An X-band wave-to-wave conversion structure

Abstract

The utility model discloses a kind of X wave band wave same conversion structure, it is related to microwave communication and radar technical field.The X wave band wave same conversion structure includes gradually changing type composite conversion main body structure, the composite conversion main body structure is composed of coaxial-waveguide transition section, dielectric-magnetic guide gradually changing composite layer and double-frequency coupling resonance layer, the coaxial-waveguide transition section uses ladder impedance conversion structure to realize the wideband impedance matching of coaxial line and waveguide.The X wave band wave same conversion structure provided by the utility model is used to realize the efficient conversion of wideband electromagnetic wave polarization mode.

Description

Technical Field

[0001] This utility model relates to the field of microwave communication and radar technology, and in particular to an X-band wave-to-wave conversion structure. Background Technology

[0002] In the fields of microwave communication and radar technology, the X-band (8-12 GHz), as the core frequency band of the centimeter wave band, has wide applications in radar systems and satellite communications. For example, synthetic aperture radar (SAR) requires a wave-to-wave converter to achieve efficient conversion between linearly polarized waves at the transmitting end and circularly polarized waves at the receiving end, in order to improve the detection accuracy of target scattering characteristics; weather radar uses polarization mode conversion technology to enhance the classification capability of precipitation particles; military communication satellites employ polarization multiplexing technology in the X-band, requiring low-loss wave-to-wave converter devices to support multi-beam antenna design.

[0003] However, existing wave-to-wave converters based on fixed-parameter dielectric substrates and metal coupling structures have many technical problems. First, there is the limitation of narrow bandwidth; traditional stepped converters have insufficient relative bandwidth and cannot cover the wide bandwidth requirements of the X-band. Second, at high frequencies, impedance mismatch leads to high insertion loss, and excitation of higher-order modes easily causes a decrease in polarization purity. In addition, traditional multi-section structures are bulky, and the cost of precision manufacturing increases significantly with increasing frequency, and process errors can easily lead to performance fluctuations. Summary of the Invention

[0004] The purpose of this invention is to provide an X-band wave-to-wave conversion structure for achieving efficient conversion of wideband electromagnetic wave polarization modes.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an X-band waveguide conversion structure, comprising a gradient composite conversion main structure, wherein the composite conversion main structure is composed of a coaxial-waveguide transition section, a dielectric-magnetic permeability gradient composite layer and a dual-frequency coupling resonant layer, wherein the coaxial-waveguide transition section adopts a stepped impedance transformation structure to achieve broadband impedance matching between the coaxial line and the waveguide.

[0006] Optionally, the dielectric-permeability gradient composite layer is disposed on the electromagnetic wave propagation path of the coaxial-waveguide transition section, and its dielectric constant and permeability are distributed in a gradient along the propagation direction to form a dynamic phase velocity matching structure.

[0007] Optionally, the dual-frequency coupling resonant layer includes a gradient metal stub array, wherein the geometric dimensions of the metal stubs vary gradient along the electromagnetic wave propagation direction to form a dual-frequency resonant coupling structure suitable for the 8-12GHz frequency band.

[0008] Optionally, the stepped impedance transformation structure adopts a multi-level Chebyshev stepped design, which achieves a gradual transition from 50Ω coaxial impedance to waveguide impedance through the gradient change of step height and length.

[0009] Optionally, the waveguide section adopts a non-standard cross-sectional size design, and its cross-sectional geometric parameters are optimized to achieve synergistic optimization of structural compactness and impedance matching.

[0010] Optionally, the coaxial-waveguide transition section is provided with a feed probe structure, and the feed probe and the end of the stepped impedance transformation structure form an end-feed standing wave matching structure.

[0011] Optionally, the gradient metal stub array adopts a frequency-band gradient design, with the low-frequency stub size adapted to the long-wavelength resonant mode and the high-frequency stub size adapted to the short-wavelength coupling mode.

[0012] Optionally, the dielectric-permeability gradient composite layer is composed of multiple layers of dielectric plates with different dielectric constants and permeabilities, and the material parameters of each layer are distributed according to a gradient law.

[0013] Compared with existing technologies, the X-band wave-to-wave conversion structure provided by this invention achieves effective coverage of the entire 8-12GHz X-band through the synergistic design of Chebyshev stepped impedance transformation and dual-frequency coupled resonant structure. This wideband characteristic enables the wave-to-wave converter to simultaneously meet the wideband detection requirements of synthetic aperture radar and the frequency-hopping operation scenarios of satellite communication, eliminating the need for dedicated devices for different frequency bands and significantly improving the system's versatility and flexibility. The dynamic phase velocity compensation mechanism of the dielectric-magnetic permeability graded composite layer effectively solves the insertion loss problem caused by impedance mismatch in the high-frequency band in traditional technologies. The integration of non-standard waveguide design and composite graded structure significantly reduces the device size compared to traditional multi-section structures, while also reducing the difficulty and cost of high-frequency band processing. The wideband, low-loss, and compact characteristics of this X-band wave-to-wave conversion structure enable it to be widely used in military and civilian X-band systems, effectively expanding the application scenarios of X-band technology. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the X-band wave-to-wave conversion structure provided in an embodiment of the present invention.

[0015] Figure 2 This is a front view of the X-band wave-to-wave conversion structure provided in an embodiment of the present invention.

[0016] Figure 3 for Figure 2 Sectional view of plane AA.

[0017] Figure reference numerals: 100-wave-same-conversion structure; 1-transition section; 2-composite layer; 3-resonant layer; 31-metal branch; 4-feed probe. Detailed Implementation

[0018] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0019] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0021] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] Please see Figures 1-3The X-band waveguide conversion structure 100 provided in this embodiment of the present invention includes a gradient composite conversion main structure. The composite conversion main structure is composed of a coaxial-waveguide transition section 1, a dielectric-magnetic permeability gradient composite layer 2 and a dual-frequency coupling resonant layer 3. The coaxial-waveguide transition section 1 adopts a stepped impedance transformation structure to achieve broadband impedance matching between the coaxial line and the waveguide.

[0024] In this application, the dielectric-permeability gradient composite layer 2 is disposed on the electromagnetic wave propagation path of the coaxial-waveguide transition section 1, and its dielectric constant and permeability are distributed in a gradient along the propagation direction to form a dynamic phase velocity matching structure.

[0025] In one embodiment provided in this application, the dual-frequency coupling resonant layer 3 includes an array of gradient metal branches 31, the geometric dimensions of which vary gradient along the direction of electromagnetic wave propagation, forming a dual-frequency resonant coupling structure suitable for the 8-12GHz frequency band.

[0026] In this application, the stepped impedance transformation structure adopts a multi-level Chebyshev stepped design, which achieves a gradual transition from 50Ω coaxial impedance to waveguide impedance through the gradient change of step height and length.

[0027] The stepped impedance transformation structure adopts the Chebyshev multi-stage stepped transformation form. Based on the requirement of wideband impedance matching, it gradually transitions the characteristic impedance of the coaxial line to the characteristic impedance of the waveguide. It utilizes the multi-resonance point effect to broaden the working bandwidth. The length of each step follows the quarter-waveguide wavelength principle in electromagnetic wave transmission theory. The impedance is gradually changed through the gradient change of step height and length.

[0028] In one embodiment provided in this application, the waveguide section adopts a non-standard cross-sectional size design, and its cross-sectional geometric parameters are optimized to achieve structural compactness and impedance matching optimization.

[0029] To meet the requirements of structural compactness, the waveguide section adopts a non-standard waveguide cross-section design. Electromagnetic field simulation software is used to analyze the impact of different cross-section parameters on impedance matching and mode transmission, optimize the waveguide cross-section geometry and size, reduce the waveguide volume while ensuring the transmission of the main mode, and achieve broadband impedance matching in conjunction with a stepped impedance transformation structure.

[0030] In this application, the coaxial-waveguide transition section 1 is provided with a feed probe 4 structure, and the feed probe 4 and the end of the stepped impedance transformation structure form an end-feed standing wave matching structure.

[0031] Feed probe 4 is set at the end of coaxial-waveguide transition section 1. The probe diameter, length and relative position with the stepped impedance transformation structure are determined by parametric design. An end-feed standing wave matching model is constructed. The probe position and step size are used as variables to establish an objective function for optimization design, providing initial parameters for subsequent electromagnetic simulation optimization.

[0032] In one embodiment provided in this application, the gradient metal stub array adopts a frequency-segment gradient design, with the low-frequency stub size adapted to the long-wavelength resonant mode and the high-frequency stub size adapted to the short-wavelength coupling mode.

[0033] Based on the size dispersion characteristics, a metal stub array 31 with geometric size gradient along the electromagnetic wave propagation direction is designed. A frequency band gradient strategy is adopted, with the stub size in the low frequency band adapted to the long wavelength resonant mode and the stub size in the high frequency band adapted to the short wavelength coupling mode. A correspondence model between the size of the metal stub 31 and the operating frequency is established, and the shape and gradient law of the stub are determined by electromagnetic theory calculation.

[0034] In this application, the dielectric-permeability gradient composite layer 2 is composed of multiple layers of dielectric plates with different dielectric constants and permeabilities, and the material parameters of each layer are distributed according to a gradient law.

[0035] Working principle: The impedance gradient matching process uses the stepped impedance transformation structure of the coaxial-waveguide transition section 1 as the basic channel for energy transmission. Through a multi-stage Chebyshev stepped design, the 50Ω characteristic impedance of the coaxial line is gradually transitioned to the characteristic impedance of the waveguide. The length of each stage of this stepped structure follows the design principle of one-quarter waveguide wavelength. The multi-resonance point effect is used to broaden the working bandwidth. When electromagnetic waves are incident from the coaxial line, the stepped impedance transformation structure effectively reduces the reflection coefficient at the waveguide-coaxial interface through the gradient impedance transition, laying the foundation for low-loss transmission for subsequent polarization mode conversion. The optimized cross-sectional dimensions of the non-standard waveguide further coordinate the adjustment of the impedance transformation gradient, achieving a balance between structural compactness and impedance matching performance.

[0036] In the dynamic phase velocity compensation process, the dielectric-permeability gradient composite layer 2, as the core unit of broadband phase modulation, dynamically matches the phase velocity of electromagnetic waves of different frequencies with its gradient-distributed dielectric constant and permeability parameters along the electromagnetic wave propagation direction. Specifically, when X-band broadband electromagnetic waves pass through the composite layer 2, low-frequency electromagnetic waves (e.g., 8 GHz) correspond to a region with higher dielectric constant and permeability, while high-frequency electromagnetic waves (e.g., 12 GHz) correspond to a region with lower dielectric constant and permeability. This gradient distribution compensates for the propagation wavelength of electromagnetic waves of different frequencies in the composite layer 2, avoiding phase mismatch problems caused by frequency differences and providing phase consistency assurance for efficient polarization mode conversion.

[0037] In the dual-frequency resonant coupling process, the gradient metal stub array 31 of the dual-frequency coupling resonant layer 3 utilizes the size dispersion characteristics to achieve full-band energy conversion. In the low-frequency band (8-10GHz), the longer metal stubs 31 excite long-wavelength resonant modes, enhancing the conversion efficiency from linearly polarized waves to circularly polarized waves through electromagnetic resonance effects. In the high-frequency band (10-12GHz), the shorter metal stubs 31 excite short-wavelength coupling modes, achieving efficient polarization mode conversion through near-field electromagnetic coupling effects. This frequency-band gradient design enables the metal stub array 31 to resonate and couple with electromagnetic waves throughout the entire X-band, avoiding the resonant frequency shift problem of traditional fixed-parameter structures in the wide bandwidth.

[0038] In the end-feed standing wave optimization process, the end-feed standing wave matching structure formed by the feed probe 4 and the end of the stepped impedance transformation structure further reduces the standing wave ratio of the incident electromagnetic wave by optimizing the probe position and step size parameters. This structure uses HFSS simulation optimization technology to parameterize the probe length, step height and the distance between them, so as to achieve dynamic optimization of the standing wave ratio in the 8-12GHz frequency band, ensure minimum reflection loss in the energy transmission process and improve the overall conversion efficiency.

[0039] As can be seen from the structure and specific implementation process of the X-band wave-to-wave converter 100, the synergistic design of Chebyshev stepped impedance transformation and dual-frequency coupled resonant structure achieves effective coverage of the entire X-band 8-12GHz frequency band. This wideband characteristic enables the wave-to-wave converter to simultaneously meet the wideband detection requirements of synthetic aperture radar and the frequency hopping operation scenario of satellite communication, without the need to design dedicated devices for different frequency bands, significantly improving the versatility and flexibility of the system.

[0040] The dynamic phase velocity compensation mechanism of the dielectric-magnetic gradient composite layer 2 effectively solves the insertion loss problem caused by impedance mismatch in the high-frequency band in traditional technology. The polarization conversion efficiency remains stable at a high level throughout the X-band, which is significantly improved compared with the traditional scheme. At the same time, the dual-frequency coupled resonant structure suppresses the excitation of higher-order modes, so that the polarization purity meets the ideal index. This is of key significance for improving the target scattering characteristic detection accuracy of radar system and the spectrum utilization of satellite communication.

[0041] The integration of non-standard waveguide design and composite gradient structure significantly reduces the device size compared to traditional multi-section structures. Meanwhile, the stepped impedance transformation structure employs an optimized stage design, avoiding the need for precision metal grid fabrication in traditional solutions and reducing the difficulty and cost of high-frequency fabrication.

[0042] The wide bandwidth, low loss, and compact design of this X-band converter enable its widespread application in both military and civilian X-band systems. In the military field, it can be adapted to next-generation multi-band radar reconnaissance equipment and anti-jamming satellite communication terminals; in the civilian field, it can be applied to high-resolution weather radar systems and broadband microwave communication base stations, effectively expanding the application scenarios of X-band technology.

[0043] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0044] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An X-band wave-to-wave conversion structure, characterized in that, The system includes a gradient-type composite conversion main structure, which consists of a coaxial-waveguide transition section, a dielectric-magnetic gradient composite layer, and a dual-frequency coupling resonant layer. The coaxial-waveguide transition section adopts a stepped impedance transformation structure to achieve broadband impedance matching between the coaxial line and the waveguide.

2. The X-band wave-to-wave conversion structure according to claim 1, characterized in that, The dielectric-permeability gradient composite layer is disposed on the electromagnetic wave propagation path of the coaxial-waveguide transition section, and its dielectric constant and permeability are distributed in a gradient along the propagation direction to form a dynamic phase velocity matching structure.

3. The X-band wave-to-wave conversion structure according to claim 2, characterized in that, The dual-frequency coupling resonant layer includes a gradient metal stub array, the geometric dimensions of which vary gradient along the electromagnetic wave propagation direction, forming a dual-frequency resonant coupling structure suitable for the 8-12GHz frequency band.

4. The X-band wave-to-wave conversion structure according to claim 3, characterized in that, The stepped impedance transformation structure adopts a multi-level Chebyshev stepped design, which achieves a gradual transition from 50Ω coaxial impedance to waveguide impedance through the gradient change of step height and length.

5. The X-band wave-to-wave conversion structure according to claim 4, characterized in that, The waveguide section adopts a non-standard cross-sectional size design, and its cross-sectional geometric parameters are optimized to achieve a combination of structural compactness and impedance matching optimization.

6. The X-band wave-to-wave conversion structure according to claim 5, characterized in that, The coaxial-waveguide transition section is provided with a feed probe structure, and the feed probe and the end of the stepped impedance transformation structure form an end-feed standing wave matching structure.

7. The X-band wave-to-wave conversion structure according to claim 6, characterized in that, The gradient metal stub array adopts a frequency-segmented gradient design, with the low-frequency stub size adapted to the long-wavelength resonant mode and the high-frequency stub size adapted to the short-wavelength coupling mode.

8. The X-band wave-to-wave conversion structure according to claim 7, characterized in that, The dielectric-permeability gradient composite layer is composed of multiple layers of dielectric plates with different dielectric constants and permeabilities, and the material parameters of each layer are distributed according to a gradient law.

Images