Parallax,

As Meindert alluded to, a small rotating focused array antenna in an
analog radar set is cheaper to make than a focused parabolic when the
gain of the parabolic is not needed. Really large stationary arrays are
used on radar that is computer focused, such as the USN Aegis missile
cruisers. They are 1 million watts on each side I think. Each element
in the array has it's own driver. Far too expensive for most pleasure
craft.

Also the frequency of radar is to far away from the cell frequencies for
it's antenna to be effective.

Regards, Ron