The animations are obtained using HP EEsof electromagnetic simulator Momentum. The layout of the phase shifter was used for simulations, while the InGaAs PIN diodes were replaced with the equivalent circiut elements. The presence of biasing network radial stubs did not affect the circuit performance and they were omitted in simulations to decrease the calculation time. The charge distribution was calculated as a function of time at the frequency of operation (f=93.5 GHz). The use of Momentum allowed us to account better for such significant at W-band elements as microstip discontinuities and airbridge and via hole parasitic inductances.