Antenna device with adjustable arbitrary polarization

Abstract

The utility model belongs to the technical field of antennas, and relates to an antenna device with adjustable arbitrary polarization, which comprises a radio frequency module and an antenna module, the radio frequency module comprises two numerical control phase shifters and two numerical control attenuators; the antenna module comprises more than two antennas, the number of the antennas is an even number, and the antennas are averagely divided into two groups; one numerical control phase shifter is connected with one group of antennas through one numerical control attenuator, and the other numerical control phase shifter is connected with the other group of antennas through the other numerical control attenuator; after the phases of the two paths of radio frequency signals are regulated and controlled by the numerical control phase shifter and the amplitudes of the two paths of radio frequency signals are regulated and controlled by the numerical control attenuator, the two groups of antennas radiate orthogonally polarized electromagnetic waves so as to realize arbitrary polarization adjustability of the antennas. According to the invention, any polarization of the antenna can be adjusted, the polarization form is flexible, and the polarization switching speed is improved.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to an antenna device with adjustable polarization. Background Art

[0002] The polarization of an antenna refers to the polarization of the electromagnetic waves radiated by the antenna in a given direction.

[0003] Traditional antennas are often single polarization antennas, such as dipole antennas, broadcast antennas, etc. In recent years, an antenna that can change the polarization direction has emerged, called a polarization-adjustable antenna. Because the polarization of the radiated electromagnetic waves can be adjusted in real time, it is more conducive to the integration of antenna functions and applications in complex environments, and has received widespread attention from researchers.

[0004] In the prior art, common polarization adjustable solutions include loading a radio frequency switch, an adjustable phase shifter, mechanical rotation, etc. at the antenna end.

[0005] Among them, the RF switch controls the on and off of the RF link through an external voltage, changes the distribution of current on the antenna surface, and thus affects the polarization of the radiated electromagnetic wave; and the method of loading an adjustable phase shifter at the front end of the antenna is to achieve the switching between linear polarization, circular polarization and orthogonal polarization of the antenna by adjusting the phase difference on different RF links; mechanical rotation is to change the direction of antenna polarization by rotating the antenna around its axis, which is often used in antenna testing.

[0006] However, although these current polarization adjustable solutions have achieved the switching of the polarization of the radiated electromagnetic waves, there are still some problems. For example, the linear polarization angle of the antenna is limited, and it can often only achieve switching between two orthogonal polarizations; the switching takes a long time, and it takes a long time to achieve the change of polarization. Utility Model Content

[0007] Based on this, it is necessary to provide an antenna device with arbitrary polarization adjustment to address the above technical problems, which can achieve arbitrary polarization adjustment of the antenna, flexible polarization form, and improve polarization switching speed.

[0008] An antenna device with adjustable polarization, comprising: a radio frequency module and an antenna module;

[0009] The radio frequency module includes: two digitally controlled phase shifters and two digitally controlled attenuators;

[0010] The antenna module includes: more than two antennas, the number of the antennas is an even number and is evenly divided into two groups;

[0011] One digitally controlled phase shifter is connected to one set of antennas through a digitally controlled attenuator, and another digitally controlled phase shifter is connected to another set of antennas through another digitally controlled attenuator;

[0012] After the phases of the two radio frequency signals are adjusted by the digitally controlled phase shifter and the amplitudes are adjusted by the digitally controlled attenuator, the two groups of antennas radiate orthogonally polarized electromagnetic waves to achieve arbitrary polarization adjustment of the antennas.

[0013] In one embodiment, the radio frequency module further includes: two radio frequency switches;

[0014] One radio frequency switch is connected to one digitally controlled phase shifter, and the other radio frequency switch is connected to another digitally controlled phase shifter.

[0015] In one embodiment, the radio frequency module further includes: a power divider;

[0016] One end of the power divider is connected to an external signal input end, and the other end is connected to two radio frequency switches respectively.

[0017] In one embodiment, it further includes: an electric control module;

[0018] One end of the electric control module is connected to the external power input terminal, and the other end is connected to the RF switch, digitally controlled phase shifter and digitally controlled attenuator in the RF module to provide voltage for the RF module and output control instructions to the RF switch, digitally controlled phase shifter and digitally controlled attenuator.

[0019] In one embodiment, the antenna module includes: four antennas;

[0020] The sides of the four antennas are connected end to end in this manner, so that the antenna module forms a square ring structure.

[0021] In one embodiment, two non-adjacent antennas are grouped together, and the polarization directions of the two antennas in one group are the same.

[0022] In one embodiment, the antenna is a Vivaldi antenna.

[0023] In one embodiment, the antenna includes: a dielectric layer, a radiation layer arranged on the top of the dielectric layer, and a feeding layer arranged on the bottom of the dielectric layer.

[0024] In one embodiment, a plurality of slots are symmetrically provided on the two radiation arms of the radiation layer, and the length direction of the slots is perpendicular to the length direction of the dielectric layer.

[0025] In one embodiment, the feed layer includes: matching branches and microstrip lines;

[0026] The matching branch is a circular structure, the microstrip line is an "L"-shaped structure, one end of the microstrip line is connected to the matching branch, and the other end is connected to the digitally controlled attenuator as a feeding port.

[0027] The above-mentioned antenna device with arbitrary polarization adjustment is designed with a radio frequency module and an electric control module including a power divider, a radio frequency switch, a digitally controlled phase shifter and a digitally controlled attenuator, which solves the problems of few polarization angles and long polarization switching time in the existing polarization adjustable antenna scheme. By jointly regulating the phase amplitude of the input signal, the antenna can achieve rapid switching of linear polarization, circular polarization, and elliptical polarization at any angle, which greatly improves the diversity of generated polarization forms and makes the polarization form of electromagnetic waves radiated by the antenna more flexible. At the same time, the control method of electrical signals is adopted, and the polarization form of the generated electromagnetic waves can be quickly switched in a very short time, making the operation more convenient and expanding the applicable field of polarization adjustable antennas. In addition, four Vivaldi antennas are used to radiate the signal modulated by the radio frequency module into free space, and superimpose the generated set polarization form. The Vivaldi antenna is an end-fire broadband antenna with good directivity, good polarization effect of generated electromagnetic waves, and miniaturization is also achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic block diagram of an antenna device with adjustable polarization in an embodiment;

[0029] Figure 2 A schematic diagram of a radio frequency module of an antenna device with adjustable polarization in an embodiment;

[0030] Figure 3 is a schematic diagram of a linearly polarized wave in the polarization of an electromagnetic wave in one embodiment;

[0031] Figure 4 is a schematic diagram of a circularly polarized wave in electromagnetic wave polarization in one embodiment;

[0032] Figure 5 is a schematic diagram of an elliptically polarized wave in the polarization of an electromagnetic wave in an embodiment;

[0033] Figure 6 A schematic diagram of an antenna module of an antenna device with adjustable polarization in an embodiment;

[0034] Figure 7 is a top view of an antenna in one embodiment;

[0035] Figure 8 is a bottom view of an antenna in one embodiment;

[0036] Fig. 9 A diagram showing simulation results in one embodiment. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0038] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0039] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "multiple groups" means at least two groups, such as two groups, three groups, etc., unless otherwise clearly and specifically defined.

[0040] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0041] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0042] The present application provides an antenna device with adjustable polarization. Figure 1 and Figure 2 As shown, in one embodiment, it includes: a radio frequency module and an antenna module.

[0043] One end of the RF module is connected to an external signal input end to receive an input signal, and the other end is connected to an antenna module. The RF module includes: a power divider, two RF switches, two digitally controlled phase shifters, and two digitally controlled attenuators.

[0044] The antenna module includes: more than two antennas, the number of antennas is an even number, and they are evenly divided into two groups, that is, the antenna module includes two groups of antennas of equal number, one of which is the first antenna, and the other is the second antenna, the first antenna and the second antenna each include more than one antenna, and the two groups of antennas radiate orthogonally polarized electromagnetic waves to radiate the signal output by the radio frequency module into free space, thereby synthesizing electromagnetic waves of specified polarization. When the number of antennas is more than four, the multiple antennas form an antenna array.

[0045] Among them, an RF switch, a digitally controlled phase shifter and a digitally controlled attenuator are connected in sequence to form a first channel, and the first channel is connected to a group of antennas (i.e., the first antenna); another RF switch, another digitally controlled phase shifter and another digitally controlled attenuator are connected in sequence to form a second channel, and the second channel is connected to another group of antennas (i.e., the second antenna).

[0046] One end of the power divider is connected to an external signal input end to receive an input signal, and the two ports of the other end are respectively connected to two RF switches to be connected to two groups of antennas through a first channel and a second channel respectively; the RF signal of the RF module input to the external signal input end is divided into two identical signals by the power divider, and after the RF switch turns on the corresponding channel, the digitally controlled phase shifter adjusts the phase of the signal, and the digitally controlled attenuator adjusts the amplitude of the signal, the two signals (i.e., output signal 1 and output signal 2) are output to the two groups of antennas, and the two groups of antennas radiate orthogonally polarized electromagnetic waves to realize arbitrary polarization adjustment of the antenna.

[0047] In the present application, the principle for achieving arbitrary polarization adjustability is the superposition of spatial wave vectors.

[0048] Specifically:

[0049] Assuming that there are any two orthogonally polarized electromagnetic waves propagating in the +z direction in space, the expression is as follows:

[0050]

[0051]

[0052] in, represents an x-polarized electromagnetic wave propagating in the +z direction, represents the unit vector along the x direction, E xm represents the amplitude of the x-polarized electromagnetic wave propagating in the +z direction, w represents the angular frequency, t represents the time, k represents the wave number, and z represents the direction of wave propagation. represents the initial phase of the x-polarized electromagnetic wave propagating along the +z direction; represents the y-polarized electromagnetic wave propagating along the +z direction, represents the unit vector along the y direction, E ym represents the amplitude of the y-polarized electromagnetic wave propagating along the +z direction, Represents the initial phase of the y-polarized electromagnetic wave propagating along the +z direction.

[0053] The two polarized electromagnetic waves are superimposed in space, and z=0, then the synthetic field becomes:

[0054]

[0055] When taking When , the expression of the synthetic field is as follows:

[0056]

[0057] When taking When , the expression of the synthetic field is as follows:

[0058]

[0059] From equations (4) and (5), it can be concluded that when the initial phases of the two electromagnetic waves are the same or differ by 180°, the amplitude and polarization direction of the composite field are given by E xm and E ym The expression of polarization angle is determined by two values:

[0060]

[0061] It can be seen that the polarization angle is a constant that does not change with time. Therefore, the polarization of the synthetic electromagnetic wave is a linearly polarized wave with a rotation angle of α, such as Figure 3 shown.

[0062] By setting the appropriate amplitude and phase, linear polarization waves of any angle can be achieved, as shown in Table 1, where E xmN and E ymN Represents the normalized magnitude of the field.

[0063] Table 1: Comparison table of amplitude phase and rotation angle of linear polarization wave

[0064] <![CDATA[E xmN ]]> 0 0.25 0.5 0.75 1 1 1 1 1 <![CDATA[E ymN ]]> 1 1 1 1 1 0 0.25 0.5 0.75 Phase difference (°) 0 0 0 0 0 180 180 180 180 Polarization angle (°) 90 75.9 63.4 53.1 45 0 166 153.4 143.1

[0065] In order to synthesize circularly polarized waves, it is necessary to satisfy the requirement that the amplitudes of the two orthogonal polarized waves are the same and the initial phases differ by 90°, that is:

[0066]

[0067] when Ahead of the times When , it is a left-hand circularly polarized wave. Ahead of the times When , it is a right-hand circularly polarized wave, such as Figure 4 shown.

[0068] Except for the above two cases, the electromagnetic waves superimposed in other cases are all elliptically polarized waves. When , the obtained wave is left-handed elliptically polarized. When , the right-handed elliptically polarized wave is obtained, such as Figure 5 shown.

[0069] The angle θ between the major axis of the elliptically polarized wave and the x-axis can be determined by the following formula:

[0070]

[0071] That is to say, by setting the amplitude and phase of the two RF signals, the generation and switching of any linear polarization wave, circular polarization wave and elliptically polarization wave can be achieved.

[0072] In one embodiment, it further includes: an electric control module, that is, the antenna device includes: an electric control module, a radio frequency module and an antenna module.

[0073] One end of the electronic control module is connected to the external power input terminal (i.e., the external power supply), and the other end is connected to the RF module. Specifically, the other end is connected to the RF switch, CNC phase shifter and CNC attenuator in the RF module, providing the required voltage for each component of the RF module and outputting corresponding control instructions to the RF switch, CNC phase shifter and CNC attenuator of the RF module.

[0074] Compared with the traditional mechanical rotation polarization control method, the use of digital controlled attenuators and digital controlled phase shifters can achieve a shorter response time. For example: the electronic control module uses an F1 series single chip with a system clock of 72MHz. Each RF switch, digital controlled phase shifter and digital controlled attenuator of the electronic control module corresponds to a chip, wherein the digital controlled phase shifter and digital controlled attenuator correspond to digital controlled chips, each of which has 6 control bits, and the digital controlled chips of two channels (first channel and second channel) have a total of 24 control bits, and the instruction execution time is about 1 / 72M*24=333.4ns. The power signal transmission time on the control board (FR4, line width 10 inches) of the electronic control module is about 1.64ns, the power signal transmission time on the RF module (4350B, line width 10 inches) is about 1.33ns, and the signal transmission time on the cable (1m) connecting the digital controlled attenuator and the antenna is about 2.5ns. The response time of the digital controlled attenuator is 60ns, and the response time of the digital controlled phase shifter is about 100ns. The total time required to switch the polarization state once is 498.87ns. Traditional mechanical rotation to change the polarization of the antenna takes several seconds, and during this time, the electronic control method can achieve more than a million polarization switches. Therefore, this application can adjust the polarization mode of electromagnetic waves in a very short time, and has great application prospects in the fields of communication and electromagnetic interference that require polarization conversion.

[0075] In one embodiment, Figures 6 to 8 As shown, the antenna module includes: four antennas; the sides of the four antennas are connected end to end in sequence so that the antenna module forms a square ring structure; two non-adjacent antennas (i.e., two opposite antennas) are grouped together, and the polarization directions of the two antennas in a group are the same (i.e., co-polarized antennas). The two adjacent antennas are arranged perpendicular to each other, and the two groups of antennas radiate orthogonally polarized electromagnetic waves. Compared with the structure in which two antennas overlap, the square ring structure has less mutual interference between the four antennas because the adjacent antennas are exactly the same and are placed crosswise, which is conducive to improving the isolation and the polarization effect of generating electromagnetic waves.

[0076] In existing designs, CPR is often used to measure the quality of antenna polarization characteristics, which is generally around -25 to -30dB. The expression of cross-polarization ratio (CPR) is as follows:

[0077]

[0078] Among them, P co is the main polarization power, P x is the cross-polarization power.

[0079] like Fig. 9 As shown in the simulation results, when the square ring structure is used in the present application to generate a 45° linear polarization wave, the CPR can reach -35dB.

[0080] Preferably, the antenna is a Vivaldi antenna (ie, a Vivaldi antenna), comprising: a dielectric layer, a radiation layer arranged on the top of the dielectric layer, and a feeding layer arranged on the bottom of the dielectric layer.

[0081] The dielectric layer provides support for the radiation layer and the feeding layer. The sides of the four antennas in the antenna module are connected end to end in sequence. The dielectric layers of the four antennas can be directly connected, or the dielectric layers of the four antennas can be spaced from each other but connected through external brackets. The specific connection method is existing technology and will not be repeated here.

[0082] A plurality of slots are symmetrically arranged on the two radiation arms of the radiation layer to form grid gaps, thereby achieving miniaturization and improving the internal impedance coefficient of the band, and the length direction of the slots is perpendicular to the length direction of the dielectric layer.

[0083] The feeding layer includes: a matching branch and a microstrip line; the matching branch is a circular structure, the microstrip line is an "L"-shaped structure, one end of the microstrip line is connected to the matching branch, and the other end is connected to the digitally controlled attenuator as a feeding port.

[0084] It should be noted that, of the two radiation layers of the same group of antennas (eg, the first antenna), one radiation layer is disposed on the outer wall of the square ring structure, and the other radiation layer is disposed on the inner wall of the square ring structure to ensure that the phases of electromagnetic waves radiated by the same group of antennas are consistent.

[0085] It should also be noted that the radiation layer and the feeding layer are both made of metal materials (such as copper), and the dielectric layer is made of non-metallic materials.

[0086] The above-mentioned antenna device with arbitrary polarization adjustment is designed with a radio frequency module and an electric control module including a power divider, a radio frequency switch, a digitally controlled phase shifter and a digitally controlled attenuator, which solves the problems of few polarization angles and long polarization switching time in the existing polarization adjustable antenna scheme. By jointly regulating the phase amplitude of the input signal, the antenna can achieve rapid switching of linear polarization, circular polarization, and elliptical polarization at any angle, which greatly improves the diversity of generated polarization forms and makes the polarization form of electromagnetic waves radiated by the antenna more flexible. At the same time, the control method of electrical signals is adopted, and the polarization form of the generated electromagnetic waves can be quickly switched in a very short time, making the operation more convenient and expanding the applicable field of polarization adjustable antennas. In addition, four Vivaldi antennas are used to radiate the signal modulated by the radio frequency module into free space, and superimpose the generated set polarization form. The Vivaldi antenna is an end-fire broadband antenna with good directivity, good polarization effect of generated electromagnetic waves, and miniaturization is also achieved.

[0087] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An antenna device with adjustable polarization, characterized in that: include: RF module and antenna module; The radio frequency module includes: two digitally controlled phase shifters and two digitally controlled attenuators; The antenna module includes: more than two antennas, the number of the antennas is an even number and is evenly divided into two groups; One digitally controlled phase shifter is connected to one set of antennas through a digitally controlled attenuator, and another digitally controlled phase shifter is connected to another set of antennas through another digitally controlled attenuator; After the phases of the two radio frequency signals are adjusted by the digitally controlled phase shifter and the amplitudes are adjusted by the digitally controlled attenuator, the two groups of antennas radiate orthogonally polarized electromagnetic waves to achieve arbitrary polarization adjustment of the antennas.

2. The antenna device with adjustable polarization according to claim 1, characterized in that: The radio frequency module also includes: two radio frequency switches; One radio frequency switch is connected to one digitally controlled phase shifter, and the other radio frequency switch is connected to another digitally controlled phase shifter.

3. The antenna device with adjustable polarization according to claim 2, characterized in that: The radio frequency module also includes: a power divider; One end of the power divider is connected to an external signal input end, and the other end is connected to two radio frequency switches respectively.

4. The antenna device with adjustable polarization according to claim 3, characterized in that: Also includes: Electronic control module; One end of the electric control module is connected to the external power input terminal, and the other end is connected to the RF switch, digitally controlled phase shifter and digitally controlled attenuator in the RF module to provide voltage for the RF module and output control instructions to the RF switch, digitally controlled phase shifter and digitally controlled attenuator.

5. The antenna device with adjustable polarization according to any one of claims 1 to 4, characterized in that: The antenna module includes: four antennas; The sides of the four antennas are connected end to end in sequence, so that the antenna module forms a square ring structure.

6. The antenna device with adjustable polarization according to claim 5, characterized in that: Two non-adjacent antennas are grouped together, and the polarization directions of the two antennas in one group are the same.

7. The antenna device with adjustable polarization according to any one of claims 1 to 4, characterized in that: The antenna is a Vivaldi antenna.

8. The antenna device with adjustable polarization according to claim 7, characterized in that: The antenna comprises: a dielectric layer, a radiation layer arranged on the top of the dielectric layer, and a feeding layer arranged on the bottom of the dielectric layer.

9. The antenna device with adjustable polarization according to claim 8, characterized in that: A plurality of slots are symmetrically arranged on the two radiation arms of the radiation layer, and the length direction of the slots is perpendicular to the length direction of the dielectric layer.

10. The antenna device with adjustable polarization according to claim 9, characterized in that: The feeding layer includes: matching branches and microstrip lines; The matching branch is a circular structure, the microstrip line is an "L"-shaped structure, one end of the microstrip line is connected to the matching branch, and the other end is connected to the digitally controlled attenuator as a feeding port.

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