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

Abstract

The invention discloses a Ka-band distributed conformal quasi-yagi antenna applied to roll angle measurement, and belongs to the technical field of microwave antennas. An antenna A and an antenna B are distributed in informatization ammunition in a conformal mode and are orthogonally installed in the spatial position, and the polarization directions of the antennas are orthogonal. In the ammunition rolling process, Ka frequency band linear polarization radio frequency signals are received respectively, the received radio frequency signals present a peak value and secondary peak value rule in one period, and analytical calculation of the ammunition rolling angle is achieved.

Description

Technical Field

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

[0002] Informationized ammunition is an ammunition that can complete corrected or guided trajectory control through information acquisition and transmission, and efficiently achieve hits, damage or information confrontation. After being launched, informationized ammunition usually rotates forward and flies forward. It receives correction instructions sent by the guidance radar, combines its own roll angle information to make trajectory corrections, and continuously controls the servo to fly toward the target. The key to flight control lies in real-time reception of guidance radar instructions and real-time measurement of the projectile's own roll angle. Roll angle measurement is the basis of informationized ammunition flight control, and the measurement accuracy will directly affect the strike accuracy of guided artillery shells.

[0003] The existing roll angle measurement relies on gyroscopes, GPS and geomagnetism. The gyroscope will produce large accumulated errors during the rolling process of the ammunition and cannot work independently for a long time. The GPS data rate is low, it is easily interfered or blocked, and the initialization time is long. The geomagnetism has a blind spot and is easily interfered. In summary, the existing roll angle measurement methods cannot solve the roll angle measurement problem of informationized ammunition. Summary of the invention

[0004] The purpose of the present invention is to overcome the 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 in this way:

[0006] A Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement, wherein the two antennas have the same structure, are conformally distributed in the informationized ammunition, are orthogonally installed in space, and have orthogonal antenna polarization directions;

[0007] The antenna comprises 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, and a rectangular groove is opened at the bottom; the material of the radome 1 is PMI foam and glass fiber cloth wrapped on the outer surface;

[0009] 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;

[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 a rectangular shape, 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 radiation structure, and 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, which are bent and extended 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 in turn; 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, and a gap is left between the two arrays. There are 14 directors distributed above the array, all parallel to the array;

[0012] The bottom plate of the metal housing 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.

[0013] 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-stage microstrip line of the antenna printed circuit board 2, and the other end is a 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 emitted by the guidance radar, and substitute the amplitude value of the received radio frequency signal 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 diagram 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 16.27mm, the height h0 is 4mm; the width W of the rectangular groove a is 5mm and the depth h is 2mm.

[0021] Furthermore, the relative dielectric constant of the dielectric substrate is 6.15, the loss tangent is 0.003, and the thickness is 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-level microstrip line width w1 is 0.27mm, length l1 is 0.86mm, the second-level microstrip line width w2 is 0.39mm, 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.

[0023] Furthermore, the lateral lengths of the two balanced feeding 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] The antenna A and the antenna B of the present invention are conformally distributed in the informationized ammunition, and are orthogonally installed in space, and the polarization directions of the antennas are orthogonal. During the rolling process of the ammunition, the Ka-band linearly polarized radio frequency signals are received respectively, and the received radio frequency signals present a peak value and a sub-peak value in one cycle, so as to realize the analytical calculation of the rolling angle of the ammunition. 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 It is a schematic structural diagram of the antenna cover in the antenna of the present invention;

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

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

[0030] Figure 5 It is a curve diagram of the received signals of antenna A and antenna B in the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[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 orthogonally installed 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 schematic diagram of the radome 1 is shown in FIG. 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 38 mm, 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 16.27mm, the height h0 is 4mm; 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 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 installed on 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 a rectangular shape, and is used to support the antenna printed circuit board 2 .

[0036] The schematic diagram of the structure of the antenna printed circuit board 2 is as follows Figure 3 As shown, the antenna printed circuit board 2 includes 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 width W of the antenna printed circuit board 2 is 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 0.254 mm. 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] 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 lines extend upward from the center of the short side of the dielectric substrate; in this embodiment, the width w1 of the first-stage microstrip line is 0.27mm, the length l1 is 0.86mm, the width w2 of the second-stage microstrip line is 0.39mm, and the length l2 is 0.86mm. The two balanced feed baluns are bent microstrip lines, which are bent and extended upward from the end of the second-stage microstrip line; in this embodiment, the lateral lengths l3 and l4 of the balanced feed balun are 0.54mm and 1.53mm respectively (the difference is about a quarter wavelength), and the longitudinal length l5 of the balanced feed balun is 0.48mm. The ends of the two balanced feed baluns extend upward in sequence with the first-stage transition section and the second-stage transition section, and the lengths l6 and l7 of the first-stage transition section and the second-stage transition section are 0.24mm and 0.93mm respectively. The end of the second-stage transition section corresponding to the first balanced feed balun extends to the left with the first array, and the end of the second-stage transition section corresponding to the second balanced feed balun extends to the right with 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 wavelength), and 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] The bottom plate of the metal housing 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.

[0039] 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-stage microstrip line of the antenna printed circuit board 2, and the other end is a 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 rolling 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, 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 ​​in one cycle, and these two maximum values ​​show the pattern of peak and sub-peak value.

[0046] In the present invention, antenna A and antenna B are conformally distributed in the informationized ammunition, installed orthogonally in space, and the polarization directions of the antennas are orthogonal. During the rolling process of the ammunition, Ka-band linearly polarized radio frequency signals are received respectively, and the received radio frequency signals present a peak value and a sub-peak value in one cycle. The amplitude value of the received radio frequency signal is substituted into the above formula to solve the roll angle α, thereby realizing the analytical calculation of the roll angle of the ammunition.

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 informationized 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 glass fiber cloth wrapped on the outer surface; 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 means of screws; The antenna printed 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 a rectangular shape, and is used to support the antenna printed board (2); The antenna printed 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, which are bent and extended upward from the end of the second-stage microstrip line; The ends of the two balanced feed baluns extend upwards with a first transition section and a second transition section in sequence; the end of the second transition section corresponding to the first balanced feed balun extends to the left with a first array, and the end of the second transition section corresponding to the second balanced feed balun extends to the right with a second array, with a gap between the two arrays; 14 directors are distributed above the arrays, all parallel to the arrays; A metal step is provided on one side of the bottom plate of the metal shell (4), 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 the 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 emitted by the guidance radar, and substitute the amplitude value of the received radio frequency signal 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 diagram function of the two antennas.

3. The Ka-band distributed conformal quasi-Yagi antenna for roll angle measurement according to claim 1, characterized in that: 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, characterized in that: Length W of the radome (1) b 20mm, width W c is 16.27mm, the height h0 is 4mm; 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, characterized in that: 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, characterized in that: 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 is 2.7mm; 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, characterized in that: The lateral lengths of the two balanced feeding 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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