Specifies the method for performing the adjacent channel power (ACP) measurement.

Syntax

Namespace: NationalInstruments.RFmx.SpecAnMX

public enum RFmxSpecAnMXAcpMeasurementMethod

Members

NameValueDescription
Normal0

The ACP measurement acquires the spectrum using the same signal analyzer setting across frequency bands. Use this value when measurement speed is desirable over higher dynamic range.

DynamicRange1

The ACP measurement acquires the spectrum using the hardware-specific optimizations for different frequency bands. Supported Devices: PXIe-5665, PXIe-5668.

SequentialFft2

The ACP measurement acquires I/Q samples specified for a duration by the ACP Sweep Time method. These samples are divided into smaller chunks. The size of each chunk is defined by the SetSequentialFftSize(string, int) method. The overlap between the chunks is defined by the ACP FFT Overlap Mode method. FFT is computed on each of these chunks. The resultant FFTs are averaged to get the spectrum and is used to compute the ACP. Sequential FFT method should be used for the following scenarios.

  1. While performing fast ACP measurements by utilizing smaller FFT sizes. However, accuracy of the results may be reduced.  

  2. When measuring signals with time-varying spectral characteristics, sequential FFT with overlap mode set to Automatic should be used.  

  3. For accurate power measurements when the power characteristics of the signal vary over time, averaging is allowed.  


The following methods have limited support when you set the RFmxSpecAnMXAcpConfiguration.ConfigureMeasurementMethod method to SequentialFft.

  • The RFmxSpecAnMXAcpConfiguration.SetRbwFilterAutoBandwidth method will only support True value.  

  • The RFmxSpecAnMXAcpConfiguration.SetRbwFilterType method will only support FftBased value.  

  • The RFmxSpecAnMXAcpConfiguration.SetSweepTimeAuto method will only support False value.  

  • The RFmxSpecAnMXAcpConfiguration.SetAveragingCount method will only support a value greater than or equal to 1.  

  • The RFmxSpecAnMXAcpConfiguration.SetNumberOfAnalysisThreads method will only support a value of 1.  

  • The RFmxSpecAnMXAcpConfiguration.SetAmplitudeCorrectionType Method will only support a value of RFCenterFrequency.  

  • The RFmxSpecAnMXAcpConfiguration.SetOffsetRelativeAttenuation Method will only support 0.  

Note

For multi-span FFT, the averaging count should be 1.