Broadband end-fire monopole antenna, communication terminal and aircraft

Abstract

The application discloses a broadband end-fire monopole antenna, a communication terminal and an aircraft, and relates to the technical field of antennas. The broadband end-fire monopole antenna comprises a metal grounding plate, an L-shaped reflecting plate, an arc-shaped slot arranged on the outer end surface of the horizontal plate of the L-shaped reflecting plate, a coaxial feeding structure, and a metal inner core and a metal outer skin of the coaxial feeding structure. The metal inner core and the metal outer skin are insulated. The upper end of the metal inner core of the coaxial feeding structure is located in the arc-shaped slot of the L-shaped reflecting plate and forms a circular ring-shaped coupling gap with the L-shaped reflecting plate. The metal outer skin of the coaxial feeding structure is connected with the metal grounding plate. The broadband end-fire monopole antenna provided by the application has the advantages of simple structure, high directivity, high temperature resistance, easy processing, and can be applied to large-scale conformal phased arrays.

Description

Technical Field

[0001] This invention relates to an antenna structure, belonging to the field of communication technology. Background Technology

[0002] In recent years, conformal phased array antennas have experienced rapid development and widespread attention. Conformal phased array antennas conform to the surface of an object, allowing full utilization of the carrier's surface space without compromising its shape or dynamic characteristics. Furthermore, compared to traditional planar phased array antennas, conformal phased array antennas offer faster, inertial-free beam scanning while also providing a larger beam scanning range. To achieve detection capabilities in the nose direction of an aircraft, low-elevation scanning capability is required for the phased array antenna. From an element perspective, a small-sized antenna with end-fire performance needs to be designed as a conformal phased array element.

[0003] Monopole antennas are widely used in wireless communication due to their simple structure and stable performance. However, a single monopole antenna only possesses omnidirectional radiation characteristics and lacks radiation capability in a specific direction. Traditional monopole log-periodic arrays with reflectors and directors can achieve ultra-wideband and end-fire characteristics, but their large size prevents their application in phased arrays. Therefore, designing a small, simple, and wide-bandwidth end-fire monopole antenna has become a major challenge. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a broadband end-fire monopole antenna with a simple structure and a wide impedance bandwidth, as well as a communication terminal and an aircraft having the broadband end-fire monopole antenna.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention first provides a broadband end-fire monopole antenna, comprising: Metal grounding plate; L-shaped reflector; the L-shaped reflector includes a vertical plate and a horizontal plate; a groove is provided on the outer end face of the horizontal plate of the L-shaped reflector; the L-shaped reflector is connected to the metal ground plate through the vertical plate, and the horizontal plate of the L-shaped reflector is parallel to the metal ground plate; as well as A coaxial feeding structure is provided; the coaxial feeding structure includes a metal inner core and a metal outer skin, which are insulated from each other; the upper end of the metal inner core of the coaxial feeding structure is located in the slot of the L-shaped reflector and forms a coupling gap of equal width with the L-shaped reflector, the width of which is 0.01-0.05 times the wavelength; the metal outer skin of the coaxial feeding structure is connected to a metal ground plane.

[0006] The present invention also provides a communication terminal, including the broadband end-fire monopole antenna provided above.

[0007] The present invention also provides an aircraft including the broadband end-fire monopole antenna described above.

[0008] Compared with the prior art, the beneficial effects of the present invention are: 1. The reflector adopts an L-shaped reflector, forming a gap with the coaxial inner core to introduce coupling capacitance, thereby introducing an additional resonant point at low frequencies and expanding the antenna bandwidth. The working bandwidth of this invention can reach 80%, while having good structural strength, simple processing, and being suitable for mass production and debugging. It is also suitable as a conformal antenna array unit.

[0009] 2. The antenna is made entirely of metal and requires no soldering. Current antennas mostly use printed circuit boards (PCBs), but PCBs have poor high-temperature resistance. Taking the commonly used FR4 antenna as an example, its long-term operating temperature is typically between 130℃ and 140℃, while its instantaneous withstand temperature can reach 150℃ to 260℃. Materials with better heat resistance, such as polyimide, can withstand temperatures up to 280℃. In short, PCBs can hardly meet the heat resistance requirements of 600℃ and above. High-temperature resistant metal materials such as titanium alloys retain high strength at 400–600℃, meeting the requirements for 600℃ high-temperature applications. Furthermore, the melting point of commonly used solder is between 183℃ and 300℃, which is insufficient for higher temperature applications. Therefore, eliminating the soldering process can improve the antenna's operating temperature. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the antenna structure of the present invention; Figure 2 yes Figure 1 Side view; Figure 3 yes Figure 1 Top view; Figure 4 This is the antenna reflection curve diagram corresponding to the present invention; Figure 5 This is a reflection curve diagram of a traditional antenna structure; Figure 6 This is the antenna gain diagram corresponding to this invention; Figure 7 This is a gain diagram for a traditional antenna structure. Detailed Implementation

[0011] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0012] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0013] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings: Example 1

[0014] like Figures 1-3 As shown, the antenna structure of this invention comprises three parts: an L-shaped reflector 1, a coaxial feed structure 2, and a metal ground plane 3. The coaxial feed structure serves as both a feed source and a monopole radiating structure and is connected to the metal ground plane. The L-shaped reflector 1 is placed above the metal ground plane. One end of the L-shaped reflector 1 is perpendicularly connected to the metal ground plane 3, and the other end is parallel to the metal ground plane 3, forming a gap of equal width with the inner core of the coaxial feed structure at its end.

[0015] The coaxial power supply structure includes a metal core, a dielectric rod, and a metal outer sheath, with the metal core and metal outer sheath being insulated by the dielectric rod.

[0016] When the inner core of the coaxial feed structure is circular, an arc-shaped groove is opened on the horizontal plate end face of the L-shaped reflector 1 that is parallel to the metal ground plate, and the gap between the L-shaped reflector 1 and the coaxial feed structure is annular.

[0017] When the inner core of the coaxial feed structure is rectangular, a square slot is opened on the horizontal plate end face of the L-shaped reflector 1 that is parallel to the metal ground plane, and the gap between the L-shaped reflector 1 and the coaxial feed structure is C-shaped.

[0018] The vertical plate length of the L-shaped reflector is the same as the length of the metal inner core extending from the surface of the metal ground plate. The horizontal plate length is 0.1-0.3 times the wavelength, the width of the L-shaped reflector is 0.25-0.5 times the wavelength, and the thickness of the L-shaped reflector is 0-0.1 times the wavelength.

[0019] The L-shaped reflector extends 0.05-0.2 times the wavelength beyond the metal ground plane.

[0020] The metal ground plane has a side length of 0.8-2 times the wavelength and a height of 0.1-0.4 times the wavelength.

[0021] L-shaped reflectors are made of metal, such as titanium alloy.

[0022] In this embodiment, the inner core of the coaxial feed structure has a diameter of 1mm and an extension length of 2.3mm; the L-shaped reflector has a length of 2.3mm perpendicular to the metal ground plane and a length of 4mm parallel to the metal ground plane; the L-shaped reflector has a width of 7mm and a thickness of 0.8mm; the annular gap formed by the L-shaped reflector and the inner core of the coaxial feed structure has a width of 0.5mm; the metal ground plane has a side length of 18mm and a height of 4mm; the antenna characteristics are obtained by simulation calculation using HFSS software.

[0023] Figures 4-7 This is a performance comparison diagram between the antenna of this invention and a conventional antenna. Figure 4 This is a reflection coefficient diagram of the antenna of the present invention. It can be seen that the corresponding reflection coefficient ≤ -10dB covers the operating bandwidth from 12.9 to 31.9GHz, with a center frequency of 22.4GHz. The antenna has a wide impedance bandwidth of 85%. Figure 5 This is a reflection coefficient diagram of a traditional antenna structure. It can be seen that the corresponding reflection coefficient ≤ -10dB has an operating bandwidth of 24.6 to 33.2GHz, a center frequency of 28.9GHz, and an impedance bandwidth of 30%. Figure 6 This is the vertical radiation pattern of the antenna of the present invention. Figure 7 This is a vertical radiation pattern of the antenna of the present invention. As can be seen, the antenna of the present invention still maintains end-fire characteristics similar to those of the traditional structure.

[0024] In summary, to achieve both high-temperature resistance and broadband characteristics, this invention designs a high-temperature resistant broadband end-fire monopole antenna. By designing the reflector as an L-shape and forming a gap with the core of the feed structure, the low-frequency impedance bandwidth of the antenna is extended while retaining its end-fire characteristics. Furthermore, the antenna is entirely made of metal components, exhibiting high-temperature resistance. The high-temperature resistant broadband end-fire monopole antenna provided by this invention has a simple structure, high directivity, high temperature resistance, and is easy to fabricate, making it suitable for large-scale conformal phased arrays. Example 2

[0025] This embodiment provides a communication terminal, including the broadband end-fire monopole antenna provided in Embodiment 1. Example 3

[0026] This embodiment provides an aircraft, including the broadband end-fire monopole antenna provided in Embodiment 1.

[0027] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any transformations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A broadband end-fire monopole antenna, characterized in that, include: Metal grounding plate; L-shaped reflector; The L-shaped reflector includes a vertical plate and a horizontal plate; a groove is provided on the outer end face of the horizontal plate of the L-shaped reflector; the L-shaped reflector is connected to the metal ground plate through the vertical plate, and the horizontal plate of the L-shaped reflector is parallel to the metal ground plate. as well as A coaxial feeding structure is provided; the coaxial feeding structure includes a metal inner core and a metal outer skin, which are insulated from each other; the upper end of the metal inner core of the coaxial feeding structure is located within the slot of the L-shaped reflector and forms a coupling gap of equal width with the L-shaped reflector, the width of which is 0.01-0.05 times the wavelength; the metal outer skin of the coaxial feeding structure is connected to a metal ground plane. The slot provided on the outer end face of the horizontal plate of the L-shaped reflector is an arc groove, which forms a circular coupling gap with the circular metal inner core. The vertical plate length of the L-shaped reflector is the same as the length of the metal inner core extending out of the metal ground plane surface, the horizontal plate length is 0.1-0.3 times the wavelength, the width of the L-shaped reflector is 0.25-0.5 times the wavelength, and the thickness of the L-shaped reflector is 0-0.1 times the wavelength. The diameter of the metal inner core is 0.01-0.1 times the wavelength, and the length extending beyond the metal ground plane is 0.05-0.2 times the wavelength.

2. The broadband end-fire monopole antenna according to claim 1, characterized in that: The coaxial power supply structure also includes a dielectric rod, through which the metal inner core and the metal outer sheath are insulated.

3. The broadband end-fire monopole antenna according to claim 1, characterized in that: The metal ground plane has a side length of 0.8-2 times the wavelength and a height of 0.1-0.4 times the wavelength.

4. The broadband end-fire monopole antenna according to any one of claims 1-3, characterized in that: The L-shaped reflector is a metal plate.

5. The broadband end-fire monopole antenna according to claim 4, characterized in that: The L-shaped reflector is made of titanium alloy.

6. A communication terminal, characterized in that, Includes the broadband end-fire monopole antenna as described in any one of claims 1-5.

7. An aircraft, characterized in that, Includes the broadband end-fire monopole antenna as described in any one of claims 1-5.

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