My last remark on the cooling: with liquid cooling a large chunk of the aircraft fuselage could be used as a radiating surface: in essence you get a big, if inefficient radiator for free. At some point, it will simply scale better than air cooling even on a weight basis.
I almost exclusively follow naval radars. I‘be seen that HENSOLDT is aiming for a fully digital fighter AESA for the NGF in the 2030 timeframe.
What I know is that the SPY-6 radar is already a fully digital AESA (in S-band). This means independent control of each transmit element and independent analog to digital sampling at each receive element. Beamforming is done digitally. On the receive side, as many beams as necessary can be generated using computational post-processing techniques on the digitally sampled RF signals. This means vastly superior scan rates and ability to track significantly more targets compared to analog beamforming solutions, like the F-22 AESA radar or the SPY-1 PESA. Analog beamforming is limited by the resolution of phaseshifters in a way that DBF is not.
Furthermore, DBF by virtue of creating sub-beams provides super-resolution in azimuth and elevation. Combined with wide-bandwidth that allows submeter resolution in range and a powerful target discrimination capability. Such radars can create detailed 3D target maps and guide radar or IR guided missiles towards actual threats, instead of decoys.
Because each element in the array is coupled to a dedicated ADC, the dynamic range of the array is vastly increased. Compared to an analog array of say 1000 elements with one ADC, a digital array with 1000 ADCs will have a 1000 times greater dynamic range.
To deal with jamming and clutter, digital radars use various techniques like Space Time Adaptive Processing for example which allows the radar to single out the jammer signal arrival angle in post-processing and nullify it.
