Radio frequency rectification circuit

Abstract

The invention discloses a radio frequency rectifying circuit which comprises an energy collecting network, a low-power rectifying branch, a high-power rectifying branch and a harmonic tuning matching network. The first end of the energy collection network is connected with the microwave source MV, the second end of the energy collection network is connected with the low-power rectification branch, the third end of the energy collection network is connected with the high-power rectification branch, and the fourth end of the energy collection network is grounded; the energy collection network comprises a micro-strip line TL1, a micro-strip line TL2, a micro-strip line TL3, a micro-strip line TL4, a micro-strip line TL5, a micro-strip line TL6 and a micro-strip line TL7, the micro-strip line TL1, the micro-strip line TL4 and the micro-strip line TL7 are symmetrically arranged, the micro-strip line TL2 and the micro-strip line TL3 are symmetrically arranged, and the micro-strip line TL5 and the micro-strip line TL6 are symmetrically arranged. The rectification efficiency and the input power range can be improved, and meanwhile the circuit size is reduced. And meanwhile, energy reflected by the two rectification branches can be efficiently utilized, and the matching dynamic range of the load is widened.

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] Nowadays, RF Energy Harvesting (REH) technology is gaining more and more attention. At present, RF energy harvesting technology plays an important role in some special scenarios, especially in the fields of security and military, such as scenes with a large number of sensors or radio frequency identification tags (RFID) and insufficient light. In addition, it is also being used more and more widely in smart transportation, medical care, and the Internet of Things (IOT). Compared with traditional power supply methods, RF energy harvesting technology has the advantages of sustainability, green and pollution-free, and no need for manual replacement.

[0003] Generally speaking, the RF energy harvesting system is mainly composed of a receiving antenna and a rectifier circuit. The energy harvesting system can collect electromagnetic energy in the surrounding environment and provide charging solutions for electronic devices that are difficult to wire or replace batteries, such as pipeline monitoring and equipment in remote areas. The rectifier circuit, as the core of the energy harvesting system, is responsible for converting the collected RF energy into DC energy and is widely used in many fields, 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 the existing rectifier circuit usually matches each branch separately, which leads to an increase in circuit size and introduces more losses. There are generally problems such as low rectification efficiency, limited extended frequency range and excessive size, which 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 the existing radio frequency rectifier circuit in the prior art. The preferred technical solutions among the many technical solutions provided in this application can produce many technical effects as described below.

[0006] To achieve the above objectives, this application provides the following technical solutions: The present application provides a radio frequency rectification circuit, comprising: an energy collection network, a low-power rectification branch, a high-power rectification branch and a harmonic tuning and matching network; the first end of the energy collection network is connected to a microwave source MV, the second end of the energy collection network is connected to the input end of the low-power rectification branch, the third end of the energy collection network is connected to the input end of the high-power rectification branch, and the fourth end of the energy collection network is grounded; the output end of the low-power rectification branch and the output end of the high-power rectification branch are both connected to the harmonic tuning and matching network; the energy collection 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 all 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] In some embodiments, the T-type matching junction includes microstrip line TL12, microstrip line TL13 and 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.

[0014] 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.

[0015] 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.

[0016] Implementing one of the above technical solutions of the present application has the following advantages or beneficial effects: In the present application, by respectively setting a low-power rectifier branch and a high-power rectifier branch for rectification, the two branches work 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 an energy collection 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, the low-power rectifier branch and the high-power rectifier branch The partial reflected waves generated by the impedance mismatch will be blocked by the energy collection 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

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. It is obvious that the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings: Figure 1 is a circuit diagram of a radio frequency rectifier circuit according to an embodiment of the present application; Figure 2 is a circuit diagram of an energy harvesting network according to an embodiment of the present application; Figure 3 is a schematic diagram of a low-power energy path of an embodiment of the present application; Figure 4 is another schematic diagram of a low-power energy path according to an embodiment of the present application; Figure 5 is a schematic diagram of a high-power energy path of an embodiment of the present application; Figure 6 is another schematic diagram of a high-power energy path according to an embodiment of the present application; Figure 7 is a curve diagram of resistance parameters in the simulation results of the embodiment of the present application; Figure 8 is a curve diagram of S parameters in the simulation results of the embodiment of the present application; Fig. 9 is a schematic diagram of rectification efficiency in the simulation results of the embodiment of the present application; Fig.10 It is another schematic diagram of the rectification efficiency in the simulation results of the embodiment of the present application.

[0018] In the figure: 1. RF rectification circuit; 10. Energy collection network; 20. Low-power rectification branch; 30. High-power rectification branch; 40. Harmonic tuning and matching network. DETAILED DESCRIPTION

[0019] 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, wherein 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 attached claims, and other embodiments may also be used, or the embodiments listed herein may be modified in structure and function without departing from the scope and essence of the present application.

[0020] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", etc. indicate the orientation or positional relationship based on the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the elements referred to must have a specific orientation, be constructed and operated in a specific orientation. The terms "first", "second", etc. 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 the present application can be understood according to the specific circumstances.

[0021] In order to illustrate the technical solution described in the present application, a specific embodiment is provided below, and only the parts related to the embodiment of the present application are shown.

[0022] like Figure 1 As shown, the present application provides a radio frequency rectification circuit 1, comprising: an energy collection network 10, a low-power rectification branch 20, a high-power rectification branch 30 and a harmonic tuning and matching network 40.

[0023] The energy collection 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. The 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.

[0024] In some embodiments, the first end of the energy collection network 10 can be connected to the microwave source MV, the second end of the energy collection network 10 is connected to the input end of the low-power rectifier branch 20, the third end of the energy collection network 10 is connected to the input end of the high-power rectifier branch 30, and the fourth end of the energy collection network 10 is 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, Port 1 in the figure is the first end of the energy collection network 10, Port 2 is the second end of the energy collection network 10, Port 3 is the third end of the energy collection network 10, and Port 4 is the fourth end of the energy collection network 10.

[0025] In some embodiments, the energy collection network 10 may include microstrip line TL1, microstrip line TL2, microstrip line TL3, microstrip line TL4, microstrip line TL5, microstrip line TL6 and microstrip line TL7, wherein microstrip line TL1, microstrip line TL4 and microstrip line TL7 are symmetrically arranged, microstrip line TL2 and microstrip line TL3 are symmetrically arranged, and microstrip line TL5 and microstrip line TL6 are symmetrically arranged.

[0026] 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 rectification 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 rectification branch 30.

[0027] 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.

[0028] In some embodiments, Figure 3 As shown in FIG. 1 , when low power energy starts to be input from Port 1 and output from Port 2 and Port 3, since the input power does not reach the diode turn-on voltage of the high power rectifier branch 30, the high power rectifier branch 30 does not work, and Z IN3 Relatively small.

[0029] According to the principle of the shortest signal path and the principle of impedance continuity, low-power energy can be output from Port1 along the microstrip line TL1 and Port2. At this time, the low-power energy input to Port3 can be output along the microstrip line TL2 to the microstrip line TL5, and then to the microstrip line TL7, or the low-power energy input to Port3 can be output along the microstrip line TL2 to the microstrip line TL4, and then to the microstrip line TL6.

[0030] In some embodiments, Figure 4 As shown, the impedance of Port3 is mismatched, and the energy is reflected back to the energy harvesting network 10. The low-power energy can be output from Port2 along the microstrip line TL6 to the microstrip line TL3. In addition, part of the low-power energy will be reflected back to Port1 and Port4. In order to reuse the reflected low-power energy, Port4 can be short-circuited, so that the low-power energy can be completely reflected back to the energy harvesting network 10.

[0031] In addition, after the first loop network, the second loop network and the third loop network, the signal phase changes will realize partial superposition and offset adjustment of signal energy at the overlap of the first loop network and the second loop network in the microstrip line TL4. Through phase characteristics (such as 90° and 180° phase difference), the reflected waves are offset at Port 1, thereby reducing the reflection coefficient S11 of Port 1 and directing the reflected energy to Port 4.

[0032] 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.

[0033] In some embodiments, Figure 5 As shown in FIG. 1 , when high power energy starts to be input from Port 1 and output from Port 2 and Port 3, 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 It is the resistance value of the high power rectifier branch 30 from the matching end to the load end.

[0034] Similarly, according to the principle of the shortest signal path and the principle of impedance continuity, high power energy can be output from Port1 along microstrip line TL2 to microstrip line TL5, and then to microstrip line TL7 from Port3, or high power energy can be output from Port1 along microstrip line TL2 to microstrip line TL4, and then to microstrip line TL6 from Port3. At this time, the high power energy input to Port2 can be output along microstrip line TL1, or the high power energy input to Port2 can be output along microstrip line TL2 to microstrip line TL4, and then to microstrip line TL3.

[0035] In some embodiments, Figure 6 As shown, the impedance of Port2 is mismatched, and the energy is reflected back to the energy harvesting network 10. The high-power energy can be output from Port3 along the microstrip line TL6 to the microstrip line TL3. In addition, part of the high-power energy will be reflected back to Port1 and Port4. In order to reuse the reflected low-power energy, Port4 can be short-circuited, so that the low-power energy can be completely reflected back to the energy harvesting network 10.

[0036] In addition, similar to low-power energy, low-power energy passes through the first loop network, the second loop network and the third loop network. Due to the change in signal phase, partial superposition and offset adjustment of signal energy will be achieved at the overlap of the first loop network and the second loop network in the microstrip line TL4. Through phase characteristics (such as 90° and 180° phase difference), the reflected waves are offset at the Port 1 port, thereby reducing the reflection coefficient S11 of the Port 1 port, and at the same time directing the reflected energy to the Port 4 port.

[0037] As the input power and frequency change, the working state of the diodes of the low-power rectifier branch 20 and the high-power rectifier branch 30 will also change, resulting in a change in the diode resistance, affecting the matching state of Port 2 and Port 3, and causing the reflection of part of the energy signal. The present application can adjust the power energy of the energy signal at Port 2 and Port 3 through two internal circulation networks, namely the first circulation network and the second circulation network, improve the dynamic change range of the load resistance, realize energy recovery and efficient utilization, and improve the rectification efficiency of the diode.

[0038] In some embodiments, Port4 can be an isolated port, and Port4 can be grounded. In this case, the energy signal can be reflected back to the energy collection 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 to the energy collection network 10, and 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 to the energy collection network 10, and 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 at the same time, the reflected energy signal is injected into Port2 and Port3 through the circulation network in the energy collection network 10.

[0039] 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 is 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.

[0040] 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.

[0041] In this case, by setting a low-power impedance matching network, the impedance matching between the microwave source MV and the diode D1 can be achieved, the insertion loss can be reduced, and the rectification efficiency can be improved; by setting the capacitor C1, the DC backflow can be prevented.

[0042] In some embodiments, the low-power impedance matching network may include a microstrip line TL8 and a microstrip line TL9. One end of the microstrip line TL8 may be 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 may be connected to the anode of the diode D1, and the other end of the microstrip line TL9 is grounded. The diode D1 may be a low-power rectifier diode, and the model of the diode D1 may be HSMS-2850.

[0043] 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.

[0044] In this case, by setting up a high-power impedance matching network, the impedance matching between the microwave source MV and the diode D2 can be achieved, the insertion loss can be reduced, and the rectification efficiency can be improved; by setting up the capacitor C2, the 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 for multiple times, thereby improving the rectification efficiency.

[0045] 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, and 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.

[0046] In some embodiments, the impedance from the input terminal to the diode impedance matching terminal can be: .

[0047] When the high-power rectifying branch 30 and the low-power rectifying branch 20 are connected to Port2 and Port3 respectively after impedance matching, the loads of Port2 and Port3 are replaced by the matched branches, and the resistance values ​​are both 50 ohms.

[0048] 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 IN3 can be considered relatively small, and the high power rectifier branch 30 is disabled. At this time, ZIN1 By Z IN2 Determined as: .

[0049] 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: .

[0050] 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.

[0051] 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 is the load resistance.

[0052] In some embodiments, the T-type matching junction may include a microstrip line TL12, a microstrip line TL13, and a microstrip line TL14, and 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. Specifically, 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. Thus, the high-power rectifier branch 30 and the low-power rectifier branch 20 can be connected through the T-type matching junction, thereby reducing the circuit size.

[0053] In some embodiments, the harmonic suppression network may include microstrip lines TL15, TL16, and TL17. Microstrip lines TL15, TL16, and TL17 are connected to one end of the microstrip line TL14 and one end of the load resistor.

[0054] 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 setting a harmonic suppression network, high-order harmonics can be prevented from passing through the load resistor on the one hand, and the DC voltage can be smoothed on the other hand.

[0055] In some embodiments, the dielectric substrate of the radio frequency 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.

[0056] 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. It can be seen that the rectification efficiency of the RF rectification circuit 1 reaches the maximum of 85.4% when the frequency is 5.8GHz and the input power is 11dBm, and the rectification efficiency is greater than 60% from -1.8dBm to 15.3dBm. At the same time, it can be seen from the S11 simulation curve of the RF rectification circuit 1 that the reflection coefficient is below -10dB from -3.5dBm to 15.5dBm, and the rectification efficiency is above 60% in the input frequency range of 4.5GHz to 6.9GHz.

[0057] In the present application, rectification is performed by respectively setting a low-power rectifier branch 20 and a high-power rectifier branch 30, and the two branches work 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 the 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 through-filter path is 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 low-power rectifier branch 20 and the high-power rectifier branch 30 The partial reflected waves generated by the impedance mismatch 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.

[0058] The above is only the 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. In addition, under the guidance of the present 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 the present application belong to the protection scope of the present application.

Claims

1. A radio frequency rectifier circuit, characterized in that: include: Energy harvesting network, low power rectification branch, high power rectification branch and harmonic tuning and matching network; The first end of the energy collection network is connected to the microwave source MV, the second end of the energy collection network is connected to the input end of the low-power rectification branch, the third end of the energy collection network is connected to the input end of the high-power rectification branch, and the fourth end of the energy collection network is grounded; the output end of the low-power rectification branch and the output end of the high-power rectification branch are both connected to the harmonic tuning and matching network; The energy collection network includes microstrip line TL1, microstrip line TL2, microstrip line TL3, microstrip line TL4, microstrip line TL5, microstrip line TL6 and 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.

2. The radio frequency rectifier circuit according to claim 1, characterized in that: 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 rectification 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 rectification branch.

3. The radio frequency rectifier circuit according to claim 1, characterized in that: 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.

4. The radio frequency rectifier circuit according to claim 3, 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.

5. The radio frequency rectifier circuit according to claim 1, characterized in that: The high-power rectification 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.

6. The radio frequency rectifier circuit according to claim 5, characterized in that: 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.

7. The radio frequency rectifier circuit according to claim 5, characterized in that: 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.

8. The radio frequency rectifier circuit according to claim 7, characterized in that: 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.

9. The radio frequency rectifier circuit according to claim 7, characterized in that: 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.

10. The radio frequency rectifier circuit according to claim 9, characterized in that: 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.

Images