Looks like they are replacing the Decatur Genesis 2 radars with the new Decatur Genesis G3 series.
Looks like K band still with some more refined DSP settings
https://www.sdgcounties.ca/sites/default/files/2021-09/Decatur G3.pdf (page 7) G3™ Features
The G3™ is a modern traffic radar device offering many advanced
capabilities. It includes 32-bit floating point digital signal processing
(DSP), a versatile detachable computer/display unit, a Ka band
directional antenna, and an easy-to-use Infrared (IR) remote control.