2.4 ghz-oriented light, thin, high-gain, reflection compensation-type irs unit

Abstract

The present invention relates to an industrial wireless network technique, and specifically relates to a 2.4 GHz-oriented light, thin, high-gain, reflection compensation-type IRS unit. The present invention mainly aims to solve complex situations such as direct link obstruction, blind spots, and dead zones in an industrial field, and satisfy the low costs and high reliability requirements of industrial wireless. Specifically, an IRS is introduced as a passive repeater to construct a reflection link to improve the coverage range of an industrial wireless network, and an unperforated metal layer structure and a three-piece top-layer connection structure are designed for the IRS. First, the unperforated metal layer structure extends a middle-layer transmission line, thereby effectively reducing the energy loss of an incident signal; and second, the three-piece top-layer connection structure provides a maximum resonance over-coupling range for two tunable devices embedded in the three-piece top layer connection structure. The present invention has low reflection gain loss and wide reflection phase span while being light and thin. In addition, the present invention also has extremely high voltage-phase adjustability and phase stability.

Description

A thin, lightweight, high-gain, reflection-compensated IRS unit for 2.4 GHz Technical Field

[0001] The present invention relates to industrial wireless network technology, in particular to a 2.4GHz oriented, light and thin high-gain reflection compensation type IRS unit. Background Art

[0002] With the rapid development of industrial manufacturing systems and the intelligentization of unmanned systems, higher demands are being placed on the deep integration of next-generation information and advanced manufacturing technologies. Industrial wireless networks, a key foundational technology for intelligent manufacturing systems, are facing significant challenges in line-of-sight links due to equipment mobility and complex building structures. Furthermore, the industrial sector places extremely high demands on the link layer of wireless communications, including aggregate transmission rates of several gigabytes per second between hundreds of nodes, transmission latency of less than 1 microsecond, and transmission reliability of 99.99% to 99.9999%. However, existing industrial wireless networks, such as WirelessHART, WIA-PA, and WISA, fail to meet the ultra-high communication performance requirements of key industrial scenarios such as factory automation, process safety automation, and power energy control. Therefore, new technologies and approaches are urgently needed to address the challenges posed by harsh environments, obstructions, and stringent performance requirements.

[0003] In recent years, a new type of relay, IRS, inspired by electromagnetic metamaterials, has attracted significant attention in wireless applications. IRS can establish an unobstructed link between transmitter and receiver, addressing the aforementioned issue of line-of-sight links. Its hardware structure directly influences the transmission efficiency of electromagnetic waves along this new link. Therefore, by designing a specific structure to achieve desired electromagnetic performance and implement specific functions, this opens the possibility of overcoming existing technical bottlenecks and improving the performance of industrial wireless networks.

[0004] Based on transmission characteristics (reflection, transmission, and scattering), IRSs can be further categorized as reflective, transmissive, and scattering. Reflective IRSs have attracted considerable attention due to the numerous metal structures and large mechanical equipment found in factory environments, which prevent electromagnetic waves from penetrating. Reflective IRSs are mostly designed for ultra-high frequency (UHF) electromagnetic wave communications, as higher-frequency electromagnetic waves are more susceptible to obstruction. Typical industrial wireless networks operate in the license-free 2.4 GHz industrial, scientific, and medical (ISM) band. IRS hardware designs are customized and unique, requiring redesign to switch between frequency bands. Therefore, high-frequency hardware designs cannot be directly applied to industrial scenarios. Most prototype designs operating near the 2.4 GHz band only consider the extremes of a single parameter or function. In reality, industrial applications often require components to simultaneously deliver the highest reliability, the richest functionality, and the lowest cost under oblique incidence conditions. Existing research has overlooked the interplay between these three requirements.

[0005] Summary of the Invention

[0006] The present invention provides a lightweight, high-gain reflection compensation IRS unit for 2.4GHz. The present invention is mainly used to solve complex situations such as direct link obstruction and blind spots in industrial sites. Specifically, IRS is introduced as a passive repeater to construct a reflection link to improve the coverage of the industrial wireless network. The designed IRS adopts a three-layer structure. The first metal layer has three metal patches and two varactor diodes embedded in it. The second metal layer is connected to the middle patch of the top layer through two middle through-holes to provide a bias voltage for the varactor diode on the top layer. The third metal layer is connected to the patches on both sides of the top layer through through-holes on both sides to provide a ground voltage for the varactor diode. The connection power supply architecture of the second metal layer and the third metal layer with the top layer forms a three-layer non-through-hole architecture. The present invention has low reflection gain loss and a wide reflection phase span while being lightweight. In addition, the present invention also has extremely high voltage-phase adjustability and phase stability.

[0007] The present invention adopts the following technical solution: a thin and light high-gain reflection compensation type IRS unit for 2.4GHz, characterized by comprising a first metal layer, a second metal layer, and a third metal layer arranged in sequence;

[0008] The first metal layer is connected to the second metal layer and the third metal layer respectively;

[0009] The second metal layer is used for connecting an external bias power supply;

[0010] The third metal layer is used for external grounding.

[0011] The first metal layer includes varactor diode I, varactor diode II, a first metal patch, a second metal patch, and a third metal patch;

[0012] The varactor diode I is provided between the first metal patch and the third metal patch, and the varactor diode I is provided with a ground voltage by the first metal patch and a bias voltage by the third metal patch;

[0013] The varactor diode II is arranged between the second metal patch and the third metal patch. The second metal patch provides the varactor diode II with a ground voltage and the third metal patch provides the varactor diode II with a bias voltage.

[0014] The varactor diode I, the varactor diode II, the first metal patch, the second metal patch and the third metal patch are located on the same plane.

[0015] The second metal layer is connected to the third metal patch of the first metal layer through a metal through hole, and is used to provide a bias voltage for the varactor diode I and the varactor diode II.

[0016] The third metal layer is connected to the first metal patch and the second metal patch respectively through metal through-hole arrays, and is used to provide a ground voltage for the varactor diode I and the varactor diode II.

[0017] A substrate for preventing short circuit is provided between the first metal layer and the second metal layer.

[0018] A substrate for preventing short circuit is provided between the second metal layer and the third metal layer.

[0019] A method for adjusting reflected waves in a 2.4 GHz thin, high-gain reflection compensation IRS unit is disclosed. The method adjusts the reflected waves by changing the reverse bias voltage of varactor diodes I and II to change the reflection coefficient. The method includes the following steps:

[0020] The impedance of the IRS unit is obtained based on the impedance of the varactor diode I and the varactor diode II, and the impedance of the passive structure consisting of the first metal patch, the second metal patch, the third metal patch, the second metal layer, the metal via, the third metal layer, and the metal via array.

[0021] According to the impedance of the IRS unit, the reflected wave characteristics are obtained through the reflection coefficient model of the IRS unit to achieve adjustment of the reflected wave.

[0022] By changing the reverse bias voltage of varactor diode I and varactor diode II, the reflection coefficient is changed to adjust the reflected wave, which is achieved by the following formula:

[0023] Where Z0 is the free space wave impedance, A IRS(ν) represents the reflection amplitude provided by the IRS unit, φ IRS (ν) represents the reflection phase provided by the IRS unit;

[0024] The impedance Z of the IRS unit s (ν)=F(Z a ,Z L (ν)), F represents the impedance Z of the IRS unit s (ν) is determined by the impedance Z of the passive structure a and the impedance Z of varactor diode I (1) and varactor diode II (2) L Joint impact, Z L (ν) represents Z L Controlled by the reverse bias voltage ν.

[0025] Applies to the following situations:

[0026] When the line-of-sight link between the transmitter and receiver is blocked, the IRS unit acts as a passive repeater to construct a reflective link and complete the communication between the transmitter and receiver. At this time, the bias voltage control of the IRS unit does not change;

[0027] When coherent interference occurs between the line-of-sight link between the transmitter and receiver and the reflection link formed by the metal inside the factory, the IRS is installed on the metal inside the factory as a passive repeater to replace the metal inside the factory to construct the reflection link. By adjusting the bias voltage of the varactor diode, the reflection phase is reversed, turning the original coherent interference into constructive interference.

[0028] When the receiving end is a certain area, the IRS unit forms a reflection phase offset by adjusting the phase difference between the columns of the board units to achieve the purpose of communication between the transmitting end and the entire area.

[0029] The present invention produces the following beneficial effects and advantages:

[0030] This invention fully considers the mutual constraints of highest reliability, richest functionality, and lowest cost in industrial wireless networks. Under the constraint of low cost, that is, the thickness of the reflector, the reflection gain loss is kept within an acceptable range while obtaining the widest possible reflection phase span. By designing a metal-free perforated structure and a three-piece top connection structure, the energy loss of the incident signal is effectively reduced. Simulation results show that under a 2.4GHz incident wave, the reflection gain loss is less than 1.6dB, the reflection phase span is approximately 290°, and it has extremely high voltage-phase adjustability and phase stability. Specifically,

[0031] 1. The metal-layer-free perforated architecture designed in the present invention can complete the metal reflective surface in the middle layer of the classic three-layer structure, extend the transmission line, avoid the interruption of the transmission line and the loss of electromagnetic energy caused by punching the metal sheet in the middle layer to facilitate the passage of through holes, and effectively improve the reflection amplitude performance.

[0032] 2. The three-piece top connection structure designed in the present invention provides the largest possible resonant overcoupling range for the two tunable devices embedded therein, which ensures sufficient reflection phase span while having little impact on the reflection gain performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic structural diagram of the present invention;

[0034] In the figure: 1 is varactor diode I, 2 is varactor diode II, 3 is the first metal patch, 4 is the second metal patch, 5 is the third metal patch, 6 is the second metal plate, 7 is the metal through hole, 8 is the third metal plate, and 9 is the metal through hole array;

[0035] FIG2 is a reflection characteristic curve diagram of the present invention at different voltages;

[0036] FIG3 is a schematic diagram of a communication structure with IRS assistance implementation. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] The present invention proposes a lightweight, high-gain reflection-compensated intelligent reflection surface (IRS) hardware for 2.4GHz. The present invention is mainly intended to solve complex situations such as direct link obstruction and blind spots in industrial sites, and meet the low-cost and high-reliability requirements of industrial wireless. Specifically: IRS is introduced as a passive repeater to construct a reflection link to improve the coverage of the industrial wireless network, and a metal-free perforated structure and a three-piece top-layer connection structure are designed for the IRS. First, the metal-free perforated structure serves as the middle-layer transmission line, effectively reducing the energy loss of the incident signal; secondly, the three-piece top-layer connection structure provides the maximum resonant overcoupling range for the two tunable devices embedded therein. The present invention has low reflection gain loss and a wide reflection phase span while being lightweight. In addition, the present invention also has extremely high voltage-phase adjustability and phase stability.

[0039] As shown in Figure 1, the present invention provides a lightweight, high-gain, reflection-compensated IRS hardware for 2.4 GHz, comprising three metal layers and two substrates. The first metal layer includes varactor diode I 1, varactor diode II 2, a first metal patch 3, a second metal patch 4, and a third metal patch 5.

[0040] Two varactor diodes are embedded between three metal patches, with metal patch I providing ground voltage and metal patch II providing bias voltage;

[0041] The second metal layer is a metal plate 6 that connects the external bias power supply and connects the units. It is connected to the third metal patch 5 of the first metal layer through two metal through-holes 7 to provide bias voltage for the two varactor diodes. A substrate is laid between the first and second metal layers to prevent short circuits.

[0042] The third metal layer is a metal plate 8 that is externally grounded and interconnects the cells. It connects to the first metal patch 3 of the first metal layer via metal vias 9 on either side, providing ground voltage for the two varactors. A substrate is also laid between the second and third metal layers to prevent short circuits.

[0043] In this embodiment, the substrate is made of F4B material, with two layers, each 1 mm thick. The metal plates (3, 4, 5, 6, 8) and the metal vias (7, 9) in the metal layer are made of 0.0175 mm brass. The varactor diode is a Skyworks SMV2019-079LF. By applying a reverse bias voltage to change the capacitance and resistance values, the impedance of the IRS unit is modified.

[0044] Impedance Z of the IRS hardware unit s The impedance Z of the passive structure (3, 4, 5, 6, 7, 8, 9) a and the impedance Z of the embedded varactor diode L Joint influence. L is controlled by voltage ν, so the impedance Z of the IRS hardware unit is s It can be expressed as Z s (ν)=F(Z a ,Z L (ν))

[0045] The reflection coefficient of the IRS hardware unit can be modeled as:

[0046] Where Z0 is the free space wave impedance, A IRS (ν) represents the reflection amplitude provided by IRS, φ IRS (ν) represents the reflection phase provided by the IRS. Changing the bias voltage of the varactor diode modifies the reflection coefficient and adjusts the reflected wave. As shown in Figure 2, simulation results show that for a 2.4 GHz incident wave, the reflection gain loss is less than 1.8 dB, and the reflection phase span is approximately 300°.

[0047] Applied to industrial wireless networks, the present invention includes the following steps:

[0048] As shown in Figure 3, an industrial wireless network includes an IRS communication structure consisting of three parts: a transmitter, a transmission channel, and a receiver.

[0049] When the line-of-sight link between the transmitter and receiver is blocked, the IRS, as a passive repeater, can construct a reflection link and complete the communication between the transmitter and receiver without changing the bias voltage control of the IRS.

[0050] When the line-of-sight link between the transmitter and receiver interferes with the reflective link formed by the metal inside the factory, the IRS, as a passive repeater, can be attached to the metal inside the project to replace the reflective link. By adjusting the bias voltage of the varactor diode, it flips the reflection phase, turning the original coherent interference into constructive interference.

[0051] When the receiving end is a certain area, the IRS can achieve the purpose of communicating with the entire area by adjusting the phase difference of the board unit column to form a reflection phase offset.

[0052] The above description is only an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the scope of protection of the present invention.

Claims

1. A thin, high-gain, reflection-compensated IRS unit for 2.4 GHz, characterized by: comprising a first metal layer, a second metal layer, and a third metal layer arranged in sequence; The first metal layer is connected to the second metal layer and the third metal layer respectively; The second metal layer is used for connecting an external bias power supply; The third metal layer is used for external grounding.

2. The 2.4 GHz thin and light high-gain reflection compensation IRS unit according to claim 1, characterized in that: The first metal layer includes a varactor diode I (1), a varactor diode II (2), a first metal patch (3), a second metal patch (4) and a third metal patch (5); The varactor diode I (1) is provided between the first metal patch (3) and the third metal patch (5), and the varactor diode I (1) is provided with a ground voltage by the first metal patch (3) and a bias voltage by the third metal patch (5); The variable capacitance diode II (2) is provided between the second metal patch (4) and the third metal patch (5); the variable capacitance diode II (2) is provided with a ground voltage by the second metal patch (4) and a bias voltage by the third metal patch (5).

3. The 2.4 GHz thin and light high-gain reflection compensation IRS unit according to claim 2, characterized in that: The varactor diode I (1), the varactor diode II (2), the first metal patch (3), the second metal patch (4) and the third metal patch (5) are located on the same plane.

4. The 2.4 GHz thin and light high-gain reflection compensation IRS unit according to claim 1, characterized in that: The second metal layer is connected to the third metal patch (5) of the first metal layer through a metal through hole (7) and is used to provide a bias voltage for the varactor diode I (1) and the varactor diode II (2).

5. The 2.4 GHz thin and light high-gain reflection compensation IRS unit according to claim 1, characterized in that: The third metal layer is connected to the first metal patch (3) and the second metal patch (4) respectively through metal through-hole arrays (9), and is used to provide a ground voltage for the varactor diode I (1) and the varactor diode II (2).

6. The 2.4 GHz thin and light high-gain reflection compensation IRS unit according to claim 1, characterized in that: A substrate for preventing short circuit is provided between the first metal layer and the second metal layer.

7. The 2.4 GHz thin and light high-gain reflection compensation IRS unit according to claim 1, characterized in that: A substrate for preventing short circuit is provided between the second metal layer and the third metal layer.

8. A method for adjusting reflected waves of a thin, high-gain reflection compensation IRS unit for 2.4 GHz, characterized in that: By changing the reverse bias voltage of the varactor diode I (1) and the varactor diode II (2), the reflection coefficient is changed to adjust the reflected wave, which includes the following steps: The impedance of the IRS unit is obtained based on the impedance of the varactor diode I (1) and the varactor diode II (2), and the impedance of the passive structure composed of the first metal patch (3), the second metal patch (4), the third metal patch (5), the second metal layer, the metal through hole (7), the third metal layer, and the metal through hole array (9); According to the impedance of the IRS unit, the reflected wave characteristics are obtained through the reflection coefficient model of the IRS unit to achieve adjustment of the reflected wave.

9. The method for adjusting reflected waves of a 2.4GHz thin and light high-gain reflection compensation IRS unit according to claim 8, characterized in that: By changing the reverse bias voltage of varactor diode I (1) and varactor diode II (2), the reflection coefficient is changed to adjust the reflected wave, which is achieved by the following formula: Where Z0 is the free space wave impedance, A IRS (ν) represents the reflection amplitude provided by the IRS unit, φ IRS (ν) represents the reflection phase provided by the IRS unit; The impedance Z of the IRS unit s (ν)=F(Z a ,Z L (ν)), F represents the impedance Z of the IRS unit s (ν) is determined by the impedance Z of the passive structure a and the impedance Z of varactor diode I (1) and varactor diode II (2) L Joint impact, Z L (ν) represents Z L Controlled by the reverse bias voltage ν.

10. The method for adjusting reflected waves of a 2.4GHz thin and light high-gain reflection compensation IRS unit according to claim 8, characterized in that: Applies to the following situations: When the line-of-sight link between the transmitter and receiver is blocked, the IRS unit acts as a passive repeater to construct a reflective link and complete the communication between the transmitter and receiver. At this time, the bias voltage control of the IRS unit does not change; When coherent interference occurs between the line-of-sight link between the transmitter and receiver and the reflection link formed by the metal inside the factory, the IRS is installed on the metal inside the factory as a passive repeater to replace the metal inside the factory to construct the reflection link. By adjusting the bias voltage of the varactor diode, the reflection phase is reversed, turning the original coherent interference into constructive interference. When the receiving end is a certain area, the IRS unit forms a reflection phase offset by adjusting the phase difference between the columns of the board units to achieve the purpose of communication between the transmitting end and the entire area.

Images