13.56 MHz current-source generator based on third harmonic power transmission using immittance conversion topology and investigation on novel immittance conversion element

A novel type of high frequency current-source inverter, operating in the megahertz-range, is presented in this paper. A special circuit, composed of a voltage-source half-bridge inverter, a distributed constant line and a parallel LC resonant circuit, has been developed for this purpose. A distributed constant line is connected between the output terminal of the inverter and the load. Here, since the length of the line is adjusted to 1/4 of the propagation wavelength λ (λ/4 condition), the output voltage of the voltage-source inverter can be converted to a current source on the load side. Furthermore, a 13.56 MHz current-source inverter based on the third harmonic power transmission method used with the previous system is developed. The experimental results from a prototype system verify the theoretical procedure. A minor problem, the excessive length of the distributed constant line, is pointed out. In order to overcome this, a novel immittance conversion element is proposed