High-voltage RF generator for ion optics

An analytical instrument comprising:

• an RF generator configured to generate an RF voltage having a first frequency;
• a first transformer having a primary winding and a secondary winding, wherein the RF generator is coupled to the primary winding of the first transformer;
• a first ion optical device, wherein the first ion optical device is coupled to the secondary winding of the first transformer;
• a second transformer having a primary winding and a secondary winding;
• an amplifier having an input and an output, wherein a first signal from the RF generator or from the first transformer is provided to the input of the amplifier, and wherein the output of the amplifier is coupled to the primary winding of the second transformer;
• a second ion optical device, wherein the second ion optical device is coupled to the secondary winding of the second transformer;
• and
• a phase difference detector having a first input and a second input, wherein the phase difference detector unit is configured to output a DC current or voltage proportional to a phase difference between signals received at the first and second inputs, wherein the first signal is provided to the first input of the phase difference detector, and wherein a second signal from the second transformer is provided to the second input of the phase difference detector unit;
• wherein the secondary winding of the first transformer and the first ion optical device form a primary LC circuit having a first resonant frequency, and wherein the first frequency of the RF voltage generated by the RF generator is configured to correspond to the first resonant frequency;
• wherein the secondary winding of the second transformer and the second ion optical device form a secondary LC circuit having a second resonant frequency, wherein the analytical instrument is configured such that at least part of the secondary LC circuit has a variable inductance, and wherein the analytical instrument is configured such that the inductance of the at least part of the secondary LC circuit varies in dependence on a magnitude of an output DC current or voltage of the phase difference detector unit such that the second resonant frequency varies in dependence on the magnitude of the output DC current or voltage of the phase difference detector unit.