Adaptive impedance matching of rectifier for a 100 MHz microwave power transfer system

Abstract

Microwave power transmission (MPT) has been one of the most promising systems in the far-field wireless power transmission system. In MPT system, the harmonic energy generated by conventional diode rectifying circuit has great impact on the overall efficiency. Moreover, the passive impedance network leads to power reflection, which is the other factor leading to the overall efficiency decline. In this study, a 10 W output 100 MHz two-stage adaptive impedance-matching rectifying circuit is proposed which can make input impedance constant. About 100 MHz belongs to the band of radio frequency (RF) and the conception of microwave. The first-stage rectifier is modelled mathematically, which plays an essential role in constructing the initial input impedance and designing the control method of second-stage converter. By adjusting the duty cycle of the secondstage converter, the impedance of the whole rectifier realises 50 Ω under various input and the output conditions by means of simulations and experiments. The simulation and experimental results are shown to verify the effectiveness of the proposed RF to direct current converter and its control method. The overall efficiency with full load is up to nearly 65%.

A high‐efficiency power management unit with wide dynamic range for RF energy harvesting system

“…Thus, the condition that dI D /dT=0 at T r , is presented in (7), where k is the Boltzmann constant. Equation ( 7) indicates a zero of TC, which can be obtained by designing a negative TC of V GS .…”

“…With the development of low-power consumption Internet of Things (IoT) smart nodes, self-sustaining power supply for IoT nodes by using energy harvesting technology is a future development trend. Benefiting from its convenient control and contactless power transmission of a far-field radiation pattern, RF energy sources feature huge potential to extend the life of batteries, and the research on RF energy harvesting technology has gradually become a research hotspot in recent years [1][2][3][4][5][6][7][8][9].…”

A review of underwater inductive wireless power transfer system

“…Wireless power transfer is the method that could deliver power without physical contact [1][2][3][4][5]. Several methods of wireless power transfer have been introduced including near-field wireless power transfer [6][7][8][9] such as inductive coupling through magnetic fields [10][11][12][13][14][15][16][17][18], capacitive coupling through electric fields [19][20][21][22][23][24][25][26][27][28], and far-field wireless power transfer such as laserbased optical power transmission [29][30][31][32][33] and RF microwave energy transmission [34][35][36][37][38][39][40]. Inductive wireless power transfer (IPT) utilizes a non-radiative magnetic field in the kHz to MHz range to realize the wireless power transfer function.…”