Dual Circular Polarization Broadband Horn Antenna

Abstract

The present invention provides a dual circular polarization broadband horn antenna, wherein the circular polarizer comprises a circular waveguide, the front end of the circular polarizer is connected to two waveguide impedance matchers, a stepped diaphragm is arranged inside the circular waveguide to divide the circular waveguide into two sides, and the stepped diaphragm in the circular waveguide is used to form left-hand circular polarization and right-hand circular polarization performance respectively, so as to realize efficient conversion and separation of left-hand circular polarization and right-hand circular polarization signals, thereby eliminating the complex orthogonal mode converter in the traditional technology, making the dual circular polarization horn structure simple, compact and light, reducing the manufacturing difficulty and processing cost, and avoiding unnecessary mode coupling and energy loss. The dual circular polarization broadband horn antenna has the advantages of wide bandwidth, high isolation, low axial ratio, good circular polarization performance, compact structure, light weight, easy processing, etc.

Description

Technical Field

[0001] The invention relates to antenna technology, in particular to a dual circular polarization broadband horn antenna. Background Art

[0002] The application of millimeter wave terahertz frequency band in wireless communication systems has attracted wide attention, especially circular polarization technology, which is widely used in satellite communications and radar systems. Circularly polarized antennas can transmit and receive electromagnetic waves with circular polarization characteristics. During the propagation of electromagnetic waves, their electric field vectors rotate in a circular trajectory in a plane perpendicular to the propagation direction. Compared with linearly polarized antennas, circularly polarized antennas have obvious advantages in multipath propagation, polarization matching, and rotational distortion in mobile communications.

[0003] There are many technical difficulties in traditional circularly polarized horn antennas. In order to achieve the conversion from linear polarization to circular polarization, a complex polarizer or special feeding structure is designed, which has very high processing requirements. In order to achieve the conversion and separation of left-handed and right-handed dual circularly polarized signals in the existing technology, a complex orthogonal mode converter design is required. The orthogonal mode converter has the disadvantages of large size and complex structure. A poorly designed orthogonal mode converter will also cause unnecessary mode coupling and energy loss. Existing circular polarizers include ridge waveguide circular polarizers, screw circular polarizers, dielectric plate circular polarizers, slotted circular polarizers, etc., which have large external dimensions.

[0004] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0005] The main purpose of the present invention is to solve the problems existing in the above-mentioned background technology and provide a dual circular polarization broadband horn antenna.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A dual circular polarization broadband horn antenna, comprising:

[0008] Two waveguide ports for receiving and inputting electromagnetic wave signals;

[0009] Two waveguide impedance matchers are respectively connected to corresponding waveguide ports to achieve impedance matching;

[0010] A circular polarizer is connected to the waveguide impedance matcher, comprising: a circular waveguide, which is a tubular structure, used to propagate electromagnetic waves from two waveguide impedance matchers; a stepped diaphragm is arranged in the circular waveguide, which is arranged along the length direction of the circular waveguide to form a stepped structure, and the inside of the circular waveguide is divided into two symmetrical cavities corresponding to the two waveguide impedance matchers; the stepped diaphragm makes the input TE 10 A portion of the mode is rotated 90° and converted to TE 01 mode, and the phase is delayed by 90°, forming orthogonal TE with the same amplitude and 90° phase difference. 10 Mode and TE 01 mode, and then synthesized into TE in the circular polarizer 11 Mode, to achieve left-hand circular polarization and right-hand circular polarization;

[0011] A conical horn is connected to the rear end of the circular polarizer and is used to radiate the synthesized circular polarization signal to form a desired radiation pattern.

[0012] Furthermore, the waveguide port is a rectangular waveguide port.

[0013] Furthermore, the waveguide impedance matcher includes a multi-stage semi-octagonal waveguide structure with decreasing cross-sections, thereby achieving a smooth transition from a rectangular waveguide to a circular waveguide.

[0014] Furthermore, each level of the half-octagonal waveguide structure expands the working bandwidth while keeping the mode unchanged.

[0015] Furthermore, the waveguide impedance matcher is composed of four levels of half-octagonal waveguides, and the length of each level of half-octagonal waveguide is λ / 8, where λ is the wavelength at the designed operating frequency.

[0016] Further, the two waveguide ports and the two waveguide impedance matchers are separated by a common rectangular partition and are arranged symmetrically about the common rectangular partition.

[0017] Furthermore, the stepped diaphragm is connected to the common rectangular partition plate and has the same thickness.

[0018] Furthermore, the stepped diaphragm is composed of multiple rectangular steps.

[0019] Furthermore, the stepped diaphragm is composed of five rectangular steps.

[0020] Furthermore, the operating center frequency is 100 GHz, the return loss and isolation in the operating frequency band are both lower than -20 dB, the axial ratio is lower than 1 dB, and the cross polarization is less than -20 dB.

[0021] The present invention has the following beneficial effects:

[0022] The present invention provides a compact dual circular polarization broadband horn, wherein the circular polarizer includes a circular waveguide, the front end of the circular polarizer is connected to a waveguide impedance matcher, a stepped diaphragm is provided inside the circular waveguide to divide the circular waveguide into two sides, and the stepped diaphragm in the circular waveguide is used to form the signal into left-hand circular polarization and right-hand circular polarization performance respectively, so as to realize efficient conversion and separation of left-hand circular polarization and right-hand circular polarization signals, thereby eliminating the traditional orthogonal mode converter, making the dual circular polarization horn structure simple, compact and light, reducing the manufacturing difficulty and processing cost, and avoiding unnecessary mode coupling and energy loss. Furthermore, the waveguide impedance matcher is designed as a multi-stage semi-octagonal waveguide structure, which not only shortens the transition size from the rectangular waveguide to the circular waveguide, but also expands the working bandwidth while keeping the mode unchanged, and realizes wide bandwidth signal coverage.

[0023] The dual circularly polarized horn antenna of the present invention has a return loss and isolation lower than -20dB in the working frequency band, an axial ratio lower than 1dB and a cross polarization lower than -20dB, and has the characteristics of wide bandwidth, high isolation and low axial ratio, thereby ensuring good circular polarization performance and high circular polarization purity of the horn antenna.

[0024] The invention has the advantages of wide bandwidth, high isolation, low axial ratio, good circular polarization performance, compact structure, light weight, etc. It has a compact structure and is easy to process, and can meet the antenna requirements of different communication systems.

[0025] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of a compact dual circularly polarized broadband loudspeaker according to an embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of a waveguide impedance matcher of a compact dual circular polarization broadband loudspeaker according to an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of a circular polarizer of a dual circular polarization broadband speaker according to an embodiment of the present invention;

[0029] Figure 4 is a graph showing return loss and isolation of a dual circularly polarized speaker in one embodiment of the present invention;

[0030] Figure 5 It is a normalized far-field radiation pattern of left-hand circular polarization on the XZ plane at 100 GHz when the dual circularly polarized broadband horn of one embodiment of the present invention is incident at the right waveguide port;

[0031] Figure 6It is the normalized far-field radiation pattern of left-hand circular polarization on a 45° plane at 100 GHz when the dual circularly polarized broadband horn of one embodiment of the present invention is incident at the right waveguide port;

[0032] Figure 7 It is a normalized far-field radiation pattern of left-hand circular polarization on the YZ plane at 100 GHz when the dual circularly polarized broadband horn of one embodiment of the present invention is incident at the right waveguide port;

[0033] Figure 8 It is a normalized far-field radiation pattern of right-hand circular polarization on the XZ plane at 100 GHz when the dual circularly polarized broadband horn of one embodiment of the present invention is incident at the left waveguide port;

[0034] Fig. 9 It is a normalized far-field radiation pattern of right-hand circular polarization on a 45° plane at 100 GHz when the dual circularly polarized broadband horn of an embodiment of the present invention is incident on the left waveguide port;

[0035] Fig.10 It is a normalized far-field radiation pattern of right-hand circular polarization on the YZ plane at 100 GHz when the dual circularly polarized broadband horn of one embodiment of the present invention is incident at the left waveguide port;

[0036] Fig.11 1 is a gain diagram of a dual circularly polarized broadband horn according to an embodiment of the present invention on an XZ plane at 100 GHz;

[0037] Fig.12 FIG. 4 is an axial ratio curve diagram of a dual circularly polarized broadband loudspeaker according to an embodiment of the present invention.

[0038] Reference numerals:

[0039] 1-right rectangular waveguide; 2-left rectangular waveguide; 3-waveguide impedance matcher; 31-first-stage semi-octagonal waveguide; 32-second-stage semi-octagonal waveguide; 33-third-stage semi-octagonal waveguide; 34-fourth-stage semi-octagonal waveguide; 4-rectangular partition; 5-circular polarizer; 6-stepped diaphragm; 61-first-stage rectangular step diaphragm; 62-second-stage rectangular step diaphragm; 63-third-stage rectangular step diaphragm; 64-fourth-stage rectangular step diaphragm; 65-fifth-stage rectangular step diaphragm; 7-circular waveguide; 8-conical horn. DETAILED DESCRIPTION

[0040] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

[0042] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood 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 one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0044] The conversion and separation of left-handed and right-handed dual circularly polarized signals are usually achieved using traditional orthogonal mode converters, but they have problems such as large size, complex structure, and difficult processing.

[0045] See also Figures 1 to 3 The embodiment of the present invention provides a dual circular polarization broadband horn antenna, comprising: two waveguide ports, which are preferably two rectangular waveguide ports (such as a right rectangular waveguide 1 and a left rectangular waveguide 2), for receiving and inputting electromagnetic wave signals; two waveguide impedance matchers 3, each connected to a corresponding waveguide port to achieve impedance matching; a circular polarizer 5, connected to the waveguide impedance matcher 3, comprising: a circular waveguide 7, which is a tubular structure, for propagating electromagnetic waves from the two waveguide impedance matchers 3 therein; a stepped diaphragm 6 is provided in the circular waveguide 7, which is arranged along the length direction of the circular waveguide 7 to form a stepped structure, and the inside of the circular waveguide 7 is divided into two symmetrical cavities corresponding to the two waveguide impedance matchers 3; the stepped diaphragm 6 makes the input TE 10 A portion of the mode is rotated 90° and converted to TE 01 mode, and the phase is delayed by 90°, forming orthogonal TE with the same amplitude and 90° phase difference. 10 Mode and TE 01 mode, and then synthesized into TE in the circular polarizer 511 mode, realizing left-hand circular polarization and right-hand circular polarization; a conical horn 8 is connected to the rear end of the circular polarizer 5, and is used to radiate the synthesized circular polarization signal to form a desired radiation mode. The stepped diaphragm 6 can be made of metal materials, such as gold, silver, copper, aluminum, etc.

[0046] See also Figure 1 and Figure 2 In a preferred embodiment, the waveguide impedance matcher 3 includes a series of semi-octagonal waveguide structures with decreasing cross-sections, so as to achieve a smooth transition from a rectangular waveguide to a circular waveguide 7. Each semi-octagonal waveguide structure expands the working bandwidth while keeping the mode unchanged.

[0047] like Figure 2 As shown, in a preferred embodiment, the waveguide impedance matcher 3 is composed of four levels of half-octagonal waveguides, specifically including a first level half-octagonal waveguide 31, a second level half-octagonal waveguide 32, a third level half-octagonal waveguide 33 and a fourth level half-octagonal waveguide 34, and the length of each level of half-octagonal waveguide is λ / 8, where λ is the wavelength at the designed operating frequency.

[0048] See also Figure 1 In a preferred embodiment, the two waveguide ports and the two waveguide impedance matchers 3 are separated by a common rectangular partition and are arranged symmetrically about the common rectangular partition. Figure 1 and Figure 3 In a more preferred embodiment, the stepped diaphragm 6 is connected to the common rectangular partition and has the same thickness. Figure 1 and Figure 3 The step-type diaphragm is composed of multiple rectangular steps. Figure 3 As shown, in a preferred embodiment, the stepped diaphragm 6 is composed of five rectangular steps, specifically including a first-level rectangular step diaphragm 61, a second-level rectangular step diaphragm 62, a third-level rectangular step diaphragm 63, a fourth-level rectangular step diaphragm 64 and a fifth-level rectangular step diaphragm 65.

[0049] The dual circularly polarized broadband horn antenna of the present invention overcomes the technical difficulties of the traditional circularly polarized antenna through innovative design, and realizes a simple, compact and lightweight antenna system. The stepped diaphragm design of the circular polarizer adopted by the present invention effectively converts the received TE 10 Mode conversion and phase delay to form orthogonal TE 10 and TE 01 mode and synthesize TE in a circular polarizer 11mode, thereby achieving efficient left-handed and right-handed circularly polarized signal conversion and separation without the need for traditional complex orthogonal mode converters. In addition, the multi-stage semi-octagonal waveguide structure of the waveguide impedance matcher not only shortens the transition size from the rectangular waveguide to the circular waveguide, but also expands the working bandwidth while keeping the mode unchanged, achieving wide-bandwidth signal coverage. The antenna of the present invention exhibits excellent performance in the operating frequency band, with a return loss and isolation lower than -20dB, an axial ratio lower than 1dB and a cross-polarization less than -20dB, ensuring high isolation and low axial ratio transmission quality, and ensuring good circular polarization performance and high circular polarization purity. Overall, the antenna of the present invention, with its advantages of wide bandwidth, high isolation, low axial ratio, compact structure, and light weight, meets the needs of modern communication systems for high-performance antennas, while reducing the manufacturing difficulty and processing cost, is easy to process, has strong adaptability, and can be widely used in a variety of communication scenarios.

[0050] The specific embodiments of the present invention are further described below.

[0051] Please also see Figures 1 to 3 A compact dual circularly polarized broadband horn antenna comprises two rectangular waveguides, a waveguide impedance matcher 3, a common rectangular partition 4, a circular polarizer 5, and a conical horn 8; the two rectangular waveguides comprise a right rectangular waveguide 1 and a left rectangular waveguide 2; the circular polarizer 5 comprises a stepped diaphragm 6 and a circular waveguide 7.

[0052] This embodiment provides a compact dual circular polarization broadband horn antenna, such as Figures 1 to 3 As shown, it includes: two rectangular waveguides, including a right rectangular waveguide 1 and a left rectangular waveguide 2, which are symmetrically placed about a common rectangular partition 4. A waveguide impedance matcher 3 is composed of four semi-octagonal waveguides, each of which has a different aspect ratio, and the cross-section decreases in order from small to large in order of the number of stages. The first-stage semi-octagonal waveguide 31 is connected to the output end of the rectangular waveguide. A circular polarizer 5 is composed of a stepped diaphragm 6 and a circular waveguide 7. The height of each step of the stepped diaphragm 6 decreases in order from small to large in order of the number of stages. The first-stage rectangular stepped diaphragm 61 is connected to the fourth-stage waveguide impedance matcher 34. A conical horn 7 is connected to one end of the circular polarizer 5 where the fifth-stage rectangular stepped diaphragm 65 is located.

[0053] Figure 2 The schematic diagram of the rectangular waveguide 1 and the waveguide impedance matcher 3 is shown. When the signal is excited at the rectangular waveguide port, the TE in the rectangular waveguide 1 10 The mode is transmitted to the circular waveguide 7 through the waveguide impedance matcher 3. Due to the presence of the stepped diaphragm 6, half of the TE 10 The mode is rotated 90° to TE 01 The orthogonal TE modes with the same amplitude and 90° phase difference are10 and TE 01 Converted into TE in circular polarizer 5 11 mode, thereby achieving left-hand circular polarization and right-hand circular polarization. The field mode of the ideal octagonal waveguide structure is close to the circular waveguide field mode. In this example, a waveguide impedance matcher 3 is designed between a rectangular waveguide 1 and a circular waveguide 7. Since the field modes corresponding to the main modes at the input port and the output port of the waveguide impedance matcher 3 are similar, by changing the aspect ratio of each level of the half-octagonal waveguide, a smooth transition from the rectangular waveguide field mode to the circular waveguide field mode is achieved. The dimensions corresponding to the waveguide impedance matcher 3 are as follows: Figure 2 As shown, a1=0.86mm, a2=0.69mm, a3=0.52mm, a4=0.35mm, b1=1.78mm, b2=1.52mm, b3=1.26mm, b4=1dmm, c1=0.495mm, c2=0.636mm, c3=0.777mm, c4=0.919mm.

[0054] Figure 3 FIG. 5 shows a schematic diagram of a circular polarizer 5. A stepped diaphragm 6 is provided inside the circular polarizer 5. The thickness of the stepped diaphragm 6 is the same as that of the common rectangular diaphragm 4, ts=0.5 mm. The stepped diaphragm 6 is used to realize the conversion and separation of left-handed and right-handed circular polarization signals. Specifically, the size of each level of the rectangular stepped diaphragm is as follows: Figure 3 As shown, h1=2.4mm, h2=1.3mm, h3=0.912mm, h4=0.558mm, h5=0.25mm, l1=0.5mm, l2=0.2mm, l3=0.835mm, l4=1.2mm, l5=1.2mm.

[0055] The operating center frequency of the compact dual circular polarization broadband horn antenna is 100 GHz. Figure 4 The return loss and isolation curves of the compact dual circular polarization broadband speaker in the working frequency band of this embodiment are shown in FIG. The return loss and isolation are lower than -20 dB, realizing a wide bandwidth and high isolation speaker. Figures 5 to 10 As shown, the normalized far-field radiation patterns of left-hand circular polarization and right-hand circular polarization in the XZ, 45° and YZ planes at 100 GHz, and the cross-polarization is less than -20 dB. Fig.11 is the gain diagram in the XZ plane at 100 GHz. Fig.12 The axial ratio diagram of left-hand circular polarization and right-hand circular polarization over the entire working bandwidth, the axial ratio is less than 1dB.

[0056] The embodiment of the present invention realizes a compact transition from a rectangular waveguide to a circular waveguide through an optimized design, and in the process completes the effective conversion and separation of left-handed and right-handed circularly polarized signals, while eliminating the complex orthogonal mode converter, thereby making the dual circularly polarized horn antenna structure more concise and compact, reducing weight, reducing the difficulty and cost of manufacturing and processing, and avoiding unnecessary mode coupling and energy loss. The dual circularly polarized horn antenna of the embodiment of the present invention has a return loss and isolation lower than -20dB in the working frequency band, an axial ratio lower than 1dB, and a cross-polarization lower than -20dB. It has the characteristics of wide bandwidth, high isolation, and low axial ratio, ensuring the good circular polarization performance and high circular polarization purity of the horn antenna. This embodiment has a compact structure and is easy to process, and can meet the antenna requirements of different communication systems.

[0057] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A dual circular polarization broadband horn antenna, characterized in that: include: Two waveguide ports for receiving and inputting electromagnetic wave signals; Two waveguide impedance matchers are respectively connected to corresponding waveguide ports to achieve impedance matching; the waveguide impedance matcher comprises four-stage semi-octagonal waveguide structures with decreasing cross-sections to achieve a smooth transition from a rectangular waveguide to a circular waveguide, the length of each stage of the semi-octagonal waveguide is λ / 8, λ is the wavelength at the designed working frequency, and each stage of the semi-octagonal waveguide structure expands the working bandwidth while keeping the mode unchanged; A circular polarizer, connected to the waveguide impedance matcher, comprises: a circular waveguide, which is a tubular structure, for propagating electromagnetic waves from two waveguide impedance matchers therein; A stepped diaphragm is arranged in the circular waveguide in a stepped structure along the length direction of the circular waveguide, and divides the interior of the circular waveguide into two symmetrical cavities corresponding to two waveguide impedance matchers; The stepped diaphragm makes the input TE 10 A portion of the mode is rotated 90° and converted to TE 01 mode, and the phase is delayed by 90°, forming orthogonal TE with the same amplitude and 90° phase difference. 10 Mode and TE 01 mode, and then synthesized into TE in the circular polarizer 11 Mode, to achieve left-hand circular polarization and right-hand circular polarization; A conical horn is connected to the rear end of the circular polarizer and is used for radiating the synthesized circular polarization signal outward.

2. The dual circular polarization broadband horn antenna according to claim 1, characterized in that: The waveguide port is a rectangular waveguide port.

3. The dual circular polarization broadband horn antenna according to any one of claims 1 to 2, characterized in that: The two waveguide ports and the two waveguide impedance matchers are separated by a common rectangular partition and are arranged symmetrically about the common rectangular partition.

4. The dual circular polarization broadband horn antenna according to claim 3, characterized in that: The stepped diaphragm is connected to the common rectangular diaphragm and has the same thickness.

5. The dual circular polarization broadband horn antenna according to any one of claims 1 to 2, characterized in that: The step-type diaphragm is composed of multiple rectangular steps.

6. The dual circular polarization broadband horn antenna according to claim 5, characterized in that: The step-type diaphragm consists of five rectangular steps.

7. The dual circular polarization broadband horn antenna according to any one of claims 1 to 2, characterized in that: The operating center frequency is 100GHz, the return loss and isolation in the operating frequency band are both lower than -20dB, the axial ratio is lower than 1dB and the cross polarization is less than -20dB.

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