CN111146585B - Antenna unit and antenna device - Google Patents

Abstract

The invention provides an antenna unit and an antenna device, wherein the antenna unit includes: a dielectric substrate, a ground plate and a square radiation patch, where a feeding point is arranged on the square radiation patch; the square radiation patch responds to the excitation of the fundamental mode signal, forming the first surface current and in response to the high-order mode excitation signal, forming the second surface current; the area where the first surface current is formed on the square radiation patch includes the first area and the second area, and the current density of the first area Greater than the current density of the second area, the area of the second surface current formed on the square radiation patch includes the third area and the fourth area, the current density of the third area is greater than the current density of the fourth area; the second area and the third area There is an overlapping area in the area; a first slot is provided on the overlapping area; a resistive structure is provided on the edge of the square radiation patch, and the resistive structure is used to make the two of any one of the first surface current and the second surface current A preset phase difference is generated between two quadrature current components.

Description

Antenna unit and antenna assembly

technical field

The present invention relates to the field of communication technology, in particular to an antenna unit and an antenna device.

Background technique

Microstrip antenna is an antenna with simple structure, low cost, small size, and light weight. It has strong design flexibility, easy conformal shape, and easy integration. It is widely used in communication, navigation, radar and other fields.

At present, in order to improve stability and cope with different working environments, the microstrip antenna is required to work at two different frequencies in the uplink and downlink, and to achieve circular polarization to reduce the reflection noise of rain, fog and clouds on the propagation path.

In the existing technical scheme of dual-frequency circular polarization for microstrip antennas, the main implementation method is to adopt a laminated structure to realize circular polarization of two resonant frequencies on different substrates. However, the size of the microstrip antenna in this scheme Larger and difficult to process; in the single-chip dual-frequency circular polarization technology scheme, the radiation patch with single-mode operation is often used, so it is necessary to make the radiation patch have a specific shape (such as long rectangle, ellipse, radiation patch set branches, etc.), so that two resonant frequencies can exist on the radiation patch at the same time, thereby achieving dual-frequency circular polarization. However, a radiation patch with a specific shape may have insufficient circular polarization axial ratio bandwidth, and two resonance The fixed frequency ratio leads to problems such as a small range of applicability.

Contents of the invention

The present invention aims to solve at least one of the technical problems in the prior art, and proposes an antenna unit and an antenna device.

In order to achieve the above object, the present invention provides an antenna unit, comprising: a dielectric substrate, ground plates respectively arranged on both sides of the dielectric substrate, and a square radiation patch, the square radiation patch is provided with a feeding point The square radiating patch is configured to form a first surface current on the square radiating patch in response to the fundamental mode excitation signal fed into the feeding point, and respond to the high A secondary mode excitation signal, forming a second surface current on the square radiation patch; the area where the first surface current is formed on the square radiation patch includes a first area and a second area, and the first area The current density of the square radiation patch is greater than the current density of the second area, and the area of the second surface current formed on the square radiation patch includes a third area and a fourth area, and the current density of the third area is greater than the current density of the second area. The current density of the fourth area; the second area and the third area have an overlapping area; wherein,

The square radiation patch is provided with a first slot, and the first slot is located in the overlapping area;

The edge of the square radiating patch is provided with a resistive structure, and the resistive structure is used to generate between two orthogonal current components of any one of the first surface current and the second surface current Preset phase difference.

Optionally, the square radiation patch has two opposite first edges and two opposite second edges, and there are two overlapping regions on the square radiation patch, and the two overlapping regions are respectively Near the two first edges of the square radiation patch, each of the overlapping regions is provided with the first slot, and the first slot is strip-shaped;

The first said square radiation patch is further provided with strip-shaped second slots, and the extension direction of the second slots intersects with the extension direction of the first slots.

Optionally, the first slots located in the same overlapping area form a first slot group, and the two first slot groups in the two overlapping areas are symmetrical about the center point;

The second slots are provided on the square radiation patch close to each second edge, and the second slots close to the same second edge form a second slot group. The second slot group is symmetrical about the center point.

Optionally, the extension direction of the first slot is parallel to the first edge, and the extension direction of the second slot is parallel to the second edge.

Optionally, the feed point is set on a diagonal of the square radiation patch;

One of the first slots is included, the second slot group includes one of the second slots and are spaced apart from each other, and the resistant structure is arranged on a pair of sides of the square radiation patch.

Optionally, the feeding point is set on the perpendicular line of the first edge or the second edge of the square radiating patch;

Two first slots spaced apart from each other, the second slot group includes two second slots spaced apart from each other, the first slot communicates with its adjacent second slot, The resistant structure is arranged on one set of diagonal corners of the square radiation patch.

Optionally, the square radiation patch is further provided with a third slot, the first slot communicates with the second slot adjacent to it through the third slot, and the third slot The extending direction of the slot intersects with the extending directions of the first slot and the second slot.

Optionally, the resistant structure includes a branched structure;

The dielectric substrate is provided with a via hole, and a connection line is provided in the via hole, and the branch structure is electrically connected to the ground plate through the connection line.

Optionally, the square radiating patch is connected to one end of a feeder line, and via holes are provided on the dielectric substrate and the ground plate, and the feeder line passes through holes on the dielectric substrate and the ground plate. Via;

The ground plate is insulated from the feeder.

Optionally, the fundamental mode is a TM10 mode, and the higher-order mode is a TM30 mode.

Optionally, the preset phase difference is 90° or 270°.

An embodiment of the present invention further provides an antenna device, which includes the above-mentioned antenna unit.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

FIG. 1 is a schematic diagram of a first structure of an antenna unit provided by an embodiment of the present invention;

Fig. 2 is the longitudinal sectional view of Fig. 1 along section line BB ' provided by the embodiment of the present invention;

Figure 3a is a schematic diagram of the current density corresponding to the fundamental mode provided by the embodiment of the present invention;

Fig. 3b is a schematic diagram of the current density corresponding to the higher-order mode provided by the embodiment of the present invention;

FIG. 4 is a schematic diagram of a second structure of the antenna unit provided by an embodiment of the present invention;

Figure 5a is a schematic diagram of the first resistance structure provided by the embodiment of the present invention;

Figure 5b is a schematic diagram of the second resistance structure provided by the embodiment of the present invention;

Figure 5c is a schematic diagram of the third resistance structure provided by the embodiment of the present invention;

Figure 5d is a longitudinal section view of Figure 5c along section line CC';

Fig. 6 is a bottom view of the antenna unit provided by the embodiment of the present invention;

Fig. 7a is a schematic diagram of the frequency band S11 curve of the fundamental mode provided by the embodiment of the present invention;

Fig. 7b is a schematic diagram of the frequency band S11 curve of the higher-order mode provided by the embodiment of the present invention;

Fig. 8a is a schematic diagram of the frequency band axial ratio of the fundamental mode provided by the embodiment of the present invention;

Fig. 8b is a schematic diagram of the frequency band axial ratio of the higher-order mode provided by the embodiment of the present invention;

Fig. 9 is a schematic diagram of the polarization characteristics after loading the resistant structure provided by the embodiment of the present invention.

Among them, reference signs include:

1. Dielectric substrate; 2. Grounding plate; 3. Square radiation patch; 31. First slot; 32. Resistant structure; 33. Second slot; 34. Third slot; 4. Feed point; 51. Connecting line; 6. Via hole; 61. Feeder line.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

An embodiment of the present invention provides an antenna unit. FIG. 1 is a schematic diagram of a first structure of the antenna unit provided by an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of FIG. 1 along section line BB' provided by an embodiment of the present invention. As shown in Fig. 1 and Fig. 2, the antenna unit of the embodiment of the present invention includes: a dielectric substrate 1, a ground plate 2 and a square radiation patch 3 respectively arranged on both sides of the dielectric substrate 1, and the square radiation patch 3 is arranged There are feed points 4. The square radiation patch 3 is configured to form a first surface current on the square radiation patch 3 in response to the fundamental mode excitation signal fed from the feed point 4, and to respond to the high-order mode excitation signal fed from the feed point 4 , forming a second surface current on the square radiation patch 3 . Figure 3a is a schematic diagram of the current density corresponding to the fundamental mode provided by the embodiment of the present invention, and Figure 3b is a schematic diagram of the current density corresponding to the higher-order mode provided by the embodiment of the present invention, as shown in Figure 3a and Figure 3b, the square radiation The region where the first surface current is formed on the patch 3 includes a first region X and a second region Y, the current density of the first region X is greater than the current density of the second region Y, and the second surface is formed on the square radiation patch 3 The current region includes a third region M and a fourth region N, and the current density of the third region M is greater than the current density of the fourth region N. There is an overlapping area between the second area Y and the third area M. Wherein, the square radiation patch 3 is provided with a first slot 31, and the first slot 31 is located in the overlapping area. The edge of the square radiation patch 3 is provided with a resistive structure 32, and the resistive structure 32 is used to generate a preset phase difference between the two orthogonal current components of any one of the first surface current and the second surface current .

In the embodiment of the present invention, the dielectric substrate 1 can be composed of single-layer dielectric or multi-layer dielectric, the ground plate 2 is connected to the signal terminal (for example, the ground terminal) that provides the reference signal, and the square radiation patch 3 is output through the feeder and the excitation signal The contact position between the feed line and the square radiation patch 3 is the feed point 4 in the embodiment of the present invention. In the embodiment of the present invention, the dual-frequency function of the antenna unit is realized by making the square radiation patch 3 work in two modes at the same time. When the square radiation patch 3 works in different modes (fundamental mode or higher order mode), it may have different electric fields, and the surface currents formed on the square radiation patch 3 by different electric fields are also different. For the convenience of expression, the current corresponding to the fundamental mode refers to the first surface current formed by the square radiation patch 3 in response to the excitation signal of the fundamental mode; the current corresponding to the high-order mode refers to the response of the square radiation patch 3 to the high The second surface current is formed by the excitation signal of the secondary mode. Among them, the fundamental mode can refer to the TM10 mode, and the higher-order mode can refer to the TM30 mode; since the shape of the radiation patch is a square, the amplitudes of the two orthogonal current components of the current corresponding to the fundamental mode and the higher-order mode Similarly, it is beneficial to improve the ratio bandwidth of the circular polarization axis.

Since the resonant frequencies of the fundamental mode and the higher-order mode are quite different, it is difficult to make the square radiation patch 3 work in both modes at the same time. Therefore, the embodiment of the present invention sets the first slot 31 in the following way to reduce the frequency of the two modes. state resonant frequency difference. Specifically, when the square radiation patch 3 works in the fundamental mode state, the area on which the first surface current is formed on the square radiation patch 3 may include a first area X and two second areas Y, and the two second areas Y are respectively located on both sides of the first area X; when the square radiation patch 3 works in the high-order mode state, the area where the second surface current is formed on the square radiation patch 3 may include a plurality of third areas M and a plurality of The fourth area N, and the fourth area N and the third area M are alternately arranged on the square radiation patch 3 . The position A in FIG. 3a and FIG. 3b is the overlapping area of the second area Y and the third area M.

The shape of the first slot 31 may be a long strip, for example, a rectangle, or an ellipse, or a combination of several shapes, which is not limited here. After the first slot 31 is set in the overlapping area, since the current direction on the square radiation patch 3 is changed, the electrical length of the current corresponding to the fundamental mode and the electrical length of the current corresponding to the higher-order mode are both changed. The first slot 31 is extended. For the current corresponding to the fundamental mode, the overlapping area is located in the area with low current density; while for the current corresponding to the high-order mode, the overlapping area is located in the area with high current density. Therefore, the first open The slot 31 can greatly increase the electrical length of the current corresponding to the higher-order mode while slightly increasing the electrical length of the current corresponding to the fundamental mode. By increasing the electrical length of the current corresponding to the fundamental mode and the electrical length of the current corresponding to the higher-order mode, the resonant frequency of the fundamental mode and the resonant frequency of the higher-order mode can be reduced, and the resonant frequency of the higher-order mode is reduced. The degree is greater than the reduction of the resonant frequency of the fundamental mode. Therefore, the difference between the resonant frequencies of the fundamental mode and the higher mode is reduced, and the frequency of the excitation signal can be adjusted within a small range to achieve the corresponding The resonant frequency, so that the antenna unit can work in two modes (fundamental mode and high-order mode) at the same time, and then realize the dual-frequency operation of the antenna.

In the embodiment of the present invention, the reactance of the square radiation patch 3 can be adjusted through the resistive structure 32, thereby adjusting the phases of the two orthogonal current components of the current corresponding to any mode, so that the phase between the two orthogonal current components A preset phase difference is generated between them, for example, the preset phase difference is 90° or 270°, so as to realize circular polarization. Wherein, the resistant structure 32 can be a structure such as a branch, an edge groove or a cut corner, and the branch can be an open circuit or a short circuit branch of a certain length, and the groove and the cut corner can be in various shapes. It should be noted that since reactance and susceptance are reciprocals of each other, in the embodiment of the present invention, by setting the resistive structure 32, not only the reactance on the square radiation patch 3 can be changed, but also the square radiation patch 3 can be changed at the same time. Susceptance above, which is beneficial to generate a preset phase difference between two orthogonal current components according to actual needs (adjusting reactance or adjusting susceptance).

The antenna unit provided by the embodiment of the present invention realizes the dual-frequency function of the antenna unit by enabling the radiation patch to work in two modes at the same time, and the shape of the radiation patch is not limited. Therefore, this The embodiment of the invention can use a square radiation patch, so that the amplitudes of the two orthogonal current components corresponding to the fundamental mode and the high-order mode are similar, and the problem of insufficient circular polarization axis ratio bandwidth is improved. At the same time, in order to realize dual-mode operation, the embodiment of the present invention adjusts the difference between the resonance frequency of the fundamental mode and the higher-order mode by slotting. The ratio of the resonant frequency of each mode can meet various requirements of antenna design.

In some specific embodiments, the position and quantity of the first groove 31 on the square radiation patch 3 can be determined according to actual needs, and other slots can also be set on the square radiation patch 3, so that the base mold and the height The amplitudes of the two orthogonal current components of the current corresponding to the secondary mode are equal, thereby further improving the ratio bandwidth of the circular polarization axis. Specifically, the square radiation patch 3 has two opposite first edges and two opposite second edges, and there are two overlapping regions on the square radiation patch 3, and the two overlapping regions are respectively close to the square radiation patch 3, each overlapping area is provided with a first slot 31. The first slot 31 is strip-shaped, and the square radiation patch 3 is further provided with a strip-shaped second slot 33 , the extension direction of the second slot 33 intersects the extension direction of the first slot 31 .

The specific structure of the antenna unit of the embodiment of the present invention will be described in detail below in conjunction with FIG. 1 to FIG. 6. Specifically, as shown in FIG. 1, the first edge is the side of the left and right sides of the square radiation patch 3 in FIG. 1, The second edge is the upper and lower sides of the square radiation patch 3 in FIG. 1 , and the extension direction of the second slot 33 may be perpendicular to the extension direction of the first slot 31 . By setting the second slot 33 on the square radiation patch 3, the electrical lengths of the two orthogonal current components of the current corresponding to the fundamental mode and the higher-order mode can be increased at the same time. Therefore, in the embodiment of the present invention, it is possible to Make the shapes of the first slot 31 and the second slot 33 meet: the electrical length of the current component increased by the first slot 31 is the same as the electrical length of the current component increased by the second slot 33, so that the fundamental mode and the higher order The amplitudes of the two orthogonal current components corresponding to the mode are equal, which further improves the axial ratio bandwidth of the circular polarization.

In some specific embodiments, the first slots 31 located in the same overlapping area form a first slot group, and the two first slot groups are symmetrical about the central point. A second slot 33 is provided near each second edge on the square radiation patch 3, and the second slots 33 near the same second edge form a second slot group, and the two second slot groups are about The center point is symmetrical.

Specifically, each set of first slot groups may include a longer first slot 31 or a combination of multiple shorter first slots 31, and each set of second slot groups may include a longer second slot 31. The combination of the slot 33 or a plurality of shorter second slots 33 is not limited here. In the embodiment of the present invention, the number and size of the first slots 31 in the two first slot groups can be made the same, so that the two first slot groups are symmetrical about the central point; The number and size of the second slots 31 in the slot sets are the same, so that the two sets of second slots are symmetrical about the central point. In some specific embodiments, the extension direction of the first slot 31 may be parallel to the first edge, and the extension direction of the second slot 33 may be parallel to the second edge.

In the embodiment of the present invention, the first slot 31 and the second slot 33 are arranged on the square radiation patch 3 in the above-mentioned way, and the resonance can be realized by changing the size of the first slot 31 and the second slot 33 The flexible adjustment of frequency, for example, can change the resonant frequency of TM30 mode by 3 times of the resonant frequency of TM10 mode to within the scope of 1.4～3 times of the resonant frequency of TM10 mode, therefore, adopt the antenna unit of the embodiment of the present invention, The adjustment range of the ratio of the resonance frequencies of the two modes is large and the degree of freedom is high.

As shown in FIG. 1 , the feeding point 4 is arranged on the diagonal of the square radiation patch 3 . The first slot group includes a first slot 31 , and the second slot group includes a second slot 33 . The first slot 31 and the second slot 33 are spaced apart from each other. The resistant structure 32 is arranged on one pair of sides of the square radiation patch 3 .

Specifically, setting the feeding point 4 on the diagonal of the square radiation patch 3 may mean that the feeding point 4 is located on any diagonal of the square radiation patch 3 or at a point nearby, and the feeding point 4 The direction of circular polarization may be different due to the different diagonal lines. The distance between the feeding point 4 and the patch center is determined by impedance matching. The first slot 31 and the second slot 33 are spaced apart from each other, so that the current can flow around the first slot 31 and the second slot 33 , prolonging the flow path of the current, thereby increasing the electrical length of the current. Wherein, the two first slots 31 may be symmetrical about the center of the square radiation patch 3, the two second slots 33 may be symmetrical about the center of the square radiation patch, and the adjacent two first slots 31 and the second The slot 33 may be symmetrical about the diagonal of the square radiating patch 3 . It should be noted that the first slot 31 is adjacent to the second slot 33 means that there is no other first slot 31 or second slot 32 between the first slot 31 and the second slot 33 . In the embodiment of the present invention, a resistive structure 32 can be provided on one or two pairs of sides of the square radiation patch 3, and the phase difference between two orthogonal current components of the current can be adjusted by introducing an imaginary part of impedance. The resistant structure 32 may be located at the center or outside the center of the side of the square radiation patch 3, which is not limited here. For example, Figure 5a is a schematic diagram of the first resistant structure provided by the embodiment of the present invention. As shown in Figure 5a, the resistant structure 32 is a branch structure, and the resistant structure 32 is located on a pair of sides of the square radiation patch 3 The center position of the edge.

FIG. 4 is a schematic diagram of the second structure of the antenna unit provided by the embodiment of the present invention. As shown in FIG. 4 , the feeding point 4 is set on the mid-perpendicular line of the first edge or the second edge of the square radiation patch 3 . The first slot group includes two first slots 31 spaced apart from each other, and the second slot group includes two second slots 33 spaced apart from each other. The first slot 31 communicates with the adjacent second slot 33 . The resistant structure 32 is arranged on one set of diagonal corners of the square radiation patch 3 .

Specifically, setting the feed point 4 on the mid-perpendicular line of the first edge or the second edge of the square radiating patch 3 may mean that the feed point 4 is located on or near the mid-perpendicular line. Depending on the vertical line where the feed point 4 is located, the directions of circular polarization may be different. The distance between the feeding point 4 and the patch center is determined by impedance matching. Adjacent to the first slot 31 and the second slot 33 means that there is no other first slot 31 or second slot 32 between the first slot 31 and the second slot 33 . As shown in Fig. 4, for the four pairs of first slots 31 and second slots 33 communicating with each other, an "L"-shaped structure is formed at the four corners of the square radiation patch 3, and any two " There is a gap between the L-shaped structures, so that the current can flow around the "L"-shaped structures, prolonging the flow path of the current, thereby increasing the electrical length of the current. Wherein, two first slot groups composed of four first slots 31 are symmetrical to the center of the square radiation patch 3, and two second slot groups composed of four second slots 33 are symmetrical to the center of the square radiation patch 3. The center is symmetrical, and the two adjacent first slots 31 and second slots 33 may be symmetrical about the diagonal of the square radiation patch 3 . In the embodiment of the present invention, the resistive structure 32 can be provided on one or two groups of diagonal corners of the square radiation patch 3, and the phase difference between the two orthogonal current components of the current can be adjusted by introducing the imaginary part of the impedance. The resistant structure 32 may be located at the center or outside the center of the side of the square radiation patch 3, which is not limited here. Wherein, the resistant structure 32 can be a structure such as a branch, an edge groove or a cut corner, and the branch can be an open circuit or a short circuit branch of a certain length, and the groove and the cut corner can be in various shapes. For example, FIG. 5 b is a schematic diagram of the second resistant structure provided by the embodiment of the present invention. As shown in FIG. 5 b , the resistant structure 32 is a group of diagonally cut corner structures located at the square radiation patch 3 .

In some specific embodiments, the square radiation patch 3 is also provided with a third slot 34, the first slot 31 communicates with the second slot 33 adjacent to it through the third slot 34, and the third slot 34 The extending direction of the first groove 31 and the extending direction of the second groove 33 are both intersected.

Figure 5c is a schematic diagram of the third resistance structure provided by the embodiment of the present invention, and Figure 5d is a longitudinal section view of Figure 5c along section line CC', as shown in Figure 5c and Figure 5d, the resistance structure 32 includes a branch structure. The dielectric substrate 1 is provided with a via hole, and a connection line 51 is provided in the via hole, and the branch structure 321 is electrically connected to the ground plate 2 through the connection line 51 . A short-circuit stub is formed by electrically connecting the stub structure 321 to the ground plane 2 .

The first groove 31 and the second groove 33 arranged in the above manner can ensure that the amplitudes of the quadrature components of the current corresponding to the fundamental mode and the higher-order mode are equal. Therefore, as long as the phase of one of the components is further transformed by (2n+1)π, where n is an integer, the resistive structure 32 can realize dual-frequency circular polarization. For example, if the phase difference between the two components of the TM10 mode is adjusted to (n+1/2)π, and the phase difference between the two components of the TM30 mode is adjusted to (n+1/2+2m)π, where m and n are integers, then dual Frequency single circular polarization; if the phase difference between the two components of the TM10 mode is adjusted to (n+1/2)π, and the phase difference between the two components of the TM30 mode is adjusted to (n+1/2+2m+1)π, then dual frequency can be realized Dual circular polarization.

Fig. 6 is a bottom view of the antenna unit provided by the embodiment of the present invention. As shown in Fig. 2 and Fig. 6, the square radiation patch 3 is connected to one end of the feeder 61, and the other end of the feeder 61 is used to connect to the output end of the excitation signal. Both the dielectric substrate 1 and the ground plane 2 are provided with via holes 6 , and the feeder passes through the via holes 6 on the dielectric substrate 1 and the ground plane 2 . The ground plate 2 is insulated from the feeder 61 . Specifically, the feeder can be an SMA coaxial cable.

Since the antenna unit provided by the embodiment of the present invention adopts a single feed point, a single-layer radiation patch, and dual-mode operation to achieve dual-frequency circular polarization, the antenna unit of the embodiment of the present invention has the advantages of small size, easy integration, simple process, The advantages of high degree of freedom in frequency design.

Fig. 7 a is the schematic diagram of the frequency band S11 curve of the fundamental mode provided by the embodiment of the present invention, and Fig. 7 b is the schematic diagram of the frequency band S11 curve of the higher order mode provided by the embodiment of the present invention, as can be seen from Fig. 7 a, the resonant frequency of the fundamental mode (frequency band S11 The frequency of the lowest point in the curve) is 2.45GHz. It can be seen from Figure 7b that the resonant frequency of the high-order mode (the frequency of the lowest point in the frequency band S11 curve) is 3.6GHz, and the ratio of the two frequencies is about 1.49, which is relatively low. Figure 8a is a schematic diagram of the frequency band axial ratio of the fundamental mode provided by the embodiment of the present invention, and Figure 8b is a schematic diagram of the frequency band axial ratio of the higher-order mode provided by the embodiment of the present invention, as shown in Figures 8a and 8b, the - The 10dB reflection bandwidth ranges from about 2.41GHz to 2.49GHz, and the 3dB axial ratio bandwidth of the fundamental mode ranges from about 2.3GHz to 2.6GHz. The 3dB axial ratio bandwidth of the fundamental mode is much larger than the -10dB reflection bandwidth of the fundamental mode. The -10dB reflection bandwidth of the higher-order mode is about 3.56GHz to 3.66GHz, and the 3dB axial ratio bandwidth of the higher-order mode is about 3.54GHz to 3.8GHz. The 3dB axial ratio bandwidth of the higher-order mode is much larger than the -10dB of the higher-order mode reflection bandwidth. Therefore, the axial ratio bandwidths of the fundamental mode and the high-order mode of the antenna unit in the embodiment of the present invention are both large. Fig. 9 is a schematic diagram of the polarization characteristics after loading the resistant structure provided by the embodiment of the present invention. As shown in Fig. 9, the polarization isolation reaches -20dB at 2.45GHz, and it also reaches above -10dB at 3.6GHz, and the polarization isolation The effect is better.

The implementation of the present invention further provides an antenna device, which includes the above-mentioned antenna unit. The antenna unit in the antenna device of the embodiment of the present invention adopts a single feed point, a single-layer radiation patch, and dual-mode operation to achieve dual-frequency circular polarization. Therefore, the antenna device of the embodiment of the present invention has the advantages of small size, easy integration, It has the advantages of simple process and high degree of freedom in frequency design.

It can be understood that, the above embodiments are only exemplary embodiments adopted for illustrating the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (7)

1. An antenna unit, comprising: a dielectric substrate, a ground plate and a square radiation patch that are respectively arranged on both sides of the dielectric substrate, and a feed point is provided on the square radiation patch; the square radiation patch The patch is configured to form a first surface current on the square radiating patch in response to the fundamental mode excitation signal fed into the feed point, and respond to the high-order mode excitation signal fed into the feed point to form a first surface current at the A second surface current is formed on the square radiation patch; the region where the first surface current is formed on the square radiation patch includes a first region and a second region, and the current density of the first region is greater than that of the The current density of the second area, the area where the second surface current is formed on the square radiation patch includes a third area and a fourth area, the current density of the third area is greater than the current density of the fourth area ; There is an overlapping area between the second area and the third area; characterized in that, The square radiation patch is provided with strip-shaped first slots, and the first slots are located in the overlapping area; The edge of the square radiating patch is provided with a resistive structure, and the resistive structure is used to generate between two orthogonal current components of any one of the first surface current and the second surface current preset phase difference; The square radiation patch has two opposite first edges and two opposite second edges; The square radiation patch is also provided with strip-shaped second slots, the extension direction of the second slots intersects with the extension direction of the first slots; The shapes of the first slot and the second slot are configured such that: the electrical length of the current component increased by the second slot is the same as the electrical length of the current component increased by the first slot, so that the basic The amplitudes of the two orthogonal current components corresponding to the mode mode and the higher mode mode are equal; The first slots located in the same overlapping area form a first slotting group, and the two first slotting groups in the two overlapping areas are symmetrical about the center point; The second slots are provided on the square radiation patch close to each second edge, and the second slots close to the same second edge form a second slot group. The second groove group is symmetrical about the center point; The feeding point is set on the perpendicular line of the first edge or the second edge of the square radiating patch; The first slot group includes two first slots spaced apart from each other, and the second slot group includes two second slots spaced apart from each other; the square radiation patch is further provided with The third slot communicates with the second slot adjacent to the first slot, and the extension direction of the third slot is the same as that of the first slot and the second slot. The extension directions of the second slots all intersect; The resistant structure is disposed on one set of diagonal corners of the square radiation patch and is located on a side of the third slot away from the center of the square radiation patch. 2 . The antenna unit according to claim 1 , wherein an extending direction of the first slot is parallel to the first edge, and an extending direction of the second slot is parallel to the second edge. 3 . 3. The antenna unit according to claim 1 or 2, wherein the resistant structure comprises a branch structure; The dielectric substrate is provided with a via hole, and a connection line is provided in the via hole, and the branch structure is electrically connected to the ground plate through the connection line. 4. The antenna unit according to claim 1 or 2, wherein the square radiating patch is connected to one end of a feeder line, and via holes are provided on the dielectric substrate and the ground plate, and the feeder line passing through the via holes on the dielectric substrate and the ground plane; The ground plate is insulated from the feeder. 5. The antenna unit according to claim 1 or 2, wherein the fundamental mode is a TM10 mode, and the higher order mode is a TM30 mode. 6. The antenna unit according to claim 1 or 2, wherein the preset phase difference is 90° or 270°. 7. An antenna device, comprising the antenna unit according to any one of claims 1 to 6.

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