CN115084866A

CN115084866A - Satellite navigation antenna and satellite navigation transceiver

Info

Publication number: CN115084866A
Application number: CN202210669329.1A
Authority: CN
Inventors: 朱良; 王冠君; 谢亚运; 刘星; 冯维星; 陆超
Original assignee: SHANGHAI HIGH GAIN INFORMATION TECHNOLOGY CO LTD
Current assignee: SHANGHAI HIGH GAIN INFORMATION TECHNOLOGY CO LTD
Priority date: 2022-06-14
Filing date: 2022-06-14
Publication date: 2022-09-20
Also published as: WO2023240792A1

Abstract

The application provides a satellite navigation antenna and satellite navigation transceiver, wherein the satellite navigation antenna includes the metal reflection floor of non-complete symmetry and is located the passive array of antenna of central point department on the metal reflection floor, and wherein, the metal reflection floor uses the major axis extreme point to follow as the starting point for the axisymmetric figure of two symmetry axes of minor axis and major axis that have mutually perpendicular on the metal reflection floor the major axis exists two gaps toward the direction of central point, the shape size of two gaps is the same and the position is followed the minor axis symmetry. According to the technical scheme, the slot is formed in the long axis direction of the metal reflection floor in the non-completely symmetrical shape of the antenna, so that the axial ratio performance and the 3db axial ratio beam width of the antenna can be effectively improved, and the quality of receiving or transmitting signals by the antenna is improved.

Description

Satellite navigation antenna and satellite navigation transceiver

Technical Field

The application relates to the technical field of antennas, in particular to a satellite navigation antenna and a satellite navigation transceiver.

Background

With the rapid development of the global satellite navigation system and the comprehensive establishment of the third generation Beidou global satellite navigation system, the application of the satellite navigation system in various industries such as aerospace, intelligent transportation, intelligent agriculture, geological disasters, environmental monitoring and the like is more and more extensive, and how the performance of the antenna is used as an important component of the front end of a satellite navigation receiver and satellite communication equipment is directly related to the measurement precision of the satellite navigation receiver and the success rate of satellite communication.

In order to obtain good performance indexes such as axial ratio, the metal reflective floor of most satellite navigation antennas is generally designed to be regular and symmetrical, for example: round, square, etc. to promote performances such as homogeneity and axial ratio of antenna in each direction of space radiation. However, due to the limitation of the shape and the volume in some directions, the metal reflective floor of the antenna can only be made into a shape similar to an ellipse or a long strip. When the passive antenna array is placed in the center of the metal reflective floor, and the metal reflective floor cannot be made into a completely symmetrical square or round shape, etc., the axial ratio of the antenna is deteriorated, thereby affecting the quality of the received signal of the antenna.

Disclosure of Invention

The application provides a satellite navigation antenna and a satellite navigation transceiver, which are used for improving the axial ratio performance when a metal reflection floor in the satellite navigation antenna adopts a non-completely symmetrical shape and improving the quality of receiving or transmitting signals by the antenna.

In a first aspect, an embodiment of the present application provides a satellite navigation antenna, where the satellite navigation antenna includes a non-completely symmetric metal reflective floor and an antenna passive array located at a central position on the metal reflective floor, and the metal reflective floor is an axisymmetric pattern having two symmetry axes, namely a short axis and a long axis, which are perpendicular to each other; two gaps exist on the metal reflection floor along the direction from the long axis to the center position by taking the end point of the long axis as a starting point, the two gaps are the same in shape and size, and the positions of the two gaps are symmetrical along the short axis.

According to the technical scheme, the axial ratio performance and the 3db axial ratio beam width of the antenna can be effectively improved by slotting the antenna in the long axis direction of the incompletely symmetrical metal reflecting floor of the antenna.

In one possible design, the metal reflective floor is rectangular, oval or diamond shaped. When the metal reflective floor is rectangular, the long axis end point refers to a central point on a short side of the rectangle.

The technical scheme is suitable for the situation that various metal reflecting floors in non-completely symmetrical shapes are adopted.

In one possible design, the length and width of the gap are determined according to the aspect ratio of the major axis to the minor axis of the metal reflective floor; the longest length of the gap is from the end point of the long axis of the metal reflection floor to the plate edge of the antenna passive array.

According to the technical scheme, the length and the depth of the specific slot are determined according to the length-width ratio of the long and short shafts in the non-completely symmetrical shape adopted by the metal reflection floor, and the axial ratio performance of the antenna can be effectively improved.

In one possible design, the length of the slot is inversely proportional to the aspect ratio, and the width of the slot is proportional to the aspect ratio.

In one possible design, the metal reflective floor is a printed circuit board, PCB, and the gap is located in a copper foil layer on the PCB.

In one possible design, the antenna passive array is one or more layers of stacked microstrip antennas, each layer of microstrip antenna comprises a passive plate and a metal radiation patch positioned on the passive plate, and a plurality of feed points are arranged on the metal radiation patch.

In one possible design, the longest length of the slot is from the end point of the long axis of the metal reflective floor to the edge of the passive plate of the underlying microstrip antenna.

In one possible design, the antenna passive element is a helical antenna, and the helical antenna includes a cylindrical passive plate and a plurality of helical metal radiating arms located on the side of the cylindrical passive plate, and a feeding point is provided at a position where the helical metal radiating arms interface with the metal reflective floor.

In a second aspect, the present application provides a satellite navigation transceiver apparatus comprising a satellite navigation antenna as set forth in any one of the possible designs of the first aspect.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1a is a schematic structural diagram of a microstrip antenna using a rectangular metal reflective floor in the prior art;

FIG. 1b is a graphical representation of the axial ratio performance of the antenna structure of FIG. 1 a;

FIG. 1c is a schematic diagram illustrating the current flow direction of the antenna structure shown in FIG. 1 a;

fig. 2a is a schematic structural diagram of a microstrip antenna using a rectangular metal reflective floor according to an embodiment of the present application;

FIG. 2b is a graphical illustration of the axial ratio performance of the antenna structure shown in FIG. 2 a;

FIG. 2c is a schematic diagram illustrating the current flow direction of the antenna structure shown in FIG. 2 a;

FIG. 3a is a schematic structural diagram of another microstrip antenna using a rectangular metal reflective floor in the prior art;

FIG. 3b is a graphical illustration of the axial ratio performance of the antenna structure shown in FIG. 3 a;

fig. 4a is a schematic structural diagram of another microstrip antenna using a rectangular metal reflective floor according to an embodiment of the present application;

FIG. 4b is a graphical illustration of the axial ratio performance of the antenna structure shown in FIG. 4 a;

FIG. 5a is a schematic structural diagram of a microstrip antenna using a rectangular metal reflective floor according to the prior art;

FIG. 5b is a schematic illustration of the axial ratio performance of the antenna structure of FIG. 5a at resonance point 1;

FIG. 5c is a schematic illustration of the axial ratio performance of the antenna structure of FIG. 5a at resonance point 2;

fig. 6a is a schematic structural diagram of another microstrip antenna using a rectangular metal reflective floor according to an embodiment of the present application;

FIG. 6b is a schematic illustration of the axial ratio performance of the antenna structure shown in FIG. 6a at resonance point 1;

FIG. 6c is a schematic illustration of the axial ratio performance of the antenna structure of FIG. 6a at resonance point 2;

FIG. 7a is a schematic structural diagram of a microstrip antenna using a rectangular metal reflective floor according to the prior art;

FIG. 7b is a graphical illustration of the axial ratio performance of the antenna structure shown in FIG. 7 a;

fig. 8a is a schematic structural diagram of another microstrip antenna using a rectangular metal reflective floor according to an embodiment of the present application;

FIG. 8b is a graphical illustration of the axial ratio performance of the antenna structure shown in FIG. 8 a;

fig. 9 is a schematic structural diagram of a microstrip antenna using an elliptical metal reflective floor according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of another microstrip antenna using an elliptical metal reflective floor according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a helical antenna using a rectangular metal reflective floor according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described in further detail with reference to the accompanying drawings, and it is obvious that the embodiments described below are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the embodiments of the present application, a plurality means two or more. The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance, nor order.

When two linear polarized waves of the antenna meet three conditions of space orthogonality, equal amplitude and 90-degree phase difference, the antenna can radiate circularly polarized waves. The circularly polarized antenna can receive electromagnetic waves emitted by the antenna of any polarization mode, and can also receive circularly polarized waves by using the antenna of any polarization mode. And the circularly polarized antenna has rotation orthogonality, for example, one antenna radiates a left-handed circularly polarized wave, and cannot be received by a right-handed circularly polarized antenna. Compared with a linear polarization antenna, the circularly polarized antenna can reduce polarization loss caused by polarization mismatch, can also inhibit multipath interference caused by rain and fog weather, buildings and the like, and improves the communication quality of the system. For application systems such as satellite communication and navigation, the linearly polarized antenna is difficult to meet the increasingly strict requirements, so the circular polarization technology is rapidly developed. Circularly polarized antennas are widely used, for example, electromagnetic waves transmitted by satellites of the gnss are circularly polarized waves. If linear polarization antenna is used for receiving, polarization loss and multipath effect exist, and if circular polarization antenna is used for receiving, the quality of received satellite signals can be greatly improved. Global satellite navigation positioning systems generally require that the 3db axis of a circularly polarized antenna be up to 120 ° wider than the beam width in order to be able to receive signals anywhere on the earth. Microstrip antennas and helical antennas are common circularly polarized antennas.

Axial Ratio (AR) is an index for far field measurement of the purity of circularly polarized waves. The axial ratio of an elliptically polarized wave, which is usually expressed in decibels as 20log AR, is defined as the ratio of the major axis to the minor axis of the polarization ellipse. When the axial ratio of the elliptical polarization is 0, the major axis and the minor axis are equal, i.e., circular polarization. To ensure the degree of circular polarization of a circularly polarized antenna, an axial ratio of less than 3db is generally required.

The application provides a satellite navigation antenna which is a circularly polarized antenna with a non-completely symmetrical metal reflection floor. Two symmetrical gaps (slots for short) are formed in the long axis end point of the metal reflecting floor which is not completely symmetrical along the long axis to the center direction, so that the current path in the short side direction of the metal reflecting floor can be increased, the difference of the amplitude of the antenna between two orthogonal polarization components caused by the incomplete symmetry of the shape of the metal reflecting floor is reduced, and the axial ratio of the antenna is reduced.

The antenna is not limited in form, meets the standard of a circularly polarized antenna, and can improve the axial ratio performance of the antenna by the scheme, for example, the antenna can be a microstrip antenna or a helical antenna.

The satellite navigation antenna in the application comprises a non-completely symmetrical metal reflecting floor and an antenna passive array located at the central position above the metal reflecting floor. Wherein:

the plane of the metal reflective floor is an axisymmetric pattern having two symmetry axes of a major axis and a minor axis perpendicular to each other, and may be an incompletely symmetric shape such as a rectangle, an ellipse, or a rhombus. The non-symmetrical metal reflective floor is also referred to as an asymmetrical metal reflective floor for short, wherein the asymmetry means that the geometric figure is not completely symmetrical, namely, the ideal shape of a square or a circle.

The metal reflective floor, which is not completely symmetrical, may be a Printed Circuit Board (PCB) with copper on the surface. The bottom surface of the PCB is integrated with a feed network of the antenna, and the feed network is used for generating a phase difference of 90 degrees between feed points of the antenna, so that the circular polarization of the antenna is realized.

The structure of the antenna passive array is different according to different antenna forms.

For example, for a single-layer microstrip antenna, the passive antenna element may include a passive plate and a metal radiating patch disposed above the passive plate, with a plurality of feed pins or feed probes disposed above the metal radiating patch, thereby forming a plurality of feed points for the antenna. The metallic radiating patch forms the metallic radiating surface of the antenna and may typically be a metallic layer, such as copper, disposed on the passive plate. The passive plate is placed on the metal reflecting floor which is not completely symmetrical, and the center of the passive plate is aligned with the center of the metal reflecting floor. The passive plate may also be referred to as a dielectric plate or an antenna dielectric plate, and may be generally square, rectangular, circular, oval, or the like. The shape and thickness of the passive plate are not particularly limited in this application.

For the spiral antenna, the passive antenna array may include a cylindrical passive plate and a plurality of spiral metal radiating arms located on the side of the cylindrical passive plate, a feeding point is disposed at a junction of the spiral metal radiating arms and the metal reflective floor, and a grounding branch is disposed near the feeding point on the cylindrical passive plate.

In the present application, in order to reduce the antenna axial ratio when the metal reflective floor of the antenna adopts a non-completely symmetrical shape, and improve the antenna performance, on the plane of the metal reflective floor, two slits (may be referred to as slots for short) are opened in the direction from the long axis to the center position, with the end point of the long axis as the starting point, the two slits have the same shape and size, and the positions are symmetrical along the short axis.

The length and width of the gap are determined according to an aspect ratio of a major axis to a minor axis of the metal reflective floor, and the length of the gap is inversely proportional to the aspect ratio and the width of the gap is proportional to the aspect ratio. The longest length of the gap is from the end point of the long axis of the metal reflecting floor to the plate edge of the antenna passive array, or from the end point of the long axis of the metal reflecting floor to the plate edge of the antenna passive plate. The gap is located on the copper foil layer above the metal reflection plate (i.e., PCB), and the thickness of the gap is the same as that of the copper foil layer in the metal reflection plate.

The optimization of antenna performance by slotting on a non-perfectly symmetrical metal reflective floor is described below using various microstrip antennas as examples.

Fig. 1a illustrates a structure of a microstrip antenna using a rectangular metal reflective floor in the prior art. The antenna comprises a metal reflecting floor 110, a passive plate 120 and a metal radiating patch 130 which are sequentially stacked from bottom to top, and a feeding point 140 formed by two feeding probes arranged on the metal radiating patch 130. The plane of the metal reflective floor 110 is rectangular, the plane of the passive plate 120 is square, and the antenna is specifically a 2-feed-point single-layer microstrip antenna.

Specifically, the size of the passive plate of the antenna is 40 × 4mm, and the planar size of the metal reflecting floor is 100 × 50 mm. As can be seen from fig. 1a, the plane of the metal reflective floor is not perfectly symmetrical with respect to the passive plate of the antenna, the length of the long side of the metal reflective floor being twice the length of the short side.

Fig. 1b shows the axial ratio performance of the antenna structure shown in fig. 1 a. As shown in fig. 1b, the axial ratio of the antenna at the antenna vertex with the central frequency point of 1575MHz and the azimuth angles of 0 ° and 90 ° is 5db, and cannot be less than 3db in the beam width range of 120 °, which causes great deterioration of the antenna axial ratio.

Fig. 1c shows the current flow direction of the antenna structure shown in fig. 1 a. As shown in fig. 1c, from the current path and direction of the metal reflective floor, since the shape of the metal reflective floor is not completely symmetrical with respect to the antenna passive array, the path that the current travels on the long side of the metal reflective floor is longer, and the path that the current travels on the short side is shorter, therefore, the beam width indexes of the antenna on the vertex axial ratio and the 3db axial ratio are both worse and far lower than the standard.

Fig. 2a illustrates an example of a structure of a microstrip antenna using a rectangular metal reflective floor according to an embodiment of the present application. As shown in fig. 2a, the antenna is also a 2-feed-point single-layer microstrip antenna, and the size is the same as that of the antenna shown in fig. 1a, but the antenna in the present application is different in that two slots 150 with a width of 1mm are symmetrically formed in a vertical direction from a short side of the metal reflective floor toward the center of the antenna, and the slot length is from the plate edge of the metal reflective bottom plate to the plate edge of the antenna passive plate.

Figure 2b shows the axial ratio performance of the antenna structure shown in figure 2 a. As can be seen from fig. 2b, the axial ratio performance of the antenna at the antenna vertex with the central frequency point of 1575MHz and the azimuth angle of 0 ° and 90 ° respectively is greatly improved, and the beam widths of the axial ratios of 0.98db and 3db are respectively and uniformly greater than 120 °. The axial ratio of the antenna is improved by 4db at the vertex, and the beam width of the axial ratio of 3db is greatly improved. Wherein, the 3db axial ratio beam width at the azimuth angle of 0 degree is improved from 0 degree to more than 120 degrees.

Fig. 2c shows a schematic diagram of the current flow direction of the antenna structure shown in fig. 2 a. As shown in fig. 2c, when a gap of 1mm is formed in a vertical direction from a short side of the metal reflective floor to the center of the antenna in view of the current path and direction of the metal reflective floor, the path through which the current travels in the long side direction of the metal reflective floor is long, and since the current needs to be bypassed when passing through the edge of the gap in the short side direction, the path length through which the current travels in the short side direction is equivalently extended. It can be seen that the beam width indexes of the antenna at the axis ratio of the vertex and the 3db axis ratio are greatly improved by slotting in the vertical direction of the short side of the metal reflection floor.

It should be noted that, both the 2-feed-point microstrip antenna shown in fig. 1a and fig. 2a, comparing the antenna structure shown in fig. 2a with the antenna structure shown in fig. 1a in terms of both the axial ratio performance and the current flow direction, it can be seen that the performance change of the 2-feed-point microstrip antenna is caused by the slot in the vertical direction of the short side of the rectangular metal reflective floor.

The performance change of the 4-feed-point microstrip antenna caused by slotting in the vertical direction of the short side of the rectangular metal reflective floor is illustrated by comparing fig. 3a with fig. 4 a.

Fig. 3a illustrates another prior art microstrip antenna structure using a rectangular metal reflective floor. The antenna in the prior art shown in fig. 3a is a single-layer microstrip antenna and is not slotted on the rectangular metal reflective floor as the antenna in the prior art shown in fig. 1a, and the size of the antenna is the same, and is a passive plate 40 × 4mm and a metal reflective floor 100 × 50mm, but the difference is that the antenna shown in fig. 3a is a 4-feed-point microstrip antenna, 4 feed points are provided on a metal radiation patch, while the antenna shown in fig. 1a is a 2-feed-point microstrip antenna, and 2 feed points are provided on a metal radiation patch. Figure 3b shows the axial ratio performance of the antenna structure shown in figure 3 a.

Fig. 4a illustrates another microstrip antenna structure using a rectangular metal reflective floor according to an embodiment of the present application. The antenna in the embodiment of the present application shown in fig. 4a and the antenna in the embodiment of the present application shown in fig. 2a are both single-layer microstrip antennas, and are all slotted in the perpendicular direction of the short side on the rectangular metal reflective floor, and the antenna is also the same in size, and is all passive plate 40 × 4mm, and metal reflective floor 100 × 50mm, but the difference is that the antenna shown in fig. 4a is a 4-feed-point microstrip antenna, 4 feed points are provided on the metal radiation patch, while the antenna shown in fig. 2a is a 2-feed-point microstrip antenna, and 2 feed points are provided on the metal radiation patch. Figure 4b shows the axial ratio performance of the antenna structure shown in figure 4 a.

By comparing the axial ratio performance at the vertex of the 4-feed-point microstrip antenna slotted on the rectangular metal reflective floor shown in fig. 3b with the axial ratio beam width of 3db of the 4-feed-point microstrip antenna slotted on the rectangular metal reflective floor shown in fig. 4b, it can be seen that a slot with a width of 1mm is formed in the direction from the short side of the rectangular metal reflective floor to the vertical direction of the passive plate edge of the antenna, and the axial ratio of the 4-feed-point microstrip antenna at the vertex can be increased from 5.9db to about 2db, and the beam width of 3db can be increased from 0 ° to more than 120 °.

The performance change of the double-layer laminated microstrip antenna caused by slotting in the direction perpendicular to the short side of the rectangular metal reflective floor is illustrated by comparing fig. 5a with fig. 6 a.

Fig. 5a illustrates a structure of a microstrip antenna using a rectangular metal reflective floor according to another prior art. The prior art antenna shown in fig. 5a and the prior art antenna shown in fig. 1a are 2-feed-point microstrip antennas, and no slot is formed on the rectangular metal reflective floor, and the size of the antenna metal reflective floor is the same. The main difference is that the antenna shown in fig. 5a is a double-layer laminated microstrip antenna, that is, the passive antenna has two layers, and a layer of passive plate and metal radiation patch with slightly smaller size are further superimposed on the passive plate and metal radiation patch at the bottom layer. Wherein, the resonance points of the top layer microstrip antenna 510 and the bottom layer microstrip antenna 520 are 1575MHz and 1227MHz, respectively, which will be referred to as resonance point 1 and resonance point 2, respectively, for convenience of description. Fig. 5b shows the axial ratio performance of the antenna structure of fig. 5a at resonance point 1, and fig. 5c shows the axial ratio performance of the antenna structure of fig. 5a at resonance point 2. As can be seen from fig. 5b and 5c, before slotting, the axial ratio of the dual-layer stacked microstrip antenna at the antenna vertex with azimuth angles of 0 ° and 90 ° is 3db at 1575MHz and 5.5db at 1227MHz, respectively, and the beam width of the 3db axial ratio at 1227MHz is 0 °.

Fig. 6a illustrates a structure of a microstrip antenna using a rectangular metal reflective floor in an embodiment of the present application. The antenna in the embodiment of the present application shown in fig. 6a and the antenna in the embodiment of the present application shown in fig. 2a are 2-feed-point microstrip antennas, and are all slotted in the perpendicular direction of the short side on the rectangular metal reflective floor, and the size of the antenna metal reflective floor is the same. The main difference is that the antenna shown in fig. 6a is a double-layer stacked microstrip antenna, and the resonance points of the top microstrip antenna 510 and the bottom microstrip antenna 520 are 1575MHz and 1227MHz, respectively. Fig. 6b shows the axial ratio performance of the antenna structure of fig. 6a at resonance point 1, and fig. 6c shows the axial ratio performance of the antenna structure of fig. 6a at resonance point 2. As can be seen from fig. 6b and 6c, after being slotted, the axial ratio of the dual-layer stacked microstrip antenna at the antenna vertex with the azimuth angle of 0 ° and 90 ° is about 2db of 1575MHz and 1.2db of 1227MHz, the beam width of the 3db axial ratio of 1575MHz reaches 120 °, and the beam width of the 3d b axial ratio of 1227MHz exceeds 120 °.

In the above example, the rectangular metal reflective ground plate of the antenna has a size of 100mm by 50mm, and an aspect ratio of 2: 1, under the condition, the groove is symmetrically formed in the vertical direction of the short axis of the metal reflecting floor, the length of the groove is set to be from the plate edge of the metal reflecting floor to the plate edge of the antenna passive plate, and the width of the groove is set to be 1mm, so that the axial ratio performance of the antenna can be effectively improved.

It should be noted that, in the present application, the length and width of the slot need to be specifically designed according to the size of the metal reflective floor. That is, the slot length is from the edge of the metal reflective floor to the edge of the antenna passive plate, and the width is not 1mm for microstrip antennas of all sizes.

The performance change for a microstrip antenna due to different slot lengths for different sizes of rectangular metal reflective floors is illustrated by comparing fig. 7a with fig. 8 a.

Fig. 7a illustrates a structure of a microstrip antenna using a rectangular metal reflective floor according to another prior art. As shown in fig. 7a, the antenna is a 2-feed-point single-layer microstrip antenna, the metal reflective floor is rectangular, the planar size is 150 × 50, the aspect ratio is 3:1, and the size of the passive plate is 40 × 4 mm. Fig. 7b shows the axial ratio performance of the antenna structure of fig. 7a, and as shown in fig. 7b, the axial ratio of the antenna structure of fig. 7a further deteriorates to 7.5db and the 3db beam width is also 0 ° as the aspect ratio of the metal reflective floor becomes larger compared to the antenna structure of fig. 1 a.

Based on the antenna structure shown in 7a, when two symmetrical gaps with the width of 1mm are formed in the vertical direction from the short edge of the metal reflection floor to the edge of the antenna passive plate, the length of the gap is up to the edge of the antenna passive plate. And (3) displaying a simulation result: at this time, the axial ratio of the antenna at the antenna vertex with the azimuth angles of 0 ° and 90 ° is 7.5db, the beam width of the 3db axial ratio is 0 °, and the improvement of the axial ratio performance of the antenna by the method is limited.

Fig. 8a illustrates an example of a structure of a microstrip antenna using a rectangular metal reflective floor provided in an embodiment of the present application. As shown in fig. 8a, compared with the antenna structure in which two symmetric slots with a slot length of 1mm are opened from the short side of the metal reflective floor to the edge of the antenna passive board in the vertical direction, the slot length of the antenna in fig. 8a is shortened to 37mm, and the width is increased to 4 mm. Figure 8b shows the axial ratio performance of the antenna structure shown in figure 8a, as shown in figure 8b, with an axial ratio of 2.5db at the antenna vertex having an azimuth angle of 0 deg. and 90 deg., respectively, and widths below 3db of-67.1 deg. to 64.2 deg. and-30.7 deg. to 28.2 deg., respectively. From the above indexes, compared with a scheme that the antenna is not slotted or is slotted to the plate edge of the passive plate, the slotting scheme can greatly improve the performance of the antenna axial ratio.

Therefore, the method of vertically slotting the short side of the antenna towards the antenna direction can improve the axial ratio performance of the antenna adopting the asymmetric metal reflection floor, but it should be noted that the length and the width of the slot need to be specifically designed according to the length-width ratio of the antenna.

It should be noted that the non-symmetrical metal reflective floor in the present application may also take other asymmetrical shapes, such as an oval or a diamond. By way of example, fig. 9 and 10 illustrate a structure of a microstrip antenna using an elliptical metal reflective floor according to an embodiment of the present application. In fig. 9, the plane of the metal reflective ground plate of the 2-feed-point single-layer microstrip antenna is an ellipse, while the planes of the antenna passive plate and the metal radiating patch are squares. In fig. 10, the plane of the metal reflective ground plate of the 2-feed-point single-layer microstrip antenna is an ellipse, the plane of the passive plate of the antenna is also an ellipse, and the plane of the metal radiating patch is a square. The axial ratio performance of the antenna can be improved by symmetrically slotting in the long axis direction of the elliptical metal reflection floor of the antenna.

Fig. 11 schematically illustrates a structure of a helical antenna using a rectangular metal reflective backplane according to an embodiment of the present application. As shown in fig. 11, the passive element of the helical antenna is placed in a central position above a rectangular metal reflective floor. The passive array specifically comprises a cylindrical passive plate and a plurality of spiral metal radiating arms positioned on the side face of the cylindrical passive plate, the cylindrical passive plate can be an FPC (flexible printed circuit), a feeding point is arranged at the junction position of the spiral metal radiating arms and the metal reflecting floor, and a grounding branch is arranged near the feeding point on the cylindrical passive plate. Two symmetrical gaps are arranged in the vertical direction of the short edge of the rectangular metal reflection floor, and the length of the groove is less than the edge of the cylindrical passive plate.

In summary, the method of slotting in the direction perpendicular to the short side (i.e. the long axis direction) of the metal reflective floor of the antenna can improve the axial ratio performance and the 3db axial ratio beam width of the asymmetric metal reflective floor antenna, thereby improving the quality of signals received or transmitted by the antenna, and the scheme is applicable to various types of circularly polarized antennas, such as single-layer microstrip antennas, stacked multiband microstrip antennas, helical antennas, and the like. The slot length and width of the antenna can vary according to the length-width ratio of the antenna reflection floor, for example, the larger the length-width ratio is, the shorter the slot length is, and the larger the width is.

Based on the same inventive concept, the present application further provides a satellite navigation transceiver device, where the satellite navigation transceiver device includes the satellite navigation antenna described in the above embodiment.

Claims

1. A satellite navigation antenna is characterized by comprising a non-completely symmetrical metal reflecting floor and an antenna passive array positioned at the central position on the metal reflecting floor, wherein the metal reflecting floor is an axisymmetric pattern with two symmetry axes of a short axis and a long axis which are perpendicular to each other;

two gaps exist on the metal reflection floor along the direction from the long axis to the center position by taking the end point of the long axis as a starting point, the two gaps are the same in shape and size, and the positions of the two gaps are symmetrical along the short axis.

2. The satellite navigation antenna of claim 1, wherein the metal reflective floor is rectangular, oval, or diamond shaped.

3. The satellite navigation antenna of claim 1, wherein the length and width of the slot are determined according to an aspect ratio of the major axis to the minor axis of the metallic reflective floor;

the longest length of the gap is from the end point of the long axis of the metal reflection floor to the plate edge of the antenna passive array.

4. The satellite navigation antenna of claim 3, wherein the length of the slot is inversely proportional to the aspect ratio and the width of the slot is proportional to the aspect ratio.

5. The satellite navigation antenna of claim 1, wherein the metal reflective floor is a Printed Circuit Board (PCB) and the slot is in a copper foil layer on the PCB.

6. The satellite navigation antenna of claim 1, wherein the antenna passive element is one or more layers of stacked microstrip antennas, each layer of microstrip antenna includes a passive plate and a metal radiating patch located above the passive plate, and the metal radiating patch has a plurality of feeding points disposed thereon.

7. The satellite navigation antenna of claim 1, wherein the passive antenna element is a helical antenna, and the helical antenna comprises a cylindrical passive plate and a plurality of helical metal radiating arms located on the side of the cylindrical passive plate, and a feeding point is disposed at a position where the helical metal radiating arms interface with a metal reflective floor.

8. A satellite navigation transceiver device, characterized in that it comprises a satellite navigation antenna according to any one of claims 1 to 7.