2D Ideal Particle System Function for 2D Lissajous FFP Motion. Successive frequency components of the ideal particle system function for 2D Lissajous FFP motion with an x/z frequency ratio of 24/25. The first 99 frequency components are shown for the two receive orientations. The first upper left rectangle displays the Lissajous pattern. Multiples of the drive frequencies are indicated by red frames. Their shape closely resembles the 1D system function shown in figure 7. Green, blue, and orange frames indicate components with identical spatial pattern. The two graphs at the left show the maximum intensity values encountered in the respective system function components.