Well the origin is not yet clear, it can be Turkish (may be tech provided from the Israelis) or from may be Singapore. As the Turkish F-5s have been upgraded by Israelis & Singapore Aerospace Technologies. Turkish F-5s have Israeli radar and majority of the avionics are from Israel, so may be the Israelis had transferred some tech to Turks and we got it from them or something like that, as these same antennas were on the SA Cheetas which also got upgraded by Israels, so my guess is there is some link with the Israelis.
And as for discussion with santro, well few things are for the time being classified, but good thing is that JF-17 can data link with both Erieye as well as Chinese AEW&Cs, same case with rest of the fighters except for the F-16s which will only talk to Erieyes. And Chinese and Erieyes won't data transfer with each other, rather only voice communication and their roles are also different, that is all i can say for now.
