Apply FFT to Report Functions
The choices in the Perform FFT on Traces in Reports dialog include:
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ang_deg |
Angle (phase) of a complex number, cut at +/-180 |
| ang_deg_val | Angle (phase of a complex number in unitless degree values. Returns simple numbers. |
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ang_rad |
Angle in radians |
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arg |
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cang_deg |
Cumulative angle (phase) of the first parameter (a complex number) in degrees, along the second parameter (typically sweep variable). Returns a double precision value cut at +/-180. |
| cang_deg_val | Cumulative angle (phase) of the first parameter of the selected simulation quantity in unitless degree values. Returns simple numbers. |
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cang_rad |
Cumulative angle of the first parameter in radians along a second parameter (typically a sweep variable) Returns a double precision value. |
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dB(x) |
20*log10(|x|) |
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dB 10normalize |
10*log [normalize(mag(x))] |
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dB 20normalize |
20*log [normalize(mag(x))] |
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dBc |
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| GetGroupDelay | |
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im |
Imaginary part of the complex number |
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mag |
Magnitude of the complex number |
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normalize |
Divides each value within a trace by the maximum value of the trace. ex. normalize(mag(x)) |
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re |
Real part of the complex number |
The evaluated value of an expression is always interpreted in SI units. However, when an angle quantity is plotted in a report, you have the option to plot values in units other than SI. If you want to plot the polar angle of a complex simulation result, S11 say, you can choose between ang_deg(S11) and ang_rad(S11). Both of these return the exact same angle quantity but in degree and radian units respectively.
Note that when used in expressions, some surprising outcomes might result. For example, the expression "1+ang_deg(S11)" represents an ‘angle’ and the number "1" is treated as "1 rad". The angle SI unit is attached to any unitless number that is added/subtracted from an angle value. If you want to treat "1" as degrees, make it explicit and use "1deg + ang_deg(S11)" instead.
If you are interested in unitless degree values, two additional functions exist: ang_deg_val(S11) and cang_deg_val(S11). These return simple numbers and are treated as such by any expression. If the complex S11 lies on the positive Y axis say, ang_deg_val(S11) would be 90 and "1 + ang_deg_val(S11)" will be 91.