Miniaturized coupling multi-band slot helical antenna of Beidou satellite navigation terminal

Abstract

The utility model relates to a miniaturized coupling multi-band slot helical antenna of a Beidou satellite navigation terminal, which is characterized in that an antenna dielectric plate is of a hollow three-dimensional structure and comprises a top dielectric substrate, a side dielectric substrate and a bottom dielectric substrate; a first metal layer is arranged on the outer surface of the side dielectric substrate, a second metal layer is arranged on the lower surface of the top dielectric substrate, and an independent metal layer is arranged on the lower surface of the bottom dielectric substrate; the first metal layer is connected with the second metal layer, and the first metal layer is not connected with the independent metal layer; a plurality of regularly arranged inclined slot spiral arms are etched on the first metal layer of the side dielectric substrate and the second metal layer of the top dielectric substrate; the upper surface of the top dielectric substrate is provided with a planar spiral structure; a coaxial line is arranged between the top dielectric substrate and the bottom dielectric substrate, an outer core of the coaxial line is connected with the second metal layer, and an inner core of the coaxial line is connected with the planar spiral structure. The antenna is small in size and low in processing cost, and can be widely used in satellite navigation system terminals.

Description

TECHNICAL FIELD

[0001] The utility model relates to antenna technical field especially is related to a miniaturization coupling multi -band slot spiral antenna of big dipper satellite navigation terminal. BACKGROUND

[0002] The BeiDou Navigation Satellite System (BDS) is a global satellite navigation system independently constructed and operated by China, and is the fourth global satellite navigation system after the United States GPS, Russia GLONASS and Europe Galileo. The BeiDou system integrates navigation, positioning and timing functions, and has unique Chinese characteristics, with wide technical innovation and application value. The four-arm spiral antenna is a superior multi-band circularly polarized antenna, widely used in the BeiDou satellite navigation system (BDS) due to its good directivity, circular polarization characteristics and wideband capability. As a key component of the BeiDou navigation terminal, the four-arm spiral antenna undertakes important tasks such as signal reception, anti-interference and multi-band coverage, and is one of the core technologies to ensure high-precision positioning and reliable communication of the navigation system.

[0003] Miniaturization of the four-arm spiral antenna is a challenging but significant design task. The main difficulty of miniaturization lies in the trade-off between antenna size and performance, because the size of the spiral antenna is closely related to the operating wavelength, and reducing the size will lead to a decrease in radiation efficiency, especially at low frequencies. At the same time, miniaturization can also cause distortion of the radiation pattern, reduce gain and coverage, and the input impedance of the antenna may be far from the matching point, making the matching network design more complex. In addition, miniaturization usually leads to a narrower bandwidth, affecting the stability of multi-band signal reception, and more compact design requires higher precision in processing technology and material, especially in the implementation of microstrip structures and multi-layer PCBs. The coupling interference problem between multi-band frequencies also becomes more prominent.

[0004] Miniaturization of the four-arm spiral antenna has significant advantages in practical applications, as it can adapt to the demand for compact space in handheld navigators, vehicle-mounted devices, drones and other devices, while reducing weight, especially suitable for aerospace applications. In addition, miniaturization design can enable stealthy installation of the antenna, improving the aesthetics of smart devices and car exteriors, and supporting high-frequency application requirements such as millimeter wave frequency bands and 5G communication, further meeting the multi-band reception function of the BeiDou navigation system. Through optimization of structural design and improvement of manufacturing process, the miniaturized four-arm spiral antenna can reduce material consumption and cost while ensuring performance, showing broad application prospects. SUMMARY

[0005] The utility model discloses a miniaturization coupling multi-band slot spiral antenna of big dipper satellite navigation terminal is covered by the application frequency band of our country sub-5G, and the frequency point offset when arbitrarily placing does not exceed the application frequency band, has very good omni-directional and high gain characteristics, low cost, simple structure, is suitable for application in small mobile base station.

[0006] In order to realize above-mentioned purpose, the utility model discloses a technical scheme is: a miniaturization coupling multi-band slot spiral antenna of big dipper satellite navigation terminal, the medium plate of antenna is hollow three-dimensional structure, including top layer medium base plate, side surface medium base plate, bottom layer medium base plate;

[0007] First metal layer is equipped with on the outer surface of side surface medium base plate, second metal layer is equipped with on the lower surface of top layer medium base plate, and independent metal layer is equipped with on the lower surface of bottom layer medium base plate;First metal layer is connected with second metal layer;First metal layer is not connected with independent metal layer, and directional radiation function is enhanced;

[0008] The first metal layer of side surface medium base plate and the second metal layer of top layer medium base plate are etched with multiple regular arrangement's oblique slot spiral arms;The upper surface of top layer medium base plate is equipped with plane spiral structure;Plane spiral structure not only is as feed structure, simultaneously is as radiation structure;

[0009] Coaxial line is arranged between top layer medium base plate and bottom layer medium base plate;Coaxial line outer core is connected with second metal layer;Coaxial line inner core is connected with plane spiral structure, to give multiple oblique slot spiral arms coupling feed according to circular polarization order respectively.

[0010] Preferably, the rectangular slot portion of the oblique slot spiral arm is etched on the second metal layer of the top layer medium base plate, and the remaining width of the slot portion gradually changes and spirally downward from the rectangular slot portion is etched on the first metal layer of the side surface medium base plate; the rectangular slot of the oblique slot spiral arm is etched on the second metal layer, which realizes the function optimization of the antenna and ensures the compactness and miniaturization of the antenna structure.

[0011] Preferably, the number of the oblique slot spiral arms is four, six or eight.

[0012] Preferably, the spiral slot on the first metal layer of the side surface medium base plate spirally rotates clockwise downward from the top, and the inclination angle is greater than 0° and less than 90°.

[0013] Preferably, the plane spiral structure is in the shape of a square, a rectangle or a circle.

[0014] Preferably, the plane spiral structure is gradually convergent to the center along a spiral path from the outer edge, and a closed end is formed at the center and connected with the inner core of the coaxial line.

[0015] Preferably, the planar spiral structure is composed of two rectangular microstrip lines with different widths, the rectangular microstrip lines start from the outer edge of the spiral and gradually encircle inward through the spiral path; the first rectangular microstrip line located at the outer edge is responsible for the initial energy transmission and matching function, and the second rectangular microstrip line located at the inner side is used to refine the structure of the spiral and guide to the center.

[0016] Preferably, the width of the first rectangular microstrip line is greater than the width of the second rectangular microstrip line.

[0017] Preferably, the shape of the antenna is a square cylinder, a cylindrical cylinder or a multi-edge prism cylinder.

[0018] Preferably, a coaxial line is arranged between the top layer dielectric substrate and the bottom layer dielectric substrate, specifically, a first through hole matched with the inner core of the coaxial line is arranged at the center of the top layer dielectric substrate, and a second through hole matched with the outer core of the coaxial line is arranged at the center of the bottom layer dielectric substrate; the lower end of the coaxial line is fixed at the second through hole through the outer core of the coaxial line, and the outer core of the coaxial line is not connected with the independent metal layer of the bottom layer dielectric substrate, and the upper end of the coaxial line is fixed at the first through hole through the inner core of the coaxial line, and the inner core of the coaxial line is connected with the closed end at the center of the planar spiral structure.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] The utility model discloses a planar spiral and slot spiral combined structure. The top square spiral microstrip line not only serves as the feeding structure of the four-arm slot spiral, but also itself serves as the radiation unit to realize satellite navigation dual-frequency circular polarization and wide impedance and axial ratio bandwidth. The utility model discloses the antenna has small volume and low processing cost, and can be widely used in satellite navigation system terminal. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the perspective view of the embodiment of the utility model;

[0022] Figure 2 It is the metal part plane development schematic view of the embodiment of the utility model; Figure 1

[0023] Figure 3 It is the front view of the embodiment of the utility model;

[0024] Figure 4 It is the plan view of the embodiment of the utility model;

[0025] Figure 5 It is the reflection coefficient simulation result schematic view of the embodiment of the utility model;

[0026] Figure 6 ​A circular polarization axial ratio bandwidth simulation result schematic diagram of the utility model embodiment;

[0027] Figure 7 A right-hand rotation gain simulation result graph of the utility model embodiment at BDS B1 frequency band;

[0028] Figure 8 A right-hand rotation gain simulation result graph of the utility model embodiment at BDS B1C frequency band;

[0029] Figure 9 A right-hand rotation gain simulation result graph of the utility model embodiment at BDS S frequency band;

[0030] In the figure, 1-top layer dielectric substrate; 2-side surface dielectric substrate; 3-bottom layer dielectric substrate; 4-inclined slot spiral arm; 5-plane spiral structure; 6-independent metal layer; 7-coaxial line outer core; 8-coaxial line inner core. DETAILED DESCRIPTION

[0031] The utility model will be described in detail below in combination with the drawings and specific embodiments. Figures 1-9 The embodiment takes the technical scheme of the utility model as the premise, gives detailed implementation mode and specific operation process, but the protection scope of the utility model is not limited to the following embodiments.

[0032] As Figures 1-4 shown, the utility model provides a miniaturized coupling multi-frequency band slot spiral antenna of beidou satellite navigation terminal, the dielectric plate of the antenna is hollow three-dimensional structure, including top layer dielectric substrate 1, side surface dielectric substrate 2, bottom layer dielectric substrate 3;

[0033] The first metal layer is arranged on the outer surface of the side surface dielectric substrate 2, the second metal layer is arranged on the lower surface of the top layer dielectric substrate 1, and the independent metal layer 6 is arranged on the lower surface of the bottom layer dielectric substrate 3;The first metal layer is connected with the second metal layer;The first metal layer is not connected with the independent metal layer 6, and the directional radiation function is enhanced;

[0034] A plurality of regularly arranged inclined slot spiral arms 4 are etched on the first metal layer of the side surface dielectric substrate 2 and the second metal layer of the top layer dielectric substrate 1;The plane spiral structure 5 is printed on the upper surface of the top layer dielectric substrate 1;The plane spiral structure 5 not only serves as a feeding structure, but also serves as a radiation structure;

[0035] A coaxial line is arranged between the top layer dielectric substrate 1 and the bottom layer dielectric substrate 3;The coaxial line outer core 7 is connected with the second metal layer;The coaxial line inner core 8 is connected with the plane spiral structure 5, so as to respectively couple and feed the plurality of inclined slot spiral arms 4 in circular polarization order.

[0036] In this embodiment, the rectangular slot part of the slanted slot spiral arm 4 is etched on the second metal layer of the top layer dielectric substrate 1, and the rest of the width of the slot part extending from the rectangular slot part is etched on the first metal layer of the side dielectric substrate 2, gradually changing and spirally downward; the rectangular slot of the slanted slot spiral arm 4 realizes the function optimization of the antenna by controlling the position of the second metal layer, while ensuring the compactness and miniaturization characteristics of the antenna structure.

[0037] In this embodiment, the shape of the rectangular slot part etched on the second metal layer of the lower surface of the top layer dielectric substrate 1 can be replaced by an elliptical shape or other irregular shape. The spiral downward slot width etched on the first metal layer of the outer surface of the side dielectric substrate 2 can be equal width.

[0038] In this embodiment, the number of slanted slot spiral arms 4 is four, six or eight.

[0039] In this embodiment, the spiral slot on the first metal layer of the side dielectric substrate 2 rotates clockwise downward from the top, with an inclination angle greater than 0° and less than 90°.

[0040] In this embodiment, the planar spiral structure 5 is square, rectangular or circular.

[0041] In this embodiment, the planar spiral structure 5 is formed by a rectangular microstrip line starting from the outer edge, gradually converging to the center along the spiral path, and forming a tight closed end at the center and connected to the inner core 8 of the coaxial line.

[0042] In this embodiment, the planar spiral structure 5 is composed of two sections of rectangular microstrip lines with different widths, starting from the outer edge of the spiral and gradually winding inward along the spiral path; the first section of rectangular microstrip line located at the outer edge is responsible for the initial energy transmission and matching function, and the second section of rectangular microstrip line located at the inner side is used to refine the structure of the spiral and guide to the center. Among them, the widths of the two sections of microstrip lines of the planar spiral structure can be equal or unequal.

[0043] In this embodiment, the width of the first section of rectangular microstrip line is greater than the width of the second section of rectangular microstrip line.

[0044] In this embodiment, the shape of the antenna is a square cylinder, a cylindrical cylinder or a multi-edge prism cylinder.

[0045] In the embodiment, the coaxial line is arranged between the top dielectric substrate 1 and the bottom dielectric substrate 3, specifically, a first through hole matched with the inner core 8 of the coaxial line is arranged at the center of the top dielectric substrate 1, and a second through hole matched with the outer core 7 of the coaxial line is arranged at the center of the bottom dielectric substrate 3; the lower end of the coaxial line is fixed to the second through hole through the outer core 7 of the coaxial line, and the outer core 7 is not connected with the independent metal layer of the bottom dielectric substrate, and the upper end of the coaxial line is fixed to the first through hole through the inner core 8 of the coaxial line, and the inner core 8 is connected with the closed end at the center of the planar spiral structure.

[0046] The thickness of the top dielectric substrate or the width of the planar spiral microstrip line controls the coupling degree of the planar spiral microstrip line and the split spiral arm.

[0047] The preferred embodiments of the utility model are described above with reference to the drawings, and the utility model is not limited by this. Any modification, equivalent replacement and improvement made by the person skilled in the art within the scope and essence of the utility model should be within the scope of the utility model.

Claims

1. A miniaturized coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal, characterized in that, The medium plate of the antenna is a hollow three-dimensional structure, comprising a top layer medium substrate, a side layer medium substrate and a bottom layer medium substrate; The first metal layer is arranged on the outer surface of the side layer medium substrate, the second metal layer is arranged on the lower surface of the top layer medium substrate, and the independent metal layer is arranged on the lower surface of the bottom layer medium substrate; the first metal layer is connected with the second metal layer, and the first metal layer is not connected with the independent metal layer; A plurality of regularly arranged inclined slot spiral arms are etched on the first metal layer of the side layer medium substrate and the second metal layer of the top layer medium substrate; The top surface of the top layer medium substrate is provided with a planar spiral structure; The coaxial line is arranged between the top layer medium substrate and the bottom layer medium substrate, the outer core of the coaxial line is connected with the second metal layer, and the inner core of the coaxial line is connected with the planar spiral structure.

2. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 1, characterized in that: The rectangular slot part of the inclined slot spiral arm is etched on the second metal layer of the top layer medium substrate, and the remaining width gradually changes and spirally downward slot part extending from the rectangular slot part is etched on the first metal layer of the side layer medium substrate; the rectangular slot of the inclined slot spiral arm is controlled at the position of the second metal layer to realize the function optimization of the antenna, while ensuring the compactness and miniaturization characteristics of the antenna structure.

3. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 1, characterized in that: The number of the inclined slot spiral arms is four, six or eight.

4. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 1, characterized in that: The spiral slot on the first metal layer of the side layer medium substrate spirally rotates clockwise downward from the top, and the inclination angle is greater than 0° and less than 90°.

5. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 1, characterized in that: The planar spiral structure is in the shape of a square, a rectangle or a circle.

6. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 1, characterized in that: The planar spiral structure is formed by a rectangular microstrip line starting from the outer edge and gradually converging to the center along a spiral path, and a close end is formed at the center and connected with the inner core of the coaxial line.

7. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 1, characterized in that: The planar spiral structure is composed of two rectangular microstrip lines with different widths, and the rectangular microstrip line starts from the outer edge of the spiral and gradually winds inward along the spiral path; the first rectangular microstrip line at the outer edge is responsible for the initial energy transmission and matching function, and the second rectangular microstrip line at the inner side is used to refine the structure of the spiral and guide to the center.

8. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 7, characterized in that: The width of the first rectangular microstrip line is greater than that of the second rectangular microstrip line.

9. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 1, characterized in that: The shape of the antenna is a square cylinder, a cylindrical cylinder or a multi-edge prism cylinder.

10. The compact coupled multi-band slot spiral antenna for a Beidou satellite navigation terminal according to claim 1, characterized in that: The coaxial line is arranged between the top layer medium substrate and the bottom layer medium substrate, specifically, a first through hole matched with the inner core of the coaxial line is arranged at the center of the top layer medium substrate, and a second through hole matched with the outer core of the coaxial line is arranged at the center of the bottom layer medium substrate; the lower end of the coaxial line is fixed to the second through hole through the outer core of the coaxial line, and the outer core of the coaxial line is not connected with the independent metal layer of the bottom layer medium substrate; the upper end of the coaxial line is fixed to the first through hole through the inner core of the coaxial line, and the inner core of the coaxial line is connected with the close end at the center of the planar spiral structure.

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