Measurement system configured for measurements at non-calibrated frequencies
A tuner system for conducting measurements on a Device Under Test (DUT) includes at least one passive tuner, and calibration data for the at least one passive tuner including a set of s-parameters at a set of calibration frequencies. A measurement on the DUT is done at a measurement frequency at which the at least one passive tuner is not calibrated. The tuner s-parameters at the measurement frequency are determined by interpolation between or extrapolation from the s-parameters at calibration frequencies.
1. A tuner system for conducting measurements on a Device Under Test (DUT), comprising:
at least one passive tuner including a tuner transmission line and at least one capacitive probe which is movable axially along the tuner transmission line;
calibration data for the at least one passive tuner comprising a set of s-parameters at a set of calibration frequencies,
where a measurement on the DUT is done at a non-calibrated measurement frequency at which the said at least one passive tuner is not calibrated; and
wherein the tuner s-parameters at said measurement frequency are determined by interpolation between or extrapolation from the s-parameters at said calibration frequencies; and
wherein calibration data at the non-calibrated measurement frequency is determined by model-based interpolation or extrapolation comprising a model with components whose values vary in a prescribed manner versus tuner state and versus frequency, wherein said model-based interpolation or extrapolation employs a capacitance model of a tuner or said model-based interpolation or extrapolation employs a transmission line model of a tuner.
2. The tuner system of claim 1 wherein said model-based interpolation or extrapolation employs a capacitance model of a tuner.
3. The tuner system of claim 1 wherein said model-based interpolation or extrapolation employs a transmission line model of a tuner.
4. A tuner system for conducting measurements on a Device Under Test (DUT) having an input and an output, comprising:
an RF source for generating signals to drive the DUT input;
a controller;
at least one passive tuner including a tuner transmission line and at least one capacitive probe which is movable axially along the tuner transmission line;
calibration data for the at least one passive tuner comprising a set of s-parameters at a set of calibration frequencies,
a digital memory for storing said calibration data;
a measurement device coupled to the DUT output;
where the controller is configured to control the RF source and the at least one passive tuner to conduct a measurement on the DUT at a non-calibrated measurement frequency at which said at least one passive tuner is not calibrated; and
wherein the tuner s-parameters at said non-calibrated measurement frequency are determined by interpolation between or extrapolation from the s-parameters at said calibration frequencies; and
wherein calibration data at the non-calibrated measurement frequency is determined by model-based interpolation or extrapolation comprising a model with components whose values vary in a prescribed manner versus tuner state and versus frequency, wherein said model-based interpolation or extrapolation employs a capacitance model of a tuner or said model-based interpolation or extrapolation employs a transmission line model of a tuner.
5. The tuner system of claim 4 wherein said model-based interpolation or extrapolation employs a capacitance model of a tuner.
6. The tuner system of claim 4 wherein said model-based interpolation or extrapolation employs a transmission line model of a tuner.