setting resonant frequency and finding circuit properties (power, current, voltage) for a wireless power transfer system

I have seen the example "Modeling Resonant Coupled Wireless Power Transfer System" and i have a few questions about that:

1) How can i set the resonant frequency of my system to 100kHz?

i have tried changeing the first lines to:

fc=100e3;
fcmin = 50e3;
fcmax = 200e3;
fband1 = 25e3:3e3:fcmin;
fband2 = fcmin:3e3:fcmax;
fband3 = fcmax:3e3:250e3;
freq = unique([fband1 fband2 fband3]);

didnt work as the reactance graph didnt show a peak, it just kept rising continuously.

2) How can i set and find properties such as voltage, power, current and efficiency?

I want to set certain values as fixed, for example a voltage of 50V and find values of the remaining.

Answer 1

[Da Huang]

Hi Yuri,

Hope the following answer your question.

1. In the wireless power transfer example, you need to change the default spiral designs to make it resonant at the frequency you want. The spiral used in the example is designed to resonant at 30MHz. The value of Rin and Rout proportional to wavelength is a good start points to try out.
2. The default voltage used to excite antenna set to 1V by default, and this is not changable in antenna toolbox. To obtain the feed current, there is a method called feedCurrent(obj,freq) will give you the current at the feeding. To get the current for a 50V excitation, you can just multiply the feedCurrent value obtained from 1V voltage excitation. The power then can be obtained from P=real(I*I'*Z). The effeiciency, there are different version of efficiency definition. Depends on what you want, you shall be able to calculate your efficiency from voltage, feedCurrent and impedance.

The system setup in the wireless power transfer example is a demonstration of what antenna toolbox can do. The system ignore the impedance matching to 50Ohm in actual system. To bettern couple your feed energy to the system, another single loop for impedance matching as shown in MIT example is recommended to be included in the system.

Da

Answer 2

[Sohag Kumar Saha]

Is it possible to use this type of Resonant coupled wpt system for Microwave frequency range like 2.45 GHZ or 5.8 GHZ ?

I want to implement such system in a WPT system working in the microwave frequency range. I tried but the result seems unsatisfatory till now....

Thanks in advance ....