Can you give me a link to this 1.3 gbps radio product? I have some Alcatel radios with waveguides on a licensed band that only do 50 megabit that I would upgrade if there was something that could get more bits out of the same bandwidth and towers.
The 1.3 Gbps full duplex capacity assumes dual linear H&V polarization simultaneously, and assumes an 80 MHz wide FDD channel split such as in the 11 GHz high/low band plan. If you're in FCC part 101 regulatory band territory, and what frequency your existing radios use and existing path, you might not have that capacity. You could have an existing 40 MHz wide channel which will be half the capacity.
If you have a 50 Mbps radio product it's also very likely you're in a single polarity so you would need to recoordinate the path (around $1500) entirely to get the same MHz in the opposite polarity.