Power Distortion-Based Servo Control Systems for Frequency Tuning RF Power Sources

• US 20140028389A1
• Filed: 10/02/2013
• Published: 01/30/2014
• Est. Priority Date: 12/29/2011
• Status: Active Grant

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: COUMOU, David J.
• Granted Patent: US 9,041,471 B2
• Time in Patent Office: Days
• US Class Current: 330/109
• CPC Class Codes: H03F 1/32 Modifications of amplifiers to reduce non-linear distortion by negative feedback H03F1/34
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 3/189 High-frequency amplifiers, e.g. radio frequency amplifiers
• CPC Class Codes: H03F 3/191 Tuned amplifiers H03F3/193, H03F3/195 take precedence

Abstract

A radio frequency system includes a power amplifier that outputs a radio frequency signal to a matching network via a transmission line between the power amplifier and the matching network. A sensor monitors the radio frequency signal and generates first sensor signals based on the radio frequency signal. A distortion module determines a first distortion value according to at least one of (i) a sinusoidal function of the first sensor signals and (ii) a cross-correlation function of the first sensor signals. A first correction circuit (i) generates a first impedance tuning value based on the first distortion value and a first predetermined value, and (ii) provides feedforward control of impedance matching performed within the matching network including outputting the first impedance tuning value to one of the power amplifier and the matching network.

Claims

1. A radio frequency system comprising:

a power amplifier that outputs a radio frequency signal to a matching network via a transmission line between the power amplifier and the matching network;

a sensor monitoring the radio frequency signal and generating first sensor signals based on the radio frequency signal;

a distortion module determining a first distortion value according to a sinusoidal function of the first sensor signals; and

a first correction circuit (i) generating a first impedance tuning value based on the first distortion value and a first predetermined value, and (ii) providing feedforward control of impedance matching performed within the matching network including outputting the first impedance tuning value to one of the power amplifier and the matching network.