High gain millimeter wave waveguide horn phased array antenna based on HTCC technology

Abstract

The invention provides a high-gain millimeter wave waveguide horn phased-array antenna unit based on an HTCC technology, and the antenna unit comprises an HTCC dielectric substrate which is formed by stacking a plurality of dielectric layers in the vertical direction, and each dielectric layer is internally provided with a metalized through hole array which is arranged along a specific path; the waveguide cavity is enclosed by waveguide walls formed by metalized through hole arrays in the multiple dielectric layers; the feed structure comprises a coaxial line fed from the bottom of the antenna unit, an inner conductor of the coaxial line extends into the waveguide cavity and is connected with a metal patch, and the metal patch is electrically connected with the waveguide wall of the waveguide cavity; and the multi-stage stepped horn structure is arranged in the HTCC dielectric substrate, is stacked above the radiation port of the waveguide cavity, and comprises at least two stages of stepped cavities with waveguide walls formed by metalized through hole arrays. The three-dimensional waveguide horn structure is planarized and multi-layered by using the HTCC technology, the embedded waveguide cavity and multi-step horn structure design is realized by using the HTCC technology, and the advantages of high gain and easy planar integration are achieved.

Description

Technical Field

[0001] This invention relates to the field of phased array antenna technology, and in particular to a high-gain millimeter-wave waveguide horn phased array antenna based on HTCC technology. Background Technology

[0002] Phased array antennas, with their advantages of rapid beam scanning, flexible multi-beamforming, and high directivity, have been widely used in 5G communication, radar detection, and satellite communication. As modern wireless systems increasingly demand higher detection ranges, communication capacities, and anti-interference capabilities, enhancing the radiation performance of phased array antennas has become a key research focus.

[0003] However, traditional phased array antenna elements face several technical challenges: while widely used microstrip patch antennas are simple in structure and easy to integrate, their inherent characteristics limit further gains; and while horn antennas can provide high element gain, their three-dimensional structure makes efficient integration with planar TR components difficult. This contradiction is particularly prominent in the millimeter-wave band.

[0004] High-temperature co-fired ceramic (HTCC) technology is a multilayer ceramic process that can realize high-density, three-dimensional interconnected structures with good high-frequency characteristics, mechanical strength and thermal stability, providing an ideal process platform for realizing high-performance and easily integrated phased array antennas in a limited space.

[0005] Chinese patent application CN202310389020.1 discloses a phased array radiation structure and its operating method based on HTCC technology. It employs a multi-layer HTCC dielectric layer stacking method to form each cavity, solving the problems of low processing accuracy, poor thermal conductivity, and low radiation efficiency in the submillimeter-wave phased array direction of existing antenna packaging processes. While the comparative patent solves the radiation problem of submillimeter-wave phased arrays using a multi-cavity approach, a solution for large-angle scanning of millimeter-wave phased arrays is still lacking. Furthermore, the comparative patent uses a waveguide interface as the feeding structure, which is not conducive to miniaturization design. Currently, there is an urgent need for a novel antenna element for the millimeter-wave band that combines high gain and integrated compatibility. Summary of the Invention

[0006] Based on the above, the purpose of this invention is to provide a high-gain millimeter-wave waveguide horn phased array antenna unit based on HTCC technology. It utilizes HTCC technology to realize the design of embedded waveguide cavity and multi-stage stepped horn structure, which has the advantages of high gain, wide operating bandwidth, good scanning characteristics and easy planar integration.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, embodiments of this application provide a high-gain millimeter-wave waveguide horn phased array antenna element based on HTCC technology, comprising:

[0009] The HTCC dielectric substrate is composed of multiple dielectric layers stacked vertically. Each dielectric layer contains an array of metallized vias arranged along a specific path. The projection of the metallized via array onto a horizontal plane forms a ring pattern. Corresponding to each metallized via array, planar metal layers are disposed in the adjacent upper and lower dielectric layers. The pattern of the planar metal layers matches the projection pattern of the metallized via array and completely covers the cross-sectional area of ​​the metallized via array, thereby forming a continuous waveguide wall together with the metallized via array.

[0010] The waveguide cavity is surrounded by waveguide walls formed by the array of metallized vias in the multiple dielectric layers;

[0011] The feeding structure includes a coaxial line fed from the bottom of the antenna element, the inner conductor of the coaxial line extending into the waveguide cavity and connected to a metal patch, the metal patch being electrically connected to the waveguide wall of the waveguide cavity;

[0012] A multi-stage stepped horn structure is disposed within the HTCC dielectric substrate and stacked above the radiation port of the waveguide cavity. It includes at least two stages of stepped cavities whose waveguide walls are formed by the metallized via array. The cross-sectional area of ​​the lowest-level stepped cavity is greater than the cross-sectional area of ​​the waveguide cavity, and the cross-sectional area of ​​the next-level stepped cavity is greater than or equal to the cross-sectional area of ​​the next-level stepped cavity.

[0013] In one alternative embodiment, the waveguide cavity, the coaxial line, and the multi-stage stepped horn structure are a concentric, coaxial, vertically interconnected structure.

[0014] In one alternative embodiment, both the waveguide cavity and the multi-stage stepped horn structure are rectangular.

[0015] In one alternative, the metal patch is electrically connected to a long side of the waveguide wall of the waveguide cavity.

[0016] In one alternative approach, the dimension 'a' of the long side of the waveguide wall of the rectangular waveguide cavity satisfies the electromagnetic wave single-mode transmission condition: a < λ0 < 2a, where λ0 is the wavelength of the antenna center operating frequency in free space.

[0017] In one alternative embodiment, the multi-stage stepped horn structure is three-stage, comprising a first-stage, a second-stage, and a third-stage stepped cavity arranged sequentially from bottom to top, wherein the cross-sectional areas of the second-stage and third-stage stepped cavities are the same and both are larger than the cross-sectional area of ​​the first-stage stepped cavity.

[0018] In one alternative embodiment, the first and second stage stepped cavities are each composed of only a single layer of the aforementioned dielectric layer, while the third stage stepped cavity is composed of multiple layers of the aforementioned dielectric layer.

[0019] In one alternative approach, a simulated slotted structure composed of the metallized via array is provided at the center of the waveguide wall of the secondary and tertiary stepped cavities, and the size of the simulated slotted structure on the tertiary stepped cavity is smaller than the size of the corresponding simulated slotted structure on the secondary stepped cavity.

[0020] In one alternative approach, the midpoints of the opposite waveguide walls of the secondary and tertiary stepped cavities, and the adjacent simulated slotted structure regions, are not provided with the metallized vias, but the corresponding regions are still provided with the planar metal layer; the line connecting the midpoints of the opposite waveguide walls is perpendicular to the length direction of the metal patch.

[0021] Secondly, embodiments of this application provide a phased array antenna, including a plurality of antenna elements as described above arranged in a two-dimensional planar array.

[0022] The present invention discloses the following technical effects:

[0023] (1) The three-dimensional waveguide horn structure is planarized and multi-layered by using HTCC technology, which makes it easy to achieve monolithic integration with the RF front-end circuit based on the same HTCC technology, greatly improving the system integration and reliability.

[0024] (2) The built-in waveguide structure has low loss. Combined with the impedance transformation and aperture expansion of the multi-stage stepped horn structure, high unit gain is achieved while achieving broadband matching.

[0025] (3) It adopts a coaxial feeding structure and a vertical bottom feeding method that is compatible with phased arrays. All antenna elements can be fed uniformly and neatly from the back of the array, which is convenient for connection with the lower-level radio frequency integrated circuits or feeding networks and is easy to integrate.

[0026] (4) Through the optimized design of the stepped structure and the side wall simulated slotted structure, the antenna unit has good large-angle scanning characteristics in a wide frequency band.

[0027] (5) HTCC process is suitable for mass production, with good consistency and controllable cost, and is especially suitable for millimeter-wave large-scale phased array antennas. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of an antenna unit provided in an embodiment of the present invention;

[0030] Figure 2 yes Figure 1 Top view;

[0031] Figure 3 yes Figure 1 Side view;

[0032] Figure 4 This is a top view of the loading first-order stepped structure provided in an embodiment of the present invention;

[0033] Figure 5 This is a side view of a loading first-order stepped structure provided in an embodiment of the present invention;

[0034] Figure 6 This is a top view of the loading second-order stepped structure provided in an embodiment of the present invention;

[0035] Figure 7 This is a side view of the loading second-order stepped structure provided in an embodiment of the present invention;

[0036] Figure 8 This is a schematic diagram of a 6x6 antenna array provided in an embodiment of the present invention;

[0037] Figure 9 This refers to the standing waves at some ports of the array provided in the embodiments of the present invention;

[0038] Figure 10 This is the E-plane scanning pattern at 31 GHz provided in this embodiment of the invention;

[0039] Figure 11 This is the E-plane scanning pattern at 34 GHz provided in the embodiments of the present invention;

[0040] Figure 12 This is the E-plane scanning pattern at 37 GHz provided in an embodiment of the present invention.

[0041] Figure label:

[0042] 1-Feed structure; 2-Waveguide cavity; 3-Metal patch; 4-HTCC dielectric substrate; 5-First-level stepped cavity; 6-Second-level stepped cavity; 7-Third-level stepped cavity; 8-Metalized via array; 9-Planar metal layer; 10-Dielectric layer; 11-Waveguide wall midpoint. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0044] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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 invention based on the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used solely for ease of description and simplification of operation, 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 the present invention. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, the terms "first" and "second" are merely used for descriptive distinction and have no special meaning.

[0047] This application provides a high-gain millimeter-wave waveguide horn phased array antenna element based on HTCC technology, such as... Figures 1 to 3 As shown, it includes:

[0048] The HTCC dielectric substrate 4 is composed of multiple dielectric layers 10 stacked at high temperature along the vertical direction. Each dielectric layer 10 has a metallized via array 8 arranged along a specific path. The projection of the metallized via array 8 in the horizontal plane forms a ring pattern. Corresponding to each metallized via array 8, a planar metal layer 9 is provided in the adjacent upper and lower dielectric layers 10. The pattern of the planar metal layer 9 matches the projection pattern of the metallized via array 8 and completely covers the cross-sectional area of ​​the metallized via array 8, so that the planar metal layer 9 and the metallized via array 8 together form a continuous waveguide wall. The internal area enclosed by the waveguide wall is not covered by the planar metal layer 9, thus forming a cavity with a specific cross-section in the HTCC dielectric substrate 4 to effectively simulate the electromagnetic boundary conditions of an ideal waveguide wall. While ensuring structural integrity and manufacturability, optimized impedance matching is achieved.

[0049] The waveguide cavity 2 is surrounded by waveguide walls formed by the array of metallized vias 8 in the multilayer dielectric layer 10, which forms a signal transmission channel. By using the reflection of electromagnetic waves by the metal boundary, the electromagnetic wave energy is confined inside the cavity and transmitted with low loss along the direction of the cavity.

[0050] The feeding structure 1 includes a coaxial line fed from the bottom of the antenna unit. The inner conductor of the coaxial line extends into the waveguide cavity 2 and is connected to a metal patch 3. The metal patch 3 is electrically connected to the waveguide wall of the waveguide cavity 2. The inner conductor is specifically a metal pillar extending upward from the bottom of the antenna unit, which is also composed of stacked metallized vias. The inner conductor, the metal patch 3, and the waveguide wall together form an "L"-shaped probe. When the signal arrives, the probe generates a strong electric field disturbance in the waveguide cavity 2, thereby effectively exciting the required TE10 mode electromagnetic wave.

[0051] A multi-stage stepped horn structure is disposed within an HTCC dielectric substrate 4 and stacked above the radiation port of the waveguide cavity 2. It comprises at least two stages of stepped cavities whose waveguide walls are formed by an array of metallized vias 8. The cross-sectional area of ​​the lowest-level stepped cavity is larger than that of the waveguide cavity 2, and the cross-sectional area of ​​the next-level stepped cavity is greater than or equal to that of the next-level stepped cavity. This multi-stage stepped horn structure improves impedance matching between the dielectric and air, expands the antenna's radiation aperture area, and increases the antenna's gain while broadening its operating bandwidth.

[0052] Specifically, the dielectric constant of the HTCC dielectric substrate 4 is 9.7, the metallized via array 8 is filled with copper, and the planar metal layer 9 is made of gold with high flatness and strong oxidation resistance.

[0053] Preferably, the waveguide cavity 2, the coaxial line, and the multi-stage stepped horn structure are concentric and coaxial vertical interconnection structures. The signal is fed in from the bottom and radiated from the top, and transmitted in a straight line along the vertical axis. The physical path is the shortest, and the shortest path directly minimizes the insertion loss and improves the antenna transmission efficiency.

[0054] Specifically, both the waveguide cavity 2 and the multi-stage stepped horn structure are rectangular, and the metal patch 3 is electrically connected to one long side of the waveguide wall of the waveguide cavity 2, thereby exciting the main mode electromagnetic wave in the waveguide cavity 2.

[0055] More specifically, the dimension 'a' of the long side waveguide wall of the rectangular waveguide cavity 2 satisfies the electromagnetic wave single-mode transmission condition: a < λ0 < 2a, where λ0 is the wavelength of the antenna center operating frequency in free space, to ensure that only the main mode is transmitted and to avoid interference from higher-order modes.

[0056] Preferably, the multi-stage stepped speaker structure has three stages, such as... Figures 1 to 7 As shown, the structure includes a first-stage stepped cavity 5, a second-stage stepped cavity 6, and a third-stage stepped cavity 7 arranged sequentially from bottom to top. The second-stage stepped cavity 6 and the third-stage stepped cavity 7 have the same cross-sectional area, both larger than that of the first-stage stepped cavity 5. The first-stage and second-stage stepped cavities 6 are each composed of a single dielectric layer 10, while the third-stage stepped cavity 7 is composed of multiple dielectric layers 10. The purpose of the first-stage stepped cavity 5 and the second-stage stepped cavity 6 is to generate precise reactance compensation. Their height directly affects their equivalent capacitance or inductance value. By designing the first-stage and second-stage stepped cavities as single layers, it is beneficial to accurately design the height of these two layers, thereby achieving fine optimization of the matching network and thus widening the operating bandwidth. The purpose of the third-stage stepped cavity 7 is to form the final radiation aperture and a gradual transition. The multi-layer design increases the vertical physical length, thereby achieving a slower and smoother impedance change, further reducing reflections in the lower frequency band and improving low-frequency matching.

[0057] Preferably, at the center of the waveguide wall of the second-stage stepped cavity 6 and the third-stage stepped cavity 7, a simulated slotted structure composed of a metallized via array 8 is provided inside the cavity, and the size of the simulated slotted structure on the third-stage stepped cavity 7 is smaller than the size of the corresponding simulated slotted structure on the second-stage stepped cavity 6. The multi-stage stepped horn structure is essentially a broadband impedance transformer. Electromagnetically, the simulated slotted structure is equivalent to a capacitor connected in parallel on the transmission path. The susceptance of this capacitor is directly related to the size of the simulated slotted structure. The second-stage stepped cavity 6 is located in the middle of the impedance transformation, where the impedance mismatch is still relatively obvious. A larger simulated slotted structure is used to compensate and tune with a stronger susceptance. The third-stage stepped cavity 7 is located at the end of the impedance transformation, where the impedance is close to matching. A smaller simulated slotted structure is used to fine-tune with a weaker susceptance to achieve the most suitable matching effect. Meanwhile, the simulated slotted structure can effectively cut off or disturb surface waves propagating along the surface of the array medium. The larger slot of the second-level stepped cavity 6 can mainly suppress surface wave components with lower frequency or higher energy. The third-level stepped cavity 7 supplements the suppression of surface waves with higher frequency or residual energy, ensuring that the antenna elements can maintain good radiation efficiency and radiation pattern shape even when the beam is scanned to a large angle after forming a large array, thus avoiding a sharp drop in performance.

[0058] Furthermore, the midpoints 11 of the opposite waveguide walls of the second-order stepped cavity 6 and the third-order stepped cavity 7, and their adjacent simulated slotted structure regions, are not provided with metallized vias 8, but the corresponding regions are still provided with planar metal layers 9; the line connecting the midpoints 11 of the opposite waveguide walls is perpendicular to the length direction of the metal patch 3. This design, by replacing the discrete via array with a continuous planar metal layer on the center line of the sidewall of the E-plane (main electric field plane), provides a low-impedance main current path, reduces ohmic loss, and improves antenna radiation efficiency; at the same time, it avoids disturbing the main current distribution, reduces the small reactance disturbances introduced by the periodic structure in this region, and helps to obtain a smooth and continuous current distribution close to that of an ideal horn, improving the radiation pattern quality and scanning stability.

[0059] This application also provides a phased array antenna, such as... Figure 8 As shown, it includes multiple antenna elements arranged in a two-dimensional planar array.

[0060] The effectiveness of this application can be further illustrated by the following simulation experiments:

[0061] The phased array antenna provided by this invention was simulated using electromagnetic simulation software. Its standing wave curve within the operating frequency band was simulated, and the results are as follows: Figure 9 The antenna's voltage standing wave ratio (VSWR) is less than 2.5 within its operating frequency band, demonstrating good impedance matching between the antenna and the transmission line.

[0062] Furthermore, the E-plane radiation pattern of the phased array antenna provided by this invention at frequencies of 31 GHz / 34 GHz / 37 GHz was simulated using simulation software, and the results are as follows. Figures 10 to 12 As shown, the peak values ​​of the main lobe in the curve all appear near the corresponding scanning angle. The main lobe is clear and points correctly at each scanning angle. When scanning to ±60°, the main lobe gain decreases gradually, which fully demonstrates that the phased array antenna has achieved excellent large-angle scanning capability in the desired operating frequency band and has achieved a 17% operating bandwidth.

[0063] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0064] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A high-gain millimeter-wave waveguide horn phased array antenna element based on HTCC technology, characterized in that, include: The HTCC dielectric substrate is composed of multiple dielectric layers stacked vertically. Each dielectric layer contains an array of metallized vias arranged along a specific path. The projection of the metallized via array onto a horizontal plane forms a ring pattern. Corresponding to each metallized via array, planar metal layers are disposed in the adjacent upper and lower dielectric layers. The pattern of the planar metal layers matches the projection pattern of the metallized via array and completely covers the cross-sectional area of ​​the metallized via array, thereby forming a continuous waveguide wall together with the metallized via array. The waveguide cavity is surrounded by waveguide walls formed by the array of metallized vias in the multiple dielectric layers; The feeding structure includes a coaxial line fed from the bottom of the antenna element, the inner conductor of the coaxial line extending into the waveguide cavity and connected to a metal patch, the metal patch being electrically connected to the waveguide wall of the waveguide cavity; A multi-stage stepped horn structure is disposed within the HTCC dielectric substrate and stacked above the radiation port of the waveguide cavity. It includes at least two stages of stepped cavities whose waveguide walls are formed by the metallized via array. The cross-sectional area of ​​the lowest-level stepped cavity is greater than the cross-sectional area of ​​the waveguide cavity, and the cross-sectional area of ​​the next-level stepped cavity is greater than or equal to the cross-sectional area of ​​the next-level stepped cavity.

2. The antenna element according to claim 1, characterized in that, The waveguide cavity, the coaxial line, and the multi-stage stepped horn structure are a concentric and coaxial vertical interconnection structure.

3. The antenna element according to claim 1, characterized in that, Both the waveguide cavity and the multi-stage stepped horn structure are rectangular.

4. The antenna element according to claim 3, characterized in that, The metal patch is electrically connected to one long side of the waveguide cavity, the waveguide wall.

5. The antenna element according to claim 3, characterized in that, The dimension 'a' of the long side of the rectangular waveguide cavity, the waveguide wall, satisfies the electromagnetic wave single-mode transmission condition: a < λ0 < 2a, where λ0 is the wavelength of the antenna center operating frequency in free space.

6. The antenna element according to claim 3, characterized in that, The multi-stage stepped horn structure is three-stage, including a first-stage, a second-stage, and a third-stage stepped cavity arranged sequentially from bottom to top. The cross-sectional areas of the second-stage and third-stage stepped cavities are the same and both are larger than the cross-sectional area of ​​the first-stage stepped cavity.

7. The antenna element according to claim 6, characterized in that, The first and second stage stepped cavities are each composed of only a single layer of the aforementioned dielectric layer, while the third stage stepped cavity is composed of multiple layers of the aforementioned dielectric layer.

8. The antenna element according to claim 7, characterized in that, At the center of the waveguide wall of the secondary and tertiary stepped cavities, a simulated slotted structure composed of the metallized through-hole array is provided in the cavity, and the size of the simulated slotted structure on the tertiary stepped cavity is smaller than the size of the corresponding simulated slotted structure on the secondary stepped cavity.

9. The antenna element according to claim 8, characterized in that, The midpoints of the opposite waveguide walls of the secondary and tertiary stepped cavities, and the adjacent simulated slotted structure regions, do not have the metallized vias, but the corresponding regions still have the planar metal layer; the line connecting the midpoints of the opposite waveguide walls is perpendicular to the length direction of the metal patch.

10. A phased array antenna, characterized in that, It includes a plurality of antenna elements arranged in the form of a two-dimensional planar array as described in any one of claims 1 to 9.

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