Strong electromagnetic shielding type navigation antenna

Abstract

The application relates to a strong electromagnetic protection type navigation antenna, which comprises a dielectric substrate (1), a metal radiation structure (2), a metal grounding plate (3), a feed structure (4) and a diode (5); the metal radiation structure (2) and the metal grounding plate (3) are arranged on opposite sides of the dielectric substrate (1); the metal radiation structure (2) comprises a first metal patch (21) and a second metal patch (22); one second metal patch (22) is arranged in each of four directions perpendicular to each other around the first metal patch (21), and the second metal patch (22) is connected with the first metal patch (21) through the diode (5); the second metal patch (22) is connected with the metal grounding plate (3) through a short circuit structure; and the feed structure (4) is connected with the first metal patch (21) and the metal grounding plate (3) respectively.

Description

Technical Field

[0001] This invention relates to the field of navigation antenna technology, and in particular to a navigation antenna with strong electromagnetic protection. Background Technology

[0002] High-power electromagnetic weapons refer to a new concept of weapons that utilize directed high-power microwave beams to destroy and kill targets. They can deliver lethal blows to information systems and weapon platforms within a certain area. Currently, significant breakthroughs have been achieved in fundamental research and key technologies such as high-power pulsed power drive source technology, high-power microwave generation, transmission, and control technology, and the mechanism of high-power microwave effects, leading to the practical application of high-power electromagnetic weapons. High-power electromagnetic radiation is extremely harmful to electronic equipment. Electromagnetic waves couple energy into the front end of the system through antennas, damaging electronic equipment through breakdown and thermal effects.

[0003] Satellite navigation systems play an increasingly important role in modern society due to their accurate positioning, wide service range, and good real-time performance. From mobile phone positioning to financial stability and national defense security, everything relies on satellite navigation systems. The navigation receiver is primarily used to receive satellite navigation and timing signals, determine ground geographical location information, and synchronize local system time; it is the core component of the entire navigation system. Currently, navigation systems such as GPS, BeiDou, and Galileo are all at altitudes of tens of thousands of kilometers above the ground. By the time the navigation signal reaches the navigation antenna aperture, the signal amplitude has significantly attenuated to the -130dBm level. To effectively receive navigation signals, the navigation receiver must possess high sensitivity. However, in the face of strong electromagnetic radiation, the higher the sensitivity, the more easily the receiver is damaged, leading to the navigation system malfunctioning.

[0004] Antennas are the primary channel for strong electromagnetic energy coupling. The energy coupled into the radio frequency front-end through antennas is not only high in power but also at similar frequencies, posing a significant threat to navigation receivers. Even with traditional limiting modules, the energy coupled into the system from antennas is insufficient to guarantee the safety of navigation receivers when facing strong electromagnetic radiation.

[0005] Currently, corresponding strong electromagnetic energy protection measures have been proposed for satellite navigation receivers in the market, for example, references [1], [2], and [3]. Among these existing technologies, there are two main ways to protect satellite navigation receivers: one is to add protection modules such as limiting and filtering at the back end of the antenna; the other is to install a strong electromagnetic shield outside the antenna. The first method changes the single-level PIN limiting structure to a multi-level protection structure, which inevitably increases the volume of the limiting structure and increases the difficulty of designing the radio frequency front end of the navigation receiver. The shield in the second method requires a large number of PIN diodes in its processing and manufacturing, resulting in a very high cost.

[0006] References

[0007] [1] Chinese Patent Application Publication No. CN111030069A, Title: Method for Electromagnetic Pulse Protection of Radio Frequency Front-End, Publication Date: 2020.04.17;

[0008] [2] Chinese Patent Application Publication No. CN107658859A, Title: An Electromagnetic Pulse Protection Method for Aircraft Communication and Navigation Systems, Publication Date: 2018.02.02;

[0009] [3] Chinese Patent Announcement No. CN207542775U, Title: An Electromagnetic Pulse Protection Suppressor for Aircraft Communication and Navigation Systems, Announcement Date: 2018.06.26. Summary of the Invention

[0010] The purpose of this invention is to provide a navigation antenna with strong electromagnetic protection.

[0011] To achieve the above-mentioned objectives, the present invention provides a strong electromagnetic protection navigation antenna, comprising: a dielectric substrate, a metal radiating structure, a metal ground plane, a feeding structure, and a diode;

[0012] The metal radiating structure and the metal ground plane are disposed on opposite sides of the dielectric substrate;

[0013] The metal radiation structure includes: a first metal patch and a second metal patch;

[0014] Around the first metal patch, a second metal patch is disposed in four mutually perpendicular directions, and the second metal patch is connected to the first metal patch by the diode.

[0015] The second metal patch is connected to the metal ground plane by a short-circuit structure;

[0016] The power supply structure is connected to the first metal patch and the metal ground plane, respectively.

[0017] According to one aspect of the invention, the first metal patch is a square metal patch;

[0018] The second metal patch is disposed opposite to the side of the first metal patch.

[0019] According to one aspect of the invention, at least one pair of diagonal cut-offs are provided for the first metal patch.

[0020] According to one aspect of the present invention, the second metal patch is connected to the first metal patch by a plurality of diodes; wherein, a plurality of connecting arms for connecting the diodes are provided on the second metal patch;

[0021] The positive terminal of the diode is connected to the connecting arm, and its negative terminal is connected to the first metal patch; or, the positive terminal of the diode is connected to the first metal patch, and its negative terminal is connected to the connecting arm.

[0022] According to one aspect of the present invention, the second metal patch further includes: a second metal patch body;

[0023] The second metal patch body has a rectangular structure;

[0024] The connecting arm has a rectangular structure;

[0025] The connecting arm is arranged perpendicular to the second metal patch body, and multiple connecting arms are arranged on the same side of the second metal patch body.

[0026] According to one aspect of the present invention, three connecting arms are provided at equal intervals along the length direction of the second metal patch body; wherein two of the connecting arms are respectively provided at opposite ends of the second metal patch body, and the remaining connecting arms are provided at the middle position of the second metal patch body.

[0027] According to one aspect of the invention, the short-circuit structure is a metallized via disposed on the dielectric substrate.

[0028] According to one aspect of the present invention, the power supply structure is a coaxial power supply structure, and the power supply structure is eccentrically connected to the first metal patch for eccentrically powering the first metal patch.

[0029] According to one aspect of the invention, the distance between the center of the feeding point at the connection position of the feeding structure and the first metal patch and the center of the first metal patch is 14 mm.

[0030] According to one aspect of the present invention, the first metal patch has a side length of 44 mm and a chamfer size of 6 mm;

[0031] The length of the second metal patch is the same as the length of the second metal patch body, and is set to 7mm. The width of the second metal patch is 4.4mm.

[0032] The depth of the notch formed by the adjacent connecting arm and the second metal patch body is 1 mm, and the length is 2 mm.

[0033] The distance between the notch and the edge of the first metal patch is 0.6 mm;

[0034] The characteristic impedance of the feed port of the feed structure is 50 ohms.

[0035] The thickness of the dielectric substrate is 1.6 mm.

[0036] According to one aspect of the present invention, the PIN diode is introduced into the antenna receiving design, realizing the integrated design of the PIN diode and the antenna, and effectively controlling the overall size of the antenna.

[0037] According to one aspect of the present invention, the navigation antenna designed in this invention has a higher power handling capability by using a PIN diode array between the first metal patch and the second metal patch.

[0038] According to one aspect of the present invention, the navigation antenna designed in the present invention is made of conventional materials such as copper sheet, FR4 substrate, and PIN diode, which is easy to process and manufacture and has low cost.

[0039] According to one aspect of the present invention, a PIN diode is introduced into the design of a navigation antenna. By utilizing the conductivity modulation effect of the PIN diode, the passband switching state of the navigation antenna is changed, so as to achieve normal coupling of low field strength navigation signals and prevent strong electromagnetic energy from coupling into the back end of the navigation antenna. Without affecting the normal navigation function, the navigation receiver is effectively protected from damage by coupled strong electromagnetic energy.

[0040] According to one aspect of the present invention, while introducing a PIN diode, the structure and parameters of the navigation antenna are comprehensively optimized to ensure that the designed navigation antenna meets the requirements for frequency, gain, axial ratio, and other indicators. When a normal navigation signal (i.e., a low-field-strength navigation signal) irradiates the surface of the protective navigation antenna, the PIN diode is in a cutoff state, the channel is open, and the navigation signal is smoothly coupled from the antenna into the back-end circuit. When strong electromagnetic energy irradiates the surface of the protective navigation antenna, the channel of the protective navigation antenna is closed, and the strong electromagnetic energy cannot be coupled from the antenna into the back-end radio frequency circuit. Attached Figure Description

[0041] Figure 1 This is a structural diagram of a strong electromagnetic protection navigation antenna according to an embodiment of the present invention;

[0042] Figure 2 This is a structural diagram of a metal radiation structure and a diode according to an embodiment of the present invention;

[0043] Figure 3 This is a structural diagram of a metal grounding plate according to an embodiment of the present invention;

[0044] Figure 4 This is an S11 curve diagram of a strong electromagnetic protection navigation antenna according to an embodiment of the present invention when it is not conducting under low field strength signal conditions;

[0045] Figure 5This is a diagram showing the far-field axial ratio of a strong electromagnetic protection navigation antenna according to an embodiment of the present invention.

[0046] Figure 6 This is a curve of S11 at the antenna feed point after the diode is turned on in a strong electromagnetic protection navigation antenna according to an embodiment of the present invention.

[0047] Figure 7 This is a functional simulation of a strong electromagnetic protection navigation antenna according to one embodiment of the present invention. Detailed Implementation

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0049] In describing embodiments of the present invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" express orientations or positional relationships based on the orientations or positional relationships shown in the relevant drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on the present invention.

[0050] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, a strong electromagnetic shielding navigation antenna is provided, comprising: a dielectric substrate 1, a metal radiating structure 2, a metal ground plane 3, a feed structure 4, and a diode 5. In this embodiment, the dielectric substrate 1 serves as the supporting structure for the entire strong electromagnetic shielding navigation antenna, wherein the metal radiating structure 2 and the metal ground plane 3 are disposed on opposite sides of the dielectric substrate 1. In this embodiment, the dielectric substrate 1 may be an FR4 dielectric substrate.

[0051] In this embodiment, the metal radiating structure 2 includes: a first metal patch 21 and a second metal patch 22; wherein, the second metal patch 22 is disposed around the first metal patch 21, specifically, multiple second metal patches 22 are disposed at intervals along the circumference of the first metal patch 21, for example, see Figure 2A second metal patch 22 is disposed opposite to the side of the first metal patch 21 in four mutually perpendicular directions (left-right and up-down directions), and the second metal patches 22 are connected to the first metal patch 21 by diodes 5. In this embodiment, the second metal patches 22 are arranged circumferentially around the first metal patch 21 at equal intervals. In this embodiment, there is a gap between the first metal patch 21 and the second metal patch 22, thereby enabling the mounting of the diodes 5.

[0052] In this embodiment, the outer dimensions of the second metal patch 22 are smaller than those of the first metal patch 21;

[0053] In this embodiment, the second metal patch 22 and the metal ground plane 3 are connected by a short-circuit structure;

[0054] In this embodiment, the power supply structure 4 is connected to the first metal patch 21 and the metal ground plane 3, respectively. The power supply structure 4 is used to send the received low field strength signal to the back end. In this embodiment, the power supply structure 4 includes an inner conductor and an outer conductor. The inner conductor is connected to the first metal patch 21, and the outer conductor is connected to the metal ground plane 3.

[0055] With the above settings, only the diode 5 needs to be set in the metal radiation junction 2 in this invention, which effectively reduces the number of diodes 5 used.

[0056] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the first metal patch 21 is a square metal patch. In this embodiment, the second metal patches 22 are respectively arranged opposite to the sides of the first metal patch 21, that is, four second metal patches 22 are provided, each second metal patch 22 being arranged opposite to each side of the first metal patch 21.

[0057] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, at least one pair of diagonals of the first metal patch 21 are cut off. In this embodiment, by chamfering the first metal patch 21, micro-element control is achieved, so that the characteristic modes of the two polarizations (horizontal and vertical) satisfy a 90° phase difference, thereby achieving the requirement of circular polarization in axial ratio. In this embodiment, only one pair of diagonals of the first metal patch 21 is cut off. Of course, both pairs of diagonals can also be cut off, which can be adjusted according to specific needs. In another embodiment, micro-element control can also be achieved by adding ridges, gaps, etc.

[0058] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the second metal patch 22 is connected to the first metal patch 21 by a plurality of diodes 5; wherein, a plurality of connecting arms 221 for connecting the diodes 5 are provided on the second metal patch 22. In this embodiment, the positive terminal of the diode 5 is connected to the connecting arm 221, and its negative terminal is connected to the first metal patch 21, or the positive terminal of the diode 5 is connected to the first metal patch 21, and its negative terminal is connected to the connecting arm 221.

[0059] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the second metal patch 22 further includes a second metal patch body 222. In this embodiment, the second metal patch body 222 has a rectangular structure; similarly, the connecting arm 221 also has a rectangular structure. In this embodiment, the connecting arm 221 is arranged perpendicularly to the second metal patch body 222, and multiple connecting arms 221 are arranged on the same side of the second metal patch body 222.

[0060] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, three connecting arms 221 are equally spaced along the length direction of the second metal patch body 222; wherein, two connecting arms 221 are respectively located at opposite ends of the second metal patch body 222, and the remaining connecting arms 221 are located at the middle position of the second metal patch body 222. In this embodiment, the three connecting arms 221 of the second metal patch 22 can be integrally formed with the second metal patch body 222, and constitute an "E"-shaped structure. In this embodiment, the second metal patch 22 has an axially symmetrical structure. Of course, in other embodiments, the connecting arms 221 can also be equally spaced along the length direction of the second metal patch body 222 in other quantities (e.g., two), and the corresponding diode model and the dimensions of the first metal patch 21, the second metal patch 22, etc., also need to be changed accordingly.

[0061] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the short-circuit structure is a metallized via disposed on the dielectric substrate 1 to realize the connection between the second metal patch body 222 and the metal ground plane 3.

[0062] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the power supply structure 4 is eccentrically connected to the first metal patch 21 for eccentrically powering the first metal patch 21.

[0063] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the distance between the connection position of the power supply structure 4 and the first metal patch 21 and the center of the first metal patch 21 is 14mm.

[0064] The above settings not only effectively achieve impedance matching, but also ensure that the navigation antenna meets the axial ratio requirements.

[0065] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the first metal patch 21 has a side length of 44 mm and a chamfer size of 6 mm. In this embodiment, the length of the second metal patch 22 is the same as the length of the second metal patch body 222 and is set to 7 mm, and the width of the second metal patch 22 is 4.4 mm; in this embodiment, the depth of the notch formed by the adjacent connecting arm 221 and the second metal patch body 222 is 1 mm and the length is 2 mm; in this embodiment, the distance between the notch and the edge of the first metal patch 21 is 0.6 mm.

[0066] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the power supply structure 4 is a coaxial power supply structure, and the characteristic impedance of its power supply port is 50 ohms.

[0067] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the thickness of the dielectric substrate 1 is 1.6 mm.

[0068] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, diode 5 is a PIN diode. In this embodiment, diode 5 is a PIN diode of model BAP5102. In the off state, its equivalent circuit is a 0.17pF capacitor connected in series with a 2-ohm resistor. In the on state, the equivalent resistance is different under different conduction currents.

[0069] Combination Figure 1 , Figure 2 and Figure 3As shown, according to one embodiment of the present invention, the navigation signal operating frequency band applicable to the strong electromagnetic protection navigation antenna of the present invention is 1.561 to 1.575 GHz. In this embodiment, within the navigation signal operating frequency band, the strong electromagnetic protection navigation antenna of the present invention can achieve normal passage of low field strength navigation signals to realize coupling between low field strength navigation signals and radio frequency circuits; when strong electromagnetic energy irradiates the antenna aperture of the present invention (i.e., the side where the metal radiating structure 2 and diode 5 are disposed), the PIN diode changes from cutoff to conduction, and the strong electromagnetic energy is blocked to prevent high field strength navigation signals from coupling to the radio frequency circuits. Specifically, when a low-field-strength navigation signal reaches the antenna aperture, the PIN diode is in the off state, the input impedance of the navigation antenna matches the impedance of the RF front-end circuit, the navigation frequency band passband of the antenna is in the open state, the navigation signal smoothly enters through the antenna and is coupled to the back-end RF circuit, and the navigation receiver can normally realize the navigation function; when strong electromagnetic radiation reaches the antenna aperture, it turns on the PIN diode, the entire input impedance of the navigation antenna is mismatched with the impedance of the RF front-end circuit, the navigation antenna passband is closed, and strong electromagnetic energy cannot be coupled from the navigation antenna into the back-end RF circuit, thus effectively avoiding damage to sensitive devices by strong electromagnetic energy.

[0070] According to the present invention, the strong electromagnetic protection type navigation antenna of the present invention can be periodically arranged to form an antenna array as needed to meet the requirements of navigation signal reception.

[0071] To further illustrate the technical effectiveness of this solution, a simulation model of a strong electromagnetic protection navigation antenna was established based on the aforementioned implementation method for simulation verification.

[0072] In this embodiment, four second metal patches 22 are arranged around the first metal patch 21, resulting in a corresponding number of 12 diodes 5. As mentioned earlier, in the off state, the equivalent circuit consists of a 0.17pF capacitor connected in series with a 2-ohm resistor. However, in the on state, the equivalent resistance varies depending on the on-current. Therefore, in this embodiment, the equivalent circuit of a 2-ohm resistor in the on state will be used as an example for explanation.

[0073] like Figure 4 As shown, the S11 curve of the feed port of the feed structure 4 shows that the resonant frequency of the designed strong electromagnetic protection navigation antenna is 1.568GHz, and the S11 is less than -10dB in the frequency range of 1.548GHz to 1.622GHz, which meets the requirements of satellite navigation antenna.

[0074] like Figure 5 As shown, the axial ratio of the navigation antenna designed in this invention is within 3dB in the range of -120° to 120°, which meets the requirements of navigation antenna specifications.

[0075] like Figure 6 As shown in the simulation results, when the diode is turned on, the input impedance of the designed satellite navigation antenna is mismatched with the back-end RF front-end circuit. At this time, strong electromagnetic energy cannot enter the RF front-end circuit through the satellite navigation antenna.

[0076] like Figure 7 As shown, this invention uses diodes to replace traditional lumped elements, and the antenna port receives waveforms under different spatial field strength irradiation conditions. Simultaneously, this invention exhibits excellent protection performance under strong electromagnetic energy irradiation.

[0077] The above description is merely an example of a specific solution of the present invention. For any devices and structures not described in detail herein, it should be understood that they are implemented using common devices and methods already available in the art.

[0078] The above is merely one embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high electromagnetic protection type navigation antenna, characterized by, The application relates to a metalized antenna, which comprises a medium substrate (1), a metal radiation structure (2), a metal ground plate (3), a feed structure (4) and a diode (5). The metal radiation structure (2) and the metal ground plate (3) are arranged on opposite sides of the medium substrate (1). The metal radiation structure (2) comprises square first metal patches (21) and second metal patches (22). One second metal patch (22) is arranged in each of four directions perpendicular to each other around the first metal patch (21), and the second metal patch (22) is connected with the first metal patch (21) by the diode (5). The second metal patch (22) is connected with the metal ground plate (3) by a short circuit structure. The feed structure (4) is connected with the first metal patch (21) and the metal ground plate (3) respectively. The second metal patch (22) is arranged opposite to the side of the first metal patch (21) in an equiangular interval manner. The second metal patch (22) is in an E-shaped structure, and the connecting arm (221) of the second metal patch (22) is connected with the first metal patch (21) by the diode (5). At least one pair of opposite diagonal cutouts is arranged on the first metal patch (21). The positive electrode of the diode (5) is connected with the connecting arm (221), and the negative electrode is connected with the first metal patch (21), or the positive electrode of the diode (5) is connected with the first metal patch (21), and the negative electrode is connected with the connecting arm (221).

2. The high electromagnetic protection navigational antenna of claim 1, wherein, The second metal patch (22) further comprises a second metal patch body (222).

3. The high electromagnetic protection navigational antenna of claim 2, wherein, The second metal patch body (222) is in a rectangular structure. The connecting arm (221) is in a rectangular structure. The connecting arm (221) is arranged perpendicular to the second metal patch body (222), and a plurality of connecting arms (221) are arranged on the same side of the second metal patch body (222). Along the length direction of the second metal patch body (222), three connecting arms (221) are arranged at equal intervals; two connecting arms (221) are arranged at two ends of the second metal patch body (222) respectively, and the remaining connecting arms (221) are arranged at the middle position of the second metal patch body (222).

4. The high electromagnetic protection navigational antenna of claim 3, wherein, The short circuit structure is a metallized via hole arranged on the medium substrate (1).

5. The high electromagnetic protection navigational antenna of claim 4, wherein, The feed structure (4) is a coaxial feed structure, and the feed structure (4) is eccentrically connected with the first metal patch (21) to eccentrically feed the first metal patch (21).

6. The high electromagnetic protection navigational antenna of claim 5, wherein, The distance between the center of the feed point of the connection position of the feed structure (4) and the first metal patch (21) and the center of the first metal patch (21) is 14 mm.

7. The high electromagnetic protection navigational antenna according to claim 6, wherein, The side length of the first metal patch (21) is 44 mm, and the cutout size is 6 mm.

8. The high electromagnetic protection navigational antenna of claim 7, wherein, ​ The length of the second metal patch (22) is consistent with the length of the second metal patch body (222), and is set to 7 mm, and the width of the second metal patch (22) is 4.4 mm; The depth of the notch formed by the adjacent connecting arm (221) and the second metal patch body (222) is 1 mm, and the length is 2 mm; The spacing between the notch and the edge of the first metal patch (21) is 0.6 mm; The characteristic impedance of the feed port of the feed structure (4) is 50 ohms; The thickness of the dielectric substrate (1) is 1.6 mm.

Images