L-type impedance matching system and method in a radio frequency energy harvesting circuit

Abstract

The invention relates to an L-type impedance matching system of a radio frequency energy acquisition circuit and a method thereof. The system comprise a sampling comparison module, a logic algorithm control module and an adjustable impedance matching network, wherein the sampling comparison module is used for carrying out continuous two-times sampling of voltages outputted by a voltage doubling rectifying circuit under the control of a logic control module and comparing the continuous two-times sampling voltages, the logic algorithm control module is used for gradually adjusting the quantity of L-type adjustable capacitance arrays merged to the adjustable impedance matching network according to the comparison result of the continuous two-times sampling voltages, and the adjustable impedance matching network is used for matching impedance between an antenna and the voltage doubling rectifying circuit according to the quantity of the merged L-type adjustable capacitance arrays. The system is advantaged in that the present impedance matching effect is acquired through determining the output voltages of the voltage doubling rectifying circuit, a complex ADC sampling or signal processing unit can be omitted, the circuit is simple, power consumption is quite low, energy is only consumed during the switching process, and the system is suitable for the weak energy acquisition environment.

Description

technical field [0001] The invention relates to an impedance matching system and method in an energy collection circuit, in particular to an L-shaped impedance matching system and method in a radio frequency energy collection circuit. Background technique [0002] Due to the vigorous development of wireless sensor network (WSN), body area network (BAN), and Internet of Things (IoT), wireless sensor nodes have been widely utilized. In order to achieve uninterrupted measurement, the sensor node needs to have a longer standby time, but its service life is limited by the bottleneck of battery technology. In order to solve the power supply problem of sensor nodes, wireless energy harvesting technology has been widely developed, which collects radio energy to provide power for sensor nodes, so as to achieve the purpose of prolonging the working time of the circuit or passive work. [0003] Energy harvesting circuits generally consist of four parts, such as figure 1 As shown, the...

AI Technical Summary

Problems solved by technology

[0012] 1. The system requires a coupler to detect the forward power signal and the reflected power signal. However, this component cannot be integrated with a CMOS process, which increases the complexity of the system;

[0013] 2. This system is too complicated. The system first needs the ADC to sample the voltage signal, then uses the processor unit to calculate the current transmission efficiency, and then controls the matching network to change until the efficiency meets the program requirements. This method has a large power consumption and cannot be applied In weak energy harvesting systems;

[0014] 3. The system uses a relay as a control unit, which is suitable for high-power transmission, but in the energy harvesting circuit, the collected energy is not enough to control components such as relays

This method also faces the problems of complex system, inability to integrate, and high power consumption, and cannot be applied to weak energy harvesting circuits

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