Looks great, thank you! Your blog is great collection of information and you have managed to make it extremely easily readable for such complex matters.
Some comments after very quickly glancing through it:
While Parabolic , Gregorian and Cassegrain antennas all have very high gain ( small main beamwidth) relative to aperture size .However , they all share the same disadvantages include: high sidelobes (make radars susceptible to low RCS targets and ground clutter)
You could also mention here that higher side lobe levels make radar also more detectable with ESM systems (more energy towards them to work with) and more susceptible to jamming as jamming signal gets through to receiver more easily (side lobe jamming).
About side lobes: Maybe you should mention that there are side lobes in both transmit and receive conditions. Transmit side lobes means unwanted energy is sent outside the main beam (lobe). This makes the radar more detectable by RWR/ESM systems. In receive condition unwanted energy is received from outside the main lobe. This can be intentional jamming or ground returns which both affect radar performance and ability to pick up targets.