A broadband circularly polarized phased array antenna for satellite communications

Abstract

The present invention discloses a broadband circularly polarized phased array antenna for satellite communication, belonging to the field of antenna technology. It includes a dipole radiation unit and a mounting substrate; the mounting substrate is provided with a placement hole for mounting the dipole radiation unit; the dipole radiation unit includes a feeding balun; the feeding balun includes a cylindrical structure, a filling medium is provided in the cylindrical structure, and two pairs of metal arms extending outward are provided on the top edge thereof, and two strip grooves extending to the top are also provided thereon; the bottom of the dipole radiation unit is connected with a feeding connector, the feeding connector and the outer shell are fixed to the mounting substrate, and the inner conductor thereof extends upward and is connected to one of the metal arms through a metal branch. The present invention has a simple structure, is easy to process, is convenient to install, has good stability, is low in cost, and is suitable for mass production.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, and in particular to a broadband circularly polarized phased array antenna for satellite communications. Background Art

[0002] In recent years, with the development of wireless communication systems, the number of users has increased day by day, and spectrum resources have become increasingly tight. Circularly polarized antennas have their own advantages in resisting multipath interference and suppressing interference from clouds and rain, and circularly polarized antennas can receive incoming waves of linear polarization in any polarization form and circular polarization that is consistent with it. Broadband technology has the advantages of fast transmission rate, low transmission power, strong endurance, strong penetration ability and high multipath resolution. It is a key component of broadband wireless communication systems and directly affects the performance of the entire broadband system. Therefore, the modern communication field urgently needs antennas with broadband circular polarization functions with high stability, strong penetration ability, large communication capacity and good confidentiality. In satellite communication systems, the use of broadband circularly polarized antennas for signal transmission can ensure the normal operation of communication links.

[0003] In satellite, ship, airborne or vehicle-mounted platform applications, strict requirements are placed on the physical properties of phased array antennas, such as space volume and weight, and their environmental adaptability. Modern communication systems often use miniaturized broadband circularly polarized antennas as transmitters and receivers of communication systems, and require antennas to meet circular polarization performance while also being small in size, light in weight, and wide in bandwidth. This places increasingly high demands on the design of circularly polarized antennas, such as operating bandwidth, axial ratio bandwidth, high gain, etc. In order to meet market competition requirements, antennas are also required to have simple structures, low costs, and mass production.

[0004] The performance of miniaturized broadband circularly polarized phased array antennas mainly depends on the performance of antenna units in the antenna array, such as operating bandwidth, beam width and gain, but it also has the following disadvantages:

[0005] 1. Working bandwidth: circularly polarized antennas are required to have characteristics such as wide working frequency band, wide beam and wide angle scanning. Common circularly polarized antennas have narrow impedance bandwidth, usually around 10%, and the circular polarization axis ratio bandwidth is limited, which does not meet the equipment requirements, limiting their application potential in satellite communications, vehicle-mounted and airborne communications, etc.

[0006] 2. High gain: The use of communication antenna units with high gain can not only improve the communication quality, but also reduce the size of the antenna array, achieve low cost and miniaturization, and solve the problem of limited satellite communication capabilities in the limited space of satellite-borne, airborne, and vehicle-borne platforms.

[0007] 3. Structure: When used on a satellite platform, the space is limited and the satellite environment is harsh. It is necessary to use a miniaturized antenna that can withstand the onboard environment. At the same time, effective mutual coupling suppression methods must be adopted to improve the isolation between antennas. Summary of the invention

[0008] In view of this, the present invention provides a broadband circularly polarized phased array antenna for satellite communication. The antenna has the characteristics of high gain, high isolation, good environmental adaptability, and resistance to satellite-borne environment, and has the advantages of simple structure, easy processing, convenient installation, good stability, low cost, and suitability for mass production.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A miniaturized broadband circularly polarized phased array antenna for satellite communication, comprising a dipole radiation unit and a mounting substrate; the mounting substrate is provided with mounting holes for mounting the dipole radiation unit; the mounting holes are evenly arranged on the mounting substrate;

[0011] The dipole radiation unit includes a feeding balun; the feeding balun includes a cylindrical structure, a filling medium is arranged in the cylindrical structure, and two pairs of metal arms extending outward are arranged on the top edge of the cylindrical structure, and two strip grooves extending to the top are also arranged on the cylindrical structure; each pair of metal arms and strip grooves are symmetrical about the center of the cylindrical structure;

[0012] The bottom of the dipole radiation unit is connected with a feeding connector, the outer conductor of the feeding connector is fixedly connected with the mounting substrate, and the inner conductor thereof extends upward and is connected with one of the metal arms through a metal branch.

[0013] Furthermore, a four-way flange for fixation is provided at the connection position between the dipole radiation unit and the feeding connector, the placement hole is a square structure, and the inner wall of the placement hole is provided with an annular protrusion corresponding to the four-way flange.

[0014] Furthermore, the placement holes on the mounting substrate are arranged in a triangular shape or a rectangular shape.

[0015] The beneficial effects of the above technical solution of the present invention are:

[0016] 1. Working bandwidth: The working bandwidth of the present invention has a percentage bandwidth of 46.5%, which can solve the problem of limited space volume and weight of phased array antenna.

[0017] 2. Wide-angle axial ratio. The present invention adopts sequential rotation feeding technology, and the axial ratio is less than 2.5dB within the range of ±60°. The broadband circularly polarized phased array antenna of the present invention uses an isolation structure to isolate the vibrator unit, has a high port isolation, and improves the isolation performance.

[0018] 3. Miniaturization. The oscillator radiation unit of the present invention has a size of 0.47 times the wavelength, has the characteristics of miniaturization, and can be used in satellite-borne, ship-borne, airborne, vehicle-borne and other communication platforms.

[0019] 4. It can realize batch production in engineering. The present invention has the characteristics of simple structure, high reliability and easy processing, which is convenient for realizing batch production in engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0021] Figure 2 yes Figure 1 Schematic diagram of the subarray structure.

[0022] Figure 3 yes Figure 1 Schematic diagram of the oscillator radiation unit structure.

[0023] Figure 4 yes Figure 3 Cross-sectional view of .

[0024] In the figure: 1. metal arm, 2. metal branch, 3. cylindrical structure, 4. outer conductor of the feed connector, 5. filling medium, 6. inner conductor, 7. four-way flange. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] A miniaturized broadband circularly polarized phased array antenna for satellite communication, comprising a dipole radiation unit and a mounting substrate; the mounting substrate is provided with mounting holes for mounting the dipole radiation unit; the mounting holes are evenly arranged on the mounting substrate;

[0027] The dipole radiation unit includes a feeding balun; the feeding balun includes a cylindrical structure 3, a filling medium 5 is provided in the cylindrical structure, and two pairs of metal arms 1 extending outward are provided on the top edge thereof, and two strip grooves extending to the top are also provided on the cylindrical structure; each pair of metal arms and strip grooves are symmetrical about the center of the cylindrical structure;

[0028] The bottom of the dipole radiation unit is connected with a feeding connector, the outer conductor 4 of the feeding connector is fixedly connected to the mounting substrate, and the inner conductor 6 thereof extends upward and is connected to one of the metal arms through the metal branch 2.

[0029] Furthermore, a four-way flange 7 for fixing is provided at the connection position between the oscillator radiation unit and the feeding connector, the placement hole is a square structure, and the inner wall of the placement hole is provided with an annular protrusion corresponding to the four-way flange.

[0030] Furthermore, the placement holes on the mounting substrate are arranged in a triangular shape or a rectangular shape.

[0031] The following is a more specific embodiment:

[0032] like Figures 1 to 4 As shown, this embodiment includes at least one broadband circularly polarized antenna subarray, and the broadband circularly polarized phased array antenna subarray includes a dipole radiation unit, a feeding connector and a mounting substrate.

[0033] The oscillator radiation unit is composed of a metal shell and an internal filling medium. The metal shell is composed of two pairs of metal arms and a feeding balun. The feeding balun is provided with two strip grooves, and the two strip grooves are symmetrical about the center of the cylindrical structure.

[0034] The size of the metal shell is adjustable, and the metal arm and the feed balun are integrally processed.

[0035] The outer conductor of the feed connector is integrally formed with the mounting substrate.

[0036] The inner conductor passes through the dipole radiation unit and the outer shell of the feeding connector. The dipole radiation unit can change the circular polarization direction by adjusting two pairs of metal arms to achieve left-hand circular polarization or right-hand circular polarization.

[0037] The arrangement of the dipole radiation units can be rectangular or triangular. In this embodiment, a triangular arrangement is adopted.

[0038] Antenna subarrays can be spliced ​​into broadband circularly polarized phased array antennas of different sizes.

[0039] In this embodiment, the antenna may be composed of M broadband circularly polarized antenna subarrays, where M is a natural number, and M is 6.

[0040] In this embodiment, the length of the dipole arm of the dipole radiation unit is 0.4 times the wavelength; the width of the strip groove of the feeding balun is 0.03 times the wavelength; and the depth of the strip groove of the feeding balun is 0.16 times the wavelength.

[0041] The metal arm connected to the cylindrical structure uses an asymmetric oscillator structure, which can be used to achieve circularly polarized radiation characteristics.

[0042] The feed balun uses a slotted coaxial line balun, and two strip slots on the feed balun are symmetrical about the center of the cylindrical structure.

[0043] The asymmetric dipole radiation unit is connected between the mounting base plate and the bottom feeding connector and is fixed by means of threads and adhesive.

[0044] As a preferred solution, the dipole radiation units in the broadband circularly polarized phased array antenna subarray are arranged in a triangular array.

[0045] The present invention can be used for array antennas, one-dimensional phased array antennas and two-dimensional phased array antennas; and can be used for satellite-borne, airborne, ship-borne and vehicle-borne platforms.

Claims

1. A broadband circularly polarized phased array antenna for satellite communications, characterized in that: It includes a vibrator radiation unit and a mounting substrate; the mounting substrate is provided with a placement hole for mounting the vibrator radiation unit; The mounting holes are evenly arranged on the mounting substrate; The dipole radiation unit includes a feeding balun; the feeding balun includes a cylindrical structure, a filling medium is arranged in the cylindrical structure, and two pairs of metal arms extending outward are arranged on the top edge of the cylindrical structure, and two strip grooves extending to the top are also arranged on the cylindrical structure; each pair of metal arms and strip grooves are symmetrical about the center of the cylindrical structure; The bottom of the dipole radiation unit is connected with a feeding connector, the outer conductor of the feeding connector is fixedly connected to the mounting substrate, and the inner conductor thereof extends upward and is connected to one of the metal arms through a metal branch; A four-way flange for fixing is provided at the connection position between the dipole radiation unit and the feeding connector, the placement hole is a square structure, and an annular protrusion corresponding to the four-way flange is provided on the inner wall of the placement hole; The mounting holes on the mounting substrate are arranged in a triangular pattern or a rectangular pattern.

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