Owning Palette: Signal Operation VIs
Requires: Full Development System
Unwraps the Phase array by eliminating discontinuities whose absolute values exceed either pi or 180, depending on the units you specify in phase unit.
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Phase is the input array of phases to unwrap. Use the phase unit input to specify the units. | ||||||||
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phase unit specifies the units for Phase and Unwrapped Phase.
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Unwrapped Phase returns Phase unwrapped. Use the phase unit input to specify the units. | ||||||||
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error returns any error or warning from the VI. You can wire error to the Error Cluster From Error Code VI to convert the error code or warning into an error cluster. |
The Unwrap Phase VI unwraps the Phase array by eliminating discontinuities. When the difference between two adjacent values in Phase exceeds pi, and phase unit is Radian in, radian out, this VI uses the following equation to calculate Unwrapped Phase:
where P_out is the Unwrapped Phase, P is the Phase, N is the length of Phase, and 
is the floor operation.
This VI uses similar equations to calculate Unwrapped Phase for the other units you specify in phase unit.
The following two graphs show the effects of unwrapping the phase. The first graph shows the original phase before you unwrap it, and the second graph shows the phase after you unwrap it.
You can apply the Unwrap Phase VI to the computed phase response of a linear time-invariant system. The phase response is defined as the complex angle of the frequency response of a system. You compute the phase response as angles within [–pi, pi], or, in other words, as angles within one circle of 2*pi radians. Because multiples of 2*pi wrap when you compute the phase response, often there are discontinuities in the phase response from one frequency bin to the next.