The CinemachineFixedSignal Asset class is a simple 3D curve definition that lets you draw the curves yourself. Cinemachine Impulse either stretches or loops the curve to fit it in the attack-sustain-decay envelope, according to your specification in the Impulse Source.
To connect a fixed signal Asset to an Impulse Source, locate it in the Project view and drag it onto the Raw Signal field in the Impulse Source Inspector.
To create a new fixed signal Asset:
In the Impulse Source Inspector, click the gear icon next to the Raw Signal field and choose New Fixed Signal.
When prompted, give the new Asset a name and choose a location to save it to.
Locate the new Asset in the Project view and select it to open the Fixed Signal Inspector.
The Inspector displays a preview of the curve for each axis. Click a preview pane to define your own curve for that axis. If you leave it blank, there is no movement along that axis.
Click one of the thumbnails at the bottom of the window to apply a curve preset. You can then edit the curve: