Control method and circuit of radio frequency rectification circuit

Abstract

The invention discloses a control method and circuit of a radio frequency rectification circuit, and relates to the technical field of radio frequency rectification, and the control method of the radio frequency rectification circuit comprises the steps: collecting a radio frequency signal through an antenna, and inputting the radio frequency signal into an impedance matching network for optimization; judging the signal state of the radio frequency signal, and if the radio frequency signal is in a positive half cycle, rectifying the positive half cycle of the radio frequency signal; if the radio frequency signal is in the negative half cycle, performing negative half cycle rectification on the radio frequency signal; and a direct current signal generated after the radio frequency signal is rectified is extracted, and the direct current signal is connected to the energy management circuit and the load for output. According to the invention, the capacitor, the rectifier tube and the Schottky diode are arranged, so that a discrete circuit in the radio frequency rectifier circuit is simple to apply, the problem of threshold value rise of the radio frequency rectifier circuit caused by multi-stage cascade connection in the differential input coupling rectifier circuit can be solved, and the problem of power consumption increase caused by current leakage of an NMOS tube is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency rectification, and in particular to a control method and circuit of a radio frequency rectification circuit. Background Art

[0002] In recent years, with the rapid development of wireless communication technology, more and more base stations, signal transmission towers and other equipment have been built. The energy emitted by these radio frequency energy sources is flooding the living environment. With the great breakthrough of silicon microelectronics technology in power consumption, more and more microwatt-level electronic microsystems have emerged, making it possible for such systems to collect energy from space for their own work. Wireless sensor networks, which are representatives of energy collection from the space environment, have been applied in many fields such as military, environmental monitoring, building status monitoring and safety monitoring of large enterprises. However, the battery, the main energy source of wireless sensor networks, has great defects in terms of volume and service life, which is not conducive to reducing the volume of the system and powering the system for a long time. Therefore, it is unrealistic to use batteries to power various sensor nodes. This requires the sensor itself to have the ability to obtain space energy to provide energy for its own work. In addition, the use of wireless energy transmission technology can be used to power helicopters and wirelessly charge robots in pipelines, and its application prospects are obvious.

[0003] With the advancement of science and technology, more and more miniature and portable electronic products are widely used in daily life and production. Using traditional methods to power these devices can no longer meet current needs. RF energy harvesting technology can effectively collect the surrounding RF signal energy and convert it into DC energy output that can be used by the device. It is an emerging method for powering low-power electronic products. The RF energy harvesting circuit mainly includes a rectifier circuit and a matching network circuit, among which the rectifier circuit is its core part, and its efficiency is directly related to the energy harvesting efficiency.

[0004] However, in the traditional complementary metal oxide semiconductor rectifier circuit, because the radio frequency energy in the space is weak, the input signal power is particularly small, and the threshold voltage of the MOS tube is high, it will have a very large impact on the power conversion efficiency of the rectifier circuit. Specifically, the prior art still has the following defects:

[0005] 1. In the actual application of RF energy collection, since the RF energy input is particularly weak, multiple cascades are required to increase the output voltage for collection and utilization. However, due to the increase in the number of cascades, the voltage between the source and substrate of the MOS tube will gradually increase, resulting in an increase in the transistor threshold voltage and a decrease in the output voltage.

[0006] 2. In the traditional complementary metal oxide semiconductor rectifier circuit, since the gate of the rectifier NMOS is directly connected to the substrate, it will cause current leakage problems, resulting in increased power consumption of the rectifier circuit.

[0007] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0008] In view of the problems in the related art, the present invention proposes a control method and circuit for a radio frequency rectifier circuit to overcome the above technical problems existing in the existing related art.

[0009] To this end, the specific technical solution adopted by the present invention is as follows:

[0010] According to one aspect of the present invention, a control method for a radio frequency rectifier circuit is provided, and the control method for a radio frequency rectifier circuit includes:

[0011] Using an antenna to collect radio frequency signals, inputting the radio frequency signals into an impedance matching network for optimization, and inputting the optimized radio frequency signals into a primary radio frequency rectification circuit;

[0012] Determine the signal state of the radio frequency signal. If the radio frequency signal is in a positive half cycle, rectify the positive half cycle of the radio frequency signal; if the radio frequency signal is in a negative half cycle, rectify the negative half cycle of the radio frequency signal;

[0013] The DC signal generated after the RF signal is rectified is extracted and connected to the energy management circuit and load output.

[0014] Further, collecting the RF signal by using the antenna, inputting the RF signal into the impedance matching network for optimization, and inputting the optimized RF signal into the primary RF rectifier circuit includes:

[0015] Inputting the radio frequency signal collected by the antenna into the impedance matching network to obtain the input voltage amplitude amplified by the impedance matching network;

[0016] Based on the input voltage amplitude amplified by the impedance matching network, the output voltage of the primary RF rectifier circuit is calculated, wherein the calculation formula of the output voltage of the primary RF rectifier circuit is:

[0017] V OUT =2(V in -V TH );

[0018] Where V OUT Represents the output voltage of the primary RF rectifier circuit; V TH represents the sum of the threshold voltages of any N-type metal oxide semiconductor rectifier and P-type metal oxide semiconductor rectifier; V in Represents the input voltage amplitude amplified by the impedance matching network.

[0019] Further, judging the signal state of the radio frequency signal, if the radio frequency signal is in a positive half cycle, rectifying the positive half cycle of the radio frequency signal; if the radio frequency signal is in a negative half cycle, rectifying the negative half cycle of the radio frequency signal includes:

[0020] Determine the signal state of the RF signal after inputting the primary RF rectifier circuit. If the RF signal is in the positive half cycle, the rectifier tube N2 and the rectifier tube P1 are forward-conducted, and the rectifier tube N1 and the rectifier tube P2 are reverse-conducted. At the same time, the diode SD1 and the diode SD4 are turned on, and the diode SD2 and the diode SD3 are turned off, thereby realizing the positive half-cycle rectification of the RF signal;

[0021] If the RF signal is in the negative half cycle, rectifier tube N1 and rectifier tube P2 are forward-conducted, rectifier tube N2 and rectifier tube P1 are reverse-conducted, and diode SD2 and diode SD3 are turned on, and diode SD1 and diode SD4 are turned off, thereby realizing rectification of the negative half cycle of the RF signal.

[0022] Furthermore, when the RF signal is in the positive half cycle, the rectifier tube N2 and the rectifier tube P1 are forward-conducted, and when the rectifier tube N1 and the rectifier tube P2 are reverse-cut off, the source of the rectifier transistor P1 is connected to the substrate, thereby reducing the source voltage and the substrate voltage of the P-type metal oxide semiconductor rectifier tube, and further reducing the threshold voltage of the P-type metal oxide semiconductor rectifier tube.

[0023] Furthermore, the calculation formula of the threshold voltage of the P-type metal oxide semiconductor rectifier is:

[0024] ;

[0025] In the formula, Represents the threshold voltage of the P-type metal oxide semiconductor rectifier, It represents the threshold voltage of the P-type metal oxide semiconductor rectifier without considering the body effect. It represents the potential difference between the source and substrate of the P-type metal oxide semiconductor rectifier. represents the body Fermi potential, and τ represents the body effect coefficient.

[0026] Furthermore, the substrate of the rectifier tube N2 is connected to the gate of the rectifier tube N2 through capacitors C3 and C4 in sequence. At this time, the voltage between the source and the substrate of the rectifier tube N2 is negative, and the threshold voltage of the rectifier tube N2 is compensated by using the calculation formula of the threshold voltage of the N-type metal oxide semiconductor rectifier tube.

[0027] Furthermore, the calculation formula of the threshold voltage of the N-type metal oxide semiconductor rectifier is:

[0028] ;

[0029] In the formula, Represents the threshold voltage of the N-type metal oxide semiconductor rectifier, It represents the threshold voltage of N-type metal oxide semiconductor rectifier without considering the body effect. Represents the potential difference between the source and substrate of an N-type metal oxide semiconductor rectifier. represents the body Fermi potential, and τ represents the body effect coefficient.

[0030] According to another aspect of the present invention, there is further provided a radio frequency rectifier circuit, which is composed of a plurality of groups of primary radio frequency rectifier circuits connected in cascade, wherein the primary radio frequency rectifier circuit includes a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a rectifier tube N1, a rectifier tube N2, a rectifier tube P1, a rectifier tube P2, a diode SD1, a diode SD2, a diode SD3 and a diode SD4;

[0031] One end of the capacitor C1 is connected to the positive electrode of the AC power supply, and the other end of the capacitor C1 is respectively connected to the source of the rectifier N1, one end of the capacitor C4, the gate of the rectifier N2, the gate of the rectifier P2, the cathode of the diode SD2, the anode of the diode SD1 and the source of the rectifier P1. The drain of the rectifier N1 is connected to the drain of the rectifier N2 and is grounded. The substrate of the rectifier N1 is connected to one end of the capacitor C3. The gate of the rectifier N1 is respectively connected to the other end of the capacitor C3, the source of the rectifier N2, the capacitor C4 and the cathode of the diode SD2. One end of C2, the anode of diode SD3, the cathode of diode SD4, the gates of rectifier P2 and rectifier P1 are connected; the substrate of rectifier P1 is respectively connected to the cathode of diode SD1 and the anode of diode SD2; the drain of rectifier P1 is connected to the drain of rectifier P2; the substrate of rectifier N2 is connected to the other end of capacitor C4, the substrate of rectifier P2 is respectively connected to the cathode of diode SD3 and the anode of diode SD4; the other end of capacitor C2 is connected to the negative electrode of the AC power supply.

[0032] Furthermore, the rectifier tube N1 and the rectifier tube N2 are both N-type metal oxide semiconductor rectifier tubes, and the width-to-length ratio of the rectifier tube N1 and the rectifier tube N2 is 50-70;

[0033] The rectifier tube P1 and the rectifier tube P2 are both P-type metal oxide semiconductor rectifier tubes, and the width-to-length ratio of the rectifier tube P1 and the rectifier tube P2 is 150-210.

[0034] Furthermore, the capacitor C1 and the capacitor C2 are both coupling capacitors, and the capacitance value of the capacitor C1 and the capacitor C2 is 0.05 μF.

[0035] The beneficial effects of the present invention are:

[0036] 1. The present invention provides capacitors, rectifier tubes and Schottky diodes, thereby simplifying the application of discrete circuits in the radio frequency rectifier circuit, and can solve the problem of rising thresholds of the radio frequency rectifier circuit caused by multi-stage cascade in the differential input coupled rectifier circuit, thereby solving the problem of increased power consumption caused by current leakage of the NMOS tube.

[0037] 2. The present invention introduces Schottky diodes and capacitors into a traditional differential coupled input rectifier circuit, and utilizes the characteristics of the Schottky diode with a small conduction voltage drop and a short reverse recovery time as well as the buffering characteristics of the capacitor to solve the problem that in practical applications of RF energy collection, since the RF energy input is particularly weak, a multi-stage cascade is required to increase the output voltage, and thus the voltage between the source and the substrate of the rectifier tube gradually increases during collection and utilization due to the increase in the number of cascades, thereby causing the output voltage to decrease. At the same time, it also solves the problem that in a traditional differential input cross-coupled rectifier circuit, since the gate of the rectifier NMOS tube is directly connected to the substrate, current leakage occurs, thereby causing the power consumption of the rectifier circuit to increase. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 is a flow chart of a control method of a radio frequency rectifier circuit according to an embodiment of the present invention;

[0040] Figure 2 is a circuit diagram of a primary radio frequency rectification circuit in a radio frequency rectification circuit according to an embodiment of the present invention;

[0041] Figure 3 is a circuit diagram of a three-stage cascaded radio frequency rectification circuit in a radio frequency rectification circuit according to an embodiment of the present invention;

[0042] Figure 4 The present invention is a schematic diagram of radio frequency energy collection in a method for controlling a radio frequency rectifier circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0044] According to an embodiment of the present invention, a control method and circuit for a radio frequency rectifier circuit are provided.

[0045] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 1 As shown, according to the control method of the radio frequency rectifier circuit of an embodiment of the present invention, the control method of the radio frequency rectifier circuit includes:

[0046] S1. Collect radio frequency signals using an antenna, input the radio frequency signals into an impedance matching network for optimization, and input the optimized radio frequency signals into a primary radio frequency rectification circuit;

[0047] S2, judging the signal state of the radio frequency signal, if the radio frequency signal is in a positive half cycle, rectifying the positive half cycle of the radio frequency signal; if the radio frequency signal is in a negative half cycle, rectifying the negative half cycle of the radio frequency signal;

[0048] S3, extracting the DC signal generated after the RF signal is rectified, and connecting the DC signal to the energy management circuit and the load output.

[0049] Among them, using an antenna to collect radio frequency signals, inputting the radio frequency signals into an impedance matching network for optimization, and inputting the optimized radio frequency signals into a primary radio frequency rectification circuit includes:

[0050] Inputting the radio frequency signal collected by the antenna into the impedance matching network to obtain the input voltage amplitude amplified by the impedance matching network;

[0051] Based on the input voltage amplitude amplified by the impedance matching network, the output voltage of the primary RF rectifier circuit is calculated, wherein the calculation formula of the output voltage of the primary RF rectifier circuit is:

[0052] V OUT =2(V in -V TH );

[0053] Where V OUT Represents the output voltage of the primary RF rectifier circuit; V TH represents the sum of the threshold voltages of any N-type metal oxide semiconductor rectifier and P-type metal oxide semiconductor rectifier; V in Represents the input voltage amplitude amplified by the impedance matching network.

[0054] The signal state of the radio frequency signal is judged, if the radio frequency signal is in a positive half cycle, the positive half cycle of the radio frequency signal is rectified; if the radio frequency signal is in a negative half cycle, the negative half cycle of the radio frequency signal is rectified, including:

[0055] The signal state of the RF signal after inputting the primary RF rectifier circuit is judged. If the RF signal is in the positive half cycle, the rectifier tube N2 and the rectifier tube P1 are forward-conducted, and the rectifier tube N1 and the rectifier tube P2 are reverse-cut off. At the same time, the diode SD1 and the diode SD4 are turned on, and the diode SD2 and the diode SD3 are turned off, thereby realizing the rectification of the positive half cycle of the RF signal; if the RF signal is in the negative half cycle, the rectifier tube N1 and the rectifier tube P2 are forward-conducted, and the rectifier tube N2 and the rectifier tube P1 are reverse-cut off. At the same time, the diode SD2 and the diode SD3 are turned on, and the diode SD1 and the diode SD4 are turned off, thereby realizing the rectification of the negative half cycle of the RF signal.

[0056] Among them, if the RF signal is in the positive half cycle, the rectifier tube N2 and the rectifier tube P1 are forward-conducted, and when the rectifier tube N1 and the rectifier tube P2 are reversely cut off, the source of the rectifier transistor P1 is connected to the substrate, thereby reducing the source voltage and the substrate voltage of the P-type metal oxide semiconductor rectifier tube, and then reducing the threshold voltage of the P-type metal oxide semiconductor rectifier tube.

[0057] In order to facilitate understanding of the above technical solution of the present invention, the control method based on the radio frequency rectification circuit provided by the present invention is described in detail below.

[0058] Figure 2 In the first-stage RF rectifier circuit shown, S, B, G, and D of the rectifier are the source, substrate, gate, and drain of the rectifier, respectively. The rectifier needs to be connected in a bridge-like manner, with the gate cross-coupled. The width and length of the MOS tube are 12μm and 0.18μm, respectively, and the width and length of the PMOS tube are 36μm and 0.18μm, respectively (the width-to-length ratio of NMOS is between 50-70, and the width-to-length ratio of PMOS should be between 150-210 to ensure the performance of the rectifier and the low power consumption of the circuit). Differential input is used, and the differential voltage is input through capacitor coupling, and connected to diodes SD1, SD2, and SD3. And diode SD4 (all four diodes are Schottky diodes, and the BAT60BE237 model is selected), its conduction voltage drop is only 0.24V at 10mA. To ensure the symmetry of the differential circuit, the coupling capacitor is C1, the capacitor C2, and C1=C2=0.05μF. The rectifier transistors are turned on in groups of two. When the input RF signal is in the positive half cycle, the rectifier tube N2 and the rectifier tube P1 are turned on, the rectifier tube N1 and the rectifier tube P2 are turned off, the capacitor C1 is charged, and the capacitor C2 is discharged and output to the load end.

[0059] After the voltage passes through the coupling capacitors C1 and C2, the node voltages at the output are set to V1 and V2 respectively. Since C1=C2, V1=-V2. At this time, the voltage between the gate and source of the rectifier tube N2 is V N2GS =V1-V2=2|V1|, and similarly, the voltage between the gate and source of the rectifier tube P1 is V P2GS=-2|V1|, when the input RF signal is in the negative half cycle, the voltage V between the gate and source of the rectifier tube N2 N2GS ' drops to -2|V1|, the voltage between the gate and source of the rectifier tube P2 is V P2GS ' is raised to 2|V1|, so the circuit structure can effectively reduce the loss caused by reverse leakage current and thus improve the power conversion efficiency of the circuit.

[0060] If the RF signal is collected by the antenna and amplified by the impedance matching network, the input voltage V RF The amplitude is V in , then the output voltage of the RF rectifier circuit is V OUT =2(V in -V TH ), where V TH It is the sum of the threshold voltages of an NMOS tube and a PMOS tube in the circuit. In a multi-stage cascade rectifier circuit, if the number of cascade stages is N, the output voltage of the rectifier current is V OUT =N(V in -V TH ).

[0061] When the input RF signal is in the positive half cycle, the rectifier N2 and the rectifier P1 are turned on, the rectifier N1 and the rectifier P2 are turned off, and the diode SD1 is turned on, so that the source of the rectifier P1 is connected to the substrate, reducing the voltage between the source and substrate of the rectifier. Because the selected Schottky diode has a small conduction voltage drop, the threshold voltage in the PMOS threshold voltage formula is small. At the same time, for the rectifier N2, the substrate is connected to the gate through the buffer capacitor C3 and the buffer capacitor C4. At this time, the voltage between the source and substrate of the rectifier N2 is negative, and the threshold voltage of the rectifier N2 will be compensated as shown in the following formula. At this time, the conduction speed of the rectifier N2 will also be improved, and the threshold voltage loss will be reduced. At this time, the diode SD4 is turned on, connecting the source and substrate of the rectifier P2, preventing the reverse leakage current caused by the floating of the substrate when the rectifier P2 is reversely cut off, and reducing the loss of the circuit. Since the circuit is a differential circuit, when the input signal is in the negative half cycle, the working state of each transistor and Schottky diode is basically similar to the positive half cycle, except that the working components are different.

[0062] Among them, the calculation formula of the threshold voltage of the P-type metal oxide semiconductor rectifier is:

[0063] ;

[0064] In the formula, Represents the threshold voltage of the P-type metal oxide semiconductor rectifier, It represents the threshold voltage of the P-type metal oxide semiconductor rectifier without considering the body effect. It represents the potential difference between the source and substrate of the P-type metal oxide semiconductor rectifier. represents the body Fermi potential, and τ represents the body effect coefficient.

[0065] Among them, the substrate of the rectifier tube N2 is connected to the gate of the rectifier tube N2 through the capacitor C3 and the capacitor C4 in sequence. At this time, the voltage between the source and the substrate of the rectifier tube N2 is negative, and the threshold voltage of the rectifier tube N2 is compensated by using the calculation formula of the threshold voltage of the N-type metal oxide semiconductor rectifier tube.

[0066] Among them, the calculation formula of the threshold voltage of the N-type metal oxide semiconductor rectifier is:

[0067] ;

[0068] In the formula, Represents the threshold voltage of the N-type metal oxide semiconductor rectifier, It represents the threshold voltage of N-type metal oxide semiconductor rectifier without considering the body effect. Represents the potential difference between the source and substrate of an N-type metal oxide semiconductor rectifier. represents the body Fermi potential, and τ represents the body effect coefficient.

[0069] In the actual working state of the circuit, the actual threshold values ​​of the PMOS and NMOS tubes are and The actual size is smaller than the threshold voltage when the body effect is ignored. , , thereby effectively weakening the impact of the rectifier tube effect on the threshold voltage, reducing the threshold voltage and improving the power conversion efficiency of the circuit.

[0070] At the same time, because in the actual application of RF energy harvesting, such as Figure 4 As shown in the figure, the RF energy collected by the antenna is small. After the voltage amplitude is increased by the impedance matching network, the rectifier tube and diode in the RF rectifier circuit are turned on. In order to obtain a higher rectified output DC voltage, Figure 2 The first-stage RF rectifier circuit in the circuit is cascaded into three stages to form a Figure 3 The RF rectifier circuit shown in the figure is connected to an energy management circuit after three stages are cascaded and then connected to a load output.

[0071] like Figure 2 As shown, according to another embodiment of the present invention, a radio frequency rectifier circuit is further provided, the radio frequency rectifier circuit is composed of a plurality of groups of primary radio frequency rectifier circuits in cascade connection, the primary radio frequency rectifier circuit includes capacitor C1, capacitor C2, capacitor C3, capacitor C4, rectifier tube N1, rectifier tube N2, rectifier tube P1, rectifier tube P2, diode SD1, diode SD2, diode SD3 and diode SD4;

[0072] One end of capacitor C1 is connected to the AC power supply V BF The positive electrode of the rectifier tube N1 is connected, the other end of the capacitor C1 is connected to the source of the rectifier tube N1, one end of the capacitor C4, the gate of the rectifier tube N2, the gate of the rectifier tube P2, the cathode of the diode SD2, the positive electrode of the diode SD1 and the source of the rectifier tube P1, the drain of the rectifier tube N1 is connected to the drain of the rectifier tube N2 and is grounded, the substrate of the rectifier tube N1 is connected to one end of the capacitor C3, the gate of the rectifier tube N1 is connected to the other end of the capacitor C3, the source of the rectifier tube N2, the cathode of the capacitor C ... The substrate of the rectifier tube N2 is connected to the other end of the capacitor C4, the substrate of the rectifier tube P2 is connected to the cathode of the diode SD3 and the anode of the diode SD4, the other end of the capacitor C2 is connected to the AC power supply V BF negative connection.

[0073] Wherein, the rectifier tube N1 and the rectifier tube N2 are both N-type metal oxide semiconductor rectifier tubes, and the width-to-length ratio of the rectifier tube N1 and the rectifier tube N2 is 50-70;

[0074] The rectifier tube P1 and the rectifier tube P2 are both P-type metal oxide semiconductor rectifier tubes, and the width-to-length ratio of the rectifier tube P1 and the rectifier tube P2 is 150-210.

[0075] The capacitor C1 and the capacitor C2 are both coupling capacitors, and the capacitance value of the capacitor C1 and the capacitor C2 is 0.05 μF.

[0076] In order to facilitate understanding of the above technical solution of the present invention, the radio frequency rectification circuit provided by the present invention is described in detail below.

[0077] The radio frequency rectifier circuit provided by the present invention solves the problem of increased power consumption caused by the threshold rise caused by multi-stage cascade and the reverse leakage current of the MOS tube itself in the traditional CMOS (combination of NMOS and PMOS tubes) radio frequency RF-DC (radio frequency signal-direct current signal) rectifier circuit. The radio frequency rectifier circuit provided by the present invention is composed of three groups of primary radio frequency rectifier circuits in cascade, wherein each basic radio frequency rectifier circuit (equivalent to the primary radio frequency rectifier circuit) is as follows: Figure 2As shown, it includes four capacitors, namely coupling capacitor C1, coupling capacitor C2, buffer capacitor C3, buffer capacitor C4; two NMOS rectifiers (equivalent to N-type metal oxide semiconductor rectifiers) N1, N2; two PMOS rectifiers (equivalent to P-type metal oxide semiconductor rectifiers) P1, PMOS rectifier P2; four Schottky diodes SD1, diode SD2, diode SD3, diode SD4. Figure 3 As shown, after the RF signal is coupled by the coupling capacitor, it is rectified by a group of rectifier transistors in pairs, and then connected to the energy management circuit and the load output after multiple stages of cascading.

[0078] In summary, with the aid of the above technical scheme of the present invention, the present invention sets capacitors, rectifiers and Schottky diodes, thereby making the discrete circuit application in the RF rectifier circuit simple, and can solve the problem of the threshold increase of the RF rectifier circuit caused by multi-stage cascading in the differential input coupled rectifier circuit, thereby solving the problem of increased power consumption caused by the current leakage of the NMOS tube; the present invention introduces Schottky diodes and capacitors in the traditional differential coupled input rectifier circuit, and solves the problem that in the actual application of RF energy collection, due to the particularly weak RF energy input, multi-stage cascading is required to increase the output voltage by utilizing the characteristics of the Schottky diode, which has a small conduction voltage drop and a short reverse recovery time, and the buffering characteristics of the capacitor, so that when collecting and utilizing the RF energy, the voltage between the source and the substrate of the rectifier tube gradually increases due to the increase in the number of cascades, thereby causing the output voltage to decrease; at the same time, it solves the problem that in the traditional differential input cross-coupled rectifier circuit, the gate of the rectifier NMOS tube is directly connected to the substrate, which causes current leakage, thereby causing the power consumption of the rectifier circuit to increase.

[0079] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for a radio frequency rectifier circuit, characterized in that: The control method of the radio frequency rectification circuit includes: Using an antenna to collect radio frequency signals, inputting the radio frequency signals into an impedance matching network for optimization, and inputting the optimized radio frequency signals into a primary radio frequency rectification circuit; Determine the signal state of the radio frequency signal. If the radio frequency signal is in a positive half cycle, rectify the positive half cycle of the radio frequency signal; if the radio frequency signal is in a negative half cycle, rectify the negative half cycle of the radio frequency signal. Extract the DC signal generated after the RF signal is rectified, and connect the DC signal to the energy management circuit and load output; The determining of the signal state of the radio frequency signal, if the radio frequency signal is in a positive half cycle, rectifying the positive half cycle of the radio frequency signal; if the radio frequency signal is in a negative half cycle, rectifying the negative half cycle of the radio frequency signal includes: Determine the signal state of the RF signal after inputting the primary RF rectifier circuit. If the RF signal is in the positive half cycle, the rectifier tube N2 and the rectifier tube P1 are forward-conducted, and the rectifier tube N1 and the rectifier tube P2 are reverse-conducted. At the same time, the diode SD1 and the diode SD4 are turned on, and the diode SD2 and the diode SD3 are turned off, thereby realizing the positive half-cycle rectification of the RF signal; If the RF signal is in the negative half cycle, rectifier tube N1 and rectifier tube P2 are forward-conducted, rectifier tube N2 and rectifier tube P1 are reverse-conducted, and diode SD2 and diode SD3 are turned on, and diode SD1 and diode SD4 are turned off, thereby realizing rectification of the negative half cycle of the RF signal.

2. The control method of a radio frequency rectifier circuit according to claim 1, characterized in that: The method of collecting radio frequency signals by using an antenna, inputting the radio frequency signals into an impedance matching network for optimization, and inputting the optimized radio frequency signals into a primary radio frequency rectification circuit comprises: Inputting the radio frequency signal collected by the antenna into the impedance matching network to obtain the input voltage amplitude amplified by the impedance matching network; Based on the input voltage amplitude amplified by the impedance matching network, the output voltage of the primary RF rectifier circuit is calculated, wherein the calculation formula of the output voltage of the primary RF rectifier circuit is: V OUT =2(V in -V TH ); Where V OUT Represents the output voltage of the primary RF rectifier circuit; V TH represents the sum of the threshold voltages of any N-type metal oxide semiconductor rectifier and P-type metal oxide semiconductor rectifier; V in Represents the input voltage amplitude amplified by the impedance matching network.

3. The control method of a radio frequency rectifier circuit according to claim 2, characterized in that: When the RF signal is in the positive half cycle, the rectifier tube N2 and the rectifier tube P1 are forward-conducted, and when the rectifier tube N1 and the rectifier tube P2 are reversely cut off, the source of the rectifier transistor P1 is connected to the substrate, thereby reducing the source voltage and the substrate voltage of the P-type metal oxide semiconductor rectifier tube, thereby reducing the threshold voltage of the P-type metal oxide semiconductor rectifier tube.

4. The control method of a radio frequency rectifier circuit according to claim 3, characterized in that: The calculation formula of the threshold voltage of the P-type metal oxide semiconductor rectifier is: ； In the formula, Represents the threshold voltage of the P-type metal oxide semiconductor rectifier, It represents the threshold voltage of the P-type metal oxide semiconductor rectifier without considering the body effect. It represents the potential difference between the source and substrate of the P-type metal oxide semiconductor rectifier. represents the body Fermi potential, and τ represents the body effect coefficient.

5. The control method of a radio frequency rectifier circuit according to claim 4, characterized in that: The substrate of the rectifier tube N2 is connected to the gate of the rectifier tube N2 through capacitors C3 and C4 in sequence. At this time, the voltage between the source and the substrate of the rectifier tube N2 is negative, and the threshold voltage of the rectifier tube N2 is compensated by using the calculation formula of the threshold voltage of the N-type metal oxide semiconductor rectifier tube.

6. The control method of a radio frequency rectifier circuit according to claim 5, characterized in that: The calculation formula of the threshold voltage of the N-type metal oxide semiconductor rectifier is: ； In the formula, Represents the threshold voltage of the N-type metal oxide semiconductor rectifier, It represents the threshold voltage of N-type metal oxide semiconductor rectifier without considering the body effect. Represents the potential difference between the source and substrate of an N-type metal oxide semiconductor rectifier. represents the body Fermi potential, and τ represents the body effect coefficient.

7. A radio frequency rectifier circuit, characterized in that: A control method for implementing the radio frequency rectifier circuit according to any one of claims 1 to 6, wherein the radio frequency rectifier circuit is composed of a plurality of groups of primary radio frequency rectifier circuits in cascade connection, wherein the primary radio frequency rectifier circuit includes capacitor C1, capacitor C2, capacitor C3, capacitor C4, rectifier tube N1, rectifier tube N2, rectifier tube P1, rectifier tube P2, diode SD1, diode SD2, diode SD3 and diode SD4; One end of the capacitor C1 is connected to the positive electrode of the AC power supply, and the other end of the capacitor C1 is respectively connected to the source of the rectifier N1, one end of the capacitor C4, the gate of the rectifier N2, the gate of the rectifier P2, the cathode of the diode SD2, the anode of the diode SD1 and the source of the rectifier P1. The drain of the rectifier N1 is connected to the drain of the rectifier N2 and is grounded. The substrate of the rectifier N1 is connected to one end of the capacitor C3. The gate of the rectifier N1 is respectively connected to the other end of the capacitor C3, the source of the rectifier N2, the cathode of the diode SD2, the anode of the diode SD1 and the source of the rectifier P1. One end of the capacitor C2, the positive electrode of the diode SD3, the negative electrode of the diode SD4, the gate of the rectifier P2 and the rectifier P1 are connected, the substrate of the rectifier P1 is respectively connected to the negative electrode of the diode SD1 and the positive electrode of the diode SD2, and the drain of the rectifier P1 is connected to the drain of the rectifier P2; the substrate of the rectifier N2 is connected to the other end of the capacitor C4, the substrate of the rectifier P2 is respectively connected to the negative electrode of the diode SD3 and the positive electrode of the diode SD4, and the other end of the capacitor C2 is connected to the negative electrode of the AC power supply.

8. The radio frequency rectifier circuit according to claim 7, characterized in that: The rectifier tube N1 and the rectifier tube N2 are both N-type metal oxide semiconductor rectifier tubes, and the width-to-length ratio of the rectifier tube N1 and the rectifier tube N2 is 50-70; The rectifier tube P1 and the rectifier tube P2 are both P-type metal oxide semiconductor rectifier tubes, and the width-to-length ratio of the rectifier tube P1 and the rectifier tube P2 is 150-210.

9. The radio frequency rectifier circuit according to claim 8, characterized in that: The capacitor C1 and the capacitor C2 are both coupling capacitors, and the capacitance value of the capacitor C1 and the capacitor C2 is 0.05 μF.

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