Feed interconnection excitation structure

Abstract

The invention provides a feed interconnection excitation structure, which relates to electronic information, radar and communication systems and comprises a radio frequency microwave substrate, an antenna radiator, a parallel guide structure and a feed transmission line. The antenna radiators are symmetrically arranged on the radio frequency microwave substrate, the parallel guide structures are arranged at the positions, close to the radio frequency microwave substrate, of the opposite planes of the antenna radiators, and the antenna radiators form two side arms of the parallel guide structures; and the feed transmission line is located in the radio frequency microwave substrate, is used for exciting the parallel guide structure, and is interconnected with one side arm of the parallel guide structure through the multi-section step transformation structure to realize broadband excitation.

Description

Technical Field

[0001] The present invention relates to electronic information, radar and communication systems, and in particular to a feed interconnection excitation structure. Background Art

[0002] As radar communication systems evolve toward multifunctionality, multi-band coverage, and miniaturization, the technical standards of RF microwave systems are constantly being refined. Ultra-wideband interconnect technology, front-end systems, and antenna systems, in particular, have become critical core technologies within the entire system. This invention addresses the practical application of ultra-wideband integrated interconnects, excitation mechanisms, and miniaturized broadband antennas for RF microwave and millimeter-wave applications.

[0003] In the design of ultra-wideband integrated antennas, miniaturization, integration, and broadbandization of the feed excitation structure are the most pressing core issues that need to be addressed, and are also the main goals of design optimization. However, most current broadband antenna structures still rely on traditional coaxial probes or broadband excitation methods similar to coaxial microstrip structures. Taking the all-metal Vivaldi antenna as an example, it is usually fed by a coaxial line inserted from the bottom. This design approach faces two major challenges: first, the overall height (cross-section) of the antenna is relatively high, which runs counter to the design goal of miniaturization; second, when the antenna needs to be hybrid integrated with active devices, conversion between coaxial and planar circuits must be performed, which not only increases the complexity of integrated interconnection but also makes it difficult to meet the high requirements of system array integration.

[0004] Patent CN202411082649.2 discloses a method for feeding an all-metal Vivaldi antenna using a bottom-inserted coaxial line. The coaxial line is interconnected to a parallel guide structure via a probe, with a metal cavity provided next to the interconnect structure to prevent short circuits. The parallel guide structure then transitions to the antenna. While this method achieves broadband excitation, the aforementioned issues remain.

[0005] In addition, existing feeder interconnection methods such as Figure 1 As shown, including coaxial feed as Figure 1 (a) and microstrip feeding as shown in Figure 1 (b) The feed interconnection conversion structure is mainly excited by a coaxial probe or a planar microstrip probe. The antenna has the following problems: 1) The overall antenna profile is high; 2) When mixed with active devices, Figure 1 (a) also requires coaxial and planar circuit conversion, and the integrated interconnection is complex, which is difficult to meet the system array integration requirements; Figure 1 (b) The device and the antenna radiating unit are in the same plane, the device can only be arranged longitudinally along the antenna aperture, and the antenna system has a high profile. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention proposes a feed interconnection excitation structure, and the specific technical solution is as follows:

[0007] A feeding interconnection excitation structure comprises a radio frequency microwave substrate, an antenna radiator, a parallel guiding structure and a feeding transmission line; the antenna radiator is symmetrically arranged on the radio frequency microwave substrate, and the parallel guiding structure is arranged at a position close to the radio frequency microwave substrate on a relative plane thereof, and the antenna radiator constitutes two side arms of the parallel guiding structure; the feeding transmission line is located within the radio frequency microwave substrate, is used to excite the parallel guiding structure, and is interconnected with a side arm of the parallel guiding structure via a multi-stage step transformation structure to achieve broadband excitation.

[0008] The present invention has the following beneficial effects:

[0009] By incorporating PCB transmission lines as the feed structure, this invention significantly optimizes the connection process with active devices and greatly improves system integration efficiency. This design not only enhances system compatibility but also facilitates subsequent expansion and upgrades.

[0010] The present invention designs the feed circuit and antenna radiating element in a vertical layout, allowing the feed to be deployed horizontally. This layout not only facilitates direct integration with the horizontal circuit system, but also significantly reduces the height of the antenna active array, strongly supporting the overall miniaturization of the system and higher-density integration.

[0011] The present invention embeds the feed transmission line into the substrate plane and directly integrates the excitation target with the feed circuit. This design avoids the complex conversion structure used in traditional methods, achieving a seamless connection between the parallel guiding structure and the planar circuit, significantly improving the integration efficiency between the circuit and the antenna.

[0012] This paper proposes an integrated, wide-band interconnected excitation feed scheme that effectively achieves wide-band transitional interconnection between the feed structure and the excitation target. This design not only improves the system's frequency adaptability but also significantly reduces antenna array losses, thereby optimizing overall performance.

[0013] The present invention successfully achieves the low profile, miniaturization and integration of broadband antennas, meeting the requirements of modern radar communication systems for miniaturization and high performance, while also providing new ideas and methods for the development of future communication technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a feeding scheme in the prior art;

[0015] Figure 2 This is a schematic diagram of an integrated antenna in a feed interconnection excitation structure according to the present invention;

[0016] Figure 3 This is a detailed diagram of the feed interconnection excitation structure of the present invention;

[0017] Figure 4 Schematic diagram of the all-metal Vivaldi antenna fed by the present invention.

[0018] The reference numerals in the figure are: 1. RF microwave substrate; 2. antenna radiator; 3. parallel guiding structure; 4. PCB transmission line; 5. step transformation structure; 6. first matching cavity; 7. second matching cavity; 8. feeding interface; 9. metal through hole; 10. connection point; 11. first step; 12. second step; 13. PCB defect ground. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned objectives, the present invention adopts the following technical solutions.

[0020] like Figure 2 As shown, the present invention proposes a feed interconnect excitation structure. The feed interconnect excitation structure includes an RF microwave substrate 1, an antenna radiator 2, a parallel guiding structure 3, a PCB transmission line 4, a step-transformation structure 5, a first matching cavity 6, and a feed interface 8. Two antenna radiators 2 are symmetrically arranged on the RF microwave substrate 1. The parallel guiding structures 3 are arranged on opposite planes of the two antenna radiators 2, close to the RF microwave substrate 1. The two antenna radiators 2 form two side arms of the parallel guiding structure 3. The PCB transmission line 4 is located within the RF microwave substrate 1, and the excitation target is the parallel guiding structure 3. Furthermore, a multi-stage step-transformation structure 5 is arranged on one side arm of the parallel guiding structure 3 and interconnected with the PCB transmission line 4 to achieve broadband excitation. The PCB transmission line 4 connects the feed interface 8 and the step-transformation structure 5. A first matching cavity 6 is designed in a cubic shape above the PCB transmission line 4. The step-transformation structure 5 is arranged on the side of the first matching cavity 6 close to the other antenna radiator 2. Two rows of metal through-holes 9 are arranged on both sides of the PCB transmission line 4. By means of the planar circuit of the radio frequency microwave substrate 1 and the vertical stepped three-dimensional structure of the parallel guiding structure 3 of the present invention, broadband integrated feeding can be achieved.

[0021] The present invention excites the parallel guiding structure 3 through the PCB transmission line 4. A multi-section metal step transformation structure 5 is designed at the connection between the parallel guiding structure 3 and the PCB transmission line 4. The bottom step of the step transformation structure 5 is interconnected with the PCB transmission line 4 on the RF microwave substrate 1 through welding or bonding technology, and wide-band matching is achieved through step impedance transformation. A square-shaped first matching cavity 6 is designed on the upper side of the PCB transmission line 4. The first matching cavity 6 is used to provide cavity matching for the interconnection of the PCB transmission line 4 and is separated from the PCB transmission line 4. The PCB transmission line 4 is connected to one side arm of the parallel guiding structure 3 through the multi-section step transformation structure 5. The PCB transmission line 4 is connected to the parallel guiding structure 3, such as Figure 2 As shown, a first matching cavity 6 is provided at the connection point to achieve electromagnetic matching between the PCB transmission line 4 and the vertical parallel guide structure 3, thereby stimulating a broadband interconnection structure. Figure 2 As shown, the other side arm of the parallel guiding structure 3 is connected to the PCB ground, and a second matching cavity 7 is provided adjacent to it. A defect (by removing part of the metal layer) is provided on the RF microwave substrate 1 below the second matching cavity 7, corresponding to the PCB ground, to form a PCB defect ground 13, improving antenna radiation and matching performance. The second matching cavity 7 can also be omitted; its inclusion depends on the antenna design.

[0022] PCB transmission lines 4 are used to interconnect with parallel metal conductors vertically, while a first matching cavity 6 is introduced to improve the matching conversion bandwidth. This achieves wide-band interconnection between the PCB transmission lines 4 and the parallel guide structures 3. In the present invention, GCPW lines or microstrip lines can also be used as PCB transmission lines 4.

[0023] like Figure 3 As shown, the multi-stage step variation structure 5 includes a bottom step, a primary step 11, and a secondary step 12. The bottom step is connected to the GCPW line 4 at a connection point 10. The bottom step and the primary step are equal in length, and the bottom step is smaller in width than the primary step 11. The primary step 11 and the secondary step 12 are equal in length, and the secondary step 12 is wider than the primary step 11. The equivalent length of the first matching cavity 6 is one-quarter of the wavelength of the center frequency.

[0024] The metal through holes 9 are two rows of metal pillars, connecting the top metal layer and the bottom metal layer of the radio frequency microwave substrate 1 .

[0025] By adopting the integrated interconnection feeding method and structure proposed in the present invention, an integrated excitation all-metal Vivaldi antenna with an operating frequency band of 4GHz to 50GHz is designed. In the implementation of the specific scheme, a ceramic-filled PTFE composite material can be selected as the dielectric substrate, and a metal step transformation structure is designed on the left radiating arm of the all-metal Vivaldi antenna. The bottom layer of the metal step transformation structure is interconnected with the GCPW line located on the surface substrate through welding or bonding processes, and the signal is connected to the radiator through multi-layer impedance transformation, thereby realizing wide-band interconnection and matching between the GCPW line and the antenna radiator. Among them, the left and right sides and the bottom of the GCPW line are connected to the right radiating arm of the all-metal Vivaldi antenna, and the signal line of the GCPW line is connected to the left radiating arm of the all-metal Vivaldi antenna. In order to solve the problem of short circuit of the GCPW line, a rectangular metal cavity is designed on the upper side of the GCPW line. By adopting the integrated wide-band interconnection feeding method and structure proposed in the present invention, relevant verification products can be processed and prepared.

[0026] like Figure 4 As shown, (a) is the antenna input port return loss S11 curve, (b) is the antenna E-plane radiation pattern, and (c) is the antenna E-plane radiation pattern. It can be seen that the antenna achieves a return loss better than -12.3dB and an antenna gain better than 2.6dB in the frequency range of 3.5-50GHz.

Claims

1. A feed interconnection excitation structure, characterized in that: The invention comprises a radio frequency microwave substrate, an antenna radiator, a parallel guiding structure and a feeding transmission line; the antenna radiator is symmetrically arranged on the radio frequency microwave substrate, and the parallel guiding structure is arranged at a position close to the radio frequency microwave substrate on a relative plane thereof, and the antenna radiator constitutes two side arms of the parallel guiding structure; the feeding transmission line is located in the radio frequency microwave substrate, is used to excite the parallel guiding structure, and is interconnected with one side arm of the parallel guiding structure through a multi-stage step transformation structure to achieve broadband excitation.

2. The feed interconnection excitation structure according to claim 1, characterized in that: The feeding transmission line is a PCB transmission line, and the PCB transmission line connects the feeding interface and the step transformation structure.

3. The feed interconnection excitation structure according to claim 1, characterized in that: A first matching cavity is provided on one side arm of the parallel guiding structure. The first matching cavity is used to provide cavity matching for interconnection of the feeding transmission line and is separated from the feeding transmission line.

4. The feed interconnection excitation structure according to claim 1, characterized in that: The other side arm of the parallel guiding structure is connected to the PCB ground.

5. The feed interconnection excitation structure according to claim 1, characterized in that: The step transformation structure realizes wide-band matching through step impedance transformation.

6. The feed interconnection excitation structure according to claim 5, characterized in that: The step transformation structure includes a bottom step, a first step and a second step. The bottom step is connected to the feeding transmission line, and the length of the first matching cavity is equivalent to a quarter wavelength of the center frequency.

7. The feed interconnection excitation structure according to claim 1, characterized in that: Two rows of metal through holes are arranged on both sides of the feeding transmission line, and the top metal layer and the bottom metal layer of the radio frequency microwave substrate are connected through the metal through holes.

8. The feed interconnection excitation structure according to claim 1, characterized in that: The feeding transmission line is a GCPW line or a microstrip line.

9. The feed interconnection excitation structure according to claim 6, characterized in that: The width of the bottom step is smaller than that of the first step, the lengths of the first step and the second step are equal, and the width of the second step is larger than that of the first step.

10. The feed interconnection excitation structure according to claim 1, characterized in that: The RF microwave substrate is made of ceramic-filled PTFE composite material.

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