In Rogue One, the Rebel Alliance was successful at their attempt to disrupt the deflector shield covering Scarif by destroying the Shield Gate. This allowed them to transmit radio messages to the fleet around the orbit. I see two major problems about this plot;
If the deflector shield was generated by the Shield Gate itself (which is strongly suggested as the Gate's destruction allowed the transmission to be made) why can't the Gate cover itself with the deflector shield? As the shield itself is there to prevent any unauthorized entry to the atmosphere, It should be able to hold even -lets say- an Imperial Star Destroyer crashing down on it. I don't think it would require much energy as the station itself is minuscule compared to the planet.
If the shield was generated by other means, destruction of the Shield Gate would have caused the whole planet to be sealed completely, covering even the only hole that can be punched in by the Shield Gate, effectively preventing the message to be transmitted by the devised plan.
I know Rogue One is not a movie trying to be very realistic, but is there any explanation that I've missed for how the Shield Gate can be destroyed in such a way as it happened in the movie or is it just a logical flaw in the script?