Patent ID: 7970562

Claim:
An apparatus for monitoring power applied to a plasma load comprising: a first input configured to receive RF samples of power that is applied to the plasma load, the RF samples including information indicative of N parameter-value pairs, each of the N parameter-value pairs including a first parameter value and a second parameter value; a reflection coefficient module configured to: obtain, for each parameter-value pair, the product of the first parameter value and the complex conjugate of the second parameter value to obtain N products, each of the N products defined by a real part and an imaginary part; obtaining, for each parameter-value pair, a product of the second parameter value and the complex conjugate of the second parameter value to obtain N real numbers; calculating an average reflection coefficient Γ, the average reflection coefficient Γ being defined by the equation: Γ = < a > + < b > j < r > wherein <a> is an average of the real parts of the N products, <b> is an average of the imaginary parts of the N products and <r> is an average of the N real numbers.