Re: EMI
It's difficult to show a real circuit but there are some rules may help
1.) Appropriate decoupling has to use, not just putting 100nF, 10nF cap. etc
e.g.
At low frequency : choose 100nF, 10nF
At around 400MHz : e.g 220pF
At around 900MHz : e.g. 68pF
At around 1.8GHz : e.g 10pF
2.) Location
For example : Directly at P.A. Vdd, oscillator Vdd to gnd and try to govern the signal loop.
3.) Small resistor and shunt cap. to gnd can add at data line to suppress the level. Of course, it won't be as good as adding an EMI filter but much cheaper.
4.) Add stripline for and small shunt cap. for very high frequency data line.
5.) Careful component placement and layout.