UHF-band miniaturized microstrip conformal missile-borne antenna

Abstract

The utility model discloses a UHF (Ultra High Frequency) band miniaturized microstrip conformal missile-borne antenna, which comprises a U-shaped slot microstrip conformal antenna I and a U-shaped slot microstrip conformal antenna II which are arranged in a mirror symmetry manner, and further comprises an equal power divider, a switching circuit board and a coaxial cable, a first output port of the equal power divider is welded with a probe, and a signal is fed into the first U-shaped slot microstrip conformal antenna. A second output port of the equal power divider is welded with a coaxial cable to be connected with the switching circuit board, and a probe is welded on the switching circuit board to feed signals into the second U-shaped slot microstrip conformal antenna. According to the missile-borne antenna provided by the scheme, the aluminum oxide ceramic dielectric is used as the dielectric substrate of the antenna, 5.88% of working bandwidth is realized in a width space with 0.11 wavelengths, meanwhile, the working temperature of 200 DEG C is met, and the impedance matching of the antenna and the feed port is relatively good.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of missile-borne antenna, especially to a UHF frequency band miniaturized microstrip conformal missile-borne antenna. BACKGROUND

[0002] With the development of precision guided weapons and intelligent ammunition, missile-borne antennas need to meet the three core requirements of miniaturization, wide frequency band and high temperature stability:

[0003] a) Miniaturization: The internal space of modern missiles is compact, and traditional antennas (such as parabolic antennas and horn antennas) are difficult to integrate due to their large size and complex structure. Although microstrip patch antennas are small in size, it is difficult to achieve wide frequency band characteristics at very small sizes (such as below 0.1 lambda).

[0004] b) Wide frequency band: Existing folding antennas expand the bandwidth by increasing the electrical length, but their radiation efficiency decreases significantly with size compression, and it is difficult to meet the demand of more than 5% relative bandwidth.

[0005] c) High temperature adaptability: The surface temperature of the antenna can reach more than 200℃ due to aerodynamic heating when the missile flies at high speed, and the traditional FR4 substrate is prone to deformation and failure at high temperatures due to high dielectric loss (tan delta > 0.02) and large thermal expansion coefficient.

[0006] Currently, existing solutions use high dielectric constant substrates (such as LTCC ceramics) or metalized polymer materials to improve size and temperature resistance, but still have the following defects:

[0007] a) Bandwidth-size contradiction: High dielectric substrates compress the wavelength, but the dielectric loss limits the bandwidth (such as LTCC antenna bandwidth usually <4%);

[0008] b) High temperature performance degradation: The existing high temperature resistant antenna has a radiation efficiency decrease of more than 10% at 200℃ (see document "High-Temperature Antenna Design for Missile Applications", IEEE Transactions, 2021), and lacks a dynamic thermal compensation mechanism;

[0009] c) Poor process compatibility: Multi-layer media stacking and metamaterial structure require complex processing technology, and it is difficult to ensure the consistency of mass production. INVENTION CONTENTS

[0010] To solve the above technical problems, the utility model provides a UHF frequency band miniaturized microstrip conformal missile-borne antenna, which can be applied to missile guidance, unmanned aerial vehicle reconnaissance and other military scenarios.

[0011] The utility model is implemented by the following technical solutions:

[0012] The application discloses a miniaturized UHF band microstrip conformal missile-borne antenna, which comprises a mirror-symmetrically arranged U-shaped slot microstrip conformal antenna I and a U-shaped slot microstrip conformal antenna II, and further comprises an equal-division power divider, a switching circuit board and a coaxial cable; an output port I of the equal-division power divider is welded with a probe to feed a signal into the U-shaped slot microstrip conformal antenna I; an output port II of the equal-division power divider is welded with the coaxial cable to connect the switching circuit board, and a probe is welded on the switching circuit board to feed a signal into the U-shaped slot microstrip conformal antenna II.

[0013] Specifically, the outer surfaces of the symmetrically arranged U-shaped slot microstrip conformal antenna I and the U-shaped slot microstrip conformal antenna II are arc-shaped and conform to the missile body.

[0014] Specifically, the U-shaped slot microstrip conformal antenna I and the U-shaped slot microstrip conformal antenna II are structurally identical and each comprises a U-shaped slot radiation patch, a copper probe, a dielectric substrate, a side ground plate, a bottom ground plate and a metal cavity.

[0015] Specifically, the metal cavity is assembled with the antenna through a screw and is assembled to the missile body through the screw.

[0016] Specifically, the U-shaped slot radiation patch comprises a metal patch with a second-order U-shaped slot obtained through an electroplating process and two symmetrically arranged adjustable parasitic microstrip patches on the two sides.

[0017] Specifically, the dielectric substrate is an alumina ceramic dielectric.

[0018] Specifically, the input end of the equal-division power divider and the input end of the coaxial cable are each provided with a connector and are assembled through the connector.

[0019] The beneficial effects of the present invention are as follows: The proposed UHF-band miniaturized microstrip conformal missile-borne antenna uses alumina ceramic as the antenna's dielectric substrate, achieving a 5.88% operating bandwidth within a 0.11-wavelength width while maintaining an operating temperature of 200°C. A second-order U-shaped slot is formed on the metal patch through electroplating. The presence of the second-order U-shaped slot changes the current distribution on the patch. The size and position of the slot determine the antenna's resonant frequency and radiation model, optimizing the formation of a multi-tuned circuit and thus widening the frequency band. The feed probe introduces a large inductive reactance, which is offset by the capacitive reactance presented by the U-shaped slot, resulting in better impedance matching between the antenna and the feed port. Three pairs of symmetrical parasitic microstrip patches are added to either side of the U-shaped slot radiating patch. Adjusting the size and position of the parasitic microstrip patches couples different frequencies, thereby widening the antenna's operating frequency. The power divider cavity and the U-shaped slot microstrip conformal antenna cavity are integrated, reducing the cross-sectional height of the antenna and power divider. By adding a welding probe on a transfer circuit board to feed the signal into the U-shaped slot microstrip conformal antenna 2, the feeding method of the U-shaped slot microstrip conformal antenna 1 and the U-shaped slot microstrip conformal antenna 2 are ensured to be consistent, and the standing waves of the U-shaped slot microstrip conformal antenna 1 and the U-shaped slot microstrip conformal antenna 2 are ensured to be close, thereby ensuring that the radiation efficiency is close. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0021] Fig. 1 This is the overall structure diagram of the UHF band miniaturized microstrip conformal missile-borne antenna in the embodiment of the utility model;

[0022] Fig. 2 Schematic diagram of two U-shaped slot microstrip conformal antennas in an embodiment of the present utility model;

[0023] Fig. 3 This is a schematic diagram of an equally divided power divider in an embodiment of the present utility model;

[0024] Fig. 4 This is a schematic diagram of a transfer circuit in an embodiment of the present utility model;

[0025] In the figure, 1-elastic body, 2-dielectric substrate, 3-U-shaped slot radiation patch, 4-adjustable parasitic microstrip patch, 5-copper probe, 6-copper screw sleeve, 7-metal cavity, 8-coaxial cable, 9-coaxial cable input end, 10-adapter circuit board, 11-connector, 12-equal power divider. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0027] It should be noted that similar reference numerals and letters refer to like items in the following drawings, and thus, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0028] The embodiments of the present application will be described below with reference to the accompanying drawings. Figs. 1-4 The embodiments of the present application will be described below with reference to the accompanying drawings.

[0029] The present application provides a UHF frequency band miniaturized microstrip conformal missile-borne antenna, comprising mirror-symmetrically arranged U-shaped slot microstrip conformal antenna one and U-shaped slot microstrip conformal antenna two, and further comprising an equal division power divider 12, an adapter circuit board 10 and a coaxial cable 8; the output port one of the equal division power divider 12 is welded with a probe to feed signals into the U-shaped slot microstrip conformal antenna one; the output port two of the equal division power divider 12 is welded with the coaxial cable 8 to connect the adapter circuit board 10, and a probe is welded on the adapter circuit board 10 to feed signals into the U-shaped slot microstrip conformal antenna two.

[0030] In a preferred embodiment, as shown in Figs. 1-4 The outer surfaces of the symmetrically arranged U-shaped slot microstrip conformal antenna one and U-shaped slot microstrip conformal antenna two are arc-shaped and conform to the missile body 1; the U-shaped slot microstrip conformal antenna one and the U-shaped slot microstrip conformal antenna two are identical in structure and each comprises a U-shaped slot radiation patch 3, a copper probe 5, a dielectric substrate 2, a side ground plate, a bottom ground plate and a metal cavity 7. The metal cavity 7 is assembled with the antenna by screws and is assembled to the missile body 1 by screws. The U-shaped slot radiation patch 3 comprises a metal patch with a second-order U-shaped slot obtained by electroplating process and adjustable parasitic microstrip patches 4 symmetrically arranged on both sides; the dielectric substrate 2 is an alumina ceramic dielectric. The input end of the equal division power divider 12 and the input end of the coaxial cable are each provided with a connector 11 and are assembled by the connector 11.

[0031] In a specific embodiment, the UHF band miniaturized microstrip conformal missile-borne antenna includes a 1x2 U-shaped slot microstrip conformal antenna, namely U-shaped slot microstrip conformal antenna one and U-shaped slot microstrip conformal antenna two, an equal division power divider 12, a relay circuit board 10, and a coaxial cable 8. The 1x2 U-shaped slot microstrip conformal antenna is placed in mirror symmetry. The input signal enters the 1x2 U-shaped slot microstrip conformal antenna through the equal division power divider 12. The output port one of the equal division power divider 12 feeds the signal into the U-shaped slot microstrip conformal antenna one through a soldering probe. The output port two of the equal division power divider 12 is relayed to a circuit board through the soldering coaxial cable 8, and the signal is fed into the U-shaped slot microstrip conformal antenna two through a soldering probe on the relay circuit board 10. By adjusting the winding arrangement and length of the power divider and the length of the coaxial cable 8, the phase and amplitude of the input signal to the 1x2 U-shaped slot microstrip conformal antenna are similar, achieving the purpose of uniform radiation on both sides of the missile body 1. The space of the missile-borne antenna is limited, and the antenna can be miniaturized. In a width space of 0.11 wavelengths, a 5.88% operating bandwidth is achieved, and the working temperature can reach 200℃.

[0032] In the present embodiment, alumina ceramic medium is used as the medium substrate 2 of the antenna. The dielectric constant of the alumina ceramic material is selected to be 9.8, which can effectively reduce the size of the antenna. The dielectric constant of alumina ceramic is usually between 9-10, but different purity and sintering process will affect this value. At room temperature 25℃: tanδ≈0.0001~0.0005, high frequency performance is excellent, suitable for 5G / radar and other millimeter wave applications; at high temperature 200℃: tanδ rises slightly, but can still be controlled within the range of 0.0002~0.0008, and the sintering process needs to be optimized to reduce grain boundary defects. Alumina ceramic material usually has high thermal stability and can maintain stable electrical properties within a wide temperature range, meeting the demand for high-temperature working temperature.

[0033] 1x2 U-shaped slot microstrip conformal antenna, each comprising a U-shaped slot radiation patch 3, a copper probe 5, a dielectric substrate 2 and a side ground plate, a bottom ground plate, a metal cavity 7. The outer surface of the antenna and the body 1 are conformal to the arc. The antenna is assembled on the cavity by screws, and the cavity is assembled to the body 1 by screws. The second-order U-shaped slot is obtained by electroplating process on the metal patch. The existence of the U-shaped slot changes the current distribution on the patch. The size and position of the slot determine the resonant frequency and radiation model of the antenna. The optimization forms a multi-tuning circuit, thereby widening the frequency band. The feed probe introduces a large inductive reactance, and the capacitive reactance of the U-shaped slot offsets the inductive reactance, so the impedance matching of the antenna and the feed probe is good. Three pairs of symmetrical parasitic microstrip patches are added to both sides of the U-shaped slot radiation patch 3. Adjusting the size and position of the parasitic microstrip patch couples out different frequencies, so that the operating frequency of the antenna is widened. The antenna realizes a bandwidth of 825MHz-875MHz in a width space of 0.11 wavelengths, realizing the miniaturization requirement of the antenna.

[0034] In order to realize the radiation of the body 1 on both sides, the 1x2 U-shaped slot microstrip conformal antenna is placed on both sides of the body 1, and an equal division power divider 12 is used to feed each antenna. The cavity of the power divider and the cavity of the U-shaped slot microstrip conformal antenna one are processed as one, reducing the profile height of the antenna. The PCB of the power divider is crimped to the cavity through the power divider cover plate. The input port of the power divider is soldered with the SMPM_JD13_L connector 11, and the input coaxial cable 8 with the SMP_KWFBS1_S connector 11 is assembled together. The output port one of the equal division power divider 12 feeds the U-shaped slot microstrip conformal antenna one, and the output port two feeds the U-shaped slot microstrip conformal antenna two. The output port one part on the PCB of the equal division power divider 12 is designed by winding. The probe is used to solder the port one and the patch of the U-shaped slot microstrip conformal antenna one, and the signal is transmitted to the U-shaped slot microstrip conformal antenna one. The copper bushing 6 is used to solder the coaxial cable 8 and assemble it to the cavity. The output port two of the equal division power divider 12 is soldered with the coaxial cable 8. The coaxial cable 8 is placed against the wall of the body 1. The other end of the coaxial cable 8 is soldered with the connector 11 SMPKWFB217, and the connector 11 SMPM_JD13_L of the adapter circuit is assembled together. The probe is used to solder the output end of the adapter circuit and the patch of the U-shaped slot microstrip conformal antenna two. Therefore, the signal is transmitted from the output port two of the equal division power divider 12 to the U-shaped slot microstrip conformal antenna two. Adjust the winding length of the output port one to make the phase of the U-shaped slot microstrip conformal antenna one and the U-shaped slot microstrip conformal antenna two close.

[0035] For the foregoing embodiments, for the sake of simplicity of description, they are all described as a series of action combinations, but those skilled in the art should know that the present application is not limited by the order of the described actions, because according to the present application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the present application.

[0036] In the above embodiments, the basic principles and main features of the present application and the advantages of the present application are described. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, modifications and changes made by those skilled in the art do not depart from the spirit and scope of the present application, and should be within the protection scope of the claims of the present application.

Claims

1. A UHF band miniaturized microstrip conformal missile-borne antenna, characterized in that: The invention comprises a U-shaped slot microstrip conformal antenna 1 and a U-shaped slot microstrip conformal antenna 2 which are arranged in a mirror-symmetrical manner, and also comprises an equal-division power divider (12), a switching circuit board (10) and a coaxial cable (8); a probe is welded to the output port 1 of the equal-division power divider (12) to feed a signal into the U-shaped slot microstrip conformal antenna 1; a coaxial cable (8) is welded to the output port 2 of the equal-division power divider (12) to connect to the switching circuit board (10), and a probe is welded on the switching circuit board (10) to feed a signal into the U-shaped slot microstrip conformal antenna 2.

2. The UHF band miniaturized microstrip conformal missile-borne antenna according to claim 1, characterized in that: The outer surfaces of the symmetrically arranged U-shaped slot microstrip conformal antenna 1 and the U-shaped slot microstrip conformal antenna 2 are arc-shaped in conformity with the projectile (1).

3. The UHF band miniaturized microstrip conformal missile-borne antenna according to claim 1, characterized in that: The U-shaped slot microstrip conformal antenna 1 and the U-shaped slot microstrip conformal antenna 2 have the same structure, both comprising a U-shaped slot radiation patch (3), a copper probe (5), a dielectric substrate (2), a side ground plate, a bottom ground plate and a metal cavity (7).

4. The UHF band miniaturized microstrip conformal missile-borne antenna according to claim 3, characterized in that: The metal cavity (7) is assembled with the antenna via screws, and is also assembled to the projectile (1) via screws.

5. The UHF band miniaturized microstrip conformal missile-borne antenna according to claim 3, characterized in that: The U-shaped slot radiation patch (3) comprises a metal patch having a second-order U-shaped slot obtained by electroplating and adjustable parasitic microstrip patches (4) symmetrically arranged on both sides.

6. The UHF band miniaturized microstrip conformal missile-borne antenna according to claim 3, characterized in that: The dielectric substrate (2) is an alumina ceramic dielectric.

7. The UHF band miniaturized microstrip conformal missile-borne antenna according to claim 1, characterized in that: The input end of the equal power divider (12) and the coaxial cable input end (9) are both provided with connectors (11) and are assembled through the connectors (11).

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