Microminiature satellite-borne UHF frequency band communication antenna

Abstract

The invention discloses an ultra-small satellite-borne UHF (Ultra High Frequency) frequency band communication antenna, which has the working frequency band covering the frequency band of 350MHz-450MHz and has the characteristics of ultra-compact size, low cost, easiness in manufacturing / assembling and wide-angular-domain circularly polarized wave beam covering. The antenna adopts a single-layer air micro-strip structure, the radiation body is of an all-metal structure, and the electrical size of the antenna is only 0.195 lambda0 * 0.195 lambda0 * 0.027 lambda0, which is reduced by 84.8% compared with the size of a traditional air micro-strip antenna. The ultra-small satellite-borne UHF band communication antenna is composed of a radiation body, a feed assembly and a bottom plate. The radiation body is used for realizing the electrical radiation performance of the whole antenna, and the feed assembly is used for realizing the feed and circular polarization performance of the whole antenna; the radiation body is composed of a gradual change slot radiation sheet and a gradual change short circuit sheet. The feed assembly is composed of a feed network, a feed probe, a feed cavity and a feed plug. And the bottom plate is connected with the star body through eight M4 screws.

Description

Technical Field

[0001] The invention belongs to the field of manned technology, and in particular relates to an ultra-small satellite-borne UHF frequency band communication antenna. Background Art

[0002] The UHF band is commonly used as a frequency band for long-distance communications due to its advantages such as strong penetration, low free space loss and simple coverage. Common antenna forms in this band include Yagi antennas, single-pole sub-antennas, etc., but these antennas are large in size and are only suitable for ground receiving stations or large mobile carriers. Satellite carriers have strict restrictions on the shape, volume and weight of antennas.

[0003] Microstrip antennas are currently the preferred form of lightweight and small antennas for satellite-borne UHF bands due to their low profile, compact size, and low cost. Due to the long wavelength of the UHF band, the electrical size of microstrip antennas designed based on traditional methods is close to half the wavelength, so it is necessary to carry out antenna miniaturization design to meet the stringent installation and layout conditions of the satellite.

[0004] Currently, the structure of UHF communication antennas is mostly in the form of an "inverted F" antenna. The "inverted F" antenna has the characteristics of compact structure and all-metal structure, but the "inverted F" antenna is a linearly polarized antenna. Communication between linearly polarized antennas has high requirements on the polarization direction and is prone to polarization mismatch problems. There is about 3dB polarization mismatch when communicating with circularly polarized antennas, which cannot meet the constraints of tight communication link margins for subsequent manned missions.

[0005] In view of the mission requirements in the manned field, taking into account the constraints of satellite environment, weight, layout and antenna performance, the UHF communication antenna is required to be designed to be ultra-small, while taking into account the working requirements of circular polarization, high gain at low elevation angles, and structural reliability. Existing technologies and achievements cannot meet the mission requirements. Summary of the invention

[0006] The technology of the present invention solves the problem: overcomes the shortcomings of the prior art and provides an ultra-small satellite-borne UHF frequency band communication antenna, which has the advantages of ultra-small size, circular polarization, high gain at low elevation angles, and structural reliability.

[0007] In order to solve the above technical problems, the present invention discloses an ultra-small satellite-borne UHF frequency band communication antenna, comprising: a radiating body, a feeding assembly, a bottom plate, a short-circuit screw, a gradient short-circuit sheet supporting screw and a gradient slot radiating sheet supporting screw;

[0008] The radiation body is connected and fixed to the bottom plate through the gradient short-circuit sheet support screws and the gradient slot radiation sheet support screws, and is electrically connected to the bottom plate through the short-circuit screws;

[0009] The feeding assembly is arranged on the bottom plate and is electrically connected with the radiation body.

[0010] In the above-mentioned ultra-small satellite-borne UHF frequency band communication antenna, the radiation body includes: a gradient slot radiation plate and a gradient short-circuit plate;

[0011] The gradient groove radiator is based on the square radiator structure, and rectangular gradient grooves are etched at symmetrical positions of the diagonal and opposite sides of the square radiator; the gradient groove radiator is connected and fixed to the base plate by gradient groove radiator support screws;

[0012] The gradient short-circuit piece is a rectangular gradient structure, with two groups in total, each group consisting of 4 rectangular gradient pieces of the same size; the gradient short-circuit piece is connected and fixed to the base plate through gradient short-circuit piece supporting screws; the gradient short-circuit piece is electrically connected to the base plate through the short-circuit screws.

[0013] In the above-mentioned ultra-small satellite-borne UHF frequency band communication antenna, a fixed-size gap is left between the tapered slot radiation plate and the tapered short-circuit plate.

[0014] In the above-mentioned ultra-small satellite-borne UHF frequency band communication antenna, the feeding assembly includes: a feeding network, two feeding probes, a feeding cavity and a feeding plug;

[0015] The feed cavity is connected to the base plate by titanium alloy screws;

[0016] The feeding network is fixed inside the feeding cavity;

[0017] The feed plug is fixed to the bottom of the feed cavity by titanium alloy screws;

[0018] Two feeding probes are used to realize dual-point feeding; wherein, one end of the feeding probe is screwed to the gradient slot radiation sheet to realize electrical conduction, and the other end is welded to the feeding network to realize electrical conduction.

[0019] In the above-mentioned ultra-small satellite-borne UHF band communication antenna, the feed network is a single-layer microstrip structure, with a feed network strip line etched on the front and a full metal strip line on the back; wherein the other end of the feed probe is welded to the feed network strip line to achieve electrical conduction.

[0020] In the above-mentioned ultra-small satellite-borne UHF band communication antenna, the feeding network strip line adopts an integrated design of a single-section network strip line and an isolated end open strip line; the isolated end open strip line is composed of a 1 / 4 wavelength microstrip line, and an isolation resistor is welded between the single-section network strip line to achieve electrical matching of the antenna isolation end.

[0021] In the above-mentioned ultra-small satellite-borne UHF frequency band communication antenna, the feed cavity is made of aluminum alloy material and is designed with a supporting groove inside; the feed network is fixed inside the feed cavity through the supporting groove.

[0022] In the above-mentioned ultra-small satellite-borne UHF frequency band communication antenna, the feed plug is an SMA plug, which is electrically connected to the feed network strip line by welding.

[0023] In the above-mentioned ultra-small satellite-borne UHF frequency band communication antenna, the base plate is connected to the satellite body by screws.

[0024] In the above-mentioned ultra-small satellite-borne UHF band communication antenna,

[0025] The material of the gradient slot radiation plate and the gradient short-circuit plate is aluminum alloy;

[0026] The support screws of the gradient slot radiation sheet are cylindrical structures and made of polyimide;

[0027] The supporting screw of the gradient short-circuit sheet is a cylindrical structure and is made of polyimide;

[0028] The short-circuit screw is a cylindrical structure made of aluminum alloy;

[0029] The feed network is made of RELONG-RA1000B dielectric plate;

[0030] The feeding probe is a cylindrical structure and is made of brass.

[0031] The present invention has the following advantages:

[0032] (1) The present invention discloses an ultra-small satellite-borne UHF frequency band communication antenna, which adopts an air microstrip solution. By adopting measures such as etching gradient grooves at the diagonal and opposite sides of the radiation plate and suspending gradient short-circuit plates around the gradient grooves, the problem of the traditional air microstrip being large in size and having poor antenna gain at low elevation angles is solved, and the antenna is ultra-small and lightweight, has high gain at low elevation angles, and has wide-angle circular polarization characteristics.

[0033] (2) The present invention discloses an ultra-small satellite-borne UHF frequency band communication antenna, the electrical dimensions of which (length × width × height) are only 0.195λ0 × 0.195λ0 × 0.027λ0, where λ0 represents the wavelength of the antenna transmission medium, which is 84.8% smaller than the size of a traditional air microstrip antenna. The gain of the antenna at an elevation angle of ±70° is 4dB higher than that of a traditional air microstrip antenna.

[0034] (3) The present invention discloses an ultra-small satellite-borne UHF band communication antenna, the operating frequency band covers the 350MHz to 450MHz band, and the antenna weighs only 300g.

[0035] (4) The present invention discloses an ultra-small satellite-borne UHF frequency band communication antenna. Except for the feed network, all other components are all made of an all-metal structure. It has strong mechanical structural characteristics, strong adaptability to the on-orbit environment, and is characterized by ultra-compact size, low cost, simple structure, and easy manufacturing / assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1It is a schematic structural diagram of an ultra-small satellite-borne UHF frequency band communication antenna in an embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the assembly of an ultra-small satellite-borne UHF frequency band communication antenna in an embodiment of the present invention;

[0038] Figure 3 is a front schematic diagram of a feeding network in an embodiment of the present invention;

[0039] Figure 4 is a schematic diagram of the back side of a feeding network in an embodiment of the present invention;

[0040] Figure 5 It is a schematic structural diagram of a feeding cavity in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0042] The present invention discloses an ultra-small satellite-borne UHF frequency band communication antenna, which has the characteristics of ultra-compact size, all-metal structure of the radiating body, low cost, easy manufacturing / assembly, wide-angle circular polarization beam coverage, etc. Figures 1 to 5 As shown, the ultra-small satellite-borne UHF frequency band communication antenna comprises: a radiation body 1, a feeding assembly 2, a bottom plate 3, a short-circuit screw 4, a gradient short-circuit sheet support screw 5 and a gradient slot radiation sheet support screw 6. The radiation body 1 is connected and fixed to the bottom plate 3 through the gradient short-circuit sheet support screw 5 and the gradient slot radiation sheet support screw 6, and is electrically connected to the bottom plate 3 through the short-circuit screw 4; the feeding assembly 2 is arranged on the bottom plate 3 and is electrically connected to the radiation body 1.

[0043] In this embodiment, the radiation body 1 may specifically include: a gradient slot radiation piece 11 and a gradient short-circuit piece 12, and the materials of the gradient slot radiation piece 11 and the gradient short-circuit piece 12 are aluminum alloy. Among them, the gradient slot radiation piece 11 is based on the square radiation piece structure, and two groups of 8 rectangular gradient slots (4 rectangular gradient slots with longer lengths and the same shape and area at the diagonal positions and 4 rectangular gradient slots with shorter lengths and the same shape and area at the opposite sides) are etched at the diagonal and opposite sides of the square radiation piece; by engraving grooves on the radiation piece, the current transmission path on the antenna surface is increased, thereby achieving the purpose of reducing the size of the antenna radiation piece; the gradient slot radiation piece 11 is used as a radiation piece of the air microstrip, and is supported and suspended above the bottom plate 3 by a gradient slot radiation piece support screw 6 with a diameter of 12mm; the gradient slot radiation piece support screw 6 is a cylindrical structure, and the material is polyimide. The gradient short-circuit sheet 12 is a rectangular gradient structure, with two groups, each group consisting of 4 rectangular gradient sheets of the same size; the gradient short-circuit sheet 12 is electrically connected to the base plate 3 through 8 short-circuit screws 4 of equal size, and the short-circuit screws 4 serve as structural support screws of the gradient short-circuit sheet 12, suspending the gradient short-circuit sheet 12 around the gradient slot of the gradient slot radiation sheet 11; the short-circuit screws 4 are cylindrical structures, made of aluminum alloy, and chemically conductively oxidized on the surface. In order to improve the structural reliability of the gradient short-circuit sheet 12, the ends of the four longer gradient short-circuit sheets 12 are connected and fixed to the base plate 3 through four gradient short-circuit sheet support screws 5; the gradient short-circuit sheet support screws 5 are cylindrical structures, made of polyimide. A fixed size gap is left between the gradient slot radiation sheet 11 and the gradient short-circuit sheet 12. The above design is used to reduce the size of the antenna radiation plate and improve the low elevation angle gain of the antenna: the gradient short-circuit plate 12 and the gradient slot radiation plate 11 are coupled to change the current transmission path on the surface of the radiation plate while connecting the antenna zero potential point and the base plate 3, thereby reducing the size of the antenna; the gradient short-circuit plate 12 acts as a parasitic unit to widen the antenna beam width and improve the low elevation angle gain of the antenna.

[0044] In this embodiment, the feeding assembly 2 may specifically include: a feeding network 21, two feeding probes 22, a feeding cavity 23 and a feeding plug 24. Among them, the feeding cavity 23 is connected to the base plate 3 by 12 M3 titanium alloy screws; the material of the base plate 3 and the feeding cavity 23 is aluminum alloy, and the surface is chemically conductively oxidized. The feeding network 21 is fixed inside the feeding cavity 23 and is composed of a single layer of dielectric; the feeding network 21 includes 1 input port and 2 output ports, and the 2 output ports are welded with the 2 feeding probes 22 to achieve reliable electrical conduction, and 1 input port is welded with the inner conductor of the feeding plug 24 to achieve electrical conduction. The feeding plug 24 is fixed to the bottom of the feeding cavity 23 by 2 M3 titanium alloy screws. The two feeding probes 22 are used to realize dual-point feeding. The gradient slot radiator 11 excites an electric field of equal amplitude and a phase difference of 90 degrees through the two feeding probes 22, thereby realizing circularly polarized radiation of the antenna; one end of the feeding probe 22 passes through the base plate 3 and is screwed to the gradient slot radiator 11 to achieve electrical conduction, and the other end is welded to the feeding network 21 to achieve electrical conduction; the feeding probe 22 is a cylindrical structure, made of brass, and gold-plated on the surface.

[0045] Preferably, the feed network 21 is a single-layer microstrip structure, which is made of RELONG-RA1000B dielectric plate. The front of the feed network 21 is etched with a feed network strip line 211, and the back is a full metal strip line 212, which is tightly attached to the bottom plate 3 and serves as the ground plate of the antenna. The other end of the feed probe 22 is welded to the feed network strip line 211 to achieve electrical conduction.

[0046] Furthermore, the feed network stripline 211 adopts an integrated design of a single-branch network stripline 2111 and an isolated end open-circuit stripline 2112; the single-branch network stripline 2111 is used to achieve broadband and circular polarization performance of the antenna. The isolated end open-circuit stripline 2112 is composed of a 1 / 4 wavelength microstrip line, and a 50Ω isolation resistor 2113 is welded between the single-branch network stripline 2111 to achieve electrical matching of the antenna isolation end.

[0047] Preferably, the feeding cavity 23 is made of aluminum alloy and is provided with a supporting groove 231 inside; the feeding network 21 is fixed inside the feeding cavity 23 through the supporting groove 231 .

[0048] Preferably, the feed plug 24 is an SMA plug, which is electrically connected to the feed network strip line 211 by welding. The inner conductor of the feed plug 24 is made of beryllium copper, and the outer shell is made of brass.

[0049] In this embodiment, the base plate 3 is connected to the star body by eight M4 screws.

[0050] After testing, the antenna operating frequency band of the present invention covers: 350MHz~450MHz frequency band, the bandwidth of antenna port return loss better than -10dB reaches 27.8% (340~450MHz), and the bandwidth of axial ratio (AR) less than 3dB reaches 25.3% (345~445MHz).

[0051] The antenna of the present invention has passed the following ground tests (including under vacuum conditions), verifying the various performances of the antenna of the present invention:

[0052] 1) Passed the mechanical environment test of satellite components, including: sinusoidal vibration, random vibration, impact test, acceleration test. The antenna can withstand the above test loads and there is no abnormal change in the structure;

[0053] 2) The satellite-borne component has passed the thermal test assessment, with the test temperature range of -105℃ to 105℃. There is no obvious change in the product appearance and performance before and after the test, and the product performance is stable.

[0054] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0055] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. An ultra-small satellite-borne UHF frequency band communication antenna, characterized in that: include: A radiating body (1), a feeding assembly (2), a bottom plate (3), a short-circuit screw (4), a gradient short-circuit sheet supporting screw (5) and a gradient slot radiating sheet supporting screw (6); The radiation body (1) is connected and fixed to the base plate (3) via a gradient short-circuit sheet support screw (5) and a gradient slot radiation sheet support screw (6), and is electrically connected to the base plate (3) via a short-circuit screw (4); The feeding component (2) is arranged on the bottom plate (3) and is electrically connected to the radiation body (1).

2. The ultra-small satellite-borne UHF frequency band communication antenna according to claim 1, characterized in that: The radiation body (1) comprises: a gradient slot radiation plate (11) and a gradient short-circuit plate (12); The gradient groove radiation sheet (11) is based on a square radiation sheet structure, and rectangular gradient grooves are etched at symmetrical positions of diagonal and opposite sides of the square radiation sheet; the gradient groove radiation sheet (11) is connected and fixed to the bottom plate (3) via gradient groove radiation sheet support screws (6); The gradient short-circuit piece (12) is a rectangular gradient structure, and there are two groups in total, each group consisting of four rectangular gradient pieces of the same size; the gradient short-circuit piece (12) is connected and fixed to the bottom plate (3) via gradient short-circuit piece supporting screws (5); the gradient short-circuit piece (12) is electrically connected to the bottom plate (3) via the short-circuit screws (4).

3. The ultra-small satellite-borne UHF frequency band communication antenna according to claim 2, characterized in that: A gap of fixed size is left between the gradient slot radiation sheet (11) and the gradient short-circuit sheet (12).

4. The ultra-small satellite-borne UHF frequency band communication antenna according to claim 2, characterized in that: A feeding assembly (2) comprising: a feeding network (21), two feeding probes (22), a feeding cavity (23) and a feeding plug (24); The feeding cavity (23) is connected to the bottom plate (3) via titanium alloy screws; The feeding network (21) is fixed inside the feeding cavity (23); The feeding plug (24) is fixed to the bottom of the feeding cavity (23) by means of titanium alloy screws; The two feeding probes (22) are used to realize dual-point feeding; wherein one end of the feeding probe (22) is screwed to the gradient slot radiation sheet (11) to realize electrical conduction, and the other end is welded to the feeding network (21) to realize electrical conduction.

5. The ultra-small satellite-borne UHF frequency band communication antenna according to claim 4, characterized in that: The feed network (21) is in the form of a single-layer microstrip structure, with a feed network strip line (211) etched on the front side and a full metal strip line (212) on the back side; wherein the other end of the feed probe (22) is welded to the feed network strip line (211) to achieve electrical conduction.

6. The ultra-small satellite-borne UHF frequency band communication antenna according to claim 5, characterized in that: The feeding network strip line (211) adopts an integrated design of a single-branch network strip line (2111) and an isolated end open-circuit strip line (2112); the isolated end open-circuit strip line (2112) is composed of a 1 / 4 wavelength microstrip line, and an isolation resistor (2113) is welded between the single-branch network strip line (2111) to achieve electrical matching of the antenna isolation end.

7. The ultra-small satellite-borne UHF frequency band communication antenna according to claim 4, characterized in that: The feeding cavity (23) is made of an aluminum alloy material and is provided with a supporting groove (231) inside; the feeding network (21) is fixed inside the feeding cavity (23) via the supporting groove (231).

8. The ultra-small satellite-borne UHF frequency band communication antenna according to claim 5, characterized in that: The feeding plug (24) is an SMA plug and is electrically connected to the feeding network strip line (211) by welding.

9. The ultra-small spaceborne UHF frequency band communication antenna according to claim 1, characterized in that: The bottom plate (3) is connected to the star body via screws.

10. The ultra-small satellite-borne UHF frequency band communication antenna according to claim 4, characterized in that: The material of the gradient slot radiation plate (11) and the gradient short-circuit plate (12) is aluminum alloy; The gradient groove radiation sheet support screw (6) is a cylindrical structure, and the material is polyimide; The gradient short-circuit sheet supporting screw (5) is a cylindrical structure, and the material is polyimide; The short-circuit screw (4) is a cylindrical structure and is made of aluminum alloy; The feeding network (21) is prepared by using RELONG-RA1000B dielectric plate; The feeding probe (22) is a cylindrical structure and is made of brass.

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