Configures the degree of the polynomial and the cost-function, for approximating the measured AM-to-PM response of the device under test.

Syntax

int32 __stdcall RFmxSpecAn_AMPMCfgAMToPMCurveFit(niRFmxInstrHandle instrumentHandle, char selectorString[], int32 amToPMCurveFitOrder, int32 amToPMCurveFitType)

Parameters

NameDirectionTypeDescription
instrumentHandle[in]niRFmxInstrHandle

This parameter specifies the RFmx session refnum. Instrument Handle In is obtained from the RFmxInstr_Initialize function.

selectorString[in]char

This parameter specifies a Selector String comprising of the signal name. If you do not specify the signal name, the default signal instance is used. The default value is "" (empty string).
Example:
""
"signal::sig1"
You can use the RFmxSpecAn_BuildSignalString function to build the selector string.

amToPMCurveFitOrder[in]int32

This parameter specifies the degree of the polynomial used to approximate the AM-to-PM characteristic of the device under test. The default value is 7.

amToPMCurveFitType[in]int32

This parameter specifies the polynomial approximation cost-function of the device under test AM-to-PM characteristic. The default value is Least Absolute Residual.

Name

Value

Description

RFMXSPECAN_VAL_AMPM_AM_TO_PM_CURVE_FIT_TYPE_LEAST_SQUARE

0 (0x0)

The measurement minimizes the energy of the polynomial approximation error.

RFMXSPECAN_VAL_AMPM_AM_TO_PM_CURVE_FIT_TYPE_LEAST_ABSOLUTE_RESIDUAL

1 (0x1)

The measurement minimizes the magnitude of the polynomial approximation error.

RFMXSPECAN_VAL_AMPM_AM_TO_PM_CURVE_FIT_TYPE_BISQUARE

2 (0x2)

The measurement excludes the effect of data outliers while minimizing the energy of the polynomial approximation error.

Returns

Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an RFmx function to determine if an error has occurred.

To obtain a text description of the status code and additional information about the error condition, call the RFmxSpecAn_GetError function.

The general meaning of the status code is as follows:

Value

Meaning

0

Success

Positive Values

Warnings

Negative Values

Errors