G-band four-ridge dual-polarization horn antenna
By introducing a four-ridged horn section, a waveguide transition section and a baffle polarizer into the horn antenna, the complexity problems of traditional horn antennas in broadband operation and dual-polarization design are solved, and a simple and easy-to-process dual-polarization effect and bandwidth expansion are achieved.
Patent Information
- Application Number
- CN202511251743.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-03
- Publication Date
- 2025-10-17
AI Technical Summary
In the existing technology, traditional horn antennas have shortcomings in broadband operation, and achieving dual polarization of quad-ridged horn antennas requires complex orthogonal mode converters and high-precision processing, which increases cost and difficulty.
A four-ridged horn section, a four-ridged waveguide transition section and a baffle polarizer are used. Through the baffle polarizer, equal-amplitude phase difference 90° feeding and conversion between linear polarization and circular polarization are achieved under single-port conditions, which simplifies the design and reduces the processing complexity.
The simple processing and wide-band operation of the dual-polarized horn antenna are achieved, the production cost is reduced, and the high-order mode excitation and resonance are suppressed in the G band.
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Figure CN120810249A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of horn antennas, and more particularly relates to a G-band four-ridge dual-polarized horn antenna. BACKGROUND
[0002] The polarization state of electromagnetic wave is an important characteristic of electromagnetic wave, which is characterized by the orientation of the electric field intensity vector at a given point in space changing with time, and is described by the trajectory of the endpoint of the electric field intensity vector changing with time, including linear polarization, circular polarization and elliptical polarization. In many cases, the polarization direction of electromagnetic wave plays a very key role in practical application, and this characteristic is used in reflector antennas, imaging systems, sensors and antenna radomes. Traditional electromagnetic wave polarization control methods include grating control, bichromic crystal control, and birefringence effect control. The size of the equipment manufactured according to these principles is much larger than the wavelength of the electromagnetic wave in the working frequency band, and it is quite complex to construct and has a high manufacturing cost. Metamaterial (artificial electromagnetic material) is a kind of artificially constructed material with special electromagnetic properties. These special electromagnetic properties enable it to control the transmission characteristics of electromagnetic waves, including the polarization characteristics of electromagnetic waves.
[0003] In modern radar and wireless communication, it is difficult to meet the requirements only by using linearly polarized antennas. High-gain circularly polarized antennas have attracted widespread attention due to their characteristics of anti-rain and fog interference and anti-multipath effect. Although the traditional horn antenna has many advantages, it has disadvantages in wideband operation. In recent years, in order to increase the frequency bandwidth of the horn antenna, people have introduced corrugated wall and ridge transition technology. Similar to the ridge waveguide, the ridge section in the horn antenna is used to reduce the lower cutoff frequency of the main mode and widen the single-mode bandwidth. In addition, this technology can be used in double-ridge or four-ridge schemes to generate single-polarized and dual-polarized horn antennas. From the microwave frequency band to the optical frequency band, dual-polarized radiation mode is one of the most commonly used techniques to improve the communication capacity, which is used for polarization diversity in radar and base station antennas. There are many dual-polarized antennas such as patch antennas, horn antennas and array antennas. However, these devices have low operating frequency, narrow frequency bandwidth and complex structure, which are greatly limited in practical application.
[0004] Specifically for four-ridge horn antennas, in order to realize circular polarization, the prior art needs to feed the antenna with two orthogonal linearly polarized field pairs with a phase difference of 90° within the working frequency band. The orthogonal mode converter is the most commonly used feeding structure, which mainly generates two orthogonal linearly polarized fields. However, due to the complexity of the orthogonal mode converter, the use of the orthogonal mode converter is not conducive to the design of a simple and compact feed source, and the sub-micron precision machining required at 220GHz will increase the production cost. SUMMARY
[0005] The G-band four-ridge dual-polarized horn antenna of the present application simultaneously realizes equal-amplitude phase-difference 90° feeding and linear polarization and circular polarization conversion under single-port condition by using a partition polarizer.
[0006] To achieve the above-mentioned object, the G-band four-ridge dual-polarized horn antenna of the present application comprises a four-ridge horn section, a four-ridge waveguide transition section and a partition polarizer, wherein:
[0007] The four-ridge horn section is used for generating two orthogonal fields and comprises a horn shell and four ridges of the same structure, the four ridges being arranged inside the horn shell and oppositely arranged to form a cross structure.
[0008] The four-ridge waveguide transition section is used for impedance matching between the four-ridge horn section and the partition polarizer and comprises a shell and four transition ridges, wherein the four transition ridges are connected with the ridges in the four-ridge horn section, respectively.
[0009] The partition polarizer is used for transmitting G-band electromagnetic waves transmitted by a signal source to the horn antenna section after dual polarization and comprises a square waveguide, a stepped metal partition, an inner impedance converter, an outer impedance converter and a feed line, wherein the stepped metal partition is arranged in the middle of the square waveguide and divides the square waveguide into two rectangular waveguides; the inner impedance converter is attached to one side of the stepped metal partition, the outer impedance converter is attached to the inside of the square waveguide and opposite to the inner impedance converter, the feed line is connected with the inner impedance converter through an inner conductor, and the inner impedance converter and the outer impedance converter are used for realizing impedance matching between the feed line and the square waveguide.
[0010] Further, the aperture area A of the four-ridge horn section is calculated by using the following formula:
[0011]
[0012] wherein G represents the directivity gain of the antenna, λ represents the wavelength of the electromagnetic wave, and η represents the aperture efficiency factor. a
[0013] Further, the four ridges in the four-ridge horn section and the four-ridge waveguide transition section are gradually tapered along the electromagnetic wave propagation direction, and the distance x between the projection of each point on the ridges on the critical interface of the four-ridge horn section and the four-ridge waveguide transition section and the center point of the critical interface satisfies the following formula:
[0014]
[0015] wherein z represents the vertical distance of the point on the ridges relative to the critical interface, b represents the side length of the square waveguide, w represents the distance of the ridges in the four-ridge horn section and the four-ridge waveguide transition section relative to the ridges on the critical interface, and L represents the length of the critical interface. f represents the length of the quadruplet ridge waveguide transition section. Further, the stepped septum polarizer comprises 5 or 6 steps, denoted as step i , i = 0, 1, …, N-1, where N = {5, 6}, wherein the length of each step step i is calculated by the following formula:
[0016]
[0017] wherein λ i represents the wavelength of the i-th step, λ -1 represents the wavelength of the input electromagnetic wave, λ i c represents the cutoff wavelength of the i-th step, λ f represents the free space wavelength.
[0018] Further, the inner impedance converter and the outer impedance converter adopt two symmetrically arranged stepped multi-section matching converters.
[0019] The G-band quadruplet dual-polarized horn antenna of the present application comprises a quadruplet horn section, a quadruplet waveguide transition section and a septum polarizer, wherein the quadruplet horn section is used to generate two orthogonal fields, the quadruplet waveguide transition section is used to match the impedance of the quadruplet horn section and the septum polarizer, and the septum polarizer is used to transmit the G-band electromagnetic wave transmitted by the signal source after dual polarization to the horn antenna section. In the septum polarizer, a stepped metal septum is arranged inside the square waveguide to divide the square waveguide into two rectangular waveguides, and an inner impedance converter and an outer impedance converter are used to match the impedance of the feeding line and the square waveguide.
[0020] The present application has the following beneficial effects:
[0021] 1) Compared with the traditional quadruplet horn antenna, the single-port feeding line can realize dual polarization, and the design is simple and easy to process;
[0022] 2) The present application is aimed at G-band electromagnetic waves, and the septum polarizer is used to realize dual circular polarization. Compared with the existing technology, the structure of the quadrature mode converter and the polarizer is simpler, and the complexity of device design and processing is reduced;
[0023] 3) The height and width of each step of the stepped metal septum in the septum polarizer can be adjusted to suppress high-order mode excitation and unwanted resonance within the working frequency band, thereby allowing the horn antenna to work in a larger frequency band. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 is a specific embodiment structure diagram of the G-band quadruplet dual-polarized horn antenna of the present application;
[0025] Figure 2 is a structural diagram of the septum polarizer in the present application;
[0026] Figure 3 is a structural diagram of the stepped metal septum in the present embodiment;
[0027] Figure 4 is a radiation pattern diagram of the left-hand circular polarization and the right-hand circular polarization of the horn antenna in the present embodiment at 140 GHz;
[0028] Figure 5 is a radiation pattern diagram of the left-hand circular polarization and the right-hand circular polarization of the horn antenna in the present embodiment at 140 GHz. DETAILED DESCRIPTION
[0029] The specific embodiments of the present application will be described below with reference to the accompanying drawings so as to be better understood by those skilled in the art. It should be particularly noted that in the following description, when detailed description of known functions and designs may obscure the main content of the present application, these descriptions will be omitted here.
[0030] EMBODIMENT
[0031] Figure 1 is a structural diagram of the specific embodiment of the G-band four-ridge dual-polarized horn antenna of the present application. As shown in the figure, the G-band four-ridge dual-polarized horn antenna of the present application comprises a four-ridge horn section 1, a four-ridge waveguide transition section 2 and a septum polarizer 3, and the two components will be described in detail below. Figure 1
[0032] The four-ridge horn section 1 is used to generate two orthogonal fields, comprising a horn shell 11 and four structurally identical ridges 12, which are placed inside the horn shell 11 and opposite to each other to form a cross structure. In the present embodiment, in order to further improve the gain coefficient of the horn antenna, the aperture area A of the four-ridge horn section 1 is calculated using the following antenna gain theoretical formula:
[0033]
[0034] wherein G represents the directivity gain of the antenna, λ represents the wavelength of the electromagnetic wave, η a represents the aperture efficiency factor, and in the present embodiment, η a is 0.49.
[0035] The four-ridge waveguide transition section 2 is used to match the impedance between the four-ridge horn section 1 and the septum polarizer 3, comprising a shell 21 and four transition ridges 22, wherein the four transition ridges 22 are respectively connected to the ridges 12 in the four-ridge horn section 1. Through the impedance matching of the four-ridge waveguide transition section 2, the impedance difference between the four-ridge horn section 1 and the septum polarizer 3 is eliminated, so that the signal can be efficiently transmitted from the septum polarizer 3 to the four-ridge horn section 1, avoiding reflection loss and performance distortion.
[0036] In order to better make the characteristic impedance of the four-ridge waveguide transition to the free space characteristic impedance, the four ridges in the four-ridge horn section 1 and the four-ridge waveguide transition section 2 are tapered gradually along the electromagnetic wave propagation direction in the embodiment, and the distance x between the projection of each point on the ridge at the critical interface of the four-ridge horn section 1 and the four-ridge waveguide transition section 2 and the center point of the critical interface satisfies the following formula:
[0037]
[0038] Wherein, z represents the vertical distance of the point on the ridge relative to the critical interface, b represents the side length of the square waveguide 31, w represents the distance of the critical interface of the four-ridge horn section 1 and the four-ridge waveguide transition section 2 relative to the ridge, L f represents the length of the four-ridge waveguide transition section 2.
[0039] The baffle polarizer 3 is used for transmitting the G-band electromagnetic wave transmitted by the signal source after being dual-polarized to the horn antenna section 1. Figure 2 is the structure diagram of the baffle polarizer in the embodiment. As shown in Figure 1 and Figure 3 , the baffle polarizer 3 in the embodiment includes a square waveguide 31, a stepped metal baffle 32, an inner side impedance converter 33, an outer side impedance converter 34 and a feed line 35, wherein the stepped metal baffle 32 is located in the middle of the square waveguide 31 and divides the square waveguide 31 into two rectangular waveguides; the inner side impedance converter 33 is attached to one side of the stepped metal baffle 32, the outer side impedance converter 34 is attached to the inside of the square waveguide 31 and opposite to the inner side impedance converter 33, and the feed line 35 is connected with the inner side converter 33 through an inner conductor, and the inner side impedance converter 33 and the outer side impedance converter 34 are used for realizing the impedance matching between the feed line 35 and the square waveguide 31.
[0040] It can be seen that the stepped metal baffle 32 in the baffle polarizer 3 divides the square waveguide 31 into two rectangular waveguides, the two rectangular waveguides decompose the main mode TE01 into two mutually perpendicular odd and even modes for separate excitation, and then left-handed circular polarization and right-handed circular polarization can be obtained at the output end of the square waveguide 31. Therefore, the baffle polarizer 3 has the functions of the orthogonal mode converter and the polarizer, and has smaller overall size and weight, and is easier to be realized in industry.
[0041] Figure 3 The structure example diagram of the stepped metal baffle in the embodiment is shown in Figure 3 As shown in the embodiment, the stepped baffle polarizer 32 is preferably provided with 5 or 6 steps from high to low, which are step i , i=0, 1, …, N-1, wherein N={5, 6}, and the length of each step step i is calculated by the following formula:
[0042]
[0043] wherein λ i represents the wavelength of the i-th step, λ -1 represents the wavelength of the input electromagnetic wave, λ i c represents the cutoff wavelength of the i-th step, λ f represents the free space wavelength.
[0044] The inner height H i of each step step i is set according to the corresponding target frequency band , so that the main mode (TE10) can propagate at a low frequency value , while ensuring that the next high-order mode (usually TE20) is in a cutoff state at a high frequency value or slightly higher. In practical applications, the inner height H i of each step can be determined in a sweep parameter manner.
[0045] In order to better realize the broadband transition of the feed line 35 to the stepped metal partition plate 32, the inner side impedance converter 33 and the outer side impedance converter 34 in the embodiment adopt two symmetrically arranged stepped multi-section matching converters.
[0046] In order to better illustrate the technical effects of the present application, a specific example is used to simulate and verify the present application.
[0047] Figure 4 is the left-hand circular polarization and right-hand circular polarization pattern of the horn antenna in the embodiment at 140GHz.
[0048] Figure 5 is the left-hand circular polarization and right-hand circular polarization pattern of the horn antenna in the embodiment at 140GHz. As shown in Figure 4 and Figure 5 , the present application can simultaneously realize left-hand circular polarization and right-hand circular polarization, and neither of them has the split lobe phenomenon, wherein the right-hand circular polarization has better directivity relative to the left-hand circular polarization; relative to 160GHz, 140GHz has higher gain, smaller side lobe and back lobe.
[0049] Although the above describes the specific embodiments of the present application illustratively, so as to facilitate the technical personnel in the technical field to understand the present application, it should be clear that the present application is not limited to the scope of the specific embodiments, and for the ordinary technical personnel in the technical field, as long as various changes are within the spirit and scope of the present application defined and determined by the appended claims, all the application creations utilizing the concept of the present application are within the scope of protection.
Claims
1. A G-band quad-ridged dual-polarized horn antenna, characterized in that: It includes a four-ridged horn section, a four-ridged waveguide transition section and a septum polarizer, wherein: The four-ridged horn section is used to generate two orthogonal fields, and includes a horn housing and four ridges with the same structure. The four ridges are located inside the horn housing and are placed opposite to each other to form a cross structure. The four-ridged waveguide transition section is used to perform impedance matching between the four-ridged horn section and the baffle polarizer, and includes a housing and four transition ridges, wherein the four transition ridges are respectively connected to the ridges in the four-ridged horn section; The partition polarizer is used to dual-polarize the G-band electromagnetic waves transmitted by the signal source and then transmit them to the horn antenna section. It includes a square waveguide, a stepped metal partition, an inner impedance converter, an outer impedance converter and a feeder. The stepped metal partition is located in the middle of the square waveguide, dividing the square waveguide into two rectangular waveguides; the inner impedance converter is attached to one side of the stepped metal partition, and the outer impedance converter is attached to the inside of the square waveguide and opposite to the inner impedance converter. The feeder is connected to the inner converter through an inner conductor. The inner impedance converter and the outer impedance converter are used to achieve impedance matching between the feeder and the square waveguide.
2. The G-band quad-ridged dual-polarization horn antenna according to claim 1, characterized in that: The aperture area A of the four-ridge horn section is calculated using the following formula: Where G represents the directional gain of the antenna, λ represents the wavelength of the electromagnetic wave, and η a represents the aperture efficiency factor.
3. The G-band quad-ridged dual-polarization horn antenna according to claim 1, characterized in that: The four ridges in the four-ridged horn section and the four-ridged waveguide transition section gradually taper along the propagation direction of the electromagnetic wave, and the distance x between the projection of each point on the critical surface of the four-ridged horn section and the four-ridged waveguide transition section and the center point of the critical surface satisfies the following formula: Where z represents the vertical distance of the point on the ridge relative to the critical surface, b represents the side length of the square waveguide, w represents the distance between the four-ridged horn section and the four-ridged waveguide transition section on the critical surface relative to the ridge, and L f Indicates the length of the quad-ridged waveguide transition section.
4. The G-band quad-ridged dual-polarization horn antenna according to claim 1, characterized in that: The stepped partition polarizer includes 5 or 6 steps, which are marked as steps from high to low. i , i=0,1,…,N-1, where N={5,6}, where each step i The length is calculated using the following formula: Among them, λ i represents the wavelength of the i-th step, λ -1 represents the wavelength of the input electromagnetic wave, represents the cutoff wavelength of the i-th step, λ f represents the free-space wavelength.
5. The G-band quad-ridged dual-polarization horn antenna according to claim 1, wherein: The inner impedance converter and the outer impedance converter are two symmetrically arranged stepped multi-stage matching converters.