Dual-frequency high-gain microstrip antenna for receiving scattering signals of low-altitude aircraft

Abstract

The utility model provides a dual-frequency high-gain microstrip antenna for receiving scattered signals of a low-altitude aircraft, which relates to the technical field of antennas and at least comprises a microstrip patch, an upper-layer dielectric plate, an air dielectric layer, a metal grounding plate, a lower-layer dielectric plate, a microstrip feeder line and a metal column, the microstrip patch is located at the top of the upper-layer dielectric plate; the air dielectric layer is arranged at the bottom of the upper dielectric plate and the top of the metal grounding plate; the lower dielectric plate is arranged at the bottom of the metal grounding plate; the microstrip feeder is arranged at the bottom of the lower dielectric plate; and the metal column penetrates through the upper dielectric plate, the air dielectric layer, the metal grounding plate and the lower dielectric plate and is connected with the bottom microstrip feeder line and the top microstrip patch. The antenna can cover main frequency bands of double LTE, has good matching characteristics and relatively high gain, and can improve the detection precision of scattered signals of a low-altitude aircraft.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of antennas, in particular to a dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals. BACKGROUND

[0002] With the development of low-altitude economy, low-altitude flight activities are increasingly frequent, and low-altitude flight safety problems also emerge in an endless stream. The core of realizing low-altitude safety protection lies in the detection of low-altitude aircraft. A microstrip antenna can be used as a receiving antenna to detect low-altitude aircraft by using urban LTE signals as signal external radiation sources.

[0003] The principle of detecting low-altitude aircraft by using urban LTE signals as signal external radiation sources lies in detecting targets by receiving signals reflected or scattered by the targets. When a radar system is established, an independent transmitter is not needed, but a dependence on existing communication infrastructure such as base stations and mobile devices is needed. The LTE signal has the characteristics of high frequency, wide bandwidth and high power density, which makes it have a significant advantage in low-altitude target detection. The wide coverage of urban base stations can ensure the continuity and stability of the signal. The microstrip antenna is a small, light and low-cost antenna type, and due to the flexibility of its design, it can meet different functional requirements. Using a microstrip antenna as a receiving antenna for receiving low-altitude aircraft scattering signals has good practical value.

[0004] However, the low gain of the microstrip antenna itself will affect the accuracy and reliability of signal detection. The high Q value and narrow frequency band of the microstrip antenna will result in the inability to cover the required LTE signal frequency band, which is not conducive to the accurate detection of low-altitude aircraft scattering signals. Therefore, a dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals is proposed. SUMMARY

[0005] The purpose of the application is to provide a dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals to improve the gain of the receiving antenna and cover the two commonly used LTE signal frequency bands.

[0006] In order to achieve the above purpose, the application provides a dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals, which at least comprises: an upper dielectric plate, the top of which is provided with a microstrip patch; an air dielectric layer, which is arranged at the bottom of the upper dielectric plate; a metal ground plate, which is arranged at the bottom of the air dielectric layer; a lower dielectric plate, which is arranged at the bottom of the metal ground plate; a microstrip feed line, which is arranged at the bottom of the lower dielectric plate; and a metal column, which is arranged at the end of the microstrip feed line and penetrates through the lower dielectric plate, the metal ground plate, the air dielectric layer and the upper dielectric plate.

[0007] The microstrip patch is an E-shaped patch.

[0008] The microstrip patch is connected to the microstrip feed line through the metal column.

[0009] The metal ground plate has a through hole at the intersection of the metal column and the metal ground plate.

[0010] The front end of the microstrip feed line is provided with a lumped excitation port for feeding.

[0011] Compared with the prior art, the present application has the following beneficial effects:

[0012] (1) The dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals, by combining the E-shaped microstrip patch with the multi-layer dielectric structure, realizes the high-gain characteristic, the maximum gain reaches 9.39dB, so that the antenna has high radiation efficiency and good directivity, and can realize detection of low-altitude aircraft scattering signals in a larger range, and can better resist attenuation in urban environments.

[0013] (2) The dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals, by combining the E-shaped microstrip patch with the multi-layer dielectric structure, the dual-frequency impedance matching is good, and the effective work in the LTE signal dual-frequency band is realized, the working frequency band of-10dB impedance bandwidth is 1.68-1.78GHz for frequency band one and 2.22-2.44GHz for frequency band two, covering the main frequency band of the low-altitude aircraft scattering LTE signal, and can be effectively applied to the reception of low-altitude aircraft scattering signals.

[0014] (3) The dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals, by designing the microstrip patch on the top of the multi-layer dielectric, designing the microstrip feed line on the back and connecting them through the metal column, the structure is simple, the processing difficulty is reduced, it is suitable for small-sized application scenarios, can realize efficient electromagnetic wave reception in limited space, and the overall cost is relatively low, and has high practical value in the reception of low-altitude aircraft scattering signals. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application and the prior art, the drawings involved in the embodiments or prior art description will be briefly introduced below, and the following drawings are only part of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained according to these drawings.

[0016] Figure 1 is the overall structure diagram of an embodiment of the present application;

[0017] Figure 2 A top view of one embodiment of the present application;

[0018] Figure 3 A schematic diagram of a metal ground plate of one embodiment of the present application;

[0019] Figure 4 A bottom view of one embodiment of the present application;

[0020] Figure 5 A front view of one embodiment of the present application;

[0021] Figure 6 A simulated scattering parameter chart of the present application;

[0022] Figure 7 A simulated voltage standing wave ratio chart of the present application;

[0023] Figure 8 A simulated gain pattern chart of the present application;

[0024] Figure 9 A simulated three-dimensional far field gain chart of the present application;

[0025] Figure 10 A simulated E-plane and H-plane pattern chart of the present application. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application.

[0027] In the description of the present application, it should be noted that the terms used herein are only for describing the specific embodiments, and do not indicate or imply that the elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the example embodiments of the present application.

[0028] As shown in Figures 1-5 The present application provides a dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals, which at least includes: an upper dielectric plate 2, the top of which is provided with a microstrip patch 1; an air dielectric layer 3, which is arranged at the bottom of the upper dielectric plate 2; a metal ground plate 5, which is arranged at the bottom of the air dielectric layer 3; a lower dielectric plate 6, which is arranged at the bottom of the metal ground plate 5; a microstrip feed line 7, which is arranged at the bottom of the lower dielectric plate 6; and a metal column 4, which is arranged at the end of the microstrip feed line 7 and penetrates through the lower dielectric plate 6, the metal ground plate 5, the air dielectric layer 3 and the upper dielectric plate 2.

[0029] In the embodiment, the air medium layer 3 is located in the middle, and the upper and lower surfaces thereof are the upper layer medium plate 2 and the metal grounding plate 5 respectively.

[0030] Further, the lower layer medium plate 6 is located on the lower surface of the metal grounding plate 5.

[0031] Preferably, the size of the width 9 of the upper layer medium plate 2 is 99 mm, the size of the length 10 is 123 mm, and the plate thickness is 0.8 mm.

[0032] Preferably, the material of the upper layer medium plate 2 is Arlon AD255A, the relative dielectric constant ε of Arlon AD255A is 2.55, and the loss tangent δ is 0.0015.

[0033] Preferably, the length and width of the air medium layer 3, the metal grounding plate 5, and the lower layer medium plate 6 are equal to those of the upper layer medium plate 2.

[0034] Preferably, the thickness of the air medium layer 3 is 10.8 mm, the relative dielectric constant ε of air is 1.0006, and the loss tangent δ is 0.

[0035] Preferably, the material of the metal grounding plate 5 is copper, the thickness is 0.022 mm, the relative dielectric constant ε of copper is 1, the loss tangent δ is 0, and the through hole 20 on the metal grounding plate is located at the intersection of the metal column 4 and the metal grounding plate 5, and the radius thereof is 1.05 mm.

[0036] Preferably, the material of the lower layer medium plate 6 is Arlon AD255A, the relative dielectric constant ε of Arlon AD255A is 2.55, and the loss tangent δ is 0.0015.

[0037] Further, as shown in FIG. 1, the microstrip patch 1 is located on the top of the upper layer medium plate 2, and the shape of the patch is E-shaped. Figure 2

[0038] Preferably, the size of the length 11 of the microstrip patch 1 is 80 mm, the size of the width 12 is 55 mm, and the patch thickness is 0.022 mm.

[0039] Preferably, the material of the microstrip patch 1 is copper, the relative dielectric constant ε of copper is 1, and the loss tangent δ is 0.

[0040] ​Preferably, two narrow grooves with a depth of 46.4 mm are cut in the middle of the patch, dividing the patch into three parts: left, middle, and right. The width 13 of the left part of the patch is 33.8 mm, the width 14 of the left narrow groove is 3.6 mm, the width 15 of the right narrow groove is 5.6 mm, the width 16 of the middle part of the patch is 12.6 mm, and the width 17 of the right part of the patch is 24.4 mm.

[0041] Preferably, the distance 18 from the right edge of the microstrip patch to the right edge of the upper dielectric substrate 2 is 21.5 mm, and the distance 19 from the rear end of the microstrip patch to the rear end of the upper dielectric substrate 2 is 22 mm.

[0042] Furthermore, such as Figure 4 As shown, the microstrip feed line 7 is located at the bottom of the lower dielectric substrate 6 and is fed by a 50Ω feed line.

[0043] Preferably, the microstrip feed line 7 is made of copper, with a length of 24.5 mm, a width of 2.7 mm, and a thickness of 0.022 mm. The relative permittivity of copper is ε=1, and the loss tangent is δ=0.

[0044] Preferably, the distance 21 from the center of the metal pillar 4 to the left edge of the lower dielectric plate 6 in the upward view is 61.5 mm, and the distance from the center to the end of the microstrip feed line is 1.62 mm.

[0045] Furthermore, such as Figure 5 As shown, the microstrip feed line 7 has a lumped excitation port 8 at its front end, and a metal post 4 serves as an intermediate connecting section to connect the microstrip patch 1 to the microstrip feed line 7 for power supply. Its height is 12.422 mm.

[0046] Specifically, the purpose of filling the space between the upper dielectric substrate 2 and the metal ground plane 5 with an air dielectric layer 3 is to utilize the low dielectric constant of air to optimize antenna performance. The structure of the microstrip antenna can be equivalent to a quasi-closed resonant cavity composed of a radiating patch, a ground plane, and a dielectric substrate. Near the resonance point, it can be characterized as a parallel RLC resonant circuit with a high quality factor. The energy stored in the antenna structure is much greater than the energy radiated. This high quality factor characteristic directly limits the impedance bandwidth and radiation efficiency of the antenna.

[0047] Since the relative dielectric constant of air is extremely close to 1, when it is used as a part of the medium of the antenna, the equivalent dielectric constant of the antenna can be significantly reduced, which can help to reduce the quality factor Q value of the antenna, and this change can effectively expand the bandwidth of the antenna and improve the gain of the antenna, so that the frequency range and strength of the signal transmission and reception of the antenna can be optimized. At the same time, using air as a part of the medium can reduce the invalid dissipation of energy, which helps to improve the overall efficiency of the antenna and ensure that more energy is used for signal radiation and reception. Moreover, the manufacturing process of the antenna is more simple and efficient, and the manufacturing cost is also significantly reduced.

[0048] Further, in order to achieve the effect of multi-band resonance, in the design of the microstrip patch 1, by opening a slot on the patch, the current direction on the surface of the antenna can be affected, and the current can be effectively bent. Due to the change of the current path, the effective length of the current actually flowing on the originally fixed-size rectangular patch is increased. This change not only further expands the bandwidth of the antenna to provide a wider frequency range for signal detection, but also adds an impedance matching resonance point to the overall circuit characteristics, so that the antenna can better match the external circuit at two frequency bands.

[0049] Further, the microstrip feed line 7 is designed on the back of the lower layer dielectric plate 6, and is connected to the microstrip patch 1 on the top through the metal column 4 penetrating the multi-layer dielectric structure. This way can effectively transmit electromagnetic energy from the feed line to the radiation patch, so as to realize the excitation of the antenna. Since the microstrip feed line 7 is located on the back of the antenna, its radiation will not directly affect the main radiation direction of the antenna, thereby improving the gain of the antenna and reducing the interference of the feed line to the antenna pattern. This design can adjust the position of the metal column 4 to make it closer to the input impedance of 50Ω, thereby reducing the reflection loss and improving the efficiency of the antenna.

[0050] Figure 6 The simulation scattering parameter diagram of the present application is good in matching effect at the two main LTE frequency bands of 1.68-1.78 GHz and 2.22-2.44 GHz.

[0051] Figure 7 The simulation voltage standing wave ratio diagram of the present application realizes a voltage standing wave ratio less than 2 at the two main LTE frequency bands of 1.68-1.78 GHz and 2.21-2.45 GHz, and the size of the voltage standing wave ratio at the resonance point is 1.06.

[0052] Figure 8 The simulation gain pattern of the present application is shown in the following table.

[0053] Figure 9 The simulation three-dimensional far-field gain diagram of the present application is shown in the following table, and the maximum gain reaches 9.39 dB.

[0054] Figure 10The simulated E-plane and H-plane patterns of the application.

[0055] Compared with the prior art, the application has the following beneficial effects:

[0056] (1) The dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals of the application realizes the high-gain characteristic through the combination of the E-shaped microstrip patch and the multilayer dielectric structure, the maximum gain reaches 9.39 dB, so that the antenna has high radiation efficiency and good directivity, can realize the detection of low-altitude aircraft scattering signals in a larger range, and can better resist attenuation in urban environments.

[0057] (2) The dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals of the application realizes the effective work in the LTE signal dual-frequency band through the combination of the E-shaped microstrip patch and the multilayer dielectric structure, the dual-frequency impedance matching is good, the working frequency band of-10 dB impedance bandwidth is realized, frequency band one is 1.68-1.78 GHz, frequency band two is 2.22-2.44 GHz, which covers the main frequency band of the low-altitude aircraft scattering LTE signal, and can be effectively applied to the reception of low-altitude aircraft scattering signals.

[0058] (3) The dual-frequency high-gain microstrip antenna for receiving low-altitude aircraft scattering signals of the application has the simple structure, reduces the processing difficulty, is suitable for small-sized application scenarios, can realize efficient electromagnetic wave reception in limited space, and has low overall cost, so it has high practical value in the reception of low-altitude aircraft scattering signals.

[0059] The above only describes the preferred embodiments of the application, and is not intended to limit the application. For those skilled in the art, it is obvious that the application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the application. Any reference signs in the claims should not be regarded as limiting the claims.

Claims

1. A dual-band high-gain microstrip antenna for receiving low-altitude aircraft-scattered signals, characterized by, The microstrip antenna comprises at least a microstrip patch, an upper dielectric plate, an air dielectric layer, a metal ground plate, a lower dielectric plate, a microstrip feed line and a metal column; the microstrip patch is located on the top of the upper dielectric plate; the air dielectric layer is arranged on the bottom of the upper dielectric plate and the top of the metal ground plate; the lower dielectric plate is arranged on the bottom of the metal ground plate; the microstrip feed line is arranged on the bottom of the lower dielectric plate; and the metal column penetrates through the upper dielectric plate, the air dielectric layer, the metal ground plate and the lower dielectric plate.

2. The dual-band high-gain microstrip antenna for receiving the signals scattered by the low-altitude flying object according to claim 1, wherein, The microstrip patch is in the shape of an E letter.

3. The dual-band high-gain microstrip antenna for receiving the signals scattered by the low-altitude flying object according to claim 1, wherein, The metal column serves as an intermediate connecting section to connect the microstrip patch and the microstrip feed line for feeding.

4. The dual-band high-gain microstrip antenna for receiving the signals scattered by the low-altitude flying object according to claim 1, wherein, The air dielectric layer serves as a transition layer between the upper dielectric plate and the metal ground plate.

5. The dual-band high-gain microstrip antenna for receiving the signals scattered by the low-altitude flying object according to claim 1, wherein, A through hole is arranged at the intersection of the metal ground plate and the metal column.

6. The dual-band high-gain microstrip antenna for receiving low-altitude aircraft scatter signals according to claim 1, wherein, The working frequency can cover two main LTE frequency bands of 1.68-1.78 GHz and 2.22-2.44 GHz.

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