Polyphase impedance transformation amplifier
View Patent ↗A method and apparatus for greatly increasing the output voltage or current transformation ratio in an impedance transformation amplifier are disclosed. Broadly, the method takes advantage of multiple, phase-synchronized impedance transformation stages, each of which preferably contributes an equal portion of the eventual output voltage or current.
1. A polyphase impedance transformation amplifier connecting an input signal to a load, comprising:
a pulse-width modulator (PWM);
gated switches controlled by the PWM for routing energy from a power source to the load in accordance with the input signal; and
a plurality of impedance-transformation stages, each controlled by the PWM for routing energy from a power supply to the power source, thereby increasing the output transformation ratio at the load.
2. The impedance transformation amplifier of claim 1 wherein each impedance-transformation stage includes an inductor in series with a gated switch controlled by the PWM.
3. The circuitry of claim 1 , wherein each impedance-transformation stage contributes an equal portion of the energy coupled to the load.
4. A method of increasing the output amplification ratio in an impedance transformation amplifier driving a load with gated switches, comprising the steps of:
providing a plurality of phase-synchronized impedance-transformation stages connected between a source of power and the gated switches; and
pulse-width modulating the transformation stages such that each contributes a respective portion of the voltage or current through the load.
5. The method of claim 4 , wherein each impedance transformation stage contributes a substantially equal portion of the voltage or current through the load.