A radio frequency rectifier circuit

Abstract

The present application discloses a radio frequency rectifier circuit, comprising: an energy harvesting network, a low-power rectifier branch, a high-power rectifier branch, and a harmonic tuning and matching network; a first end of the energy harvesting network is connected to a microwave source MV, a second end of the energy harvesting network is connected to the low-power rectifier branch, a third end of the energy harvesting network is connected to the high-power rectifier branch, and a fourth end of the energy harvesting network is grounded; the energy harvesting network comprises microstrip lines TL1, TL2, TL3, TL4, TL5, TL6, and TL7, wherein microstrip lines TL1, TL4, and TL7 are symmetrically arranged, microstrip line TL2 is symmetrically arranged with microstrip line TL3, and microstrip line TL5 is symmetrically arranged with microstrip line TL6. The present application can improve rectification efficiency and input power range while reducing circuit size. At the same time, it can efficiently utilize the energy reflected by the two rectifier branches and improve the matching dynamic range of the load.

Description

Technical Field

[0001] The present application relates to the technical field of radio frequency circuits, and in particular to a radio frequency rectifier circuit. Background Art

[0002] Radio frequency energy harvesting (REH) technology is gaining increasing attention. It plays a crucial role in specific scenarios, particularly in security and military settings, such as those with a large number of sensors or radio frequency identification (RFID) tags and low light conditions. It is also gaining widespread application in smart transportation, healthcare, and the Internet of Things (IoT). Compared to traditional power supply methods, RF energy harvesting offers advantages such as sustainability, environmental friendliness, and the need for manual replacement.

[0003] Generally speaking, RF energy harvesting systems primarily consist of a receiving antenna and a rectifier circuit. These systems collect electromagnetic energy from the surrounding environment, providing charging solutions for electronic devices that are difficult to route wires or replace batteries, such as those used in pipeline monitoring and remote locations. The rectifier circuit, at the heart of the energy harvesting system, converts the collected RF energy into DC energy. These systems are widely used in a variety of applications, including solar satellite systems, microwave-powered helicopters, wireless power sensors, biomedical implantable devices, radio frequency identification (RFID), and drone charging.

[0004] However, the matching structure of existing rectifier circuits usually performs matching on each branch separately, which increases the circuit size and introduces more losses. There are common problems such as low rectification efficiency, limited extended frequency range, and excessive size. These problems often limit its application in miniaturized equipment. Summary of the Invention

[0005] The purpose of this application is to provide a radio frequency rectifier circuit to solve the technical problem of low rectification efficiency of existing radio frequency rectifier circuits in the prior art. The various technical effects that can be produced by the preferred technical solution among the many technical solutions provided in this application are described in detail below.

[0006] To achieve the above objectives, this application provides the following technical solutions:

[0007] The present application provides a radio frequency rectification circuit, comprising: an energy harvesting network, a low-power rectification branch, a high-power rectification branch, and a harmonic tuning and matching network; a first end of the energy harvesting network is connected to a microwave source MV, a second end of the energy harvesting network is connected to an input end of the low-power rectification branch, a third end of the energy harvesting network is connected to an input end of the high-power rectification branch, and a fourth end of the energy harvesting network is grounded; an output end of the low-power rectification branch and an output end of the high-power rectification branch are both connected to the harmonic tuning and matching network; the energy harvesting network comprises a microstrip line TL1, a microstrip line TL2, a microstrip line TL3, a microstrip line TL4, a microstrip line TL5, a microstrip line TL6, and a microstrip line TL7, wherein the microstrip line TL1, the microstrip line TL4, and the microstrip line TL7 are symmetrically arranged, the microstrip line TL2 is symmetrically arranged with the microstrip line TL3, and the microstrip line TL5 is symmetrically arranged with the microstrip line TL6.

[0008] In some embodiments, one end of the microstrip line TL1 is connected to one end of the microstrip line TL2 and the microwave source MV, the other end of the microstrip line TL1 is connected to one end of the microstrip line TL3 and the input end of the low-power rectifier branch, the other end of the microstrip line TL2 is connected to one end of the microstrip line TL4 and one end of the microstrip line TL5, the other end of the microstrip line TL3 is connected to the other end of the microstrip line TL4 and one end of the microstrip line TL6, the other end of the microstrip line TL5 is connected to one end of the microstrip line TL7 and is grounded, and the other end of the microstrip line TL6 is connected to the other end of the microstrip line TL7 and the input end of the high-power rectifier branch.

[0009] In some embodiments, the low-power rectification branch includes a capacitor C1, a low-power impedance matching network and a diode D1; one end of the capacitor C1 is connected to the other end of the microstrip line TL1 and one end of the microstrip line TL3, the other end of the capacitor C1 is connected to one end of the low-power impedance matching network, the other end of the low-power impedance matching network is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the harmonic tuning matching network.

[0010] In some embodiments, the low-power impedance matching network includes a microstrip line TL8 and a microstrip line TL9; one end of the microstrip line TL8 is connected to the other end of the capacitor C1 and one end of the microstrip line TL9, the other end of the microstrip line TL8 is connected to the anode of the diode D1, and the other end of the microstrip line TL9 is grounded.

[0011] In some embodiments, the high-power rectifier branch includes a capacitor C2, a high-power impedance matching network, a diode D2 and an inductor L1; one end of the capacitor C2 is connected to the other end of the microstrip line TL6 and the other end of the microstrip line TL7, the other end of the capacitor C2 is connected to one end of the high-power impedance matching network, the other end of the high-power impedance matching network is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the inductor L1, and the inductor L1 is connected to the harmonic tuning matching network.

[0012] In some embodiments, the high-power impedance matching network includes a microstrip line TL10 and a microstrip line TL11; one end of the microstrip line TL10 is connected to the other end of the capacitor C2 and one end of the microstrip line TL11, the other end of the microstrip line TL10 is connected to the anode of the diode D2, and the other end of the microstrip line TL11 is grounded.

[0013] In some embodiments, the harmonic tuning matching network includes a T-type matching junction, a harmonic suppression network and a load resistor; the first end of the T-type matching junction is connected to the cathode of the diode D1, the second end of the T-type matching junction is connected to the other end of the inductor L1, the third end of the T-type matching junction is connected to one end of the harmonic suppression network, the other end of the harmonic suppression network is connected to one end of the load resistor, and the other end of the load resistor is grounded.

[0014] In some embodiments, the T-type matching junction includes a microstrip line TL12, a microstrip line TL13, and a microstrip line TL14; the other end of the microstrip line TL12 is connected to the other end of the microstrip line TL13 and the other end of the microstrip line TL14.

[0015] In some embodiments, the harmonic suppression network includes microstrip line TL15, microstrip line TL16 and microstrip line TL17; the microstrip line TL15, the microstrip line TL16 and the microstrip line TL17 are all connected to one end of the microstrip line TL14 and one end of the load resistor.

[0016] In some embodiments, the microstrip line TL15 is a quarter-wavelength microstrip line, the microstrip line TL16 is an eighth-wavelength microstrip line, and the microstrip line TL17 is a twelfth-wavelength microstrip line.

[0017] Implementing one of the above-mentioned technical solutions of the present application has the following advantages or beneficial effects: In the present application, by separately setting a low-power rectifier branch and a high-power rectifier branch for rectification, the two branches operate in the low-power area and the high-power area respectively, which can improve the rectification efficiency and the input power range, and at the same time, the dual-branch single-load single-tube series rectifier structure can reduce the circuit size. By setting up an energy harvesting network, the energy reflected by the two rectifier branches can be efficiently utilized, and the matching dynamic range of the load can be improved, so that the direct-through filter path can be combined into one while maintaining the prerequisite for high-efficiency rectification. When the input power, frequency and output load of the sub-rectifier circuit change, part of the reflected waves generated by the low-power rectifier branch and the high-power rectifier branch due to impedance mismatch will be blocked by the energy harvesting network and returned to the low-power rectifier branch and the high-power rectifier branch for reuse, thereby improving the rectification efficiency and reducing the sensitivity of the entire RF rectifier circuit to changes in input power, frequency and output load. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive work. In the drawings:

[0019] Figure 1 1 is a circuit diagram of a radio frequency rectifier circuit according to an embodiment of the present application;

[0020] Figure 2 is a circuit diagram of an energy harvesting network according to an embodiment of the present application;

[0021] Figure 3 is a schematic diagram of a low-power energy path according to an embodiment of the present application;

[0022] Figure 4 is another schematic diagram of a low-power energy path according to an embodiment of the present application;

[0023] Figure 5 is a schematic diagram of a high-power energy path according to an embodiment of the present application;

[0024] Figure 6 is another schematic diagram of the high-power energy path of an embodiment of the present application;

[0025] Figure 7 is a curve diagram of resistance parameters in the simulation results of the embodiment of the present application;

[0026] Figure 8 is a schematic diagram of a curve of S parameters in the simulation results of an embodiment of the present application;

[0027] Figure 9 is a schematic diagram of the rectification efficiency in the simulation results of the embodiment of the present application;

[0028] Figure 10 This is another schematic diagram of the rectification efficiency in the simulation results of the embodiment of the present application.

[0029] In the figure: 1. RF rectification circuit; 10. Energy harvesting network; 20. Low-power rectification branch; 30. High-power rectification branch; 40. Harmonic tuning and matching network. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present application clearer, the various exemplary embodiments to be described below will refer to the corresponding drawings, which constitute a part of the exemplary embodiments, in which various exemplary embodiments that may be used to implement the present application are described. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following exemplary embodiments do not represent all implementation methods consistent with the present disclosure. It should be understood that they are only examples of processes, methods and devices that are consistent with some aspects disclosed in the present application as detailed in the appended claims, and other embodiments may also be used, or structural and functional modifications may be made to the embodiments listed herein without departing from the scope and essence of the present application.

[0031] In the description of this application, it should be understood that the terms "center", "longitudinal", "transverse" and the like indicate the orientation or positional relationship based on the figures, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the elements referred to must have a specific orientation, be constructed and operated in a specific orientation. The terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The term "multiple" means two or more. The terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a communication connection, a direct connection, an indirect connection through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0032] In order to illustrate the technical solution described in this application, a specific embodiment is provided below, and only the parts related to the embodiment of this application are shown.

[0033] like Figure 1As shown, the present application provides a radio frequency rectification circuit 1, comprising: an energy harvesting network 10, a low-power rectification branch 20, a high-power rectification branch 30 and a harmonic tuning and matching network 40.

[0034] The energy harvesting network 10 can collect and distribute reflected energy, the low-power rectifier branch 20 and the high-power rectifier branch 30 are used to convert AC energy into DC energy, and the harmonic tuning and matching network 40 can be used to filter the energy signal. Reflected energy can refer to the reflected wave generated by the low-power rectifier branch 20 and the high-power rectifier branch 30 due to impedance mismatch. The energy signal of the present application can be simply referred to as energy, and can include low-power energy and high-power energy. The low-power energy can also be called a low-power energy signal, and the high-power energy can also be called a high-power energy signal.

[0035] In some embodiments, the first end of the energy harvesting network 10 can be connected to the microwave source MV, the second end of the energy harvesting network 10 can be connected to the input end of the low-power rectifier branch 20, the third end of the energy harvesting network 10 can be connected to the input end of the high-power rectifier branch 30, and the fourth end of the energy harvesting network 10 can be grounded. The output end of the low-power rectifier branch 20 and the output end of the high-power rectifier branch 30 can be connected to the harmonic tuning matching network 40. The microwave source MV can refer to the power input end. Figure 2 As shown in the figure, Port1 is the first end of the energy harvesting network 10, Port2 is the second end of the energy harvesting network 10, Port3 is the third end of the energy harvesting network 10, and Port4 is the fourth end of the energy harvesting network 10.

[0036] In some embodiments, the energy harvesting network 10 may include a microstrip line TL1, a microstrip line TL2, a microstrip line TL3, a microstrip line TL4, a microstrip line TL5, a microstrip line TL6 and a microstrip line TL7, wherein the microstrip line TL1, the microstrip line TL4 and the microstrip line TL7 are symmetrically arranged, the microstrip line TL2 and the microstrip line TL3 are symmetrically arranged, and the microstrip line TL5 and the microstrip line TL6 are symmetrically arranged.

[0037] Specifically, one end of the microstrip line TL1 can be connected to one end of the microstrip line TL2 and the microwave source MV, the other end of the microstrip line TL1 can be connected to one end of the microstrip line TL3 and the input end of the low-power rectifier branch 20, the other end of the microstrip line TL2 can be connected to one end of the microstrip line TL4 and one end of the microstrip line TL5, the other end of the microstrip line TL3 can be connected to the other end of the microstrip line TL4 and one end of the microstrip line TL6, the other end of the microstrip line TL5 can be connected to one end of the microstrip line TL7 and grounded, and the other end of the microstrip line TL6 can be connected to the other end of the microstrip line TL7 and the input end of the high-power rectifier branch 30.

[0038] In some embodiments, one end of the microstrip line TL1 can be the first end of the energy collection network 10, the other end of the microstrip line TL1 can be the second end of the energy collection network 10, one end of the microstrip line TL7 can be the fourth end of the energy collection network 10, and the other end of the microstrip line TL7 can be the third end of the energy collection network 10.

[0039] In some embodiments, as Figure 3 As shown, when low power energy starts to be input from Port1 and output from Port2 and Port3, since the input power does not reach the turn-on voltage of the diode of the high power rectifier branch 30, the high power rectifier branch 30 does not work, and Z IN3 Relatively small.

[0040] Based on the shortest signal path principle and impedance continuity principle, low-power energy can be output from Port1 along microstrip line TL1 and Port2. At this time, low-power energy input to Port3 can be output along microstrip line TL2 to microstrip line TL5 and then to microstrip line TL7. Alternatively, low-power energy input to Port3 can be output along microstrip line TL2 to microstrip line TL4 and then to microstrip line TL6.

[0041] In some embodiments, as Figure 4 As shown, the impedance mismatch at Port 3 causes energy to be reflected back to the energy harvesting network 10. Low-power energy can be output from Port 2 along microstrip line TL6 to microstrip line TL3. Additionally, some low-power energy is reflected back to Port 1 and Port 4. To reuse the reflected low-power energy, Port 4 can be short-circuited, allowing the low-power energy to be fully reflected back to the energy harvesting network 10.

[0042] Furthermore, the signal phase shifts through the first, second, and third loops, partially superimposing and canceling the signal energy at the intersection of the first and second loops on microstrip line TL4. Phase characteristics (such as 90° and 180° phase differences) cancel each other out at Port 1, reducing the reflection coefficient S11 at Port 1 while directing the reflected energy to Port 4.

[0043] Among them, the first circulation network may include microstrip line TL1, microstrip line TL2, microstrip line TL3 and microstrip line TL4, the second circulation network may include microstrip line TL4, microstrip line TL5, microstrip line TL6 and microstrip line TL7, and the third circulation network may include microstrip line TL1, microstrip line TL2, microstrip line TL3, microstrip line TL5, microstrip line TL6 and microstrip line TL7.

[0044] In some embodiments, as Figure 5 As shown in the figure, when high power energy starts to be input from Port1 and output from Port2 and Port3, since the input power does not reach the breakdown voltage of the diode of the low power rectifier branch 20, the low power rectifier branch 20 does not work, and Z IN2 Relatively small. Figure 1 As shown, Z IN1 Z is the resistance from the circuit port to the load end. IN2 is the resistance of the low-power rectifier branch 20 from the matching end to the load end, Z IN3 is the resistance of the high-power rectifier branch 30 viewed from the matching end to the load end.

[0045] Similarly, according to the shortest signal path principle and impedance continuity principle, high-power energy can be output from Port1 along microstrip line TL2 to microstrip line TL5, and then to microstrip line TL7, and then output from Port3. Alternatively, high-power energy can be output from Port1 along microstrip line TL2 to microstrip line TL4, and then to microstrip line TL6, and then output from Port3. In this case, high-power energy input to Port2 can be output along microstrip line TL1, or high-power energy input to Port2 can be output along microstrip line TL2 to microstrip line TL4, and then to microstrip line TL3.

[0046] In some embodiments, as Figure 6 As shown, Port 2 has an impedance mismatch, causing energy to be reflected back to the energy harvesting network 10. High-power energy can be output from Port 3 along microstrip line TL6 to microstrip line TL3. Additionally, some high-power energy is reflected back to Port 1 and Port 4. To reuse the reflected low-power energy, Port 4 can be short-circuited, allowing the low-power energy to be fully reflected back to the energy harvesting network 10.

[0047] Similar to low-power energy, the low-power energy passes through the first, second, and third loop networks. Due to changes in signal phase, the energy is partially superimposed and offset along microstrip line TL4, where the first and second loop networks overlap. Phase characteristics (such as 90° and 180° phase differences) cancel each other out at Port 1, reducing the reflection coefficient S11 at Port 1 while directing the reflected energy toward Port 4.

[0048] As input power and frequency change, the operating state of the diodes in low-power rectifier branch 20 and high-power rectifier branch 30 also changes, causing changes in diode resistance, affecting the matching state of Port 2 and Port 3, and causing reflection of some energy signals. This application utilizes two internal loop networks, namely a first loop network and a second loop network, to adjust the power of the energy signal at Port 2 and Port 3, thereby increasing the dynamic range of load resistance, enabling energy recovery and efficient utilization, and improving the rectification efficiency of the diodes.

[0049] In some embodiments, Port4 can be an isolated port and can be grounded. In this case, the energy signal can be reflected back into the energy harvesting network 10 by grounding Port4. Specifically, when the low-power rectifier branch 20 is working and the high-power rectifier branch 30 has not yet reached the diode operating voltage, the low-power energy input to Port3 will be reflected back into the energy harvesting network 10, while the low-power energy reflected to Port2 will be output from Port2. When the high-power rectifier branch 30 is working and the diode of the low-power rectifier branch 20 breaks down, the high-power energy input to Port2 will be reflected back into the energy harvesting network 10, while the high-power energy reflected to Port3 will be output from Port3. When the low-power rectifier branch 20 and the high-power rectifier branch 30 are working simultaneously, the reflected energy signal is injected into Port2 and Port3 through the circulation network within the energy harvesting network 10.

[0050] In some embodiments, the electrical length E of the microstrip line TL1, the microstrip line TL4, and the microstrip line TL7 can be 90 degrees, and the resistance value can be The characteristic resistance is 70.7 ohms. The electrical length E of microstrip lines TL2, TL3, TL5, and TL6 is 90 degrees, and the resistance is 60.5 ohms.

[0051] In some embodiments, the low-power rectifier branch 20 may include a capacitor C1, a low-power impedance matching network, and a diode D1. One end of the capacitor C1 may be connected to the other end of the microstrip line TL1 and one end of the microstrip line TL3, the other end of the capacitor C1 may be connected to one end of the low-power impedance matching network, the other end of the low-power impedance matching network may be connected to the anode of the diode D1, and the cathode of the diode D1 may be connected to the harmonic tuning matching network 40. The capacitor C1 may be a low-power DC blocking capacitor.

[0052] In this case, by setting a low-power impedance matching network, impedance matching between the microwave source MV and the diode D1 can be achieved, insertion loss can be reduced, and rectification efficiency can be improved; by setting the capacitor C1, DC backflow can be prevented.

[0053] In some embodiments, the low-power impedance matching network may include microstrip lines TL8 and TL9. One end of microstrip line TL8 may be connected to the other end of capacitor C1 and one end of microstrip line TL9. The other end of microstrip line TL8 may be connected to the anode of diode D1. The other end of microstrip line TL9 is grounded. Diode D1 may be a low-power rectifier diode, and the model of diode D1 may be HSMS-2850.

[0054] In some embodiments, the high-power rectifier branch 30 may include a capacitor C2, a high-power impedance matching network, a diode D2, and an inductor L1. One end of the capacitor C2 is connected to the other end of the microstrip line TL6 and the other end of the microstrip line TL7, the other end of the capacitor C2 is connected to one end of the high-power impedance matching network, the other end of the high-power impedance matching network is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the inductor L1, and the inductor L1 is connected to the harmonic tuning matching network 40. The capacitor C2 may be a high-power DC blocking capacitor.

[0055] In this case, by setting up a high-power impedance matching network, impedance matching between the microwave source MV and the diode D2 can be achieved, insertion loss can be reduced, and rectification efficiency can be improved; by setting up the capacitor C2, DC backflow can be prevented; by adding a series inductor L1 at the rear end of the diode D2, the reflected low-power energy can be rectified again through the diode D1 multiple times, thereby improving the rectification efficiency.

[0056] In some embodiments, the high-power impedance matching network may include a microstrip line TL10 and a microstrip line TL11. One end of the microstrip line TL10 is connected to the other end of the capacitor C2 and one end of the microstrip line TL11. The other end of the microstrip line TL10 is connected to the anode of the diode D2. The other end of the microstrip line TL11 is grounded. The diode D2 may be a high-power rectifier diode, and the model of the diode D2 may be HSMS-2860.

[0057] In some embodiments, the impedance from the input terminal to the diode impedance matching terminal can be:

[0058] .

[0059] When the high-power rectifier branch 30 and the low-power rectifier branch 20 are connected to Port 2 and Port 3 respectively after impedance matching, the loads of Port 2 and Port 3 are replaced by the matched branches, and the resistance value of both is 50 ohms.

[0060] When low power energy is input, the input voltage does not reach the turn-on voltage of the diode D2 of the high power rectifier branch 30. Therefore, Z IN3can be considered relatively small, and the high power rectifier branch 30 is disabled. IN1 By Z IN2 Determined as:

[0061] .

[0062] When high power energy is input, Z IN2 will become very small because the input voltage has exceeded the breakdown voltage of diode D1. In this case, most of the power is absorbed by the high-power rectifier branch 30, and the low-power rectifier branch 20 can be considered to be inoperative. In the high input power range, Z IN3 Greater than Z IN2 In this case, the diode D1 resistance is transformed into Z after impedance matching. IN3 Then Z IN1 By Z IN3 Determined as:

[0063] .

[0064] When the input power is between high input power and low input power, impedance matching between the source end and the rectifier circuit can be achieved as long as the input impedance of the two-branch rectifier circuit is close to 50 ohms after being connected in parallel.

[0065] In some embodiments, the harmonic tuning matching network 40 may include a T-type matching junction, a harmonic suppression network, and a load resistor. A first end of the T-type matching junction may be connected to the cathode of the diode D1, a second end of the T-type matching junction may be connected to the other end of the inductor L1, a third end of the T-type matching junction may be connected to one end of the harmonic suppression network, the other end of the harmonic suppression network may be connected to one end of the load resistor, and the other end of the load resistor may be grounded. Figure 1 The resistance R shown in L1 This is the load resistance.

[0066] In some embodiments, the T-type matching junction may include microstrip line TL12, microstrip line TL13, and microstrip line TL14, with the other end of microstrip line TL12 connected to the other ends of microstrip line TL13 and microstrip line TL14. Specifically, one end of microstrip line TL12 serves as the first end of the T-type matching junction, one end of microstrip line TL13 serves as the second end of the T-type matching junction, and one end of microstrip line TL14 serves as the third end of the T-type matching junction. Thus, the T-type matching junction can connect the high-power rectifier branch 30 and the low-power rectifier branch 20, reducing circuit size.

[0067] In some embodiments, the harmonic suppression network may include microstrip lines TL15, TL16, and TL17. Microstrip lines TL15, TL16, and TL17 are each connected to one end of microstrip line TL14 and one end of a load resistor.

[0068] In some embodiments, microstrip line TL15 may be a quarter-wavelength microstrip line, microstrip line TL16 may be an eighth-wavelength microstrip line, and microstrip line TL17 may be a twelfth-wavelength microstrip line. By providing a harmonic suppression network, high-order harmonics can be prevented from passing through the load resistor while also smoothing the DC voltage.

[0069] In some embodiments, the dielectric substrate of the RF rectifier circuit 1 may be Rogers 4003C, the substrate thickness may be 0.508 mm, the dielectric constant may be 3.55, the conductor thickness may be 0.035 mm, and the circuit operating frequency may be 5.8 GHz.

[0070] The simulation results of the RF rectifier circuit 1 of the embodiment of the present application are as follows: Figures 7 to 10 As shown in the figure, the rectification efficiency of RF rectifier circuit 1 reaches its maximum of 85.4% at a frequency of 5.8 GHz and an input power of 11 dBm, and the rectification efficiency is greater than 60% from -1.8 dBm to 15.3 dBm. Furthermore, the S11 simulation curve of RF rectifier circuit 1 shows that the reflection coefficient is below -10 dB from -3.5 dBm to 15.5 dBm, and the rectification efficiency is above 60% within the input frequency range of 4.5 GHz to 6.9 GHz.

[0071] In the present application, rectification is performed by respectively setting a low-power rectifier branch 20 and a high-power rectifier branch 30. The two branches operate in the low-power area and the high-power area respectively, which can improve the rectification efficiency and the input power range. At the same time, the dual-branch single-load single-tube series rectifier structure can reduce the circuit size. By setting up an energy collection network 10, the energy reflected by the two rectifier branches can be efficiently utilized, and the matching dynamic range of the load can be improved, so that the direct-through filter path can be combined into one while maintaining the prerequisite for high-efficiency rectification. When the input power, frequency and output load of the sub-rectifier circuit change, the partial reflected waves generated by the impedance mismatch of the low-power rectifier branch 20 and the high-power rectifier branch 30 will be blocked by the energy collection network 10 and returned to the low-power rectifier branch 20 and the high-power rectifier branch 30 for reuse, thereby improving the rectification efficiency and reducing the sensitivity of the entire RF rectifier circuit 1 to changes in input power, frequency and output load.

[0072] The foregoing is merely a preferred embodiment of the present application. Those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present application. Furthermore, under the guidance of this application, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be included within the scope of protection of this application.

Claims

1. A radio frequency rectifier circuit, characterized in that: include: Energy harvesting network, low-power rectifier branch, high-power rectifier branch and harmonic tuning and matching network; A first end of the energy harvesting network is connected to a microwave source MV, a second end of the energy harvesting network is connected to an input end of the low-power rectifier branch, a third end of the energy harvesting network is connected to an input end of the high-power rectifier branch, and a fourth end of the energy harvesting network is grounded; an output end of the low-power rectifier branch and an output end of the high-power rectifier branch are both connected to the harmonic tuning and matching network; The energy harvesting network includes a microstrip line TL1, a microstrip line TL2, a microstrip line TL3, a microstrip line TL4, a microstrip line TL5, a microstrip line TL6 and a microstrip line TL7, wherein the microstrip line TL1, the microstrip line TL4 and the microstrip line TL7 are symmetrically arranged, the microstrip line TL2 is symmetrically arranged with the microstrip line TL3, and the microstrip line TL5 is symmetrically arranged with the microstrip line TL6; One end of the microstrip line TL1 is connected to one end of the microstrip line TL2 and the microwave source MV, the other end of the microstrip line TL1 is connected to one end of the microstrip line TL3 and the input end of the low-power rectifier branch, the other end of the microstrip line TL2 is connected to one end of the microstrip line TL4 and one end of the microstrip line TL5, the other end of the microstrip line TL3 is connected to the other end of the microstrip line TL4 and one end of the microstrip line TL6, the other end of the microstrip line TL5 is connected to one end of the microstrip line TL7 and is grounded, and the other end of the microstrip line TL6 is connected to the other end of the microstrip line TL7 and the input end of the high-power rectifier branch; The low-power rectification branch includes a capacitor C1, a low-power impedance matching network, and a diode D1; one end of the capacitor C1 is connected to the other end of the microstrip line TL1 and one end of the microstrip line TL3, the other end of the capacitor C1 is connected to one end of the low-power impedance matching network, the other end of the low-power impedance matching network is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the harmonic tuning matching network; The high-power rectifier branch includes a capacitor C2, a high-power impedance matching network, a diode D2, and an inductor L1; one end of the capacitor C2 is connected to the other end of the microstrip line TL6 and the other end of the microstrip line TL7, the other end of the capacitor C2 is connected to one end of the high-power impedance matching network, the other end of the high-power impedance matching network is connected to the anode of the diode D2, the cathode of the diode D2 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the harmonic tuning matching network; The diode D1 is a low-power rectifier diode, and the model of the diode D1 is HSMS-2850; the diode D2 is a high-power rectifier diode, and the model of the diode D2 is HSMS-2860.

2. The radio frequency rectifier circuit according to claim 1, characterized in that: The low-power impedance matching network includes a microstrip line TL8 and a microstrip line TL9; one end of the microstrip line TL8 is connected to the other end of the capacitor C1 and one end of the microstrip line TL9, the other end of the microstrip line TL8 is connected to the anode of the diode D1, and the other end of the microstrip line TL9 is grounded.

3. The radio frequency rectifier circuit according to claim 1, wherein: The high-power impedance matching network includes a microstrip line TL10 and a microstrip line TL11; one end of the microstrip line TL10 is connected to the other end of the capacitor C2 and one end of the microstrip line TL11, the other end of the microstrip line TL10 is connected to the anode of the diode D2, and the other end of the microstrip line TL11 is grounded.

4. The radio frequency rectifier circuit according to claim 1, wherein: The harmonic tuning matching network includes a T-type matching junction, a harmonic suppression network and a load resistor; the first end of the T-type matching junction is connected to the cathode of the diode D1, the second end of the T-type matching junction is connected to the other end of the inductor L1, the third end of the T-type matching junction is connected to one end of the harmonic suppression network, the other end of the harmonic suppression network is connected to one end of the load resistor, and the other end of the load resistor is grounded.

5. The radio frequency rectifier circuit according to claim 4, characterized in that: The T-type matching junction includes a microstrip line TL12, a microstrip line TL13 and a microstrip line TL14; one end of the microstrip line TL12 is the first end of the T-type matching junction, one end of the microstrip line TL13 is the second end of the T-type matching junction, and one end of the microstrip line TL14 is the third end of the T-type matching junction; the other end of the microstrip line TL12 is connected to the other end of the microstrip line TL13 and the other end of the microstrip line TL14.

6. The radio frequency rectifier circuit according to claim 5, characterized in that: The harmonic suppression network includes a microstrip line TL15, a microstrip line TL16, and a microstrip line TL17; the microstrip line TL15, the microstrip line TL16, and the microstrip line TL17 are all connected to one end of the microstrip line TL14 and one end of the load resistor.

7. The radio frequency rectifier circuit according to claim 6, characterized in that: The microstrip line TL15 is a quarter-wavelength microstrip line, the microstrip line TL16 is a one-eighth-wavelength microstrip line, and the microstrip line TL17 is a one-twelfth-wavelength microstrip line.

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