Using Square Wave Input for Wireless Power Transfer

2016 ◽  
Vol 6 (1) ◽  
pp. 431 ◽  
Author(s):  
Kazuya Yamaguchi ◽  
Takuya Hirata ◽  
Ichijo Hodaka
Keyword(s):  
Resonant Frequency ◽  
High Power ◽  
Power Supply ◽  
Wireless Power Transfer ◽  
Wave Form ◽  
Power Transfer ◽  
Wireless Power ◽  
Sinusoidal Wave ◽  
Square Wave ◽  
Ac Power

A wireless power transfer (WPT) circuit is composed of a transmitting circuit with an AC power supply and a receiving circuit with a load, and the circuits are wirelessly connected each other. Then a designer chooses the wave form of the AC power supply. Many papers about WPT adopt a sinusoidal wave as the input. The frequency of the sinusoidal wave is generally determined to the resonant frequency of the circuit for high power transfer. Since the number of circuit elements in the power supply to generate a square wave is much less than that of a sinusoidal wave, WPT with a square wave input should be treated. In fact, some papers about WPT adopt a square wave as the input, and adjust the frequency of the square wave to the resonant frequency of the circuit. In this paper, we examine how the frequency of a square wave input affects power and efficiency of WPT circuits, and propose a procedure how to determine the frequency of the input to improve power and efficiency. Finally we discuss which wave should be adopted as an input and how the frequency of the input should be determined, regardless of whether resonant phenomena occur or not.

scholarly journals Using Square Wave Input for Wireless Power Transfer

2016 ◽  
Vol 6 (1) ◽  
pp. 431
Author(s):  
Kazuya Yamaguchi ◽  
Takuya Hirata ◽  
Ichijo Hodaka
Keyword(s):  
Resonant Frequency ◽  
High Power ◽  
Power Supply ◽  
Wireless Power Transfer ◽  
Wave Form ◽  
Power Transfer ◽  
Wireless Power ◽  
Sinusoidal Wave ◽  
Square Wave ◽  
Ac Power

A wireless power transfer (WPT) circuit is composed of a transmitting circuit with an AC power supply and a receiving circuit with a load, and the circuits are wirelessly connected each other. Then a designer chooses the wave form of the AC power supply. Many papers about WPT adopt a sinusoidal wave as the input. The frequency of the sinusoidal wave is generally determined to the resonant frequency of the circuit for high power transfer. Since the number of circuit elements in the power supply to generate a square wave is much less than that of a sinusoidal wave, WPT with a square wave input should be treated. In fact, some papers about WPT adopt a square wave as the input, and adjust the frequency of the square wave to the resonant frequency of the circuit. In this paper, we examine how the frequency of a square wave input affects power and efficiency of WPT circuits, and propose a procedure how to determine the frequency of the input to improve power and efficiency. Finally we discuss which wave should be adopted as an input and how the frequency of the input should be determined, regardless of whether resonant phenomena occur or not.

scholarly journals The Interaction between Load Circuits and Decision of Frequency for Efficient Wireless Power Transfer

2018 ◽  
Vol 8 (3) ◽  
pp. 1331
Author(s):  
Kazuya Yamaguchi
Keyword(s):  
Power Supply ◽  
Natural Frequencies ◽  
Wireless Power Transfer ◽  
Transfer System ◽  
Power Transfer ◽  
Wireless Power ◽  
Ac Power ◽  
Wireless Power Transfer System ◽  
Efficient Transfer ◽  
The Ideal

<pre>This paper derives an expression of efficiency of wireless power transfer on a situation that there are two devices towards one AC power supply. The interaction between a power supply and load is paid attention on a conventional wireless power transfer system, in contrast, the interaction between loads must be taken account of on the situation too. This is attributed to a possibility that a load disturbs the energy transmitted from a power supply to another load. Moreover each load needs different frequency of power supply for the ideal transfer since they have different natural frequencies on many situations. This paper models a circumstance that there are a power supply and two loads with a state space equation, and proposes how to decide a frequency of power supply to realize efficient transfer for each load.</pre>

scholarly journals Wireless power transfer to a micro implant device from outside of human body

2019 ◽  
Vol 9 (3) ◽  
pp. 1541
Author(s):  
Kazuya Yamaguchi ◽  
Kazuma Onishi ◽  
Kenichi Iida
Keyword(s):  
Human Body ◽  
Power Supply ◽  
Calculated Result ◽  
Wireless Power Transfer ◽  
Load Resistance ◽  
State Equation ◽  
Power Transfer ◽  
Wireless Power ◽  
Ac Power ◽  
Parasitic Components

<pre>This paper states wireless power transfer (WPT) from an AC power supply to a micro implant device in human body. At first, an equivalent circuit of WPT which contains biomedical tissue is constructed with an AC power supply, parasitic components, load resistance, and inductances. Then a state equation which stands for the behavior of circuit is found, and the expression of efficiency is derived as the ratio of the power of power supply and load. Finally an experiment is conducted based on the theoretical calculation, and the error between experimental and calculated result is computed and examined.</pre>

scholarly journals Microwave Wireless Power Transfer System Based on a Frequency Reconfigurable Microstrip Patch Antenna Array

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 415
Author(s):  
Haiyue Wang ◽  
Lianwen Deng ◽  
Heng Luo ◽  
Junsa Du ◽  
Daohan Zhou ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Antenna Array ◽  
Patch Antenna ◽  
Wireless Power Transfer ◽  
Microstrip Patch Antenna ◽  
Market Demand ◽  
Power Transfer ◽  
Wireless Power ◽  
Microstrip Patch ◽  
Wide Range

The microwave wireless power transfer (MWPT) technology has found a variety of applications in consumer electronics, medical implants and sensor networks. Here, instead of a magnetic resonant coupling wireless power transfer (MRCWPT) system, a novel MWPT system based on a frequency reconfigurable (covering the S-band and C-band) microstrip patch antenna array is proposed for the first time. By switching the bias voltage-dependent capacitance value of the varactor diode between the larger main microstrip patch and the smaller side microstrip patch, the working frequency band of the MWPT system can be switched between the S-band and the C-band. Specifically, the operated frequencies of the antenna array vary continuously within a wide range from 3.41 to 3.96 GHz and 5.7 to 6.3 GHz. For the adjustable range of frequencies, the return loss of the antenna array is less than −15 dB at the resonant frequency. The gain of the frequency reconfigurable antenna array is above 6 dBi at different working frequencies. Simulation results verified by experimental results have shown that power transfer efficiency (PTE) of the MWPT system stays above 20% at different frequencies. Also, when the antenna array works at the resonant frequency of 3.64 GHz, the PTE of the MWPT system is 25%, 20.5%, and 10.3% at the distances of 20 mm, 40 mm, and 80 mm, respectively. The MWPT system can be used to power the receiver at different frequencies, which has great application prospects and market demand opportunities.

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