A high temperature resistant coupled-fed microstrip Yagi antenna

Abstract

The present invention relates to a high-temperature resistant coupled-fed microstrip Yagi antenna. The antenna comprises a dielectric layer, a high-temperature titanium alloy coated on the upper surface of the dielectric layer and etched with a reflective patch, an active patch, and a plurality of guide patches. Below the dielectric layer, a common ground layer, a feed layer, and an aperture-coupled feed structure are sequentially arranged. The aperture-coupled feed structure and a heat generating source located on the upper surface of the dielectric layer are separated by a radome, a dielectric layer, a common ground layer, and a feed layer. This increases the distance between the heat source and the aperture-coupled feed structure, thereby reducing the amount of heat transferred to the aperture-coupled feed structure and lowering the temperature of the aperture-coupled feed structure. The present invention utilizes quartz ceramic as the antenna's carrier layer and feed layer, ensuring minimal degradation of the antenna's electrical performance under high-temperature conditions. Furthermore, the aperture-coupled feed method reduces the impact of the high temperature of the outermost layer of the antenna on the antenna feed structure, thereby improving the antenna's high-temperature resistance.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a high-temperature resistant coupled-feed microstrip Yagi antenna. Background Art

[0002] The Yagi antenna is an end-fire antenna with advantages such as high gain, high front-to-back ratio, and end-fire. However, traditional Yagi antennas are not easy to conform to high-speed aircraft, and the high temperatures generated by the aerodynamic heating phenomenon of high-speed aircraft can cause the antenna performance to deteriorate sharply. Currently, high-temperature resistant antennas are mainly considered from two aspects: one is the selection of high-temperature resistant materials, and the other is to consider the antenna structure to make the antenna have high-temperature resistance. Therefore, how to design an antenna that can be used on high-speed aircraft is currently a matter of consideration.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a high-temperature resistant coupled-fed microstrip Yagi antenna, which solves the problem that traditional Yagi antennas are not easy to conform to high-speed aircraft and the high temperature generated by the aerodynamic heating phenomenon of high-speed aircraft will cause the antenna performance to deteriorate sharply.

[0005] The objectives of the present invention are achieved through the following technical solutions: a high-temperature resistant coupled-fed microstrip Yagi antenna, comprising a dielectric layer, an upper surface of which is coated with a high-temperature titanium alloy and etched with a reflective patch, an active patch, and a plurality of guide patches; a common ground layer, a feed layer, and an aperture-coupled feed structure are sequentially arranged below the dielectric layer; the aperture-coupled feed structure and a heat generating source located on the upper surface of the dielectric layer are separated by a radome, a dielectric layer, a common ground layer, and a feed layer, thereby increasing the distance between the heat source and the aperture-coupled feed structure, reducing the heat transferred to the aperture-coupled feed structure, and lowering the temperature of the aperture-coupled feed structure.

[0006] The aperture-coupled feeding structure includes a feeding microstrip line etched on the lower surface of the feeding layer and with an open-circuit end. A coaxial line is provided on one side of the feeding microstrip line. The inner and outer conductors of the coaxial line are respectively connected to the feeding microstrip line and a common ground layer to realize aperture-coupled feeding. The feeding microstrip line and the coaxial line are separated from a heat generating source located on the upper surface of the dielectric layer by an antenna cover, a dielectric layer, a common ground layer, and a feeding layer. This increases the distance between the heat source and the feeding microstrip line and the coaxial line, thereby reducing the heat transferred to the feeding microstrip line and the coaxial line, thereby lowering the temperature of the feeding microstrip line and the coaxial line.

[0007] The dielectric layer and the feed layer are both made of high-temperature resistant quartz ceramic. At room temperature, the dielectric constant of the dielectric layer and the feed layer is 3.78, and the loss tangent is 0.008. At high temperature, the dielectric constant of the dielectric layer and the feed layer is 4.1, and the loss tangent is 0.02. The electrical parameters change little with temperature, which further reduces the heat transferred to the feed microstrip line and the coaxial line, thereby reducing the temperature of the feed microstrip line and the coaxial line.

[0008] The plurality of guide patches include a first group of guide patches and a second group of guide patches, the first group of guide patches includes a first guide patch and a second guide patch, and the second group of guide patches includes a third guide patch and a fourth guide patch; the reflective patch is arranged on one side of the active patch, the first group of guide patches and the second group of guide patches are arranged in sequence on the other side of the active patch, and the first group of guide patches is located between the active patch and the second group of guide patches.

[0009] The first and second guiding patches are arranged behind the active patch, and the first guiding patch and the active patch are in the same horizontal direction, and the second guiding patch is located obliquely below the first guiding patch; the third guiding patch is arranged obliquely behind the first guiding patch and in the same horizontal direction as the first guiding patch, and the fourth guiding patch is arranged obliquely behind the second guiding patch and in the same horizontal direction as the second guiding patch; the distance between the first and second guiding patches is smaller than the distance between the third and fourth guiding patches; by adjusting the spacing between the active patch and the reflective patch, the first group of guiding patches, and the second group of guiding patches, and adjusting the spacing between the two groups of guiding patches in the horizontal and vertical directions respectively, the impedance bandwidth, directivity, gain and front-to-back ratio performance of the antenna are improved.

[0010] The present invention has the following advantages: a high-temperature resistant coupled-fed microstrip Yagi antenna, which uses quartz ceramic as the antenna's bearing layer and feeding layer, can ensure that the antenna's electrical performance deteriorates little under high temperature conditions, and uses aperture-coupled feeding to reduce the impact of the high temperature of the outermost layer of the body on the antenna feeding structure, thereby improving the antenna's high-temperature resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a front view of the structure of the present invention;

[0012] Figure 2 A top view of the structure of the present invention;

[0013] Figure 3 This is a schematic diagram of thermal simulation results of the present invention;

[0014] Figure 4 This is a comparison curve of the reflection coefficient of the present invention under high and low temperature conditions;

[0015] Figure 5This is a comparison diagram of the E-plane direction at 5.5 GHz under high and low temperature conditions of the present invention;

[0016] In the figure: 1-active patch, 2-first guide patch, 3-second guide patch, 4-third guide patch, 5-fourth guide patch, 6-reflection patch, 7-dielectric layer, 8-common ground layer, 9-feeding layer, 10-feeding microstrip line, 11-coaxial line. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided below in conjunction with the drawings is not intended to limit the scope of protection of the present application for which protection is claimed, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. The present invention is further described below in conjunction with the drawings.

[0018] like Figure 1 and Figure 2 As shown, the present invention specifically relates to a high-temperature resistant coupled-fed microstrip Yagi antenna for use on high-speed aircraft, operating in the range of 5.21 GHz to 6.47 GHz. The antenna comprises a dielectric layer 7, on the upper surface of which a high-temperature titanium alloy is applied and a reflective patch 6, an active patch 1, and a plurality of guide patches are etched. A common ground layer 8, a feed layer 9, and an aperture-coupled feed structure are sequentially arranged below the dielectric layer 7. A slot is formed on the common ground layer 8 at a position directly below the active patch 1. The aperture-coupled feed structure and a heat generating source located on the upper surface of the dielectric layer 7 are separated by a radome, a dielectric layer 7, a common ground layer 8, and a feed layer 9. This increases the distance between the heat source and the aperture-coupled feed structure, reduces the amount of heat transferred to the aperture-coupled feed structure, and lowers the temperature of the aperture-coupled feed structure.

[0019] The aperture-coupled feeding structure includes a feeding microstrip line 10 etched on the lower surface of the feeding layer 9 and having an open-circuit end. A coaxial line 11 is provided on one side of the feeding microstrip line 10. The inner and outer conductors of the coaxial line 11 are respectively connected to the feeding microstrip line 10 and the common ground layer 8 to realize aperture-coupled feeding. The feeding microstrip line 10 and the coaxial line 11 are separated from the heat generating source located on the upper surface of the dielectric layer 7 by an antenna cover, a dielectric layer 7, a common ground layer 8 and a feeding layer 9. This increases the distance between the heat source and the feeding microstrip line 10 and the coaxial line 11, thereby reducing the heat transferred to the feeding microstrip line 10 and the coaxial line 11, thereby lowering the temperature of the feeding microstrip line 10 and the coaxial line 11.

[0020] The aperture coupling feeding method can effectively increase the distance between the feeding structure and the surface of the high-speed aircraft. Compared with the traditional microstrip feeder direct feeding, the thickness of the dielectric layer 7 and the feeding layer 9 is increased by two layers (5mm). Figure 3 As shown in the figure, it can be seen from the thermal simulation diagram that when the antenna cover has the same thickness of 6mm, the temperature of the feeding structure (at 11mm) of the coupled feeding method will be about 150℃ lower than the temperature of the feeding structure (at 5mm) of the microstrip direct feeding method.

[0021] Furthermore, the dielectric material used in antennas for high-speed aircraft must first ensure basic electrical performance. Specifically, it must meet certain electrical parameter requirements: a dielectric constant between 1 and 4, and a loss tangent between 0.001 and 0.1. Furthermore, the material must meet certain mechanical properties. Furthermore, and more importantly, the material must have a relatively high melting point, while its electrical parameters remain relatively stable over temperature and exhibit strong resistance to thermal shock.

[0022] Therefore, the dielectric layer 7 and the feed layer 9 of the present invention are both made of high-temperature resistant quartz ceramic material. The melting point of quartz ceramic is about 1750°C. The antenna can withstand a high temperature of 1000°C and will not suffer structural damage in a high-temperature environment. Moreover, its electrical parameters are stable with temperature changes. From room temperature, i.e., 25°C, to 1000°C, the dielectric constant changes from 3.78 to 4.1, and the loss tangent changes from 0.008 to 0.02. The changes are small, and the antenna performance will not deteriorate drastically under high temperature conditions. The heat transferred to the feed layer 9 and the feed microstrip line 10 is reduced, thereby reducing the temperature of the feed layer 9 and the feed microstrip line 10. In addition, it has a low expansion coefficient and excellent thermal shock resistance, which can increase the service life of the antenna in a high-temperature environment. Therefore, according to the external load environment of the high-speed aircraft, the dielectric layer 7 and the feed layer 9 of the present invention are made of high-temperature resistant quartz ceramic material.

[0023] The multiple guiding patches include a first group of guiding patches and a second group of guiding patches, the first group of guiding patches includes a first guiding patch 2 and a second guiding patch 3, and the second group of guiding patches includes a third guiding patch 4 and a fourth guiding patch 5; the reflective patch 6 is arranged on one side of the active patch 1, and the first group of guiding patches and the second group of guiding patches are arranged in sequence on the other side of the active patch 1, and the first group of guiding patches is located between the active patch 1 and the second group of guiding patches.

[0024] The first guiding patch 2 and the second guiding patch 3 are arranged behind the active patch 1, and the first guiding patch 2 and the active patch 1 are in the same horizontal direction, and the second guiding patch 3 is located obliquely below the first guiding patch 2; the third guiding patch 4 is arranged obliquely behind the first guiding patch 2 and in the same horizontal direction as the first guiding patch 2, and the fourth guiding patch 5 is arranged obliquely behind the second guiding patch 3 and in the same horizontal direction as the second guiding patch 3; the distance between the first guiding patch 2 and the second guiding patch 3 is smaller than the distance between the third guiding patch 4 and the fourth guiding patch 5.

[0025] The present invention comprises two groups of director patches. The first group of director patches is located near the active patch. By adjusting the spacing between the two patches, the gap capacitance between the first group of director patches and the active patch can be changed, thereby changing the coupling strength. By placing the first group of director patches in this manner, the directivity and impedance bandwidth of the antenna beam can be adjusted by changing the spacing between the first group of director patches. The second group of director patches is located away from the active patch. By changing the spacing between the second group of director patches, the gain of the antenna can be effectively increased because the effective aperture of the antenna is increased. Therefore, the impedance bandwidth, directivity, gain, and front-to-back ratio of the antenna can be improved overall by adjusting the spacing between the active patch and the reflective patch, the first group of director patches, the second group of director patches, and the spacing between the two groups of director patches.

[0026] Furthermore, the dielectric layer 7 is 3 mm thick and measures 100 mm × 50 mm. The feed layer 9 is 2 mm thick and measures 100 mm × 50 mm. The active patch 1 is located in the center of the dielectric layer 7 and measures 10 mm × 10 mm. The first, second, third, and fourth guide patches 2, 3, 3, and 5 all measure 9.5 mm × 9 mm. The spacing between the first and second guide patches 2, 3, and the active patch 1 is 1.6 mm. The spacing between the first and second guide patches 2, 3, and 3 is 1.6 mm. The spacing between the third and fourth guide patches 4, 5, and the first and second guide patches 3 is 1.6 mm. The spacing between the third and fourth guide patches 4, 5, and the first and second guide patches 3 is 20 mm. The reflector patch 6 measures 30 mm × 3 mm and is 1.6 mm away from the active patch 1.

[0027] like Figure 4 and Figure 5 As shown, the present invention has a reflection coefficient of no more than -10dB in the 5.21GHz-6.47GHz frequency band. At the 5.5GHz resonance point, the maximum radiation direction on the E-plane is at Theta = 30°, the maximum gain is 6.7dBi, and the front-to-back ratio is 11.4dB, demonstrating end-fire characteristics. At 1000°C, the operating frequency band shifts to a lower frequency of 5.0GHz-6.26GHz. At the 5.5GHz resonance point, the maximum radiation direction on the E-plane is at Theta = 37°, the maximum gain is 5.9dBi, and the front-to-back ratio is 10.6dB, maintaining end-fire characteristics.

[0028] The foregoing description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Rather, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the concept described herein through the above teachings or techniques or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be protected by the appended claims.

Claims

1. A high temperature resistant coupled-fed microstrip Yagi antenna, characterized by: It includes a dielectric layer (7), a high-temperature titanium alloy is applied on the upper surface of the dielectric layer (7) and a reflective patch (6), an active patch (1) and a plurality of guide patches are etched thereon, a common ground layer (8), a feed layer (9) and an aperture-coupled feed structure are sequentially arranged below the dielectric layer (7), and the aperture-coupled feed structure and a heat generating source located on the upper surface of the dielectric layer (7) are separated by a radome, a dielectric layer (7), a common ground layer (8) and a feed layer (9), thereby increasing the distance between the heat source and the aperture-coupled feed structure, reducing the amount of heat transferred to the aperture-coupled feed structure, and lowering the temperature of the aperture-coupled feed structure; The aperture-coupled feeding structure includes a feeding microstrip line (10) etched on the lower surface of the feeding layer (9) and having an open-circuit end. A coaxial line (11) is provided on one side of the feeding microstrip line (10). The inner and outer conductors of the coaxial line (11) are respectively connected to the feeding microstrip line (10) and the common ground layer (8) to realize aperture-coupled feeding. The feeding microstrip line (10) and the coaxial line (11) are separated from a heat generating source located on the upper surface of the dielectric layer (7) by an antenna cover, a dielectric layer (7), a common ground layer (8) and a feeding layer (9). The distance between the heat source and the feeding microstrip line (10) and the coaxial line (11) is increased, so that the heat transferred to the feeding microstrip line (10) and the coaxial line (11) is reduced, thereby reducing the temperature of the feeding microstrip line (10) and the coaxial line (11).

2. The high temperature resistant coupled-fed microstrip Yagi antenna according to claim 1, characterized in that: The dielectric layer (7) and the feed layer (9) are both made of high-temperature resistant quartz ceramic material. At room temperature, the dielectric constant of the dielectric layer (7) and the feed layer (9) is 3.78, and the loss tangent is 0.

008. At high temperature, the dielectric constant of the dielectric layer (7) and the feed layer (9) is 4.1, and the loss tangent is 0.

02. The electrical parameters change little with temperature, which further reduces the heat transferred to the feed microstrip line (10) and the coaxial line (11), thereby reducing the temperature of the feed microstrip line (10) and the coaxial line (11).

3. The high temperature resistant coupled-fed microstrip Yagi antenna according to claim 1, characterized in that: The plurality of guide patches include a first group of guide patches and a second group of guide patches, the first group of guide patches includes a first guide patch (2) and a second guide patch (3), and the second group of guide patches includes a third guide patch (4) and a fourth guide patch (5); the reflective patch (6) is arranged on one side of the active patch (1), the first group of guide patches and the second group of guide patches are arranged in sequence on the other side of the active patch (1), and the first group of guide patches is located between the active patch (1) and the second group of guide patches.

4. The high temperature resistant coupled-fed microstrip Yagi antenna according to claim 3, characterized in that: The first guiding patch (2) and the second guiding patch (3) are arranged behind the active patch (1), and the first guiding patch (2) and the active patch (1) are in the same horizontal direction, and the second guiding patch (3) is located obliquely below the first guiding patch (2); the third guiding patch (4) is arranged obliquely behind the first guiding patch (2) and in the same horizontal direction as the first guiding patch (2), and the fourth guiding patch (5) is arranged obliquely behind the second guiding patch (3) and in the same horizontal direction as the third guiding patch (4). The two guiding patches (3) are in the same horizontal direction; the distance between the first guiding patch (2) and the second guiding patch (3) is smaller than the distance between the third guiding patch (4) and the fourth guiding patch (5); and the impedance bandwidth, directivity, gain and front-to-back ratio of the antenna are improved by adjusting the spacing between the active patch (1) and the reflective patch (6), the first group of guiding patches, and the second group of guiding patches, and respectively adjusting the spacing between the two groups of guiding patches in the horizontal and vertical directions.

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