Controllable Phase Shifter

This example shows an implementation of a first order phase shifting filter. The filter is characterized by the transfer function H(s) = (sC - gm1)/(sC + gm1). Double-click on the Set Design Parameters block to set the desired phase shift, amplitude of the input signal, and the frequency of the input signal. The block mask calls a function which sets the parameter values in the model workspace.

This model can be used to generate the filter frequency response. Using operational transconductance amplifiers permits digital control of the phase delay by varying the values of the current source gm1.

Model

Simulation Results from Simscape Logging

The plot below shows the input and output voltages of the phase shifting filter. The gain is 1, and the output signal is offset by the specified phase.

Frequency Response

The plot below shows frequency response of the phase shifting filter. The specified operating condition is shown on the frequency response plot.