Load independent voltage and current gain resonant topologies

1 . A resonant converter comprising:

an input stage;

an output stage; and

a resonant network stage without magnetically coupled resonant inductors, the resonant network stage comprising at least one inductor and at least one capacitor, wherein the resonant network stage is electrically coupled between the input stage and the output stage, wherein the resonant network stage provides a constant current gain at a first operating frequency and wherein the resonant network stage provides a constant voltage gain at a second operating frequency that differs from the first operating frequency, wherein:

the output stage is configured to be electrically coupled to a load having either a constant current operating mode or a constant voltage operating mode, or both,

the resonant network stage provides the constant current gain or the constant voltage gain based on a control signal generated by a frequency modulator for switching between the first operating frequency and the second operating frequency,

the first operating frequency is a resonant frequency of the at least one inductor and the at least one capacitor,

the second operating frequency is between 1.27-1.90 times the resonant frequency,

the load is a high-voltage capacitor,

the constant current operating mode is a charging phase of the high-voltage capacitor, and

the constant voltage operating mode is a refresh phase of the high-voltage capacitor.

2 . The resonant converter of claim 1 , wherein an impedance at the input stage is inductive in nature around a resonant frequency of the resonant network stage.

3 . The resonant converter of claim 1 , wherein the load is subject to load changes.

4 . The resonant converter of claim 1 , wherein the constant current gain and the constant voltage gain are each passed from the input stage and through the output stage.

5 . The resonant converter of claim 1 , wherein the first operating frequency or the second operating frequency is a resonant frequency of the resonant network stage.

6 . An apparatus comprising:

a resonant converter including:

an input stage,

an output stage, and

a resonant network stage without magnetically coupled resonant inductors, the resonant network stage comprising at least one inductor and at least one capacitor, wherein:

the resonant network stage is electrically coupled between the input stage and the output stage,

the resonant network stage provides a constant current gain at a first operating frequency,

the resonant network stage provides a constant voltage gain at a second operating frequency that differs from the first operating frequency,

the first operating frequency is a resonant frequency of the at least one inductor and the at least one capacitor, and

the second operating frequency is between 1.27-1.90 times the resonant frequency;

a load attached to the output stage, wherein the load has a first operating mode requiring the constant current and a second operating mode requiring the constant voltage, wherein:

the load is a high-voltage capacitor,

the first operating mode is a constant voltage operating mode,

the first operating mode is a charging phase of the high-voltage capacitor,

the second operating mode is a constant current operating mode, and

the second operating mode is a refresh phase of the high-voltage capacitor; and

a frequency modulator configured to switch between the first operating frequency and the second operating frequency to provide the load with the constant current gain and the constant voltage gain.

7 . The apparatus of claim 6 , wherein an impedance at the input stage is inductive in nature around an operating frequency of the resonant network stage.

8 . The apparatus of claim 6 , wherein the load is subject to load changes when powered.

9 . The apparatus of claim 6 , wherein the constant current gain and the constant voltage gain are each passed from the input stage and through the output stage.

10 . The apparatus of claim 6 , wherein the first operating frequency or the second operating frequency is a resonant frequency of the resonant network stage.

11 . A method for power conversion, comprising:

receiving, at an input stage, a direct current (DC) voltage, wherein the input stage is operating at a first operating frequency providing an alternating current (AC) voltage to an input of a resonant network stage without magnetically coupled resonant inductors;

providing, at the resonant network stage operating with the AC voltage, a constant current gain or a constant voltage gain, wherein the resonant network stage comprises at least one inductor and at least one capacitor;

generating, at an output stage electrically connected to a load having a first operating mode requiring a constant current and a second operating mode requiring a constant voltage, one of the constant current or the constant voltage, wherein

the load is a high-voltage capacitor,

the first operating mode is a charging phase of the high-voltage capacitor, and

the second operating mode is a refresh phase of the high-voltage capacitor;

changing, at the input stage, from the first operating frequency to a second operating frequency, wherein:

the input stage has the other of the constant current gain or the constant voltage gain at the second operating frequency,

the first operating frequency is a resonant frequency of the at least one inductor and the at least one capacitor,

the second operating frequency is between 1.27-1.90 times the resonant frequency,

the changing step is initiated by a control signal transmitted from a frequency modulator; and

generating, at the output stage for the load, the other of the constant current or the constant voltage.