Ka-band distributed conformal quasi-yagi antenna applied to roll angle measurement

Abstract

The application discloses a Ka-band distributed conformal quasi-Yagi antenna applied to roll angle measurement and belongs to the technical field of microwave antennas.The antenna A and the antenna B are conformally distributed on information ammunition, are orthogonally installed in spatial positions, and are orthogonal in polarization directions.In the roll process of the ammunition, Ka-band linear polarization radio frequency signals are respectively received, and the received radio frequency signals present a rule of peak values and sub-peak values in a period, so that the roll angle of the ammunition is analyzed and calculated.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave antennas, and in particular relates to a Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement. Background Art

[0002] Informationized ammunition is capable of completing trajectory control through information acquisition and transmission, including correction or guidance, to efficiently achieve hits, damage, or information countermeasures. After launch, informationized ammunition typically rotates forward, receiving correction commands from the guidance radar and combining them with its own roll angle information to perform trajectory corrections, continuously controlling the servos to fly toward the target. The key to flight control lies in real-time reception of guidance radar commands and real-time measurement of the projectile's own roll angle. Roll angle measurement is the foundation of informationized ammunition flight control, and its accuracy directly affects the strike accuracy of the guided projectile.

[0003] Existing roll angle measurement methods rely on gyroscopes, GPS, and geomagnetism. Gyroscopes accumulate significant errors during ammunition roll, preventing them from operating independently for extended periods. GPS data rates are low, susceptible to interference or obstruction, and require long initialization times. Geomagnetism has blind spots and is susceptible to interference. Consequently, existing roll angle measurement methods are unable to address the challenges of measuring the roll angle of information-based ammunition. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement.

[0005] The technical problem proposed by the present invention is solved as follows:

[0006] A Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement. The two antennas have the same structure and are conformally distributed within the informationized munition. They are installed orthogonally in space and have orthogonal polarization directions.

[0007] The antenna includes a radome 1, an antenna printed circuit board 2, a supporting foam 3, a metal shell 4 and a radio frequency cable assembly 5;

[0008] The outer surface of the radome 1 is a cylindrical surface conforming to the informationized ammunition, with a rectangular parallelepiped groove at the bottom; the material of the radome 1 is PMI foam and the outer surface is wrapped with glass fiber cloth;

[0009] The metal shell 4 is semi-enclosed, and the radome 1 is bonded to the metal shell 4. The rectangular groove of the radome 1 forms a rectangular cavity. The metal shell 4 is fixed to the informationized ammunition by screws.

[0010] The antenna printed circuit board 2 and the supporting foam 3 are embedded in the rectangular cavity; the supporting foam 3 is made of PMI foam and is in the shape of a rectangular parallelepiped, and is used to support the antenna printed circuit board 2;

[0011] The antenna printed circuit board 2 includes a dielectric substrate, a metal floor, and a radiating structure. The radiating structure and metal floor are located on the upper and lower surfaces of the dielectric substrate, respectively. The radiating structure comprises, from bottom to top, a microstrip line, a balanced feed balun, a transition section, an array, and a director. Two cascaded microstrip lines extend upward from the center of the short side of the dielectric substrate. The two balanced feed baluns are bent microstrip lines, extending upward from the ends of the second-stage microstrip line. The ends of the two balanced feed baluns extend upward with a first-stage transition section and a second-stage transition section, respectively. The end of the second-stage transition section corresponding to the first balanced feed balun extends to the left with a first array, and the end of the second-stage transition section corresponding to the second balanced feed balun extends to the right with a second array, with a gap between the two arrays. Fourteen directors are distributed above the array, all parallel to the array.

[0012] A metal step is provided on one side of the bottom plate of the metal housing 4 , and the metal floor of the antenna printed circuit board 2 is connected to the metal step.

[0013] The RF cable assembly 5 is a coaxial cable, the inner core of one end of which extends out as a metal probe and is connected to the first-stage microstrip line of the antenna printed circuit board 2, and the other end is an SMP-K interface.

[0014] Furthermore, the analytical calculation process of the roll angle of the informationized ammunition using the above antenna is as follows:

[0015] During the rolling process of the informationized ammunition, the two antennas respectively receive the Ka-band linearly polarized radio frequency signals transmitted by the guidance radar. The amplitude value of the received radio frequency signal is substituted into the following formula to solve the rolling angle α of the informationized ammunition:

[0016] E A =E0f(α)sinα

[0017] E B =E0f(α+π / 4)cosα

[0018] Among them, E A and E B are the amplitude values ​​of the RF signals received by the two antennas, E0 is the field strength of the arriving ammunition when no rolling occurs, and f is the directional pattern function of the two antennas.

[0019] Furthermore, the radius R of the cylindrical surface of the radome 1 is 38 mm, and the chamfer angle θ between the cylindrical surface and the side surface is 60°.

[0020] Furthermore, the length W of the radome 1 b 20mm, width W c is 16.27 mm, the height h0 is 4 mm; the width W of the rectangular groove a is 5mm and the depth h is 2mm.

[0021] Furthermore, the dielectric substrate has a relative dielectric constant of 6.15, a loss tangent of 0.003, and a thickness of 0.254 mm.

[0022] Furthermore, the width W of the antenna printed circuit board 2 a 5mm, length W b The metal floor is rectangular, with the bottom edge coinciding with the short side of the dielectric substrate, and the height h g The first-stage microstrip line has a width w1 of 0.27mm and a length l1 of 0.86mm. The second-stage microstrip line has a width w2 of 0.39mm and a length l2 of 0.86mm. The lengths l6 and l7 of the first and second transition sections are 0.24mm and 0.93mm, respectively. The gap s between the arrays is 0.09mm, and the total length l8 of the two arrays is 2.55mm.

[0023] Furthermore, the lateral lengths of the two balanced feed baluns differ by a quarter wavelength; the longitudinal spacing between the director closest to the array and the array is 0.1 wavelength to 0.4 wavelength, and the spacing d between the directors is 0.1 wavelength to 0.4 wavelength.

[0024] The beneficial effects of the present invention are:

[0025] Antennas A and B, described in the present invention, are conformally distributed within the information-based ammunition, mounted orthogonally in space, and have orthogonal polarizations. During the ammunition's rolling motion, they each receive Ka-band linearly polarized RF signals. The received RF signals exhibit a pattern of peaks and sub-peaks within a cycle, enabling analytical calculation of the ammunition's roll angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the quasi-Yagi antenna of the present invention, wherein (a) is a front view, (b) is a main view, (c) is a side view, and (d) is a top view;

[0027] Figure 2 This is a schematic structural diagram of the antenna cover in the antenna of the present invention;

[0028] Figure 3 Schematic diagram of the dimensions of the antenna printed circuit board in the antenna of the present invention;

[0029] Figure 4 This is a schematic diagram of ammunition rolling in the application scenario of the antenna of the present invention;

[0030] Figure 5 Graph showing the signals received by antenna A and antenna B in the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and examples.

[0032] This embodiment provides a Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement. The two antennas have the same structure and are conformally distributed in the informationized ammunition. They are installed orthogonally in space and their polarization directions are orthogonal. The front view of the antenna structure is shown in FIG. Figure 1 (a) shows the main view. Figure 1 (b) shows the side view. Figure 1 (c) shows the top view. Figure 1 As shown in (d), it includes a radome 1, an antenna printed circuit board 2, a supporting foam 3, a metal shell 4 and a radio frequency cable assembly 5.

[0033] The structural diagram of the radome 1 is as follows Figure 2 As shown, the outer surface is a cylindrical surface conforming to the ammunition, with a rectangular groove at the bottom; the radius R of the cylindrical surface is 38mm, and the chamfer angle θ between the cylindrical surface and the side surface is 60°. In this embodiment, the length W of the radome 1 is b 20mm, width W c is 16.27 mm, the height h0 is 4 mm; the width W of the rectangular groove a The main material of the radome 1 is PMI foam, and the outer surface is wrapped with a layer of glass fiber cloth.

[0034] The metal shell 4 is semi-enclosed, the radome 1 is bonded to the metal shell 4, and a rectangular cavity is formed at the rectangular groove of the radome 1; the metal shell 4 is fixed to the informationized ammunition by screws.

[0035] The antenna printed circuit board 2 and the supporting foam 3 are embedded in the rectangular cavity; the supporting foam 3 is made of PMI foam and is in the shape of a rectangular parallelepiped, and is used to support the antenna printed circuit board 2 .

[0036] The structural diagram of the antenna printed circuit board 2 is as follows Figure 3 As shown, it includes a dielectric substrate, a metal floor and a radiation structure, the radiation structure and the metal floor are respectively located on the upper and lower surfaces of the dielectric substrate; the width W of the antenna printed board 2 a 5mm, length W b The relative dielectric constant of the dielectric substrate is 6.15, the loss tangent is 0.003, and the thickness is 0.254mm. The metal floor is rectangular, with the bottom edge coinciding with the short side of the dielectric substrate, and the height h g It is 2.7mm.

[0037] From bottom to top, the radiating structure includes a microstrip line, a balanced feed balun, a transition section, an array, and a director. Two cascaded microstrip lines extend upward from the center of the short side of the dielectric substrate. In this embodiment, the first-stage microstrip line has a width w1 of 0.27 mm and a length l1 of 0.86 mm, while the second-stage microstrip line has a width w2 of 0.39 mm and a length l2 of 0.86 mm. The two balanced feed baluns are bent microstrip lines, extending upward from the ends of the second-stage microstrip line. In this embodiment, the lateral lengths l3 and l4 of the balanced feed baluns are 0.54 mm and 1.53 mm, respectively (a difference of approximately a quarter wavelength), and the longitudinal length l5 of the balanced feed baluns is 0.48 mm. The ends of the two balanced feed baluns extend upward with a first-stage transition section and a second-stage transition section, respectively. The lengths l6 and l7 of the first-stage transition section and the second-stage transition section are 0.24 mm and 0.93 mm, respectively. The first balanced-feed balun's second-stage transition section extends to the left from the end of the first array, and the second balanced-feed balun's second-stage transition section extends to the right from the end of the second array. The gap s between the arrays is 0.09mm, and the total length l8 of the two arrays is 2.55mm. There are 14 directors distributed above the array, all parallel to the array. The longitudinal spacing d0 between the director closest to the array and the array is 0.89mm (0.1-0.4 wavelengths). The director length l a It is 0.91mm (10-20% shorter than the array length), and the spacing d between directors is 1.1mm (0.1-0.4 wavelength).

[0038] A metal step is provided on one side of the bottom plate of the metal housing 4 , and the metal floor of the antenna printed circuit board 2 is connected to the metal step.

[0039] The RF cable assembly 5 is a coaxial cable, the inner core of one end of which extends out as a metal probe and is connected to the first-stage microstrip line of the antenna printed circuit board 2, and the other end is an SMP-K interface.

[0040] The Ka-band distributed conformal quasi-Yagi antenna used for roll angle measurement described in this embodiment receives the Ka-band linearly polarized radio frequency signals emitted by the guidance radar during the rolling process of the informationized ammunition.

[0041] like Figure 4 As shown, the electromagnetic wave emitted by the guidance radar is horizontally polarized, so the wavefront of the electric field emitted by the guidance radar reaching the ammunition is is the unit vector in the horizontal direction of the earth, E0 is the field strength reaching the ammunition, and the ammunition roll angle is α. The two antennas are respectively denoted as antenna A and antenna B, and their polarization directions are:

[0042]

[0043] The directional patterns of antenna A and antenna B are Then the electric fields received by antenna A and antenna B are:

[0044]

[0045] like Figure 5 As shown in FIG. 1 , the received signals of antenna A and antenna B roughly show sine or cosine changes with the roll angle, and both have two maximum values ​​within one cycle, and these two maximum values ​​show a peak and sub-peak pattern.

[0046] In the present invention, antennas A and B are conformally distributed within the informationized ammunition, mounted orthogonally in space, and have orthogonal polarization directions. During the ammunition's rolling motion, each receives a Ka-band linearly polarized RF signal. The received RF signal exhibits a pattern of peaks and sub-peaks within a cycle. The amplitude of the received RF signal is substituted into the above formula to calculate the roll angle α, enabling analytical calculation of the ammunition's roll angle.

Claims

1. A Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement, characterized in that: The two antennas have the same structure, are conformally distributed in the information munition, are installed orthogonally in space, and have orthogonal antenna polarization directions. The antenna comprises an antenna cover (1), an antenna printed circuit board (2), a supporting foam (3), a metal shell (4) and a radio frequency cable assembly (5); The outer surface of the radome (1) is a cylindrical surface conforming to the informationized ammunition, and a rectangular parallelepiped groove is opened at the bottom; the material of the radome (1) is PMI foam and the outer surface is wrapped with glass fiber cloth; The metal shell (4) is in a semi-enclosed shape, the radome (1) is bonded to the metal shell (4), and a rectangular cavity is formed at the rectangular groove of the radome (1); the metal shell (4) is fixedly mounted on the informationized ammunition by screws; The antenna printed circuit board (2) and the supporting foam (3) are embedded in the rectangular parallelepiped cavity; the supporting foam (3) is made of PMI foam and is in the shape of a rectangular parallelepiped, and is used to support the antenna printed circuit board (2); The antenna printed circuit board (2) comprises a dielectric substrate, a metal floor and a radiation structure, wherein the radiation structure and the metal floor are respectively located on the upper and lower surfaces of the dielectric substrate; The radiation structure includes a microstrip line, a balanced feed balun, a transition section, an array, and a director from bottom to top. The two-stage cascaded microstrip line extends upward from the center of the short side of the dielectric substrate. The two balanced feed baluns are bent microstrip lines, extending upward from the end of the second-stage microstrip line; The ends of the two balanced-feed baluns extend upward with a first-stage transition section and a second-stage transition section, respectively. The end of the second-stage transition section corresponding to the first balanced-feed balun extends to the left with a first array, and the end of the second-stage transition section corresponding to the second balanced-feed balun extends to the right with a second array, with a gap between the two arrays. There are 14 directors distributed above the arrays, all parallel to the arrays. The bottom plate of the metal shell (4) is provided with a metal step on one side, and the metal floor of the antenna printed circuit board (2) is connected to the metal step; The radio frequency cable assembly (5) is a coaxial cable, the inner core of one end of which extends out as a metal probe and is connected to the first-level microstrip line of the antenna printed board (2), and the other end of which is an SMP-K interface.

2. The Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement according to claim 1, characterized in that: The analytical calculation process of the roll angle of informationized ammunition using the above antenna is as follows: During the rolling process of the informationized ammunition, the two antennas respectively receive the Ka-band linearly polarized radio frequency signals transmitted by the guidance radar. The amplitude value of the received radio frequency signal is substituted into the following formula to solve the rolling angle α of the informationized ammunition: E A =E0f(α)sinα E B =E0f(α+π / 4)cosα Among them, E A and E B are the amplitude values ​​of the RF signals received by the two antennas, E0 is the field strength of the arriving ammunition when no rolling occurs, and f is the directional pattern function of the two antennas.

3. The Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement according to claim 1, wherein: The radius R of the cylindrical surface of the radome (1) is 38 mm, and the chamfer angle θ between the cylindrical surface and the side surface is 60°.

4. The Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement according to claim 1, wherein: Length W of the radome (1) b 20mm, width W c is 16.27 mm, the height h0 is 4 mm; the width W of the rectangular groove a is 5mm and the depth h is 2mm.

5. The Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement according to claim 1, wherein: The relative dielectric constant of the dielectric substrate is 6.15, the loss tangent is 0.003, and the thickness is 0.254 mm.

6. The Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement according to claim 1, wherein: Width W of antenna printed circuit board (2) a 5mm, length W b The metal floor is rectangular, with the bottom edge coinciding with the short side of the dielectric substrate, and the height h g The width w1 of the first-level microstrip line is 0.27mm, and the length l1 is 0.86mm; the width w2 of the second-level microstrip line is 0.39mm, and the length l2 is 0.86mm; the lengths l6 and l7 of the first-level transition section and the second-level transition section are 0.24mm and 0.93mm respectively; the gap s between the arrays is 0.09mm, and the total length l8 of the two arrays is 2.55mm.

7. The Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement according to claim 1, wherein: The lateral lengths of the two balanced feed baluns differ by a quarter wavelength; the longitudinal spacing between the director closest to the array and the array is 0.1 wavelength to 0.4 wavelength, and the spacing d between the directors is 0.1 wavelength to 0.4 wavelength.

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