A rectifier and oscillator fused wireless energy harvesting circuit

Abstract

The application belongs to the technical field of wireless energy collection chips, and discloses a wireless energy collection circuit with rectifier and oscillator fusion, which comprises a main rectifier, a main resonance network or matching network, an LC oscillator, a switch SW1, a load capacitor C1, an auxiliary rectifier and an auxiliary resonance network or matching network; the LC oscillator shares a main inductive antenna and the main resonance network or matching network with the main rectifier; and a power supply end of the LC oscillator is provided by the auxiliary rectifier to collect energy and store the energy in the load capacitor C1. The application optimizes the sensitivity and energy conversion efficiency of the rectifier on the two rectifiers respectively, and ingeniously combines the rectifier and the oscillator, without changing the resonance network and rectification module of the main rectifier. The application can not only increase the sensitivity of the rectifier, so that the rectifier can receive weak energy at a farther distance, but also improve the sensitivity and energy conversion efficiency of the whole system.

Description

Technical Field

[0001] This invention belongs to the field of wireless energy harvesting chip technology, and particularly relates to a wireless energy harvesting circuit that integrates a rectifier and an oscillator. Background Technology

[0002] Typically, wireless power harvesting chips require a resonant voltage from the antenna, after resonance through a resonant network, sufficient to activate the rectifier module before rectification can begin. To improve energy conversion efficiency—the efficiency from the open-circuit end of the antenna to the rectifier's output—a differential rectifier module is employed. This necessitates that the energy harvested from the antenna, after resonance through the resonant network, be sufficient to activate the rectifier module. Traditional differential rectifier module structures require a turn-on voltage exceeding the MOSFET threshold voltage. However, some weak energy received from the antenna is insufficient to activate the rectifier module, thus failing to be shaped and being wasted, thereby limiting the rectifier's sensitivity. Summary of the Invention

[0003] The purpose of this invention is to provide a wireless energy harvesting circuit that integrates a rectifier and an oscillator to solve the above-mentioned technical problems.

[0004] To solve the above-mentioned technical problems, the specific technical solution of the wireless energy harvesting circuit integrating rectifier and oscillator of the present invention is as follows:

[0005] A wireless energy harvesting circuit integrating a rectifier and an oscillator includes a main rectifier and a main resonant network or matching network. The main rectifier is connected to the main resonant network or matching network. The main resonant network or matching network consists of a main inductive antenna and a main resonant capacitor. It includes an LC oscillator, a switch SW1, a load capacitor C1, an auxiliary rectifier, and an auxiliary resonant network or matching network. One end of the LC oscillator is connected to the main resonant network or matching network, and the other end is connected to the switch SW1. The other end of the switch SW1 is connected to the load capacitor C1 and one end of the auxiliary rectifier. The other end of the auxiliary rectifier is connected to the auxiliary resonant network or matching network. The other end of the load capacitor C1 is grounded. The LC oscillator and the main rectifier share the main inductive antenna and the main resonant network or matching network. The power supply of the LC oscillator is provided by the energy harvested and stored in the load capacitor C1 by the auxiliary rectifier.

[0006] Furthermore, when the load capacitor C1 provides a DC voltage sufficient for the LC oscillator to operate normally, the switch SW1 closes, the load capacitor C1 begins to supply power to the LC oscillator, the amplitude of the resonant voltage of the main resonant network or matching network increases, and the rectifier module of the main rectifier starts to work.

[0007] Furthermore, the auxiliary rectifier has higher sensitivity than the main rectifier, and the turn-on voltage of the auxiliary rectifier module is lower than that of the main rectifier module.

[0008] Furthermore, the main rectifier is a rectifier with high energy conversion efficiency.

[0009] Furthermore, the LC oscillator consists of two PMOS transistors, two NMOS transistors, a main inductive antenna, and a main resonant capacitor. The two PMOS transistors and two NMOS transistors are connected in a differential configuration. The sources and substrates of the two PMOS transistors are both connected to the load capacitor C1 of the auxiliary rectifier, and the sources and substrates of the NMOS transistors are both connected to ground. The drains of the PMOS transistors and the drains of the NMOS transistors are connected and serve as the output after resonance of the main resonant network or matching network. The gates of the NMOS transistors on the same side are connected to the gates of the PMOS transistors and connected to the drains on the opposite side. The inductance and capacitance of the LC oscillator reuse the main inductive antenna and the main resonant capacitor of the main rectifier.

[0010] Furthermore, the sources and substrates of the two PMOS transistors of the LC oscillator are both connected to one end of switch SW1, and the other end of switch SW1 is connected to load capacitor C1.

[0011] Furthermore, the main rectifier is an Nth-order differential rectifier, the auxiliary rectifier is an Nth-order Dickson rectifier, and the LC oscillator is a differential LC oscillator.

[0012] The wireless energy harvesting circuit integrating a rectifier and an oscillator of the present invention has the following advantages: The present invention optimizes the sensitivity and energy conversion efficiency of the rectifier in two separate rectifiers, and cleverly combines the rectifier and the oscillator. It does not require changes to the resonant network and rectifier module of the main rectifier. This not only increases the sensitivity of the rectifier, enabling it to receive weak energy from a greater distance, but also improves the sensitivity and energy conversion efficiency of the entire system. The present invention cleverly integrates the LC oscillator and the rectifier, and achieves excellent sensitivity performance while reducing the area by using a multiplexed resonant network. Attached Figure Description

[0013] Figure 1 This is the circuit schematic diagram of the present invention;

[0014] Figure 2 This is a circuit schematic diagram of an embodiment of the present invention;

[0015] Figure 3 This is a circuit schematic diagram of an embodiment of the present invention. Detailed Implementation

[0016] To better understand the purpose, structure, and function of this invention, a wireless energy harvesting circuit integrating a rectifier and an oscillator will be described in further detail below with reference to the accompanying drawings.

[0017] like Figure 1 As shown, a wireless energy harvesting circuit integrating a rectifier and an oscillator is presented. The auxiliary rectifier avoids the problem of the main rectifier module being difficult to turn on. An LC oscillator is used, and the energy supply to the load capacitor C1 is controlled by switch SW1. This ensures that the LC oscillator provides an effective resonant voltage amplification to the main rectifier and avoids the large area occupied by the inductor and capacitor in the LC oscillator. Simultaneously, in this structure, the main rectifier can optimize energy conversion efficiency to the best level and achieve a reasonably high sensitivity, thus working more effectively with the auxiliary rectifier to utilize the weak energy in space.

[0018] Specifically, a wireless energy harvesting circuit integrating a rectifier and an oscillator includes a main rectifier, an auxiliary rectifier, an LC oscillator, a main resonant network or matching network, an auxiliary resonant network or matching network, a switch SW1, a load capacitor C1, and an energy harvesting capacitor C2. The main resonant network or matching network consists of a main inductive antenna and a main resonant capacitor, while the auxiliary resonant network or matching network consists of an auxiliary inductive antenna and an auxiliary resonant capacitor. One end of the main rectifier is connected to the main resonant network or matching network, and the other end is connected to the energy harvesting capacitor C2. One end of the LC oscillator is connected to the main resonant network or matching network, and the other end is connected to the switch SW1. The other end of the switch SW1 is connected to the load capacitor C1 and the auxiliary rectifier. The other end of the auxiliary rectifier is connected to the auxiliary resonant network or matching network. The other ends of both the load capacitor C1 and the energy harvesting capacitor C2 are grounded. The LC oscillator shares the main inductive antenna and the main resonant network or matching network with the main rectifier. The power supply of the LC oscillator is provided by the auxiliary rectifier collecting energy and storing it in the load capacitor C1. When the load capacitor C1 provides a DC voltage sufficient for the LC oscillator to operate normally, the switch SW1 is closed, and the load capacitor C1 starts to supply power to the LC oscillator. The amplitude of the resonant voltage of the main resonant network or matching network (i.e., the output voltage of the LC oscillator) will increase, enabling the rectifier module of the main rectifier to start working and charge the energy harvesting capacitor C2, thereby increasing the sensitivity of the entire system.

[0019] In the auxiliary rectifier, the energy conversion efficiency does not need to be very high, but its sensitivity must be higher than that of the main rectifier, that is, it can receive weaker energy than the main rectifier. In addition, the turn-on voltage of the rectifier module of the auxiliary rectifier must also be lower than that of the main rectifier module. In this way, although the auxiliary rectifier sacrifices energy conversion efficiency, it can receive weaker energy than the main rectifier and rectify it, so that the energy is stored in the load capacitor C1 for use by the LC oscillator.

[0020] The resonant section of the LC oscillator consists of the main inductive antenna and the main resonant network or matching network of the multiplexed main rectifier. The requirement for the LC oscillator is that it can operate effectively under low supply voltage. The power supply terminal of the LC oscillator is connected to one side of switch SW1. The output terminal of the LC oscillator is connected to the main resonant network or matching network. One end of the auxiliary rectifier is connected to the auxiliary resonant network or matching network, and the other end is connected to switch SW1 and load capacitor C1. The power supply terminal of the LC oscillator is provided by the auxiliary rectifier collecting energy and storing it in the load capacitor C1. When the load capacitor C1 provides a DC voltage sufficient for the LC oscillator to operate normally, switch SW1 is closed, and the load capacitor C1 starts to supply power to the LC oscillator. The amplitude of the resonant voltage of the main resonant network (i.e., the output voltage of the LC oscillator) will increase, enabling the rectifier module of the main rectifier to start working.

[0021] The main rectifier requires a high energy conversion efficiency rectifier for energy shaping.

[0022] Example:

[0023] like Figure 2 This illustration shows a specific example of a circuit integrating a rectifier and an oscillator according to the present invention, applied in an energy harvesting chip. In this example, the LC oscillator section is mainly detailed. The auxiliary rectifier can be any rectifier satisfying the description above; here, a traditional N-order rectifier is used as an example. The LC oscillator consists of two PMOS transistors, two NMOS transistors, a main inductive antenna, and a main resonant capacitor. The two PMOS transistors and two NMOS transistors are connected differentially. The sources and substrates of the two PMOS transistors are both connected to the load capacitor C1 of the auxiliary rectifier (in actual connection, a switch SW1 controls the on / off state between the LC oscillator and the load capacitor C1). The sources and substrates of the NMOS transistors are both connected to ground. The drains of the PMOS transistors and NMOS transistors are connected and serve as the output after resonance of the main resonant network or matching network. The gates of the NMOS transistors on the same side are connected to the gates of the PMOS transistors and connected to the drains on the opposite side. The inductance and capacitance of the LC oscillator reuse the main inductive antenna and main resonant capacitor of the main rectifier.

[0024] like Figure 3This diagram illustrates a specific example of a circuit integrating a rectifier and an oscillator, applied in an energy harvesting chip. In this example, the main rectifier is an N-order differential rectifier operating at 433MHz, achieving the highest possible energy transfer efficiency and sensitivity. The auxiliary rectifier is an N-order Dickson rectifier (the orders of the main and auxiliary rectifiers can be optimized based on actual conditions to obtain a suitable rectifier order; N-order is used here to represent it), operating at 2.4GHz. Its NMOS transistors are zero-threshold MOS transistors to reduce the turn-on voltage of the rectifier module, enabling it to receive weak energy from space. The selection of the rectifier structure and frequency can be determined based on actual conditions. The LC oscillator is a differential LC oscillator, which allows energy that did not reach the turn-on voltage of the main rectifier module to be shaped by the main rectifier module through the LC oscillator, thereby improving the sensitivity of the main rectifier. This allows the overall system to harvest and rectify even weaker energy from a greater distance.

[0025] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A wireless power harvesting circuit integrating a rectifier and an oscillator, comprising a main rectifier and a main resonant network or matching network, wherein the main rectifier is connected to the main resonant network or matching network, and the main resonant network or matching network consists of a main inductive antenna and a main resonant capacitor, characterized in that, The system includes an LC oscillator, a switch SW1, a load capacitor C1, an auxiliary rectifier, and an auxiliary resonant network or matching network. One end of the LC oscillator is connected to the main resonant network or matching network, and the other end is connected to the switch SW1. The other end of the switch SW1 is connected to the load capacitor C1 and one end of the auxiliary rectifier. The other end of the auxiliary rectifier is connected to the auxiliary resonant network or matching network. The other end of the load capacitor C1 is grounded. The LC oscillator and the main rectifier share the main inductive antenna and the main resonant network or matching network. The power supply of the LC oscillator is provided by the auxiliary rectifier collecting energy and storing it in the load capacitor C1.

2. The wireless power harvesting circuit integrating a rectifier and an oscillator according to claim 1, characterized in that, When the load capacitor C1 provides a DC voltage sufficient for the LC oscillator to operate normally, the switch SW1 closes, the load capacitor C1 starts to supply power to the LC oscillator, the amplitude of the resonant voltage of the main resonant network or matching network increases, and the rectifier module of the main rectifier starts to work.

3. The wireless power harvesting circuit integrating a rectifier and an oscillator according to claim 1, characterized in that, The auxiliary rectifier has a higher sensitivity than the main rectifier, and the turn-on voltage of the auxiliary rectifier module is lower than that of the main rectifier module.

4. The wireless power harvesting circuit integrating a rectifier and an oscillator according to claim 1, characterized in that, The main rectifier is a high-energy-conversion-efficiency rectifier.

5. The wireless power harvesting circuit integrating a rectifier and an oscillator according to claim 1, characterized in that, The LC oscillator consists of two PMOS transistors, two NMOS transistors, a main inductive antenna, and a main resonant capacitor. The two PMOS transistors and two NMOS transistors are connected in a differential configuration. The sources and substrates of the two PMOS transistors are both connected to the load capacitor C1, and the sources and substrates of the two NMOS transistors are both connected to ground. The drains of the PMOS transistors and the drains of the NMOS transistors are connected and serve as the output of the main resonant network or matching network after resonance. The gates of the NMOS transistors on the same side are connected to the gates of the PMOS transistors and connected to the drains on the opposite side. The inductance and capacitance of the LC oscillator are multiplexed from the main inductive antenna and the main resonant capacitor of the main rectifier.

6. The wireless power harvesting circuit integrating a rectifier and an oscillator according to claim 5, characterized in that, The sources and substrates of the two PMOS transistors of the LC oscillator are both connected to one end of switch SW1, and the other end of switch SW1 is connected to load capacitor C1.

7. The wireless power harvesting circuit integrating a rectifier and an oscillator according to claim 1, characterized in that, The main rectifier is an Nth-order differential rectifier, the auxiliary rectifier is an Nth-order Dickson rectifier, and the LC oscillator is a differential LC oscillator.

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