RF output to 1W over a wide band (800 - 2700 MHz)

We have been asked to boost a product RF output to 1W over a wide band (800 - 2700 MHz). Which RF power transistor would you recommend? LDMOS? Bipolar?
Freescale? ST? others? In the past, we have used the NEC/CEL NE5520379A LDMOS at UHF, but it does not seem to go high enough in frequency.

Ancillary question: can we keep the supply to +5VDC, or is there a compelling reason to increase the supply voltage.

Any recommendation will be greatly appreciated.

Thank you