The EF was developed for cold war style air combats and that's why the development was aimed on comparable air superioirty fiighters and why the most important capabilities till today are, big radar, high speed, maximum BVR missile load and the high maneuverability of course. All this makes it to one of the best fighters in this field against all 4th, or older gen fighters, but in future, things will be different!
Even the EF consortium understood that radar will not be very useful against 5th gen fighters and that's why other features are important to detect the enemy and that's why they also added latest IRST and EWS capabilities besides the radar:
As you can see, according the EF consortium itself, passive detection and passive SA are the important capabilities for future air combats and not the active radar!
Which brings us directly to the Rafale, where you first have to understand, that the diameter of Rafales radar is not limited by the size of the nose but by the integration of FSO!
As you can see on the following pics, the FSO is fully integrated into the nose, which takes away internal space, that otherwise could be used for a bigger radar. The PIRATE of the EF on the other side, is mounted on the side of the nose, as an external part and even the retractable refuelling probe is not fully integrated, to safe more internal space:
Some more pics of the RBE 2 / FSO combo:
Especially this last pic, of the back side shows the difference of the diameter that the radar has in the front and that it could have without the FSO.
Now why would the French limit their fighter in such this way and reduce the radar detection range?
Because they understood from the start, that passive detection features and fully passive SA as an equal alternative to the radar will be important for the future!
That why they compromised purposely on radar diameter/detection range (which doesn't tell you much about how capable the radar is), to integrate more passive sensors (IR and TV channel), as well as focus on fully passive SA and sophisticated geolocating capabilities, to remain less observable, but fully capable in air combats as well as ground strikes, without the need to use an active radar!
These capabilities had impressed in several exercises, but now even in real combat in Libya, where numerous reports are praising the the FSO / SPECTRA combo as the key advantage of Rafale! Be it the penetration of enemy airspace in reconnaissance, air superiority, or strike roles (while Libyan air defence and air force were fully operational), the long range target identification capabilities of FSO, or the passive geolocation and weapon cueing capabilities of SPECTRA in SEAD. All this was done today and with the F3 version, while India will get even the F3+ with further improved passive sensors and more capabilities in addition to the AESA radar.
