Metasurface unit and its base station

Abstract

The present application provides a metasurface unit and a base station thereof, the metasurface unit including a resonator unit (100) configured to receive two paths of polarized incident signals or to emit two paths of polarized reflected signals, a power divider (200) connected to the resonator unit (100) and configured to combine the two paths of polarized incident signals input by the resonator unit (100) into a combined signal and / or demultiplex the input reflected signal into two paths of polarized reflected signals and output them to the resonator unit (100), and a phase shifter (300) connected to the power divider and configured to perform phase modulation on the combined signal input by the power divider (200) and output the phase-modulated reflected signal to the power divider (200).

Description

[Technical Field]

[0001] This application is based on and claims priority from a Chinese patent application having application number 202210275987.2 and filing date March 21, 2022, the entire contents of which are hereby incorporated by reference into this application.

[0002] The present application relates to the field of communications, but is not limited thereto, and in particular to metasurface units and base stations thereof. [Background technology]

[0003] Artificial electromagnetic metasurfaces are periodically arranged arrays of units that can change the propagation characteristics of electromagnetic waves and realize various special functions. For example, by designing a specific phase difference between the reflected and incident waves of each unit, the array can achieve electromagnetic beamforming at a specific angle. Conventional artificial electromagnetic metasurfaces are static structures whose electromagnetic properties cannot be changed, making them unable to meet today's communications needs. Recently, the concept of programmable metasurfaces has been proposed. This involves incorporating a radio frequency switch into the resonant unit of the metasurface unit. This allows the resonant frequency of the signal to be adjusted by changing the state of the radio frequency switch, thereby controlling the reflected phase. This allows the metasurface to exhibit dynamic electromagnetic properties, thereby achieving programmable multi-beamforming functionality.

[0004] Parameter fluctuations in the radio frequency switch can easily cause a resonant frequency offset in the resonator unit, affecting the phase modulation accuracy of the metasurface unit. To solve this problem, a combination of a resonator unit and a phase shifter is generally used, and the radio frequency switch is placed in the phase shifter to separate the resonator unit from the radio frequency switch. However, this requires one phase shifter for each polarization signal, which results in relatively high hardware costs. Summary of the Invention [Problem to be solved by the invention]

[0005] The following is a summary of the subject matter described in detail herein. This summary does not limit the scope of the claims.

[0006] An embodiment of the present application provides a metasurface unit and its base station. [Means for solving the problem]

[0007] According to a first aspect, an embodiment of the present application provides a metasurface unit, which includes a resonator unit configured to receive two paths of polarized incident signals or emit two paths of polarized reflected signals, a power divider connected to the resonator unit and configured to combine the two paths of polarized incident signals input by the resonator unit into a combined signal and / or split the input reflected signal into two paths of polarized reflected signals and output them to the resonator unit, and a phase shifter connected to the power divider and configured to perform phase modulation on the combined signal input by the power divider and output the phase-modulated reflected signal to the power divider.

[0008] According to a second aspect, an embodiment of the present application provides a base station, the base station including the metasurface unit according to the first aspect.

[0009] Other features and advantages of the present application will be set forth in the specification which follows, and in part will be obvious from the specification, or may be learned by the practice of the present application. The objectives and other advantages of the present application will be realized and obtained by the structure particularly pointed out in the description, claims and drawings. The drawings are intended to provide a further understanding of the technical solution of the present application, constitute a part of the specification, and are used to interpret the technical solution of the present application together with the examples of the present application, but are not intended to limit the technical solution of the present application. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a metasurface unit according to Example 1 of the present application. [Figure 2] FIG. 1 is a front view of a power splitter according to a first embodiment of the present application. [Figure 3] 1 is a diagram showing the internal structure of a phase shifter according to a first embodiment of the present application. [Figure 4] FIG. 10 is a diagram showing the internal structure of a phase shifter according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing the internal structure of a phase shifter according to a third embodiment of the present application. [Figure 6] Schematic diagram of 2-bit reflection amplitude at the infinite periodic boundary of the metasurface unit of the example of the present application. [Figure 7] Schematic diagram of the 2-bit reflection phase at the infinite periodic boundary of the metasurface unit of the example of this application. DETAILED DESCRIPTION OF THE INVENTION

[0011] In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be described in more detail below with reference to the drawings and examples. The examples described herein are only used to interpret the present application and are not intended to limit the present application.

[0012] Although the schematic diagram of the device shows a division into functional modules, in some cases the division into modules in the device may differ, or the steps shown or described may be performed in a different order than in the flowchart. The terms "first," "second," etc. in the specification, claims, or drawings are used to distinguish between similar objects, and are not necessarily intended to describe a specific order or sequence.

[0013] The present application provides a metasurface unit and a base station therefor, the metasurface unit including: a resonator configured to receive two polarized incident signals or emit two polarized reflected signals; a power divider connected to the resonator and configured to combine the two polarized incident signals input by the resonator into a combined signal and / or split the input reflected signal into two polarized reflected signals and output them to the resonator; and a phase shifter connected to the power divider and configured to phase modulate the combined signal input by the power divider and output the phase-modulated reflected signal to the power divider. According to the technical solution of this embodiment, by using the power divider to achieve the combining and splitting of the two polarized signals, the two polarized signals share the same phase shifter, which effectively reduces the number of phase shifters in the metasurface unit and reduces hardware costs.

[0014] In the following, examples of the present application will be further described with reference to the drawings.

[0015] Referring to FIG. 1 , the present application provides a metasurface unit, the metasurface unit comprising: a resonator unit 100 configured to receive a dual-path polarized incident signal or to emit a dual-path polarized reflected signal; a power divider 200 connected to the resonator unit 100, configured to combine two paths of polarized incident signals input by the resonator unit 100 into a combined signal, and / or to demultiplex an input reflected signal into two paths of polarized reflected signals, and output the signals to the resonator unit 100; The phase shifter 300 is connected to the power divider 200 and configured to perform phase modulation on the combined signal input by the power divider 200 and output the reflected signal obtained by the phase modulation to the power divider 200.

[0016] In the operating frequency band of the metasurface unit, the resonant unit 100 can realize a dual polarization operating mode, that is, the resonant unit 100 receives electromagnetic wave signals incident from two polarizations in space through resonance, and then combines the two polarized incident signals into one combined signal by the power divider 200, inputs the combined signal into the phase shifter 300 for phase modulation, and then reflects the signal to the power divider 200, where the reflected signal is divided into two polarized reflected signals, which are then radiated in the form of electromagnetic waves by the resonant unit 100 to form a reflected wave.

[0017] According to the structure of the metasurface unit of this embodiment, the phase shifter 300 and the resonator unit 100 are independent devices, and the device parameters of the phase shifter 300 do not affect the resonant frequency of the resonator unit 100, effectively ensuring phase modulation accuracy and allowing the metasurface unit to be applied to all frequency bands. Furthermore, the resonator unit 100 adopts a dual polarization design, in which two polarized signals with different polarizations are combined by the power divider 200 and then connected to the phase shifter 300. The two polarized signals share one phase shifter 300 for phase modulation, supporting dual polarization mode while realizing a halving effect of the phase shifter 300 in the metasurface unit and effectively reducing hardware costs.

[0018] Below, various embodiments of the metasurface unit are described using several examples.

[0019] Example 1: 1 , in this embodiment, the resonator unit 100, the power divider 200, and the phase shifter 300 are all independent devices, the resonator unit 100 includes a first polarization port 101 and a second polarization port 102, the power divider 200 includes a first power divider port 205 and a second power divider port 204, the first polarization port 101 is connected to the first power divider port 205, and the second polarization port 102 is connected to the second power divider port 204. The power divider 200 further includes a third power divider port 203, and the phase shifter 300 includes a phase shifter port 311, and the third power divider port 203 is connected to the phase shifter port 311. The resonator unit 100 is configured to receive a first polarized incident signal and a second polarized incident signal, input the first polarized incident signal to the first power divider port 205 via the first polarization port 101, and input the second polarized incident signal to the second power divider port 204 via the second polarization port 102, where the polarization directions of the first polarized incident signal and the second polarized incident signal are orthogonal to each other. The resonator unit 100 is further configured to emit a first polarized reflected signal and a second polarized reflected signal, where the polarization directions of the first polarized reflected signal and the second polarized reflected signal are orthogonal to each other, and the first polarized reflected signal is input by the power divider 200 via the first power divider port 205, and the second polarized reflected signal is input by the power divider 200 via the second power divider port 204. The power divider 200 is configured to combine the first polarized incident signal and the second polarized incident signal as a combined signal, and input the combined signal to the phase shifter 300 via the third power divider port 203, so that the phase shifter 300 performs phase modulation on the combined signal to obtain a reflected signal. The power divider 200 is further configured to obtain the reflected signal input via the phase shifter port 311 by the phase shifter 300, and split the reflected signal into a first polarized reflected signal and a second polarized reflected signal.

[0020] The resonating unit 100 may be a microstrip antenna unit or a dipole antenna unit, or may be other radiating units with a resonating function, and this embodiment does not excessively limit the device selection of the resonating unit 100.

[0021] To achieve a dual-polarized operation model, the polarized input signal received by the resonator unit 100 and the polarized output signal emitted therefrom may be orthogonal polarized signals. For example, the first polarized input signal may be an electromagnetic wave signal polarized at 45 degrees in space, and the second polarized input signal may be an electromagnetic wave signal polarized at -45 degrees in space. The combined signal is then input to the phase shifter 300 for phase modulation. The resulting reflected signal is then split into a first polarized reflected signal polarized at 45 degrees and a second polarized reflected signal polarized at -45 degrees in the power divider 200, which then radiates the resulting reflected signal in the form of an electromagnetic wave via the resonator unit 100 to form a reflected wave. The polarization directions described in the above example do not limit the technical solution of this embodiment, as long as they ensure that the polarization directions of the input and output polarized signals are orthogonal to each other.

[0022] The reflected signal in this embodiment may be a signal obtained after phase modulation of a first polarized incident signal, or a signal obtained after phase modulation of a second polarized incident signal. The metasurface unit in this embodiment splits the reflected signal using a power divider 200. After phase modulation of the first polarized incident signal with a polarization direction of 45 degrees, a first polarized reflected signal with a polarization direction of 45 degrees and a second polarized reflected signal with a polarization direction of -45 degrees can be obtained, effectively increasing the number of signal polarization types. Of course, the processing process for the second polarized incident signal with a polarization direction of -45 degrees is similar, and will not be further described here.

[0023] The power divider 200 may be a Wilkinson power divider, a 3 dB bridge, a T-junction, or an integrated component with a power dividing function, and this embodiment does not excessively limit the device selection of the power divider 200.

[0024] The phase shifter 300 may be a device consisting of multiple transmission line segments and radio frequency switches, with each transmission line segment connected by a radio frequency switch, forming a series or parallel connection relationship between the multiple transmission line segments, and achieving different phase shift effects according to the combination of the states of the radio frequency switches. Of course, the phase shifter 300 may also be an integrated component with a phase shift function, and this embodiment does not excessively limit the structure of the phase shifter 300.

[0025] Also, referring to FIG. 2, the power divider 200 further includes a power divider transmission line 201 and an isolation resistor 202, and the power divider transmission line 201 is connected to a first power divider port 205, a second power divider port 204, and a third power divider port 203, respectively. The isolation resistor 202 is installed between a first segment line and a second segment line of the power divider transmission line 201, where the first segment line is configured to connect the first power divider port 205 and the second segment line is configured to connect the second power divider port 204.

[0026] 2 is a Wilkinson power divider. When receiving electromagnetic waves, the resonator unit 100 inputs two polarized incident signals through the first power divider port 205 and the second power divider port 204, respectively, and realizes signal multiplexing by the power divider 200. Similarly, when emitting electromagnetic waves, the phase shifter 300 inputs a reflected signal through the third power divider port 203, and the power divider 200 allocates the reflected signal to the two polarized waves of the resonator unit, thereby realizing radiation of two-path polarized signals.

[0027] 2, the power divider transmission line 201 may be a stripline structure, respectively connecting the first power divider port 205, the second power divider port 204, and the third power divider port 203, and an isolation resistor 202 is installed between the first segment line connected to the first power divider port 205 and the second segment line connected to the second power divider port 204, thereby achieving isolation of the two-path polarized signals. The isolation resistor 202 may be a surface-mount resistor, and the resistance value may be adjusted according to actual needs.

[0028] 3 , the phase shifter 300 further includes a DC blocking capacitor 302, a radio frequency switch module, and an AC blocking inductor 308, which are connected in series, with the DC blocking capacitor 302 connected to a phase shifter port 311. The phase shifter 300 includes a first phase shifter transmission line 301, a second phase shifter transmission line 304, a third phase shifter transmission line 305, and a fourth phase shifter transmission line 307. The radio frequency switch module includes a first radio frequency switch 310, a second radio frequency switch 309, and a third radio frequency switch 306. The DC blocking capacitor 302 and the first radio frequency switch 310 are connected via the first phase shifter transmission line 301. The first radio frequency switch 310 and the second radio frequency switch 309 are connected in series via the second phase shifter transmission line 304. The second radio frequency switch 309 and the third radio frequency switch 306 are connected in series via a third phase shifter transmission line 305. The third radio frequency switch 306 and the AC blocking inductor 308 are connected via a fourth phase shifter transmission line 307. A DC bias line 303 is connected to each of the first phase shifter transmission line 301, the second phase shifter transmission line 304, and the third phase shifter transmission line 305.

[0029] In this embodiment, the first phase shifter transmission line 301, the second phase shifter transmission line 304, the third phase shifter transmission line 305 and the fourth phase shifter transmission line 307 are connected in series through three radio frequency switches to form a complete transmission line. The above transmission lines may adopt a microstrip line or a stripline structure, which can be selected according to actual needs.

[0030] The DC blocking capacitor 302 can isolate direct current and prevent bias current from entering the power divider 200. The AC blocking inductor 308 can isolate radio frequency signals and prevent them from entering the bias circuit 303. The DC blocking capacitor 302 and the AC blocking inductor 308 can be patch devices or distributed capacitors and distributed inductors, and the types and parameters can be selected according to actual needs.

[0031] The three radio frequency switches in this embodiment may be PIN diodes, varactor diodes, triodes, field effect transistors, single-pole single-throw / single-pole multi-throw switches, etc., and this embodiment does not excessively limit the selection of the radio frequency switches.

[0032] In the phase shifter 300 of this embodiment, three radio frequency switches are connected via the first phase shifter transmission line 301, the second phase shifter transmission line 304, and the third phase shifter transmission line 305, and the phase shifter transmission lines are connected in series. This allows four phases, i.e., two-bit phase states, to be realized through the different states of the three radio frequency switches, effectively improving the phase quantization accuracy and providing excellent scalability. For example, a combined signal is input through the phase shifter port 311 and passes through the DC blocking capacitor 302 before entering the radio frequency switch module. The combined signal passes through the open radio frequency switch, reaches an open-circuit or short-circuit terminal, and is reflected. The different combinations of the open states of the three radio frequency switches can realize four states, where when all three radio frequency switches are off, the combination state is “00” and the corresponding reflection phase is 0 degrees; when the first radio frequency switch 310 is on, the combination state is “01” and the corresponding reflection phase is minus 90 degrees; when the first radio frequency switch 310 and the second radio frequency switch 309 are on, the combination state is “10” and the corresponding reflection phase is minus 180 degrees; and when the first radio frequency switch 310, the second radio frequency switch 309, and the third radio frequency switch 306 are on, the combination state is “11” and the corresponding reflection phase is minus 270 degrees. A schematic diagram of the reflection amplitude obtained using the metasurface unit of this embodiment can be seen in FIG. 6, where the combination states corresponding to the four curves from top to bottom at the abscissa of 2.5 GHz are “00,” “01,” “11,” and “10,” respectively. The schematic diagram of the reflection phase can be seen in Figure 7, where the four curves correspond to the combination states "00", "01", "10" and "11" from top to bottom at the abscissa of 2.5 GHz. As can be seen from Figures 6 and 7, the reflection phase and reflection amplitude are different in different combination states, which shows that the metasurface unit has strong scalability and relatively high phase quantification accuracy.

[0033] Example 2: The metasurface unit of this example is similar to that of Example 1, with the following main differences.

[0034] 4 , the phase shifter 300 includes a first phase shifter transmission line 301, a second phase shifter transmission line 304, a third phase shifter transmission line 305, a fourth phase shifter transmission line 307, and a fifth phase shifter transmission line 313. The radio frequency switch module includes a third radio frequency switch 306 and a group of radio frequency switches 312, and the group of radio frequency switches 312 includes a first radio frequency switch 310 and a second radio frequency switch 309. The DC blocking capacitor 302 and the first radio frequency switch 310 are connected via a first phase shifter transmission line 301, the first radio frequency switch 310 and the second radio frequency switch 309 are connected in parallel via a second phase shifter transmission line 304 and a fifth phase shifter transmission line 313, the second radio frequency switch 309 and the third radio frequency switch 306 are connected in series via a third phase shifter transmission line 305, and the third radio frequency switch 306 and the AC blocking inductor 308 are connected via a fourth phase shifter transmission line 307.

[0035] In the radio frequency switch module of this embodiment, the second phase shifter transmission line 304 and the fifth phase shifter transmission line 313 are connected in parallel, and a 2-bit phase response can be achieved by changing the states of the three radio frequency switches. The difference is that the installation direction of the second radio frequency switch 309 in this embodiment is different from that of the second radio frequency switch 309 in embodiment 1, and two DC blocking capacitors 302 and a bias circuit 303 are installed in the fifth phase shifter transmission line 313 accordingly. The difference between this embodiment and embodiment 1 is the connection method between the radio frequency switch and the transmission line; other principles are essentially the same, and will not be further described here.

[0036] Example 3: The metasurface unit of this example is similar to that of Example 2, with the following main differences.

[0037] Referring to FIG. 5, the radio frequency switch module includes at least two radio frequency switch groups 312 connected in series with each other.

[0038] In this embodiment, by adding one radio frequency switch group 312 based on the second embodiment, an 8-bit phase state is realized by five radio frequency switches in the phase shifter 300, and the accuracy of phase adjustment can be further improved. The principle that the switch states of the five radio frequency switches determine the reflection phase is similar to that of the second embodiment, but only one bit is added to describe the 8-bit state, for example, the combined state is "000" in the all-off state and "111" in the all-on state, which will not be further described here for the sake of simplicity.

[0039] Except for the above differences, the other parts of the metasurface unit of this embodiment can be referred to the description of Example 2, and for the sake of simplicity, they will not be further described here.

[0040] The present application also provides a base station including the metasurface unit described in any one of the above embodiments.

[0041] After applying any one of the metasurface units in the above embodiments to a base station, a power divider is installed in the metasurface unit, so that in dual polarization mode, the two-path polarization signals share one phase shifter, effectively reducing the number of phase shifters and hardware costs.

[0042] An embodiment of the present application includes a resonator unit configured to receive two polarized incident signals or emit two polarized reflected signals, a power divider connected to the resonator unit and configured to combine the two polarized incident signals input by the resonator unit into a combined signal and / or split the input reflected signal into two polarized reflected signals and output them to the resonator unit, and a phase shifter connected to the power divider and configured to phase modulate the combined signal input by the power divider and output the phase-modulated reflected signal to the power divider. According to the technical solution of this embodiment, by using the power divider to achieve the combining and splitting of the two polarized signals, the two polarized signals share the same phase shifter, which effectively reduces the number of phase shifters in the metasurface unit and reduces hardware costs.

[0043] Although the above describes some embodiments of the present application, the present application is not limited to the above-described embodiments, and a person skilled in the art may make various equivalent modifications or substitutions on the condition that they do not violate the scope of the present application, and all of these equivalent modifications or substitutions are included in the scope limited by the claims of the present application.

Claims

1. a resonator unit configured to receive a dual-path polarized incident signal or to emit a dual-path polarized reflected signal; A power divider connected to the resonator unit and configured to combine two paths of polarized incident signals input by the resonator unit into one path of combined signal, and / or to split one path of input reflected signal into two paths of polarized reflected signals, and output them to the resonator unit, wherein the polarization directions of the two paths of polarized incident signals are orthogonal to each other, and the polarization directions of the two paths of polarized reflected signals are orthogonal to each other; A metasurface unit characterized by including a phase shifter connected to the power divider and configured to perform phase modulation on the combined signal input by the power divider and output the reflected signal obtained by phase modulation to the power divider.

2. the resonator unit includes a first polarization port and a second polarization port, the power divider includes a first power divider port and a second power divider port, the first polarization port is connected to the first power divider port, and the second polarization port is connected to the second power divider port; the resonator unit is configured to receive a first polarized incident signal and a second polarized incident signal, input the first polarized incident signal to the first power divider port via the first polarization port, and input the second polarized incident signal to the second power divider port via the second polarization port, wherein the polarization directions of the first polarized incident signal and the second polarized incident signal are orthogonal to each other; The metasurface unit of claim 1, wherein the resonator unit is further configured to radiate a first polarized reflected signal and a second polarized reflected signal, wherein the polarization directions of the first polarized reflected signal and the second polarized reflected signal are orthogonal to each other, and the first polarized reflected signal is input by the power divider through the first power divider port, and the second polarized reflected signal is input by the power divider through the second power divider port.

3. the power divider further includes a third power divider port, the phase shifter includes a phase shifter port, the third power divider port is connected to the phase shifter port; the power divider is configured to combine the first polarized incident signal and the second polarized incident signal as the combined signal, input the combined signal to the phase shifter via the third power divider port, cause the phase shifter to perform phase modulation on the combined signal, and obtain the reflected signal; The metasurface unit of claim 2, wherein the power divider is further configured to acquire the reflected signal input by the phase shifter through the phase shifter port and split the reflected signal into the first polarization reflected signal and the second polarization reflected signal.

4. the power divider further includes a power divider transmission line and an isolation resistor, the power divider transmission line being connected to the first power divider port, the second power divider port, and the third power divider port, respectively; 4. The metasurface unit of claim 3, wherein the isolation resistor is installed between a first segment line and a second segment line of the power divider transmission line, where the first segment line is configured to connect the first power divider ports and the second segment line is configured to connect the second power divider ports.

5. The metasurface unit of claim 3, wherein the phase shifter further includes a DC blocking capacitor, a radio frequency switch module, and an AC blocking inductor connected in series, the DC blocking capacitor being connected to the phase shifter port, and the radio frequency switch module being configured to perform phase modulation on the combined signal to obtain the reflected signal.

6. the phase shifter includes a first phase shifter transmission line, a second phase shifter transmission line, a third phase shifter transmission line, and a fourth phase shifter transmission line; the radio frequency switch module includes a first radio frequency switch, a second radio frequency switch, and a third radio frequency switch; 6. The metasurface unit of claim 5, wherein the DC blocking capacitor and the first radio frequency switch are connected via the first phase shifter transmission line, the first radio frequency switch and the second radio frequency switch are connected in series via the second phase shifter transmission line, the second radio frequency switch and the third radio frequency switch are connected in series via the third phase shifter transmission line, and the third radio frequency switch and the AC blocking inductor are connected via the fourth phase shifter transmission line.

7. The metasurface unit of claim 6, wherein a DC bias line is connected to each of the first phase shifter transmission line, the second phase shifter transmission line, and the third phase shifter transmission line.

8. the phase shifter includes a first phase shifter transmission line, a second phase shifter transmission line, a third phase shifter transmission line, a fourth phase shifter transmission line, and a fifth phase shifter transmission line; the radio frequency switch module includes a third radio frequency switch and a group of radio frequency switches; and the group of radio frequency switches includes a first radio frequency switch and a second radio frequency switch; The metasurface unit of claim 5, wherein the DC blocking capacitor and the first radio frequency switch are connected via the first phase shifter transmission line, the first radio frequency switch and the second radio frequency switch are connected in parallel via the second phase shifter transmission line and the fifth phase shifter transmission line, the second radio frequency switch and the third radio frequency switch are connected in series via the third phase shifter transmission line, and the third radio frequency switch and the AC blocking inductor are connected via the fourth phase shifter transmission line.

9. The metasurface unit of claim 8 , wherein the second phase shifter transmission line and the fifth phase shifter transmission line are each connected to a DC bias line.

10. The metasurface unit of claim 8 , wherein the radio frequency switch module includes at least two groups of the radio frequency switches connected in series with each other.

11. A base station comprising a metasurface unit according to any one of claims 1 to 10.

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