C-band dual circularly polarized leaky-wave antenna

Abstract

The application discloses a C-band double-sense circularly-polarized leaky-wave antenna, and belongs to the technical field of microwave antennas. A parasitic patch is designed to control electromagnetic field distribution through a strip slot. A transmission line is located at the center of a dielectric substrate and is kept at a reasonable interval from the parasitic patch to realize a leaky-wave function. A metal floor serves as a reflecting surface to suppress back lobe radiation and improve forward gain. Through ±10° rotation of the strip slot, left-handed circular polarization is realized in a 6.235-6.583 GHz frequency band, and right-handed circular polarization is realized in a 7.423-7.474 GHz frequency band. Meanwhile, through the collaborative design of the parasitic patch array structure and the transmission line, wide-frequency impedance matching of S11<-10 dB is achieved in a full frequency band, and the main beam is stably directed to the vicinity of 22°.

Description

Technical Field

[0001] This invention relates to the field of microwave antenna technology, specifically to a C-band dual-sensor circularly polarized leaky wave antenna. Background Technology

[0002] Leaky wave antennas achieve directional communication through "leaky wave radiation along the transmission structure," and have become a research hotspot in the field of high-frequency communication due to their compact structure and controllable radiation direction. However, with the increasing demand for circular polarization in communication systems, the development of circularly polarized leaky wave antennas faces the following technical limitations:

[0003] Most circularly polarized leaky antennas only support single rotation, making them unsuitable for scenarios requiring dual rotation switching, such as "separate satellite transceiver and multi-standard compatible systems." Furthermore, traditional structures aiming for bandwidths above 6GHz are prone to impedance mismatch due to mode interference, and S11 often only meets requirements within narrowband. Moreover, at high frequencies, the main beam angle of leaky antennas is prone to significant frequency drift, making it difficult to maintain within the target range of 20°-30°, thus affecting the reliability of directional communication. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a C-band dual-sensor circularly polarized leaky wave antenna, which is suitable for millimeter-wave communication, satellite communication and 5G / 6G high-speed data transmission scenarios in the 6GHz-8GHz frequency band, and has the characteristics of wideband impedance matching, dual-rotation circular polarization and controllable main beam angle.

[0005] The objective of this invention is achieved as follows:

[0006] A C-band dual-sensor circularly polarized leaky antenna includes a dielectric substrate and a metal ground plane; the upper surface of the dielectric substrate is provided with transmission lines and parasitic patches.

[0007] The parasitic patches are circular and include type I parasitic patches and type II parasitic patches. The type I parasitic patches are arranged along line I, and their centers are all located on line I. The type II parasitic patches are arranged along line II, and their centers are all located on line II. Line I and line II are parallel to each other. The type II parasitic patches are located between two adjacent type I parasitic patches and are connected to and partially overlap with the type I parasitic patches on both sides of them.

[0008] Each parasitic patch has a strip groove;

[0009] The transmission line is a rectangular patch; the transmission line is located between line I and line II, and has no contact with the parasitic patch.

[0010] Furthermore, there is no contact between similar parasitic patches.

[0011] Furthermore, the diameter of the type I parasitic patch is larger than that of the type II parasitic patch.

[0012] Furthermore, the type II parasitic patch and the two type I parasitic patches connected to it form a V-shaped structure.

[0013] Furthermore, the transmission line spans each parasitic patch and divides the parasitic patch into two parts, the two parts of which include a main body and a spare part; the strip is located on the main body.

[0014] Furthermore, the grooves on the type I parasitic patch are parallel to each other; the grooves on the type II parasitic patch are parallel to each other.

[0015] The present invention has the following beneficial effects:

[0016] 1. This invention, through the ingenious design of the slot angle on the parasitic patch, achieves left-hand circular polarization (6.235 - 6.583 GHz) and right-hand circular polarization (7.423 - 7.474 GHz) in specific sub-frequency bands. This dual-directional circular polarization characteristic allows the antenna to flexibly provide suitable polarization modes according to different communication scenarios and requirements, greatly improving the antenna's applicability and flexibility. It can be widely used in wireless communication, radar detection, and other fields with diverse polarization requirements.

[0017] 2. This invention, through the unique design of the parasitic patch, the reasonable spacing between the Type I and Type II parasitic patches and the transmission line, and the overall synergistic optimization of each component, successfully achieves an S11 value of less than -10dB across the entire frequency band. This achievement effectively reduces signal reflection, improves the antenna's signal reception and transmission efficiency over a wide frequency range, and enables the antenna to operate stably in a wider range of frequency bands, providing strong support for high-speed, high-capacity wireless communication.

[0018] 3. This invention, through the meticulous design and synergistic effect of components such as parasitic patches, strip slots, transmission lines, and metal ground planes, stabilizes the main beam at approximately 22°. This stable main beam direction enhances the antenna's directional radiation performance, improving the accuracy and reliability of signal transmission. It offers significant advantages in communication and detection scenarios requiring precise pointing, such as satellite communication and directional radar detection. Attached Figure Description

[0019] Figure 1 This is a top view of an embodiment of the present invention.

[0020] Figure 2 This is a side view of an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram showing the positional relationship between the Type I parasitic patch and the Type II parasitic patch in an embodiment of the present invention.

[0022] Figure 4This is a schematic diagram of the structure of the parasitic patch in an embodiment of the present invention.

[0023] Figure 5 This is the impedance matching S11 curve of the antenna.

[0024] Figure 6 This is the axial ratio curve of the antenna.

[0025] Figure 7 This is a gain diagram of the antenna at two frequency points. Detailed Implementation

[0026] The present invention will now be described in further detail.

[0027] This embodiment is a C-band dual-sensor circularly polarized leaky antenna, including a dielectric substrate 2 and a metal ground plane 5. The transmission line 4 is located on the dielectric substrate 2, and parasitic patches 1 are distributed on both the top and bottom. Each parasitic patch 1 has a strip groove 3.

[0028] The dielectric substrate 2 serves as the support for the antenna and the medium for electromagnetic wave propagation, providing a stable physical structure for all antenna components and influencing the propagation characteristics of electromagnetic waves. The parasitic patch 1, located on the dielectric substrate 2, is used to transmit electromagnetic signals. Its unique structure and layout facilitate broadband signal transmission and provide a foundation for subsequent polarization characteristics. A stripe 3 is positioned on the parasitic patch 1, adjusting the antenna's polarization characteristics by altering the distribution of the electromagnetic field. The transmission line 4, located close to the parasitic patch 1, is responsible for transmitting signals to the metal ground plane 5 or other related components, ensuring effective signal transmission. The metal ground plane 5, acting as the antenna's reflective surface, reflects electromagnetic waves, enhancing the antenna's directional radiation capability. Simultaneously, it works in conjunction with the parasitic patch 1, stripe 3, and other components to achieve broadband impedance matching and stable beam pointing.

[0029] In this embodiment, the parasitic patch 1 is circular, including a type I parasitic patch 1-1 and a type II parasitic patch 1-2. The type I parasitic patches 1-1 are arranged along line I, and their centers are all located on line I. The type II parasitic patches 1-2 are arranged along line II, and their centers are all located on line II. Line I and line II are parallel to each other. The type II parasitic patch 1-2 is located between two adjacent type I parasitic patches 1-1, and is connected to and partially overlaps with the type I parasitic patches 1-1 on both sides of it.

[0030] Each parasitic patch 1 is spaced apart from the transmission line 4 and has a stripe groove 3 to achieve wave leakage. The transmission line 4 spans each parasitic patch 1 and divides the parasitic patch 1 into two parts, which include a main body part 7 and a spare part 6; the stripe groove 3 is located on the main body part 7.

[0031] When the rotation angle of the groove 3 is ±10°, different polarization directions can be achieved in two frequency bands. The dielectric substrate 2 has a thickness of 1.6 mm, uses Rogers RT / duroid 5880 (tm) dielectric constant 2.2 and loss tangent 0.0009, and is used to support and isolate the conductive layer.

[0032] by Figures 1 to 4 Taking the antenna structure as an example,

[0033] The dielectric substrate 2 is a double-layer Rogers RT / duroid 5880 dielectric substrate with a thickness of 1.6 mm, a dielectric constant of 2.2, and a loss tangent of 0.0009. This material has excellent dielectric properties and low loss characteristics, which can effectively support the antenna structure and reduce signal transmission loss. The metal ground plane 5 is printed between the two dielectric substrates as an electromagnetic wave reflecting surface, suppressing back lobe radiation and improving forward gain.

[0034] Parasitic patch 1 is located on both sides of transmission line 4 but does not contact transmission line 4. Transmission line 4 has two ports at each end for power feeding. Strip grooves 3 are etched on parasitic patch 1 to form a leaky antenna by perturbing the current distribution, and achieve left-hand circular polarization (6.235 - 6.583 GHz) and right-hand circular polarization (7.423 - 7.474 GHz) in the sub-frequency bands respectively.

[0035] Structural dimensions (the following data are in millimeters):

[0036] a=20; b=175; c=6.3; d=4.8; e=18

[0037] The diameter of Class I parasitic patch 1-1 is 20 mm, and the diameter of Class II parasitic patch 1-2 is 18 mm.

[0038] Appendix Figure 5 The graph shows the antenna return loss curve. The antenna's S11 is less than -10dB across the entire frequency band.

[0039] Appendix Figure 6 The displayed graph shows the antenna axial ratio, which is significantly less than 3dB in the ranges of 6.235GHz - 6.583GHz and 7.423GHz - 7.474GHz, achieving circular polarization.

[0040] Appendix Figure 7 The diagram shows the antenna gain at two frequencies. The main beam of the antenna is concentrated at a fixed angle of 22° and has low sidelobes.

[0041] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A C-band dual-sensor circularly polarized leaky wave antenna, characterized in that, It includes a dielectric substrate (2) and a metal ground plane (5); the upper surface of the dielectric substrate (2) is provided with a transmission line (4) and a parasitic patch (1); The parasitic patch (1) is circular and includes a type I parasitic patch (1-1) and a type II parasitic patch (1-2). The type I parasitic patches (1-1) are arranged in an array along line I, and their centers are all located on line I. The type II parasitic patches (1-2) are arranged in an array along line II, and their centers are all located on line II. Line I and line II are parallel to each other. The type II parasitic patch (1-2) is located between two adjacent type I parasitic patches (1-1) and is connected to and partially overlaps with the type I parasitic patches (1-1) on both sides of it. Each parasitic patch (1) is provided with a strip groove (3); the rotation angle of the strip groove of the Class I parasitic patch (1-1) and the Class II parasitic patch (1-2) is ±10°; The transmission line (4) is a rectangular patch; the transmission line (4) is located between line I and line II, and has no contact with the parasitic patch (1); The transmission line (4) spans each parasitic patch (1) and divides the parasitic patch (1) into two parts, namely the main body part (7) and the surplus part (6); the strip groove (3) is located on the main body part (7).

2. The C-band dual-sensor circularly polarized leaky antenna according to claim 1, characterized in that, There is no contact between parasitic patches of the same type (1).

3. A C-band dual-sensor circularly polarized leaky antenna according to claim 1, characterized in that, The diameter of the Class I parasitic patch (1-1) is larger than that of the Class II parasitic patch (1-2).

4. A C-band dual-sensor circularly polarized leaky antenna according to claim 1, characterized in that, The type II parasitic patch (1-2) and the two type I parasitic patches (1-1) connected thereto form a V-shaped structure.

5. A C-band dual-sensor circularly polarized leaky antenna according to claim 1, characterized in that, The strip grooves (3) on the type I parasitic patch (1-1) are parallel to each other; the strip grooves (3) on the type II parasitic patch (1-2) are parallel to each other.

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