阅读说明：本技术 一种可在正入射和大倾斜入射角下进行1/2/3比特调相的可重构智能超表面 (Reconfigurable intelligent super-surface capable of carrying out 1/2/3-bit phase modulation under normal incidence and large-inclination incidence angles ) 是由 程强 梁竟程 崔铁军 于 2021-09-03 设计创作，主要内容包括：本发明公开了一种可在正入射和大倾斜入射角下进行1/2/3比特调相的可重构智能超表面,智能超表面包括：n个基本单元周期排列,每列单元组成子阵,其中,该子阵由同一信号控制,并且各个子阵由控制电路提供控制信号。本发明通过引入变容二极管作为电容可调器件,使得入射到本发明的电磁波的反射波的相位实现连续的、大裕度的动态可调范围,且控制方式简单快捷；本发明通过引入低损耗的可调器件,可使其在实现相位连续动态变化时保持较高的能量效率；本发明通过引入大量金属柱隔离单元间的互耦,可以在大角度斜入射下仍然保持稳定的幅度和相位响应,相较于传统设计具有更好的鲁棒性。(The invention discloses a reconfigurable intelligent super surface capable of carrying out 1/2/3-bit phase modulation under normal incidence and large inclined incidence angles, which comprises: the n basic units are arranged periodically, each column of units forms a sub-array, wherein the sub-array is controlled by the same signal, and the control circuit provides control signals for the sub-arrays. The invention leads the phase of the reflected wave of the electromagnetic wave to realize continuous and large-margin dynamic adjustable range by introducing the variable capacitance diode as a capacitance adjustable device, and the control mode is simple and quick; the invention can keep higher energy efficiency when realizing continuous dynamic change of the phase by introducing the low-loss adjustable device; by introducing a large amount of mutual coupling among the metal column isolation units, the invention can still keep stable amplitude and phase response under large-angle oblique incidence, and has better robustness compared with the traditional design.)

1. A reconfigurable intelligent super-surface capable of 1/2/3 bit phase modulation at normal incidence and at high oblique incidence angles, the intelligent super-surface comprising: the n basic units are arranged periodically, each column of units forms a sub-array, wherein the sub-array is controlled by the same signal, and the control circuit provides control signals for the sub-arrays.

2. The reconfigurable intelligent super-surface capable of 1/2/3-bit phase modulation at normal incidence and large oblique incidence according to claim 1, wherein the base unit comprises, in order from top to bottom:

the first layer is formed by connecting a variable capacitance diode in series with two metal rectangular sheets, wherein the two metal rectangular sheets are arranged in parallel, two narrow metal strips parallel to the metal rectangular sheets are also arranged between the two metal rectangular sheets and connected with the metal rectangular sheets close to the metal rectangular sheets respectively, and the two narrow metal strips are connected in series through the variable capacitance diode;

the second layer is a dielectric substrate;

the third layer is a metal layer;

and rows of metal holes are further arranged between the first layer and the third layer, and the two narrow metal strips are used as direct current bias lines to provide direct current voltage for the variable capacitance diode.

3. A reconfigurable intelligent super-surface for 1/2/3 bit phase modulation at normal incidence and large oblique incidence according to claim 2, wherein the metal holes are arranged in two rows, one of the metal holes being arranged on one side of the long side of one metal rectangular plate, and the other metal hole being arranged on one side of the long side of the other metal rectangular plate.

4. A reconfigurable intelligent super surface for 1/2/3 bit phase modulation at normal incidence and large oblique incidence angles, according to claim 3, wherein the varactor diode produces a capacitance change of 0.6-2.6 pF when fed back with a voltage change of 0-30V.

5. The reconfigurable intelligent super-surface capable of 1/2/3-bit phase modulation at normal incidence and large-tilt incidence according to claim 4, wherein the backward reflection phase of the electromagnetic wave at a given frequency point under different control voltages changes by more than 320 °.

6. The reconfigurable intelligent super-surface capable of 1/2/3-bit phase modulation at normal incidence and large oblique incidence angles according to claim 5, wherein the different control voltages specifically comprise: 0V, 3V, 4V, 4.6V, 5.3V, 6.0V, 8V, 20V.

Technical Field

The invention relates to the technical field of reconfigurable intelligent super surfaces, in particular to a reconfigurable intelligent super surface capable of carrying out 1/2/3-bit phase modulation under normal incidence and large inclined incidence angles.

Background

Due to the huge potential of the reconfigurable intelligent super surface in the aspect of controlling the propagation environment, the performance of a wireless communication network is improved, and the reconfigurable intelligent super surface has wide attention in the wireless field. Firstly, experimental results show that due to the dispersion characteristic of space, the phase response of the traditional reconfigurable intelligent super-surface is sensitive to the incident angle of electromagnetic waves, so that the traditional reconfigurable intelligent super-surface design can only work in the range of vertical incidence and a small incident angle, which is particularly obvious in the reconfigurable intelligent super-surface with higher bit encoding, and because the reconfigurable intelligent super-surface with higher bit encoding has lower tolerance and wider phase shift range, the accurate control of the phase response of the reconfigurable intelligent super-surface with higher bit encoding is also particularly important. Secondly, the traditional phase shift reconfigurable intelligent meta-surface loaded with PIN tubes requires more active devices in the case of higher bit-encoding design, which makes it more difficult to integrate it into a unit structure of limited size, and this also does not meet the requirements of low cost large-scale industrial production.

Disclosure of Invention

In view of the above, the present invention is directed to a reconfigurable intelligent super-surface capable of performing 1/2/3-bit phase modulation at normal incidence and large oblique incidence, which is used to solve the technical problems mentioned in the background art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a reconfigurable intelligent super-surface capable of 1/2/3 bit phase modulation at normal incidence and at high oblique incidence angles, the intelligent super-surface comprising: the n basic units are arranged periodically, each column of units forms a sub-array, wherein the sub-array is controlled by the same signal, and the control circuit provides control signals for the sub-arrays.

Further, the basic unit comprises, from top to bottom:

the first layer is formed by connecting a variable capacitance diode in series with two metal rectangular sheets, wherein the two metal rectangular sheets are arranged in parallel, two narrow metal strips parallel to the metal rectangular sheets are also arranged between the two metal rectangular sheets and connected with the metal rectangular sheets close to the metal rectangular sheets respectively, and the two narrow metal strips are connected in series through the variable capacitance diode;

the second layer is a dielectric substrate;

the third layer is a metal layer;

and rows of metal holes are further arranged between the first layer and the third layer, and the two narrow metal strips are used as direct current bias lines to provide direct current voltage for the variable capacitance diode.

Furthermore, the metal holes are arranged in two rows and are respectively arranged on two sides of the basic unit, one of the metal holes is arranged on one side of the long edge of one metal rectangular sheet, and the other metal hole is arranged on one side of the long edge of the other metal rectangular sheet.

Furthermore, the varactor diode generates 0.6-2.6 pF capacitance change when the voltage of the backward feed is changed by 0-30V.

Furthermore, under different control voltages and at a given frequency point, the backward reflection phase change range of the electromagnetic waves exceeds 320 DEG

Further, the different control voltages specifically include: 0V, 3V, 4V, 4.6V, 5.3V, 6.0V, 8V, 20V.

The invention has the beneficial effects that:

1. the principle of the invention is simple, and the real-time, continuous and dynamic regulation and control of the reflected wave of the electromagnetic wave incident on the invention can be realized only by changing the reverse bias voltage on the variable capacitance diode; the invention can be used for the application of 3-bit coded intelligent super surface and can also be used for 1/2-bit coded intelligent super surface.

2. The invention uses a plurality of basic units to form a basic sub-array, which is controlled by the same signal, thus reducing the interference to the unit reflection coefficient caused by different boundaries and reducing the design complexity of the feed network; correspondingly, compared with the prior art, the invention can obtain high-efficiency and high-bit-coding phase regulation and control.

3. Compared with the prior art, the invention can work under the condition of vertical incidence and can obtain stable amplitude phase electromagnetic response under the irradiation of oblique incidence electromagnetic waves within the range of +/-60 degrees.

Drawings

FIG. 1 is a schematic structural diagram of a reconfigurable intelligent metasurface provided in example 1;

FIG. 2 is a front view of the reconfigurable intelligent super surface provided in example 1;

FIG. 3 is a side view of the reconfigurable intelligent super surface provided in example 1;

FIG. 4 is a schematic dimension marking diagram of the reconfigurable intelligent super surface provided in example 1;

FIG. 5 is a graph of the amplitude versus frequency for each state (8) for the 3-bit encoded case of the reconfigurable intelligent super surface provided in example 1;

FIG. 6 is a graph of phase versus frequency for each state (8) for the 3-bit encoded case of the reconfigurable intelligent meta-surface provided in example 1;

FIG. 7 is a graph of the maximum adjustable phase variation range with frequency for the reconfigurable intelligent super-surface provided in example 1;

FIG. 8 is a graph of amplitude versus frequency for different oblique incidence angles for the 3-bit encoded case of the reconfigurable intelligent super-surface provided in example 1;

FIG. 9 is a graph of phase versus frequency for different oblique incidence angles for the 3-bit encoded case of the reconfigurable intelligent super-surface provided in example 1;

FIG. 10 is a graph of the phase versus angle of incidence for the case of 3-bit encoding for the reconfigurable intelligent super-surface provided in example 1 and for the case of a conventional reconfigurable intelligent super-surface;

in the drawings:

1-varactor, 2-metal rectangular sheet, 3-dielectric substrate, 4-metal layer, 5-metal hole, and 6-narrow metal strip.

Detailed Description

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

Example 1

Referring to fig. 1-7, the present embodiment provides a reconfigurable intelligent super-surface capable of performing 1/2/3-bit phase modulation at normal incidence and large oblique incidence angles, which specifically includes: the n basic units are arranged periodically, each column of units forms a sub-array, wherein the sub-array is controlled by the same signal, and the control circuit provides control signals for the sub-arrays.

Specifically, in this embodiment, the basic unit includes, in order from top to bottom:

the first layer is formed by connecting a variable capacitance diode 1 in series with two metal rectangular sheets 2;

the second layer is a dielectric substrate 3;

the third layer is a metal layer 4;

wherein rows of metal holes 5 are also provided between the first and third layers.

Specifically, in the present embodiment, the varactor 1 generates a capacitance change of 0.6 to 2.6pF when a voltage of 0 to 30V is fed back.

Specifically, in the present embodiment, the backward reflection phase of the electromagnetic wave at a given frequency point varies by more than 320 ° under different control voltages.

Specifically, in this embodiment, the different control voltages specifically include: 0V, 3V, 4V, 4.6V, 5.3V, 6.0V, 8V, 20V.

Specifically, the metal-dielectric-metal sandwich structure provided in this example can be easily prepared using standard Printed Circuit Board (PCB) technology, and more specifically:

F4B dielectric slab (. epsilon.) at 3.3mm thickness_r2.65, tan δ 0.001) rows of metal holes 4 with a diameter of 0.4mm are drilled;

the thickness of the surface copper layer is 0.035 μm, and the surface copper layer is mainly composed of two identical metal rectangular sheets 2;

the bottom layer is a complete copper layer coated with the thickness of 0.035 mu m and used as a ground layer, so that the reflection-type reconfigurable intelligent super surface is realized;

the varactor 1 is used for connecting two metal rectangular sheets 2 on the uppermost layer, and is used as a phase tuning device with adjustable state, when the phase tuning device is biased reversely, junction capacitance required by the varactor can change along with voltage change, and the characteristic enables the varactor 1 to tune the resonant frequency of reflected electromagnetic waves or control the phase shift of the electromagnetic waves at specific frequency; two metal rectangular sheets 2 are arranged in parallel, two narrow metal strips 6 parallel to the metal rectangular sheets 2 are also arranged between the two metal rectangular sheets 2, and the narrow metal strips 6 are connected with the metal rectangular sheets 2 which are respectively close to each other, in particular through metal blocks which protrude from the metal rectangular sheets 2, then the two narrow metal strips 6 are connected in series through the varactor diode 1, and the two narrow metal strips 6 are used as direct current bias lines to provide the appropriate direct current voltage required by the varactor diode 1 in a given state.

Specifically, as shown in fig. 1 to 4, the sizes of the basic unit, the metal rectangular sheet 2, the narrow metal strip 6, the metal block, and the metal hole 5 in the present embodiment are:

the height H of the metal hole is 3.3mm, and the length P of the basic unit on the x axis_x25.4mm, the length Py of the basic unit on the y-axis is 27.2mm, and the length L of the long side of the narrow metal strip₁Length L of long side of metal block being 8.8mm₂Length L of long side of the metal rectangular sheet is 4.2mm₃19.9mm, length W of the short side of the narrow metal strip₁1.1mm, length W of short side of metal block₂0.4mm, length W of short side of the metal rectangular sheet₃The diameter D of the metal holes is 0.4mm, and the space S of the metal holes is 0.8 mm.

The reconfigurable intelligent super-surface capable of performing 1/2/3-bit phase modulation at normal incidence and large oblique incidence angles provided by the embodiment can change the phase of a reflected wave of an electromagnetic wave incident on the embodiment by changing the bias voltage on the varactor diode 1 under the normal incidence of the electromagnetic wave, and specifically:

for an N-bit coded smart metasurface, the initial phase isPhase of the nth stateIs located atThis means that an N-bit coded smart super-surface needs to satisfy at least 0-360 DEG x (2)^N-1)/2^NAnd a phase variation range of 360 °/2 intervals can be obtained^N2 of (2)^NPhase states, more specifically:

for a 3-bit coded intelligent super-surface, the phase change range of 0-315 degrees is satisfied, and 8 phase states with the interval of 45 degrees can be obtained.

For a 2-bit coded intelligent super-surface, the phase variation range of 0-270 degrees is satisfied, and 4 phase states with the interval of 90 degrees can be obtained.

For a 1-bit coded intelligent super-surface, the phase change range of 0-180 degrees is satisfied, and 2 phase states with 180-degree intervals can be obtained.

Specifically, a 3-bit coded intelligent super surface can also be used as the 1/2/3-bit coded intelligent super surface, for example, in the case of 3-bit coding, at normal incidence of 3.15GHz, there are 8 coding states, specifically: 0^#，1^#，2^#，…，7^#And the amplitudes and phases of the 8 encoding states are shown in fig. 5 and 6, respectively. The reflection amplitude of each coding state is larger than-2 db, so that efficient reflection phase control is realized. Code 0 at normal incidence is given in FIG. 7^#And code 7^#The phase difference between the two, namely the maximum phase difference, can be seen from the figure, the maximum phase shift range of more than 315 degrees can be obtained between 3G and 3.35GHz, so that the working bandwidth of the 3-bit intelligent super surface is 3G to 3.35 GHz.

Specifically, in order to obtain a certain stability of the intelligent super-surface provided by the present embodiment when the intelligent super-surface is obliquely incident, two rows of metal holes 5 are designed in the present embodiment. The metal hole 5 is formed by drilling a through hole on the dielectric substrate 3 of the second layer and then metalizing the through hole, and in the embodiment, the hole diameter is 0.4mm, and the pitch is 0.8 mm.

The maximum phase difference at oblique incidence is also given in fig. 7, which shows that a phase shift range exceeding 315 deg. can be obtained when the bias voltage is increased from-30V to 0V, regardless of the angle of incidence, when the angle of incidence is less than 60 deg.. The amplitude phase response at oblique incidence is given in fig. 8 and 9, and the amplitude and phase for the 8 encoded states at 0 °, 30 ° and 60 ° incidence are shown in fig. 8 and 9, respectively.

Fig. 10 shows the phases of the intelligent super-surface provided by the present embodiment at different oblique incidence angles, and the phases of the conventional intelligent super-surface at different oblique incidence angles. It can be seen that the intelligent super-surface provided by the embodiment has higher phase stability when the oblique incidence angle changes compared with the conventional intelligent super-surface.

In this embodiment, a specific test method is further provided, which specifically includes:

step S1, placing the transmitting antenna and the receiving antenna at two sides of the reconfigurable intelligent super surface provided by the embodiment, where the normal is symmetrical, and the distance between the transmitting antenna and the reconfigurable intelligent super surface needs to exceed 3 m;

step S2, a voltage source is applied to a matched control circuit of the reconfigurable intelligent super surface;

step S3, the transmitting antenna and the receiving antenna are respectively connected to the 1,2 ports of the vector network analyzer by the radio frequency transmission line;

step S4, recording the amplitude and the phase of the electromagnetic waves received under different control voltages;

step S5, replacing the reconfigurable intelligent super-surface provided by this embodiment with a metal plate of the same size;

step S6, recording the amplitude and the phase of the received electromagnetic wave;

step S7, using the amplitude and phase of the received electromagnetic wave when the metal plate is placed as the reference, dividing the amplitude received when the reconfigurable intelligent super surface is placed at different voltages by the amplitude of the received electromagnetic wave when the metal plate is placed, so as to obtain the relative amplitude received when the reconfigurable intelligent super surface in this embodiment is placed at the corresponding voltage, and correspondingly, subtracting the phase of the received electromagnetic wave when the metal plate is placed from the phase received when the reconfigurable intelligent super surface in this embodiment is placed at different voltages, so as to obtain the relative phase received when the reconfigurable intelligent super surface is placed at the corresponding voltage.

In summary, the invention provides a reconfigurable intelligent super surface capable of performing 1/2/3-bit phase modulation under normal incidence and large-inclination incidence angles, and by loading a varactor diode in each unit, the system can realize a phase shift range of 0-315 degrees and 8 coding states with an interval of 45 degrees, and can simultaneously meet the phase requirement of 1/2/3-bit reconfigurable intelligent super surface. In addition, the metal via holes are introduced between the adjacent units, so that the invention can work under the normal incidence condition and the large inclined incidence angle condition. The angular insensitivity of the present invention ensures the stability of the phase and amplitude responses of these 8 states at normal and oblique incidence. In summary, the reconfigurable intelligent super-surface capable of performing 1/2/3-bit phase modulation at normal incidence and large-inclination incidence angle provided by the invention has important practical application potential in wireless communication networks applying the reconfigurable intelligent super-surface and the architecture of the next generation wireless communication system.

The invention is not described in detail, but is well known to those skilled in the art.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.