Perhaps not 'modern', but years ago I worked on one that used a Travelling Wave Tube with 275kV on the collector, was 13 feet long, water cooled, and lived in a concrete pit lined with lead. Even with a .001% duty cycle, there was 5kW of RF, which would cook you!
When I did my radhaz course back in the '90s, we did an exercise on a 2MW S band radar
Try this one
Type 85 air defence search radar 12 S Band trasmitters through one head each of 4.5 - 8 MW.