Metamaterial antenna radio frequency energy collecting and rectifying device based on complementary split-ring resonators

Abstract

The invention relates to a metamaterial antenna radio frequency energy collecting and rectifying device based on complementary split-ring resonators, and belongs to the technical field of wireless energy collection and transmission. The device comprises an antenna unit and a rectifying and filtering unit which are connected with each other, and the rectifying and filtering unit receives radio frequency energy output by the antenna unit, rectifies and filters the radio frequency energy and then converts the radio frequency energy into direct current signals to be output. The antenna unit comprises a dielectric substrate and an antenna array element. The antenna array elements are linearly arranged and integrated on the surface of the dielectric substrate, and each antenna array element is loaded with a complementary split-ring resonator. The rectifying and filtering unit comprises an impedance matching circuit, a rectifying circuit and a filtering circuit. One end of the impedance matching circuit is connected with the antenna unit, the other end of the impedance matching circuit is connected with the rectifying circuit, the rectifying circuit converts and rectifies radio frequency energy output by the antenna unit into direct current signals, and the filtering circuit receives the direct current signals output by the rectifying circuit, filters and outputs the direct current signals.

Description

Technical Field

[0001] The present invention belongs to the field of wireless energy harvesting and transmission, and relates to a radio frequency energy harvesting and rectifying device based on a metamaterial antenna with complementary split-ring resonators. Background Art

[0002] With the rapid development of the Internet of Things (IoT), 5G communication, and smart devices, the application scenarios of low-power electronic devices are becoming increasingly extensive, covering multiple fields such as healthcare, environmental monitoring, industrial automation, wireless sensor networks, and intelligent transportation systems. These devices are usually deployed in environments where it is difficult to replace the battery or access traditional power sources, such as implantable medical devices, remote environmental monitoring nodes, and industrial sensors. Traditional battery-powered methods have problems such as limited lifespan, high replacement costs, and environmental pollution. There is an urgent need for a sustainable and maintenance-free power supply solution. Radio frequency energy harvesting technology has emerged, which captures radio frequency signals in the environment and converts them into electrical energy, providing a green and sustainable energy solution for low-power devices.

[0003] Radio frequency energy harvesting technology uses radio frequency signals widely present in the environment (such as Wi-Fi, Bluetooth, cellular networks, radio and television signals, etc.) as energy sources, and has the following advantages: 1) Sustainability: Radio frequency signals are ubiquitous, and with the popularization of wireless communication infrastructure, the radio frequency energy density in the environment continues to increase. It is estimated that the radio frequency energy density in urban environments can reach 0.1 - 1 μW / cm2, which is sufficient to drive low-power devices. 2) Maintenance-free: Radio frequency energy harvesting devices do not require battery replacement, reducing equipment maintenance costs and downtime. 3) Environmental friendliness: By recycling radio frequency energy in the environment, the dependence on traditional batteries is reduced, and the generation of electronic waste is decreased. 4) Wide applicability: It is applicable to scenarios such as medical implant devices, wireless sensor networks, and smart homes, and is especially suitable for deployment in remote or difficult-to-maintain areas.

[0004] A radio frequency energy harvesting device usually consists of an antenna, an impedance matching circuit, a rectifying circuit, and an energy storage unit. It captures radio frequency signals in the environment through the antenna and converts them into high-frequency alternating current. The performance of the antenna directly affects the energy harvesting efficiency, and it is usually required to have high gain, wide bandwidth, and miniaturization characteristics. The impedance matching between the antenna and the rectifying circuit is achieved through the impedance matching circuit to maximize the energy transfer efficiency and reduce signal reflection. The high-frequency alternating current is converted into direct current through the rectifying circuit, and common rectifying devices include Schottky diodes and MOSFETs. The rectified electrical energy is stored through the energy storage unit to power the load device, and common energy storage components include supercapacitors and micro-batteries.

[0005] At present, in radio frequency energy harvesting devices, microstrip patch antennas need to develop towards high-performance directions such as wide bandwidth, high gain, miniaturization, and multi-band. However, the various indicators of microstrip patch antennas restrict each other. To reduce the antenna size, it is necessary to sacrifice bandwidth or radiation efficiency. At the same time, there are problems such as the inability to supply the high-frequency alternating current output by the antenna, low rectification efficiency, and inability to be applied for a long time. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a radio frequency energy harvesting and rectifying device based on a metamaterial antenna with complementary split ring resonators, to solve the problems of low radio frequency energy harvesting efficiency, insufficient antenna gain, and large losses in the energy conversion and management process in the prior art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A radio frequency energy harvesting and rectifying device based on a metamaterial antenna with complementary split ring resonators, comprising an antenna unit and a rectifying and filtering unit connected to each other, wherein the rectifying and filtering unit receives the radio frequency energy output by the antenna unit, and after rectification and filtering, it is converted into a direct current signal for output.

[0009] Furthermore, the antenna unit includes a dielectric substrate and antenna elements. The antenna elements are linearly arranged and integrated on the surface of the dielectric substrate. The linearly arranged antenna elements are used to receive radio frequency signals in the environment; complementary split ring resonators are loaded on each antenna element to enhance the resonance performance and gain of the antenna elements.

[0010] Furthermore, the rectifying and filtering unit includes an impedance matching circuit, a rectifying circuit, and a filtering circuit. Among them, one end of the impedance matching circuit is connected to the antenna unit, and the other end is connected to the rectifying circuit. The impedance matching circuit realizes the impedance matching between the antenna unit and the rectifying circuit, preventing the circuit from reflecting energy back to the antenna unit; the rectifying circuit converts and rectifies the radio frequency energy output by the antenna unit into a direct current signal; the filtering circuit is connected to the rectifying circuit, receives the direct current signal output by the rectifying circuit, and outputs it after filtering.

[0011] Furthermore, the impedance matching circuit is a single stub; the rectifying circuit is based on a full-wave rectifying circuit and combines Schottky diodes or rectifying diodes for rectification to improve the rectification efficiency; the filtering circuit adopts a third-order low-pass filter.

[0012] Furthermore, the complementary split ring resonators are engraved on each antenna element in the form of an array arrangement, and its array form is preferably a square matrix, such as a 2×2, 3×3 array, etc.

[0013] Furthermore, the complementary split ring resonators are two nested split ring resonators with opposite opening directions, and the split ring resonators can be split circular rings, split rectangular rings, etc.

[0014] Further, a rectangular groove is provided on the ground plane of the dielectric substrate, and a microstrip line is arranged in the rectangular groove to form a feeding network, and a resonant cavity is formed between the ground plane of the dielectric substrate and each antenna element through the feeding network.

[0015] Further, each antenna element is connected to a radio frequency signal input port through a feeder.

[0016] Further, the antenna element is a radiation patch.

[0017] The beneficial effects of the present invention are as follows: The present invention provides a radio frequency energy harvesting and rectifying device for a metamaterial antenna based on complementary split ring resonators. In this device, the complementary split ring resonator structure is introduced into the array antenna elements. Through the negative dielectric constant characteristic of the complementary split ring resonator structure, the gain and directivity of the antenna can be significantly improved, and the radio frequency energy harvesting efficiency can be increased by about 20%-30%, meeting the requirements of low-power devices. The present invention also optimizes the rectifier circuit design, introduces an impedance matching circuit to avoid energy reflux, and combines low-pass filtering of the rectified output, so that the rectification efficiency of the device is increased to more than 50%. In addition, the present invention collects ambient radio frequency signals and converts them into direct current signals for output, can supply electrical energy to the device itself as an energy source, replaces traditional battery power supply, reduces the need for battery replacement, and reduces the operation and maintenance costs. In addition, by optimizing the antenna and circuit design, the system operation reliability is improved, the overall service life of the device is extended, and it can be well applied in fields such as healthcare, environmental monitoring, industrial automation, wireless sensor networks, and intelligent transportation systems that require low-power devices and apparatuses.

[0018] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in preferred detail below with reference to the accompanying drawings, where:

[0020] Figure 1 is a schematic diagram of the antenna unit structure provided by an embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of the rectifier circuit principle;

[0022] Figure 3 is a schematic diagram of the impedance matching circuit principle;

[0023] Figure 4 It is a schematic diagram of the principle of a filtering circuit. Specific implementation manners

[0024] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0025] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and cannot be understood as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0026] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or position relationship, it is based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0027] An embodiment of the present invention provides a radio frequency energy harvesting and rectifying device based on complementary split ring resonators, which includes antenna elements, complementary split ring resonators, a dielectric substrate, and a rectifying and filtering unit. Among them, the antenna elements are linearly arranged on the dielectric substrate, and each antenna element is connected to one end of a feeder, and the other end of the feeder is connected to a radio frequency signal input port. The complementary split ring resonators are integrated on each antenna element in an array form to improve the energy harvesting efficiency. The rectifying and filtering unit is connected to the output end of the antenna unit and outputs a DC voltage after rectification and filtering.

[0028] The working principle of the device is as follows. The antenna unit part of the device collects radio frequency signals in the environment through the antenna array formed by antenna elements. The complementary split-ring resonator structures loaded on each antenna element can enhance the resonance performance and gain of the element through their negative permittivity characteristics. In the rectification and filtering unit of the device, the radio frequency signals received by the antenna enter the rectification and filtering circuits for full-wave rectification and filtering to eliminate high-order harmonics and convert the radio frequency energy into direct current.

[0029] A specific embodiment of the device described in the present invention includes an antenna unit and a rectification and filtering unit.

[0030] Among them, the antenna unit is as Figure 1 shown, and it includes:

[0031] A dielectric substrate, the material of which can be FR4, with a dielectric constant of 4.4 and a thickness of 1.6 mm, and a rectangular groove is provided on the ground plane of the dielectric substrate;

[0032] Antenna elements, the antenna elements are arranged in a 4×1 linear array on the dielectric substrate, each element is a rectangular radiation patch, and each element is connected to the radio frequency signal input port through a feeder;

[0033] Complementary split-ring resonators, which are loaded on each antenna element. Specifically, they are engraved on each antenna element in the form of a 2×2 array arrangement.

[0034] In this embodiment, the rectification and filtering unit includes a rectification circuit, a filtering circuit, and an impedance matching circuit; as Figure 2 shown, the rectification circuit is based on full-wave rectification, and HSMS-2862 Schottky diodes are used to improve the rectification efficiency; as Figure 4 shown, the filtering circuit is a third-order low-pass filter; as Figure 3 shown, the impedance matching circuit is a single stub to achieve impedance matching between the antenna element and the rectification circuit and prevent the circuit from reflecting energy back to the antenna part.

[0035] Among them, a rectangular groove is provided on the ground plane of the dielectric substrate, and the rectangular groove is fed by a microstrip line. Using the feeding network, an electromagnetic field is generated between the antenna element and the ground plane, and an electromagnetic radiation field is formed outward through the edges of the antenna element and the ground plane;

[0036] Since the device is applied in a high-frequency environment, the energy in the circuit is no longer transmitted through current but through the electromagnetic field. Therefore, microstrip lines are used to replace traditional wires in the impedance matching circuit, rectification circuit, and filtering circuit.

[0037] In another embodiment of the present invention, for the rectification part of the rectification and filtering unit, the Schottky diodes therein can be replaced with rectification diodes with higher performance, so as to further improve the rectification efficiency of the metamaterial antenna radio frequency energy collection and rectification device.

[0038] In summary, the present invention provides a radio frequency energy harvesting and rectifying device for a metamaterial antenna based on complementary split-ring resonators. The device harvests radio frequency energy through the antenna, then transmits the radio frequency energy to the rectifying circuit for rectification, and converts it into direct current for output. By introducing the complementary split-ring resonator structure into the array antenna, the device significantly improves the gain and directivity of the antenna, increasing the radio frequency energy harvesting efficiency of the antenna part by about 20% - 30%, meeting the requirements of low-power devices. In addition, the device optimizes the design of the rectifying circuit, combines low-pass filtering and impedance matching, and improves the rectification efficiency to more than 50%.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A metamaterial antenna radio frequency energy collection and rectification device based on complementary split resonant rings, characterized in that: It includes an antenna unit and a rectifying and filtering unit that are connected to each other; the rectifying and filtering unit receives the radio frequency energy output by the antenna unit, and converts it into a direct current signal for output after rectification and filtering. The antenna unit includes a dielectric substrate and antenna elements; the antenna elements are linearly arranged and integrated on the surface of the dielectric substrate, and the linearly arranged antenna elements are used to receive radio frequency signals in the environment; the complementary open resonant ring is loaded on each of the antenna elements to enhance the resonance performance and gain of the antenna elements.

2. The device according to claim 1, characterized in that The complementary open resonant rings are arranged in an array and engraved on each of the antenna array elements.

3. The device according to claim 1 or 2, characterized in that: The complementary open resonant rings are two nested open resonant rings with openings in opposite directions.

4. The device according to claim 1, characterized in that The ground plane of the dielectric substrate is provided with a rectangular groove, and a microstrip line is arranged in the rectangular groove to form a feeding network, and a resonant cavity is formed between the ground plane of the dielectric substrate and each of the antenna array elements through the feeding network.

5. The device according to claim 1, characterized in that Each of the antenna array elements is connected to a radio frequency signal input port via a feeder line.

6. The device according to claim 1, characterized in that The rectifying and filtering unit includes an impedance matching circuit, a rectifying circuit and a filtering circuit; one end of the impedance matching circuit is connected to the antenna unit, and the other end is connected to the rectifying circuit; the rectifying circuit converts and rectifies the radio frequency energy output by the antenna unit into a direct current signal; the filtering circuit is connected to the rectifying circuit, receives the direct current signal output by the rectifying circuit, and outputs it after filtering.

7. The device according to claim 1, 2, 4, 5 or 6, characterized in that The antenna array element is a radiation patch.

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