Rt duroid vs Alumina substrate

Hi,

I have an implementation of a psk transmitter system. What is a better choice of substrate for x-band kind of frequencies?

Option 1: RT duroid substrates
Option 2: Alumina substrates

if you have plastic packaged parts that need to be surface mount soldered, then the Duroid
If you have bare chips that need gold wirebonds, and you will be epoxy attaching the chips, then Alumina.