Vehicle-mounted GNSS antenna based on capacitive structure loading

Abstract

The application belongs to the technical field of antennas, and discloses a vehicle-mounted GNSS antenna based on capacitive structure loading. The antenna comprises a radiation metal sheet, a capacitive coupling metal sheet, a short-circuit needle, a metal floor, a feeding point, and the bottom end of the short-circuit needle is vertically connected to one side surface of the metal floor; the capacitive coupling metal sheet is parallel to the metal floor and is connected to the top end of the short-circuit needle; the radiation metal sheet is suspended above the capacitive coupling metal sheet and is parallel to the capacitive coupling metal sheet, and the feeding point is arranged on the surface of the radiation metal sheet. The entire antenna structure of the application does not adopt ceramic medium, is easy to be integrally designed and processed, and is easy to realize the miniaturization and light weight of the antenna size; the capacitive structure takes air as medium, is beneficial to reduce the Q value and loss of the antenna, expand the wideband of the antenna, and improve the radiation efficiency of the antenna.

Description

Technical Field

[0001] This application belongs to the field of antenna technology, specifically relating to a vehicle-mounted antenna. Background Technology

[0002] Currently, vehicle-to-everything (V2X) and autonomous driving have become hot topics. As the front-end connecting vehicles to everything, antennas are showing a trend towards integration, primarily combining cellular, GNSS, AM / FM, C-V2X, and Wi-Fi technologies. Due to the unique working environment and the coexistence of multiple communication systems, higher requirements are placed on the operating temperature and anti-interference capabilities of antenna modules. GNSS positioning, as a crucial component of intelligent driving and autonomous driving, naturally takes center stage. GNSS antennas are mainly used as transmitting antennas in co-frequency relay systems and as receiving antennas in GPS navigation and positioning systems. GNSS satellite signals are divided into four systems: BDS, GPS, GLONASS, and GALILEO, with frequencies between 1.1 GHz and 1.6 GHz and circular polarization. The signal strength is around 166 dBm, which is relatively weak. These characteristics necessitate the use of dedicated antennas for GPS signal reception.

[0003] Existing GNSS ceramic antennas for high-precision vehicle positioning employ a multi-feed design to ensure the coincidence of the antenna's phase center and geometric center, essentially achieving hemispherical radiation of the radiation pattern and minimizing the antenna's influence on measurement errors. However, due to the ceramic structure used, the antenna is relatively large and heavy, which is not conducive to antenna miniaturization and also affects the overall appearance of the vehicle. Summary of the Invention

[0004] To address the aforementioned problems, this application provides a vehicle-mounted GNSS antenna based on capacitive structure loading, thereby reducing the size of the GNSS antenna and improving its integration.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] A vehicle-mounted GNSS antenna based on capacitive structure loading includes:

[0007] The device comprises a radiating metal sheet, a capacitive coupling metal sheet, a shorting pin, a metal ground plane, and a power supply point. The bottom end of the shorting pin is vertically connected to one side surface of the metal ground plane. The capacitive coupling metal sheet is parallel to the metal ground plane and connected to the top end of the shorting pin. The radiating metal sheet is suspended above the capacitive coupling metal sheet and is parallel to the capacitive coupling metal sheet. The power supply point is located on the surface of the radiating metal sheet.

[0008] In this application, the metal ground plane is at the bottom layer, serving as the ground for the entire antenna structure. A shorting pin is used to short-circuit the capacitively coupled metal plate to the metal ground plane, achieving signal closed-loop connection. The capacitively coupled metal plate is shorted to the metal ground plane via the shorting pin, and a radiating metal plate is suspended parallel above it, forming a capacitive structure to capacitively load the radiating metal plate. The thickness of the gap between the radiating metal plate and the capacitively coupled metal plate affects the antenna's operating bandwidth and frequency.

[0009] The radiating metal sheet can be shaped in regular symmetrical ways, such as square, circle, and hexagon, which is convenient for realizing circularly polarized electromagnetic waves. To achieve a half-wavelength resonant mode, the side length or diagonal length of the radiating metal sheet is located near half of the working wavelength.

[0010] The feed points can be single, two, or four, symmetrically distributed around the geometric center of the radiating metal sheet, enabling single-fed, dual-fed, and quad-fed antennas. The antenna can be fed using one, two, or four feed points to excite the resonant mode of the metal radiating sheet, achieving operation at a specific frequency.

[0011] For a single feed point, the phase delay and advance in the two polarization directions can be achieved by adjusting the side length of the metal sheet, making one pair of sides slightly longer and the other pair slightly shorter, thus achieving a 90-degree current phase difference, which is then superimposed in the far field to form a circularly polarized wave.

[0012] In the case of dual feed points, the positions of the two feed points are rotated 90 degrees around the center. At this time, the radiating metal sheet is a regular shape, such as a square. By directly applying excitation with equal amplitude but 90 degrees phase difference to the two feed ports, the circular polarization radiation of the antenna is achieved.

[0013] In the case of four feed points, the positions of the four feed points are rotated 90 degrees around the center. At this time, the radiating metal sheet is a regular shape, such as a square. By directly applying excitation with equal amplitude but 90 degrees phase difference to the four feed ports, the circular polarization radiation of the antenna is achieved.

[0014] Single-feed antennas are simple and convenient to implement circular polarization, but they are more susceptible to environmental influences and have lower stability. Two-feed antennas have higher circular polarization stability, but it is weaker than four-feed antennas. The specific implementation method can be selected and compromised according to the actual engineering needs.

[0015] Beneficial effects

[0016] The high-stability vehicle-mounted GNSS antenna based on capacitive structure loading proposed in this invention consists of, from top to bottom, a radiating metal sheet, a capacitive coupling metal sheet, a shorting pin, and a metal ground plane. All these components are excellent conductors of metal, facilitating integrated design and fabrication, and significantly reducing costs. Eliminating the previously heavy ceramic substrate reduces weight by over 80%, making it easier to miniaturize and lighten the antenna. Furthermore, the capacitive structure uses air as the medium, which helps reduce the antenna's Q value and losses, expands its bandwidth, and improves its radiation efficiency. Attached Figure Description

[0017] Figure 1 Example 1: Schematic diagram of a vehicle-mounted GNSS antenna based on capacitive structure loading;

[0018] Figure 2 Example 1: Front view of a vehicle-mounted GNSS antenna based on capacitive structure loading;

[0019] Figure 3 Example 2: Schematic diagram of a vehicle-mounted GNSS antenna based on capacitive structure loading;

[0020] Figure 4 Example 3: Schematic diagram of the integrated structure of the radiating metal sheet, capacitive coupling metal sheet, and short-circuit pin;

[0021] Figure 5 Example 3: Schematic diagram of a vehicle-mounted GNSS antenna based on capacitive structure loading;

[0022] Figure 6 Example 3: Front view of a vehicle-mounted GNSS antenna based on capacitive structure loading;

[0023] Wherein: 1 is the radiating metal sheet, 2 is the capacitive coupling metal sheet, 3 is the shorting pin, 4 is the metal ground plate, and 5 is the feed point. Detailed Implementation

[0024] The above-described solution will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. The implementation conditions used in the embodiments may be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are generally those in routine experiments.

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. In the description of this application, unless otherwise stated, "a number" means two or more.

[0026] Example 1

[0027] A vehicle-mounted GNSS antenna based on capacitive structure loading, such as Figure 1 and Figure 2 The device includes: a radiating metal plate 1, a capacitive coupling metal plate 2, a shorting pin 3, a metal ground plate 4, and a feed point 5; the bottom end of the shorting pin is vertically connected to one side surface of the metal ground plate; the capacitive coupling metal plate is parallel to the metal ground plate and connected to the top of the shorting pin; the radiating metal plate is suspended above the capacitive coupling metal plate and parallel to the capacitive coupling metal plate, and the feed point is set on the surface of the radiating metal plate; there are several capacitive coupling metal plates, and each capacitive coupling metal plate is connected to the metal ground plate by a corresponding shorting pin.

[0028] In this application example, more specifically, the radiating metal plate is rectangular, and four capacitive coupling metal plates are positioned near the four corners of the rectangular radiating metal plate. There is one single feed point. The rectangle mentioned here should include squares. The current polarization direction of this type of capacitively loaded vehicle-mounted GNSS antenna is along the diagonal of the radiating metal plate, allowing for further reduction in antenna size.

[0029] This application presents a vehicle-mounted GNSS antenna based on a capacitive structure. The signal is input through a feed point, passes through a radiating metal sheet, and is coupled into a capacitive coupling metal sheet. It then passes through a short-circuit pin to the metal ground plane, forming a closed-loop signal circuit. The radiating metal sheet and the capacitive coupling metal sheet constitute the main body of the antenna's operation. The capacitive loading of the capacitive coupling metal sheet reduces the size of the radiating metal sheet. The entire antenna structure of this invention does not use ceramic dielectric, reducing the overall Q value of the antenna, which effectively improves the antenna's operating bandwidth. The operating frequency of the antenna can be effectively adjusted by regulating the loading of the capacitive metal sheet.

[0030] The vehicle-mounted GNSS antenna based on capacitive structure loading in this application consists of, from top to bottom, a radiating metal sheet, a capacitive coupling metal sheet, a shorting pin, and a metal ground plane. All of these structures are made of metallic materials, making them easy to manufacture in one piece.

[0031] Example 2

[0032] A vehicle-mounted GNSS antenna based on capacitive structure loading, such as Figure 3 As shown, the radiating metal sheet is rectangular in shape, and four capacitive coupling metal sheets are set up near the midpoint of the rectangular side of the radiating metal sheet.

[0033] The current polarization direction of this type of vehicle-mounted GNSS antenna based on capacitive structure loading is along the side length of the radiating metal sheet, which can make the antenna polarization purity higher.

[0034] Example 3

[0035] A vehicle-mounted GNSS antenna based on capacitive structure loading, such as Figure 4As shown, it includes a radiating metal sheet 1, a capacitive coupling metal sheet 2, and a shorting pin 3; the radiating metal sheet 1 and the capacitive coupling metal sheet 2 are parallel and connected by the shorting pin 1; as... Figure 5 and Figure 6 As shown, the capacitive coupling metal sheet is suspended above the metal floor 4 and parallel to the metal floor, and the feed point is set on the surface of the radiating metal sheet.

[0036] There are several capacitive coupling metal plates, and each capacitive coupling metal plate is connected to the radiating metal plate by a corresponding shorting pin.

[0037] In this embodiment, more specifically, the radiating metal sheet, the capacitive coupling metal sheet, and the short-circuit pin are an integrated structure, formed by integrally pressing and bending a metal sheet or metal film; four capacitive coupling metal sheets are provided, respectively located near the four corner points of the rectangle of the radiating metal sheet, and four feed points are provided, symmetrically distributed on the surface of the radiating metal sheet.

[0038] In this embodiment, the capacitive loading on the radiating metal plate can be adjusted by changing the distance between the capacitive coupling metal plate and the metal ground plane. The signal from the feed point flows through the radiating metal plate, then through the short-circuit pin into the capacitive coupling metal plate, and finally through coupling into the metal ground plane, thus achieving a closed-loop signal circuit. This method can significantly reduce the size of the vehicle-mounted GNSS antenna based on capacitive structure loading, which is beneficial for improving the antenna's integration.

[0039] The above embodiments are only for illustrating the technical concept and features of this application, and are intended to enable those skilled in the art to understand the content of this application and implement it accordingly. They should not be used to limit the scope of protection of this application. All equivalent changes or modifications made in accordance with the spirit and essence of this application should be included within the scope of protection of this application.

Claims

1. A vehicle-mounted GNSS antenna based on capacitive structure loading, characterized in that... include: Radiation-emitting metal sheet, capacitive coupling metal sheet, short-circuit pin, and metal ground plate; The radiating metal sheet is parallel to the capacitive coupling metal sheet and connected through the shorting pin; The capacitive coupling metal sheet is suspended above and parallel to the metal floor, with the feed point located on the surface of the radiating metal sheet. The radiating metal sheet, capacitive coupling metal sheet, and short-circuit pin are all integral structures, formed by integrally pressing and bending a metal sheet or metal film. The radiating metal sheet is rectangular in shape, and four capacitive coupling metal sheets are respectively located near the four corners of the rectangular radiating metal sheet. Each capacitive coupling metal sheet is connected to the radiating metal sheet by a corresponding short-circuit pin. The four feed points are symmetrically distributed on the surface of the radiating metal sheet, and the overall position of the four feed points is symmetrical about the geometric center of the radiating metal sheet. The signal is input through the feed points, flows through the radiating metal sheet, enters the capacitive coupling metal sheet through the short-circuit pin, and then enters the metal floor through coupling, thus realizing a closed-loop signal circuit.

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