dual circularly polarized horn antenna proposed by the present invention has a measured standing wave at port 7 that is less than 1.64 within a frequency band of 117% of the relative bandwidth.

[0055] Fig. 9 This is the measured result of the isolation of port 7 of the present invention; the ultra-wideband dual circularly polarized horn antenna proposed by the present invention has a measured isolation of port 7 greater than 12 decibels within a frequency band of 117% of the relative bandwidth.

[0056] Figure 10 to Figure 12This is the measured result of the directional pattern of the present invention; the directional pattern of the ultra-wideband dual circularly polarized horn antenna proposed by the present invention has good axial symmetry, and the measured gain reaches 7.2 dB to 16.4 dB within the working frequency band.

[0057] Fig.13 The measured curve of gain variation with frequency of the present invention is as follows: the measured gain of the ultra-wideband dual circularly polarized horn antenna proposed by the present invention increases linearly with frequency within a frequency band of 117% of the relative bandwidth, and no obvious "concave" phenomenon occurs.

[0058] Fig.14 This is the measured result of the axial ratio of the present invention; the ultra-wideband dual circularly polarized horn antenna proposed by the present invention has an actually measured axial ratio of less than 1.14 dB within a frequency band of 117% of the relative bandwidth.

[0059] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. An ultra-wideband dual circular polarization horn antenna, characterized in that: It comprises a speaker body, a feeding cavity and a circular polarizer which are connected in sequence; the speaker body is a square-circle conversion structure, wherein one end of the speaker body close to the feeding cavity is a square structure, and one end of the speaker body away from the feeding cavity is a circular structure.

2. The ultra-wideband dual circular polarization horn antenna according to claim 1, characterized in that: Ridges are arranged in the speaker body; the ridges are in four groups and are arranged at equal intervals around the circumference of the circular structure; two adjacent groups of ridges are perpendicular to each other, and the projections of the four groups of ridges are located on the midline of the square structure; The edge of the ridge away from the speaker body is in a curve; the curve is a quarter sine curve.

3. The ultra-wideband dual circular polarization horn antenna according to claim 2, characterized in that: A gap is formed between one end of the ridge close to the feeding cavity and the inner side surface of the speaker body, and the gap is in a triangular shape.

4. The ultra-wideband dual circular polarization horn antenna according to claim 1, characterized in that: The feeding cavity comprises a feeding body mounted on the horn body, a cable mounted on the body and performing feeding, and a pressing block for fixing the cable on the body; the other end of the cable is connected to the circular polarizer.

5. The ultra-wideband dual circular polarization horn antenna according to claim 4, characterized in that: The circular polarizer comprises a polarization body installed on a feeding body and connected to a cable, and a circuit board installed in the polarization body; the polarization body is provided with two interfaces for external input and output of the antenna, and two ports for cable plugging.

6. The ultra-wideband dual circular polarization horn antenna according to claim 5, characterized in that: The cables are semi-steel cables with an arc-shaped structure, and the planes where the two groups of cables are located are perpendicular to each other.

7. The ultra-wideband dual circular polarization horn antenna according to claim 5, characterized in that: The circuit board comprises three layers of dielectric boards which are stacked and pressed in sequence; A C-shaped strip line is printed on both sides of the dielectric plate in the middle of the three layers; the two ends of one strip line are respectively connected to an interface and a port, and the two ends of another strip line are respectively connected to another interface and another port.

8. The ultra-wideband dual circular polarization horn antenna according to claim 7, characterized in that: The two strip lines are arranged in a staggered manner relative to each other along the opening direction.

9. The ultra-wideband dual circular polarization horn antenna according to claim 7, characterized in that: The dielectric plate is circular and has a diameter of 0.51λ max The total thickness of the three dielectric plates is 0.0155λ max .

10. An ultra-wideband dual circularly polarized horn antenna according to any one of claims 1 to 9, characterized in that: The size of the ultra-wideband dual circularly polarized horn antenna is Φ0.68λ max ×2.35λ max The size of the speaker is Φ0.68λ max ×1.92λ max , the wall thickness of the speaker is 0.0083λ max ; The size of the feed cavity is 0.54λ max ×0.54λ max ×0.1λ max , the size of the circular polarizer is Φ0.63λ max ×0.26λ max ; Among them, λ max is the maximum working wavelength.

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