CN116995416A

CN116995416A - Dual polarized antenna

Info

Publication number: CN116995416A
Application number: CN202210443063.9A
Authority: CN
Inventors: 李鸿铭
Original assignee: Futaihua Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Futaihua Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2022-04-25
Filing date: 2022-04-25
Publication date: 2023-11-03

Abstract

The application provides a dual-polarized antenna, which comprises an antenna unit, a first antenna unit and a second antenna unit, wherein the antenna unit comprises a dielectric substrate, a metal patch and a microstrip line; the metal patch is arranged on one surface of the medium substrate, a first gap, a second gap, a third gap and a fourth gap are formed in the metal patch, the sizes of the four gaps are the same, the first gap and the third gap are arranged oppositely and are connected to form a straight line, the second gap and the fourth gap are arranged oppositely and are connected to form a straight line, the two straight lines form a cross shape, and the four formed cross angles are right angles; the microstrip line is arranged on the other surface of the medium substrate, one end of the microstrip line is provided with a feed-in point, the feed-in point feeds in radio frequency signals, and the radio frequency signals are output from the other end of the microstrip line and then input into the four gaps so as to generate a linear polarization electric field.

Description

Dual polarized antenna

Technical Field

The application relates to the technical field of antennas, in particular to a dual-polarized antenna.

Background

With the continuous development of communication technology, various communication products, such as mobile phones, tablet computers, notebook computers, etc., have become necessary in life. Various communication products are also being developed towards functional diversity, light weight, full screen, and more rapid and efficient data transmission, which requires more and more efficient antenna operation, and less space for antenna design.

Disclosure of Invention

In view of the foregoing, the present application is directed to a dual polarized antenna that solves the above-mentioned problems.

The application provides a dual-polarized antenna, which comprises an antenna unit, wherein the antenna unit comprises a dielectric substrate, a metal patch and a microstrip line; the metal patch is arranged on one surface of the medium substrate, a first gap, a second gap, a third gap and a fourth gap are formed in the metal patch, the sizes of the first gap, the second gap, the third gap and the fourth gap are the same, the first gap and the third gap are opposite to each other and are connected to form a straight line, the second gap and the fourth gap are opposite to each other and are connected to form a straight line, the straight line formed by connecting the first gap and the third gap and the straight line formed by connecting the second gap and the fourth gap form a cross shape, four cross angles formed by the first gap, the second gap, the third gap and the fourth gap are all right angles, and the cross center of the cross shape coincides with the center point of the metal patch; the microstrip line is arranged on the other surface of the medium substrate, one end of the microstrip line is provided with a feed-in point, the feed-in point feeds in radio frequency signals, and the radio frequency signals are output from the other end of the microstrip line and are input into the first gap, the second gap, the third gap and the fourth gap so as to generate a linear polarization electric field.

Further, a first distributed inductor is arranged at one end of the first gap, which is close to the cross center, a first distributed capacitor is arranged at one end of the second gap, which is close to the cross center, a second distributed inductor is arranged at one end of the third gap, which is close to the cross center, and a second distributed capacitor is arranged at one end of the fourth gap, which is close to the cross center; the radio frequency signals are input into the first distributed inductor, the first distributed capacitor, the second distributed inductor and the second distributed capacitor to respectively generate a first electric field, a second electric field, a third electric field and a fourth electric field, wherein the electric field strength and the direction of the first electric field are the same as those of the third electric field, and the electric field strength and the electric field direction of the second electric field are the same as those of the fourth electric field.

Further, when the first electric field and the second electric field are combined to form a first combined electric field, and the third electric field and the fourth electric field are combined to form a second combined electric field, the first combined electric field and the second combined electric field are orthogonal and equal-amplitude linear horizontal polarization electric fields with the same direction, and the dual-polarized antenna realizes horizontal polarization.

Further, when the first electric field and the fourth electric field are combined to form a third combined electric field, and the third electric field and the second electric field are combined to form a fourth combined electric field, the third combined electric field and the fourth combined electric field are orthogonal and equal-amplitude linear vertical polarized electric fields with the same direction, and the dual-polarized antenna realizes vertical polarization.

Further, the dual-polarized antenna further comprises a circuit unit and a voltage source, wherein the voltage source provides voltage for the circuit unit; the circuit unit is electrically connected with the antenna unit, and the voltage in the circuit unit is changed by changing the voltage of the voltage source, so that the effective electric length of the antenna unit is adjusted.

Further, the circuit unit comprises a first direct current circuit and a second direct current circuit, the first direct current circuit is arranged on one surface of the dielectric substrate, on which the metal patch is arranged, and is distributed around the metal patch, and the first direct current circuit is used for connecting the anode of the voltage source; the second direct current circuit is arranged on one surface of the dielectric substrate, on which the microstrip line is arranged, and is distributed at the edge of the dielectric substrate, and the second direct current circuit is used for being connected with the negative electrode of the voltage source.

Further, four varactors are arranged in the circuit unit, and each varactor is arranged at one end of the corresponding gap close to the circuit unit; the four varactors are in turn connected to each other with the same electrodes for generating a bias current.

Further, two ends of each varactor are respectively provided with a capacitor, and the capacitors are used for isolating the corresponding varactors and the metal patches so as to prevent the varactors and the metal patches from being shorted.

Further, a first group of radio frequency chokes are respectively arranged on the anode of each varactor, and the first group of radio frequency chokes are electrically connected with the first direct current circuit and are connected to the anode of the voltage source; the cathode of each varactor is respectively provided with a second group of radio frequency choke coils, and the second group of radio frequency choke coils are electrically connected with a second direct current circuit and are connected to the cathode of a voltage source; the first group of radio frequency chokes and the second group of radio frequency chokes are used for realizing the conduction of direct current between the corresponding varactors and the circuit unit.

Further, the first direct current circuit and the second direct current circuit are both provided with a plurality of radio frequency chokes, and the radio frequency chokes are used for realizing the conduction of direct current in the circuit unit.

According to the dual-polarized antenna provided by the application, the antenna unit with the cross slot structure is arranged, and the radiation frequency of the dual-polarized antenna is adjusted by adjusting the length of the distributed inductor arranged in the cross slot, so that the design of the dual-polarized antenna can be reduced. In addition, the circuit unit in the dual-polarized antenna only uses one voltage source to control the capacitance values of the four varactors, and then the antenna resonant frequency of the dual-polarized antenna can be adjusted by changing the voltage of the voltage source. Furthermore, the antenna resonant frequency of the dual-polarized antenna can be adjusted by adjusting the electric field direction of the crossed slots and the length of the distributed inductor, so that dual polarization of the dual-polarized antenna is realized.

Drawings

Fig. 1 is a schematic structural diagram of a dual polarized antenna according to an embodiment of the present application at a first angle;

fig. 2 is a schematic structural diagram of a dual polarized antenna according to an embodiment of the present application at a second angle;

fig. 3 is a schematic structural diagram of a dual polarized antenna according to an embodiment of the present application at a third angle;

fig. 4 is a schematic diagram of the structure of a circuit unit in the dual polarized antenna shown in fig. 2;

fig. 5 is a schematic diagram of a dual polarized antenna according to an embodiment of the present application in a horizontal polarization state;

fig. 6 is a schematic diagram of a dual polarized antenna according to an embodiment of the present application in a vertical polarization state;

fig. 7 is a schematic diagram of a dual polarized antenna according to an embodiment of the present application in non-horizontal polarization and vertical polarization states;

fig. 8 is another schematic diagram of a dual polarized antenna according to an embodiment of the present application in non-horizontal polarization and vertical polarization states;

fig. 9 is a simulation graph of a dual polarized antenna when varactors are of different capacitance values.

Description of the main reference signs

Dual polarized antenna 100

Antenna unit 10

Dielectric substrate 11

Metal patch 12

First metal patch 121

Second metal patch 122

Third metal patch 123

Fourth metal patch 124

Microstrip line 13

Feed-in point 131

First slit 141

Second slit 142

Third slit 143

Fourth gap 144

First distributed inductor 145

Second distributed inductor 146

First distributed capacitance 147

Second distributed capacitance 148

Circuit unit 20

Radio frequency choke 201

First direct current circuit 21

Second DC circuit 22

First varactor 23

Second varactor 24

Third varactor 25

Fourth varactor 26

First capacitor 231

Second capacitor 232

First RF choke 233

Second RF choke 234

First welding point A1

First metal via B1

The application will be further described in the following detailed description in conjunction with the above-described figures.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

The terms "first" and "second" and the like in the description of the application and in the above-described figures are used for distinguishing between different objects and not for describing a particular sequential order. Furthermore, the term "include" and any variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or modules is not limited to only those steps or modules but may include other steps or modules not expressly listed or inherent to such process, method, article, or apparatus.

Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

Referring to fig. 1, a dual polarized antenna 100 according to an embodiment of the application is shown. Dual polarized antenna 100 includes antenna element 10.

The antenna unit 10 includes a dielectric substrate 11, a metal patch 12, and a microstrip line 13. The dielectric substrate 11 has a square shape. Of course, in other embodiments, the shape of the dielectric substrate 11 is not limited.

Referring to fig. 2, a metal patch 12 is disposed on one surface of a dielectric substrate 11. Four slits of the same size, namely, a first slit 141, a second slit 142, a third slit 143 and a fourth slit 144 are formed in the metal patch 12. The first slit 141 is disposed opposite to the third slit 143 and connected to form a straight line, and the second slit 142 is disposed opposite to the fourth slit 144 and connected to form a straight line. The straight line formed by connecting the first slit 141 and the third slit 143 and the straight line formed by connecting the second slit 142 and the fourth slit 144 form a cross shape, four crossing angles formed by the first slit 141, the second slit 142, the third slit 143 and the fourth slit 144 are all right angles, and the crossing center of the cross shape coincides with the center point of the metal patch 12. Correspondingly, the metal patch 12 is equally divided into four metal patches of the same size, namely a first metal patch 121, a second metal patch 122, a third metal patch 123 and a fourth metal patch 124.

The first distributed inductor 145 is arranged at one end of the first gap 141 close to the crossing center, the first distributed capacitor 147 is arranged at one end of the second gap 142 close to the crossing center, the second distributed inductor 146 is arranged at one end of the third gap 143 close to the crossing center, and the second distributed capacitor 148 is arranged at one end of the fourth gap 144 close to the crossing center. It is understood that the first distributed inductor 145, the second distributed inductor 146, the first distributed capacitor 147 and the second distributed capacitor 148 are disposed near the center of the dielectric substrate 11.

The first distributed inductor 145 and the second distributed inductor 146 are each composed of a plurality of bent metal wires arranged at intervals. The first distributed capacitance 147 and the second distributed capacitance 148 are each composed of a pair of small-sized rectangular metal patches arranged at intervals.

Referring to fig. 1 again, the microstrip line 13 is disposed on the other surface of the dielectric substrate 11, i.e. the microstrip line 13 and the metal patch 12 are disposed on two different surfaces of the dielectric substrate 11.

Referring to fig. 3, in some embodiments, the microstrip line 13 may be an open stepped microstrip line. Specifically, the microstrip line 13 is in an elongated strip shape, one end of the microstrip line 13 is disposed at an edge of one side of the dielectric substrate 11, and the other end extends toward a center position of the dielectric substrate 11 and extends to a position spaced from the edge of the other side of the dielectric substrate 11.

As shown in fig. 3, a feed point 131 is disposed at one end of the microstrip line 13 disposed at the edge of the dielectric substrate 11. The feeding point 131 is used for feeding the radio frequency signal. Specifically, the radio frequency signal may be fed from the feeding point 131, and then output from one end of the microstrip line 13 near the center of the dielectric substrate 11, and fed from the first distributed inductor 145, the second distributed inductor 146, the first distributed capacitor 147 and the second distributed capacitor 148 to the corresponding slits by means of coupling feeding, so that the corresponding slits generate corresponding electric fields. For example, the first slot 141 generates a first electric field, the second slot 142 generates a second electric field, the third slot 143 generates a third electric field, and the fourth slot 144 generates a fourth electric field. The first electric field and the third electric field have the same electric field strength and direction, and the second electric field and the fourth electric field have the same electric field strength and direction.

It can be understood that the included angles formed by the first slit 141, the second slit 142, the third slit 143 and the fourth slit 144 are all right angles. Thus, the first electric field may combine with the second electric field to form a first combined electric field, and the third electric field may combine with the fourth electric field to form a second combined electric field. The first composite electric field and the second composite electric field are orthogonal and equal-amplitude linear horizontal polarized electric fields with the same direction, so that the dual-polarized antenna 100 realizes horizontal polarization. For another example, in some embodiments, the first electric field may combine with the fourth electric field to form a third combined electric field, which may combine with the second electric field to form a fourth combined electric field. The third combined electric field and the fourth combined electric field are orthogonal and equal-amplitude linear vertical polarized electric fields with the same direction, so that the dual-polarized antenna 100 realizes vertical polarization.

It can be understood that in the embodiment of the present application, the first distributed inductor 145 and the second distributed inductor 146 correspond to a portion of the microstrip line 13. Furthermore, by adjusting the length of the bent metal line (i.e., adjusting the first distributed inductor 145 and the second distributed inductor 146), the radiation efficiency of the microstrip line 13 can be effectively adjusted. For example, when the length of the bent metal line is longer, the radiation efficiency of the microstrip line 13 is larger.

Referring to fig. 2 and 3 again, dual-polarized antenna 100 further includes circuit unit 20. The circuit unit 20 is electrically connected to a voltage source (not shown) and the antenna unit 10. The voltage source provides a voltage to the circuit unit 20, and by changing the voltage of the voltage source, the magnitude of the voltage in the circuit unit 20 can be changed to adjust the effective electrical length of the dual polarized antenna 100.

Referring to fig. 4, the circuit unit 20 includes a first dc circuit 21 and a second dc circuit 22 (see fig. 3). The first dc circuits 21 are disposed on the surface of the dielectric substrate 11 on which the metal patches 12 are disposed, and are distributed around the metal patches 12. The second dc circuit 22 is disposed on a surface of the dielectric substrate 11 on which the microstrip line 13 is disposed, and is distributed at an edge of the dielectric substrate 11.

In the embodiment of the present application, the first dc circuit 21 is used for connecting to the positive electrode of a voltage source (not shown), and the second dc circuit 22 is used for connecting to the negative electrode of the voltage source. The effective electrical length of dual polarized antenna 100 is adjusted by adjusting the voltage of circuit unit 20. For example, when the voltage of the circuit unit 20 is enhanced, the effective electrical length of the dual polarized antenna 100 can be effectively increased. Accordingly, in the embodiment of the present application, dual polarized antenna 100 may reduce the size of antenna element 10 thereof by increasing the voltage of circuit element 20.

It can be understood that, as shown in fig. 3, the first dc circuit 21 and the second dc circuit 22 are both provided with a plurality of rf chokes 201 for conducting dc current and suppressing ac current, so as to ensure stable transmission of dc current in the circuit unit 20.

The circuit unit 20 is further provided with a plurality of identical varactors, the number of varactors corresponds to the number of slots, and each varactor is respectively disposed at one end of the corresponding slot far from the center of the intersection. For example, in the embodiment of the present application, the circuit unit 20 includes four varactors, namely, a first varactor 23, a second varactor 24, a third varactor 25, and a fourth varactor 26. The first varactor 23, the second varactor 24, the third varactor 25, and the fourth varactor 26 are disposed at ends of the first slit 141, the second slit 142, the third slit 143, and the fourth slit 144, which are far from the center of intersection, respectively.

It will be appreciated that in embodiments of the present application, a plurality of varactors are sequentially connected to each other with the same electrodes to energize the varactors. For example, the anode of the first varactor 23 is electrically connected to the anode of the second varactor 24, the cathode of the second varactor 24 is electrically connected to the cathode of the third varactor 25, and the anode of the third varactor 25 is electrically connected to the anode of the fourth varactor 26 to generate a bias current.

It will be appreciated that each varactor is provided with a capacitor at each end to isolate the varactor from the metal patch 12 and prevent shorting of the anode and cathode of the varactor to the metal patch 12. For example, taking the first varactor 23 as an example, a first capacitor 231 is disposed at one end of the cathode of the first varactor 23, and a second capacitor 232 is disposed at one end of the anode of the first varactor 23. Similarly, two ends of the other varactors are respectively provided with a capacitor, which is not described herein.

It can be understood that two rf chokes are disposed on each varactor and electrically connected to the first dc circuit 21 and the second dc circuit 22 respectively, so that the varactors are connected to the circuit unit 20 through the rf chokes, and the rf chokes are used for conducting dc current and suppressing ac current, so as to ensure stable transmission of dc current between the varactors and the circuit unit 20. Specifically, taking the first varactor 23 as an example, a first rf choke 233 is disposed at one end of the cathode of the first varactor 23, and a second rf choke 234 is disposed at one end of the anode of the first varactor 23. Similarly, the two ends of the other varactors are also provided with rf chokes, which are not described here again.

In the embodiment of the present application, four metal through holes are disposed on the second dc circuit 22 and distributed on four top corners of the dielectric substrate 11, and the rf choke coil disposed on the varactor diode can be soldered with the metal through holes to electrically connect the varactor diode with the second dc circuit 22. For example, in the embodiment of the present application, the first rf choke 233 is electrically connected to the cathode of the first varactor 23, and the first rf choke 233 is electrically connected to the second dc circuit 22 by soldering with the first metal via B1. Furthermore, the cathode of the first varactor 23 is electrically connected to the second dc circuit 22 through the first rf choke 233, and is connected to the negative V-electrode of the voltage source.

In the embodiment of the present application, the rf choke coil disposed on the varactor diode may be directly soldered to the first dc circuit 21 to electrically connect the varactor diode and the first dc circuit 21. For example, the second rf choke 234 is electrically connected to the anode of the first varactor 23, and the second rf choke 234 is directly soldered to the first dc circuit 21 to form an electrical connection, and the soldering results in the first soldering point A1. Further, the anode of the first varactor is electrically connected to the first dc circuit 21 through the second rf choke 234, and is electrically connected to the positive pole v+ of the voltage source.

Thus, the circuit unit 20 can control the capacitance values of the first varactor 23, the second varactor 24, the third varactor 25, and the fourth varactor 26 by using only one voltage source. By changing the voltage of the voltage source, the antenna resonant frequency of the dual-polarized antenna 100 can be adjusted, so that the dual-polarized antenna 100 operates in a plurality of frequencies, and the utilization rate of the dual-polarized antenna 100 is improved.

Fig. 5 is a schematic diagram of dual-polarized antenna 100 in a horizontal polarization state according to an embodiment of the application. When the directions of the electric fields generated in the first slot 141 and the third slot 143 (for example, the electric field direction is 135 °) are the same, and the directions of the electric fields generated in the second slot 142 and the fourth slot 144 (for example, the electric field direction is 45 °) are the same, the electric field strength of the resultant electric field formed is enhanced in the horizontal direction, so that the dual-polarized antenna 100 realizes horizontal polarization.

Fig. 6 is a schematic diagram of dual-polarized antenna 100 in a vertical polarization state according to an embodiment of the present application. When the directions of the electric fields generated in the first slot 141 and the third slot 143 (for example, the electric field direction is 45 °) are the same, and the directions of the electric fields generated in the second slot 142 and the fourth slot 144 (for example, the electric field direction is 135 °), the electric field strength of the resultant electric field formed is enhanced in the vertical direction, so that the dual polarized antenna 100 realizes vertical polarization.

Fig. 7 is a schematic diagram of dual polarized antenna 100 in non-horizontal polarization and vertical polarization states according to an embodiment of the present application. When the directions of the electric fields generated in the first slot 141 and the third slot 143 are different, for example, the direction of the electric field generated in the first slot 141 is 45 ° and the direction of the electric field generated in the third slot 143 is 135 °, the resultant electric field formed is not enhanced in the horizontal direction or the vertical direction, and the dual polarized antenna 100 does not realize horizontal polarization or vertical polarization.

Referring to fig. 8, a dual polarized antenna 100 according to an embodiment of the application is shown in a non-horizontal polarized state and a vertical polarized state. When the electric field direction of the second slot 142 is different from the electric field direction generated in the fourth slot 144, for example, the electric field direction generated in the second slot 142 is 135 ° direction, and the electric field direction generated in the fourth slot 144 is 45 ° direction, the resultant electric field formed is not enhanced in the horizontal direction or the vertical direction, and the dual polarized antenna 100 does not realize the horizontal polarization or the vertical polarization.

Thus, dual polarization can be achieved by providing the first to fourth slits 141 to 144 such that the first slit 141 and the third slit 143, and the second slit 142 and the fourth slit 144 enhance the electric field strength in the same direction, the dual polarized antenna 100 achieves horizontal polarization or vertical polarization.

Referring to fig. 9, a graph of reflection coefficient simulation of dual-polarized antenna 100 is shown when the varactors have different capacitance values. The curve S901 is a reflection coefficient curve of the dual-polarized antenna 100 when the capacitance of the varactor diode is 0.3 picofarads (pF). Curve S902 is a reflection coefficient curve of dual polarized antenna 100 when the capacitance of the varactor diode is 0.66pF, curve S903 is a reflection coefficient curve of dual polarized antenna 100 when the capacitance of the varactor diode is 0.98pF, and curve S901 is a reflection coefficient curve of dual polarized antenna 100 when the capacitance of the varactor diode is 2.22 pF.

Obviously, as apparent from fig. 9, when the capacitance of the varactor diode is 0.3pF, 0.66pF, 0.98pF, 2.22pF and 2.6pF, the dual-polarized antenna 100 can generate effective resonance, so that the frequency band utilization rate of the dual-polarized antenna 100 is improved.

The dual polarized antenna 100 according to the present application adjusts the radiation frequency of the dual polarized antenna 100 by arranging the antenna unit 10 and adjusting the length of the distributed inductor arranged in the cross slot, so that the dual polarized antenna 100 can be designed in a reduced size. In addition, the circuit unit 20 in the dual-polarized antenna 100 controls the capacitance values of the four varactors using only one voltage source, and thus the antenna resonant frequency of the dual-polarized antenna 100 can be adjusted by changing the voltage of the voltage source. Furthermore, the antenna resonant frequency of the dual-polarized antenna 100 can also be adjusted by adjusting the electric field direction of the cross slot and the length of the distributed inductor, thereby realizing dual polarization of the dual-polarized antenna 100.

It will be appreciated by persons skilled in the art that the above embodiments have been provided for the purpose of illustration only and not for the purpose of limitation, and that the appropriate modifications and variations of the above embodiments should be within the scope of the application as claimed.

Claims

1. The dual-polarized antenna is characterized by comprising an antenna unit, wherein the antenna unit comprises a dielectric substrate, a metal patch and a microstrip line;

the metal patch is arranged on one surface of the medium substrate, a first gap, a second gap, a third gap and a fourth gap are formed in the metal patch, the first gap, the second gap, the third gap and the fourth gap are the same in size, the first gap and the third gap are oppositely arranged and are connected to form a straight line, the second gap and the fourth gap are oppositely arranged and are connected to form a straight line, the straight line formed by connecting the first gap and the third gap and the straight line formed by connecting the second gap and the fourth gap form a cross shape, four cross angles formed by the first gap, the second gap, the third gap and the fourth gap are all right angles, and the cross center of the cross shape coincides with the center point of the metal patch;

the microstrip line is arranged on the other surface of the dielectric substrate, one end of the microstrip line is provided with a feed-in point, the feed-in point feeds in a radio frequency signal, and the radio frequency signal is output from the other end of the microstrip line and is input into the first gap, the second gap, the third gap and the fourth gap so as to generate a linear polarization electric field.

2. The dual polarized antenna of claim 1, wherein a first distributed inductance is disposed at an end of the first slot near the center of the intersection, a first distributed capacitance is disposed at an end of the second slot near the center of the intersection, a second distributed inductance is disposed at an end of the third slot near the center of the intersection, and a second distributed capacitance is disposed at an end of the fourth slot near the center of the intersection;

the radio frequency signals are input into the first distributed inductor, the first distributed capacitor, the second distributed inductor and the second distributed capacitor to generate a first electric field, a second electric field, a third electric field and a fourth electric field respectively, wherein the electric field strength and the direction of the first electric field are the same as those of the third electric field, and the electric field strength and the direction of the second electric field are the same as those of the fourth electric field.

3. The dual polarized antenna of claim 2, wherein when the first electric field and the second electric field are combined to form a first combined electric field, and the third electric field and the fourth electric field are combined to form a second combined electric field, the first combined electric field and the second combined electric field are orthogonal and equal-amplitude linear horizontal polarized electric fields with the same direction, and the dual polarized antenna realizes horizontal polarization.

4. The dual polarized antenna of claim 2, wherein when the first electric field and the fourth electric field combine to form a third combined electric field, the third combined electric field and the fourth combined electric field are orthogonal and equal-amplitude linear vertical polarized electric fields with the same direction, the dual polarized antenna achieves vertical polarization.

5. The dual polarized antenna of claim 1, further comprising a circuit unit and a voltage source, said voltage source providing a voltage to said circuit unit; the circuit unit is electrically connected with the antenna unit, and the voltage in the circuit unit is changed by changing the voltage of the voltage source, so that the effective electric length of the antenna unit is adjusted.

6. The dual polarized antenna of claim 5, wherein said circuit unit comprises a first direct current circuit and a second direct current circuit, said first direct current circuit is disposed on a surface of said dielectric substrate on which said metal patch is disposed and distributed around said metal patch, said first direct current circuit is used for connecting with an anode of said voltage source; the second direct current circuit is arranged on one surface of the dielectric substrate, on which the microstrip line is arranged, and is distributed at the edge of the dielectric substrate, and the second direct current circuit is used for connecting the negative electrode of the voltage source.

7. The dual polarized antenna of claim 6, wherein four varactors are disposed in said circuit unit, each varactor being disposed at an end of a corresponding slot near said circuit unit; the four varactors are sequentially connected to each other with the same electrode to energize for generating a bias current.

8. The dual polarized antenna of claim 7, wherein each varactor diode is provided with a capacitor at two ends, said capacitor being used for isolating the corresponding varactor diode from the metal patch so as to prevent the varactor diode from being shorted with the metal patch.

9. The dual polarized antenna of claim 7, wherein a first set of radio frequency chokes are respectively disposed on anodes of each of said varactors, said first set of radio frequency chokes being electrically connected to said first direct current circuit and to a positive pole of said voltage source;

a second group of radio frequency chokes are respectively arranged on the cathode of each varactor, and are electrically connected with the second direct current circuit and connected to the cathode of the voltage source;

the first set of radio frequency chokes and the second set of radio frequency chokes are used for realizing the conduction of direct current between the corresponding varactors and the circuit unit.

10. The dual polarized antenna of claim 6, wherein said first dc circuit and said second dc circuit are each provided with a plurality of rf chokes for conducting dc current in said circuit unit.