Broadband flexible rectification circuit with harmonic suppression network for microwave energy transmission

Abstract

The invention discloses a broadband flexible rectifying circuit with a harmonic suppression network for microwave energy transmission, which comprises a flexible dielectric substrate and a commutator circuit arranged on the flexible dielectric substrate, and is characterized in that the commutator circuit comprises a capacitor, a first conical microstrip line, an F-type harmonic suppression network, a Schottky diode and a straight-through filter; wherein one end of the capacitor is connected with the feed interface, the other end of the capacitor is connected with one end of the first conical microstrip line, the other end of the first conical microstrip line is connected with the F-type harmonic suppression network and the straight-through filter, the F-type harmonic suppression network is further connected with the Schottky diode, and the straight-through filter is further connected with the load; the invention aims to design a flexible rectification circuit which works at 5.8 GHz, is applied to microwave energy transmission, is broadband and high in efficiency, is easy to be conformal with load equipment and has certain self-adaptability. And an F-type harmonic suppression network is added to enhance the energy conversion capability of the flexible rectification circuit.

Description

Technical Field

[0001] The invention belongs to the field of wireless energy transmission, and in particular relates to a broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission. Background Art

[0002] Microwave Power Transmission (MPT) technology uses space electromagnetic waves as the energy transmission medium to achieve long-distance energy transmission. In the entire MPT system, the rectenna at the receiving end plays an extremely critical role. The rectenna consists of two main components, including a receiving antenna that can effectively collect microwave energy transmitted in space, and a microwave rectifier circuit that can realize microwave-to-DC (MW-DC) energy conversion. The rectification efficiency of the rectifier circuit is affected by many factors, such as input power, load impedance, diode performance, matching network design, etc. In practical applications, the broadband rectifier circuit has the ability to respond to signals in multiple frequency ranges, ensuring that signals of multiple frequencies can be effectively converted into energy.

[0003] At present, rectifier circuits based on rigid dielectric substrates cannot meet the demand for power supply for flexible and wearable electronic devices. Rectifier circuits that cannot be bent or have poor bending performance not only have a negative impact on the user experience, but also increase the overall size of the device because the rectifier circuit cannot conform to the device, which is not conducive to miniaturization design. In contrast, rectifier circuits based on flexible materials have excellent flexibility and ductility. They can not only conform to the carrier while realizing the rectification function of microwave energy, but also are more adaptable to complex structural surfaces. Compared with rigid rectifier circuits, flexible rectifier circuits have significant advantages and broad application prospects in fields with special requirements for appearance and structure, such as IoT wearable devices, medical care, aerospace and other popular fields. Therefore, the study of flexible rectifier circuits with good bending performance has become a new challenge facing microwave energy harvesting technology.

[0004] Therefore, this patent invents a liquid metal rectifier circuit for microwave energy transmission at 5.8GHz by applying liquid metal printing technology and flexible materials. The liquid metal rectifier circuit will give full play to the advantages of liquid gallium-indium alloy composite materials and flexible dielectric substrates, such as repairability, flexibility, reconfigurability, fatigue resistance, and corrosion resistance, and will be used in integrated small electronic devices to achieve the reception and transmission of electromagnetic waves, and to be used for wireless energy transmission over long distances. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission provided by the present invention solves the problems of impedance mismatch caused by the working frequency band offset of the traditional rectifier circuit, as well as the problems of poor conformality, difficulty in resisting mechanical deformation, and poor environmental adaptability.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission, comprising a flexible dielectric substrate and a rectifier circuit arranged on the flexible dielectric substrate, wherein the rectifier circuit comprises a capacitor, a first tapered microstrip line, a class F harmonic suppression network, a Schott diode and a pass-through filter;

[0007] One end of the capacitor is connected to the feeding interface, the other end of the capacitor is connected to one end of the first tapered microstrip line, the other end of the first tapered microstrip line is respectively connected to a class F harmonic suppression network and a pass-through filter, the class F harmonic suppression network is also connected to a Schott diode, and the pass-through filter is also connected to a load;

[0008] The first tapered microstrip line is used for impedance matching, the class F harmonic suppression network is used to achieve short-circuiting of even-order harmonic signals and opening of odd-order harmonic signals by precisely controlling the impedance state of the harmonic frequency, the pass-through filter is used to allow signals in a specific frequency band to pass through while attenuating signals in other frequency bands, and the Schott diode is used for rectification.

[0009] Further: the class F harmonic suppression network includes a first open-circuit branch, a second open-circuit branch and a transmission line;

[0010] Wherein, one end of the transmission line is respectively connected to the first open-circuit branch, the second open-circuit branch and the other end of the first tapered microstrip line.

[0011] The beneficial effects of the above further scheme are as follows: the Class F harmonic suppression network significantly improves efficiency, optimizes output waveform, reduces harmonic distortion, and provides broadband matching capability by effectively controlling the impedance state of harmonics; the first tapered microstrip line can continuously adjust impedance, thereby achieving good matching within a wide frequency band and reducing the impact of frequency changes; the flexible dielectric substrate is made of flexible material, has good mechanical properties, can conform well to the load, and can be stretched, bent, twisted, and deformed while maintaining its stable performance.

[0012] Furthermore: the cathode of the Schott diode is connected to the other end of the transmission line, and the anode of the Schott diode is grounded through a short-circuit stub.

[0013] Furthermore: the model of the Schott diode is HSMS-2860.

[0014] Further: the straight-through filter comprises a second tapered microstrip line, a third open-circuit branch and a fourth open-circuit branch;

[0015] One end of the second tapered microstrip line is connected to the other end of the first tapered microstrip line, and the other end of the second tapered microstrip line is connected to the third open-circuit branch, the fourth open-circuit branch and the load respectively.

[0016] Furthermore: an equivalent ground plane is arranged below the flexible dielectric substrate.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention provides a broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission, which overcomes the problem of impedance mismatch caused by the working frequency band offset of the traditional rectifier circuit, and adopts a linear first tapered microstrip line to control the impedance curve of the input power level, so that the rectifier circuit can obtain higher conversion efficiency and wide working frequency band, and can realize broadband and high-efficiency wireless energy transmission.

[0019] (2) The present invention overcomes the shortcomings of poor conformality, difficulty in resisting mechanical deformation, and poor environmental adaptability of traditional rectifier circuits. The present invention uses flexible materials and liquid metals to enable the flexible rectifier circuit to bend and twist according to different environments while maintaining its stable performance, and has a certain degree of adaptability.

[0020] (3) The purpose of the present invention is to design a flexible rectifier circuit that works at 5.8 GHz and is used for microwave energy transmission. It is broadband, highly efficient, easy to conform to the load device and has a certain degree of adaptability. A class F harmonic suppression network is added to enhance the energy conversion capability of the flexible rectifier circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The schematic diagram of the broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission of the present invention is shown in FIG.

[0022] Figure 2 It is a side view of the broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission of the present invention. DETAILED DESCRIPTION

[0023] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0024] like Figure 1As shown, in one embodiment of the present invention, a broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission includes a flexible dielectric substrate and a rectifier circuit arranged on the flexible dielectric substrate, wherein the rectifier circuit includes a capacitor, a first tapered microstrip line TL5, a class F harmonic suppression network, a Schott diode and a pass filter;

[0025] Among them, one end of the capacitor is connected to the feeding interface, the other end of the capacitor is connected to one end of the first tapered microstrip line TL5, the other end of the first tapered microstrip line TL5 is respectively connected to the F-type harmonic suppression network and the pass-through filter, the F-type harmonic suppression network is also connected to the Schott diode, and the pass-through filter is also connected to the load.

[0026] The first tapered microstrip line TL5 is used for impedance matching, the class F harmonic suppression network is used to achieve short-circuiting of even-order harmonic signals and open-circuiting of odd-order harmonic signals by precisely controlling the impedance state of the harmonic frequency, the pass-through filter is used to allow signals in a specific frequency band to pass through while attenuating signals in other frequency bands, and the Schott diode is used for rectification.

[0027] In this embodiment, the material of the flexible dielectric substrate is polycondensation type polyimide, which is a flexible material with good mechanical properties, anti-bending and easy conformal properties.

[0028] The RF source on the flexible dielectric substrate is connected to the rectifier circuit through the feed interface. The rectifier circuit is made of gallium-indium alloy and is printed on the upper surface of the flexible dielectric substrate through liquid metal printing technology to convert the received microwave energy into DC energy. Since the rectifier circuit is made of liquid metal printing, it can withstand a large degree of deformation, has good conformality and certain adaptability, can be used in the field of wireless energy transmission, has a wide bandwidth and high efficiency, and can be used in the field of flexible electronic devices.

[0029] The capacitor adopts a 100pF surface mount capacitor, which is commonly used in modern high-density circuit design and has low parasitic effects and good high-frequency performance.

[0030] The first tapered microstrip line TL5 realizes continuous impedance change through a gradual cross-sectional structure, and can achieve good impedance matching within a wide frequency band.

[0031] like Figure 1 As shown, in this embodiment, the F-class harmonic suppression network includes a first open-circuit branch TL3, a second open-circuit branch TL4 and a transmission line TL2;

[0032] One end of the transmission line TL2 is connected to the other ends of the first open branch TL3 , the second open branch TL4 and the first tapered microstrip line TL5 , respectively.

[0033] In this embodiment, the Class F harmonic suppression network can achieve matching of the second harmonic impedance to near the short-circuit point and the third harmonic impedance to near the open-circuit point within a certain frequency range. This design greatly reduces power loss and improves the conversion efficiency from DC to RF or RF to DC. The Class F harmonic suppression network significantly improves efficiency, optimizes output waveforms, reduces harmonic distortion, and provides broadband matching capabilities by effectively controlling the impedance state of harmonics.

[0034] The cathode of the Schott diode is connected to the other end of the transmission line, and the anode of the Schott diode is grounded through the short-circuit stub TL1.

[0035] In this embodiment, a Schott diode is connected below the class F harmonic suppression network for rectification.

[0036] The model of the Schottky diode is HSMS-2860, wherein the forward voltage drop of the Schottky diode is usually low, generally between 0.2V and 0.3V.

[0037] The straight-through filter comprises a second tapered microstrip line TL6, a third open-circuit branch TL7 and a fourth open-circuit branch TL8;

[0038] One end of the second tapered microstrip line TL6 is connected to the other end of the first tapered microstrip line TL5, and the other end of the second tapered microstrip line TL6 is connected to the third open branch TL7, the fourth open branch TL8 and the load respectively.

[0039] In this embodiment, the pass-through filter connects the third open branch TL7 and the fourth open branch TL8 through the second tapered microstrip line TL6, wherein the second tapered microstrip line TL6 can significantly reduce signal reflection, thereby reducing return loss. The third open branch TL7 and the fourth open branch TL8 achieve the function of a wide stopband pass filter through a smooth impedance transition, and the other end of the second tapered microstrip line TL6 can be connected to a load to power the load.

[0040] like Figure 2 As shown, an equivalent grounding plate is arranged under the flexible dielectric substrate as equivalent grounding. The thickness of the broadband flexible rectifier circuit is 0.807 mm, the thickness of the rectifier circuit is 0.035 mm, the thickness of the flexible dielectric substrate is 0.8 mm, and the thickness of the equivalent grounding plate is 0.035 mm.

[0041] The beneficial effects of the present invention are as follows: the present invention provides a broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission, which overcomes the problem of impedance mismatch caused by the operating frequency band offset of the traditional rectifier circuit, and adopts a linear first tapered microstrip line to control the impedance curve of the input power level, so that the rectifier circuit obtains higher conversion efficiency and wide operating frequency band, and can realize broadband and high-efficiency wireless energy transmission.

[0042] The present invention overcomes the shortcomings of poor conformality, difficulty in resisting mechanical deformation, and poor environmental adaptability of traditional rectifier circuits. The present invention adopts flexible materials and liquid metals, so that the flexible rectifier circuit can be bent and twisted according to different environments while maintaining its stable performance, and has a certain degree of adaptability.

[0043] The purpose of the present invention is to design a flexible rectifier circuit that works at 5.8GHz and is used for microwave energy transmission. It is broadband, highly efficient, easy to conform to the load device and has a certain degree of adaptability. A class F harmonic suppression network is added to enhance the energy conversion capability of the flexible rectifier circuit.

[0044] In the description of the present invention, it is necessary to understand that the orientation or positional relationship indicated by the terms "center", "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "radial", etc. is based on the orientation or positional relationship shown in the drawings, and 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, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used only for descriptive purposes, and cannot be understood as indicating or implying the relative importance or the number of implicitly specified technical features. Therefore, the features defined by "first", "second", and "third" may explicitly or implicitly include one or more of the features.

Claims

1. A broadband flexible rectifier circuit with a harmonic suppression network for microwave energy transmission, characterized in that: It includes a flexible dielectric substrate and a rectifier circuit arranged on the flexible dielectric substrate, wherein the rectifier circuit includes a capacitor, a first tapered microstrip line, a class F harmonic suppression network, a Schott diode and a through filter; One end of the capacitor is connected to the feeding interface, the other end of the capacitor is connected to one end of the first tapered microstrip line, the other end of the first tapered microstrip line is respectively connected to a class F harmonic suppression network and a pass-through filter, the class F harmonic suppression network is also connected to a Schott diode, and the pass-through filter is also connected to a load; The first tapered microstrip line is used for impedance matching, the class F harmonic suppression network is used to achieve short-circuiting of even-order harmonic signals and opening of odd-order harmonic signals by precisely controlling the impedance state of the harmonic frequency, the pass-through filter is used to allow signals in a specific frequency band to pass through while attenuating signals in other frequency bands, and the Schott diode is used for rectification.

2. The broadband flexible rectifier circuit with harmonic suppression network for microwave energy transmission according to claim 1, characterized in that: The class F harmonic suppression network includes a first open-circuit branch, a second open-circuit branch and a transmission line; Wherein, one end of the transmission line is respectively connected to the first open-circuit branch, the second open-circuit branch and the other end of the first tapered microstrip line.

3. The broadband flexible rectifier circuit with harmonic suppression network for microwave energy transmission according to claim 2, characterized in that: The cathode of the Schott diode is connected to the other end of the transmission line, and the anode of the Schott diode is grounded through a short-circuit stub.

4. The broadband flexible rectifier circuit with harmonic suppression network for microwave energy transmission according to claim 3 is characterized in that: The model of the Schott diode is HSMS-2860.

5. The broadband flexible rectifier circuit with harmonic suppression network for microwave energy transmission according to claim 2, characterized in that: The straight-through filter comprises a second tapered microstrip line, a third open-circuit branch and a fourth open-circuit branch; One end of the second tapered microstrip line is connected to the other end of the first tapered microstrip line, and the other end of the second tapered microstrip line is connected to the third open-circuit branch, the fourth open-circuit branch and the load respectively.

6. The broadband flexible rectifier circuit with harmonic suppression network for microwave energy transmission according to claim 1, characterized in that: An equivalent grounding plate is arranged below the flexible dielectric substrate.

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