Converts either the power, amplitude, or gain (amplitude ratio) spectrum to alternate formats including Log (decibel and dbm) and spectral density.


icon

Inputs/Outputs

  • cdbl.png impedance (Ohm) —

    reference impedance, in Ohm, used to convert spectrum to dBm.

  • cstr.png signal unit (V) —

    signal unit is a string containing the unit of the input time domain signal. The default setting is in volts.

    If the original signal unit was in volts, then this input should contain the letter V for volts.

  • c1ddbl.png Spectrum in —

    Spectrum in, on input, contains the spectrum of a time domain signal. It can be of type specified by the spectrum type selector.

  • cenum.png spectrum type —

    spectrum type specifies the type of spectrum wired to Spectrum. The default is 0.

    0
    Power (Vrms²)
    1
    Amplitude (Vrms)
    2
    Gain (amplitude ratio)
  • cenum.png log/linear —

    log/linear specifies linear or log spectrum output. The default is 1.

    0
    Linear
    1
    DB
    2
    DBm
  • cenum.png display unit —

    display unit is the output unit for the spectrum.

    You can set display unit to one of the values listed in the following table. The last four selections are amplitude spectral density (4,5) and power spectral density (6,7). The control cluster window constants contains constants for the selected window (from the Scaled Time Domain Window VI). You need this input only when you use the spectral density output formats (the last four output unit selections).

    0
    Vrms
    (volts rms)
    1
    Vpk
    (volts peak)
    2
    Vrms² volts
    (squared rms)
    3
    Vpk² volts
    (squared peak)
    4
    Vrms/sqrt(Hz) volts
    (rms per root Hz)
    5
    Vpk/sqrt(Hz) volts
    (peak per root Hz)
    6
    Vrms²/Hz volts
    (squared rms per Hz)
    7
    Vpk²/Hz volts
    (squared peak per Hz)
  • cdbl.png df —

    df is the line frequency interval of the input spectrum. The default is 1.0.

    You need this input only when you use the spectral density output formats (the last four display unit selections).

  • cnclst.png window constants —

    window constants contains the window constants for the selected window. You obtain window constants from the Scaled Time Domain Window VI.

    You need this input only when you use the spectral density output formats, the last four display unit selections. The default values are set to those of the rectangular window (no window).

  • cdbl.png eq noise BW —

    eq noise BW is the equivalent noise bandwidth (ENBW) of the window that was used. The default is 1.0.

    You can use this value to divide a sum of individual power spectra of the power spectrum or to compute the power in a given frequency span.

  • cdbl.png coherent gain —

    coherent gain is the inverse of the scaling factor applied to the window. The default is 1.0.

  • i1ddbl.png Spectrum out —

    Spectrum out, on output, contains the spectrum in the form specified by log/linear and display units.

  • istr.png spectrum unit —

    spectrum unit is a string containing the unit of the output spectrum.

    If the output spectrum is in decibels form, the unit is prepended by dB.