I programmed the registers as shown in 1000-registers.JPG and I got 1000-spe-ana.jpg on the spectume analyzer but when I changed the frequency to 850-registers.JPG, then I got 850-spe-ana.JPG.... could you explain why? Thanks! Gio
Check to see that both RF outputs are terminated in 50 Ohm loads. Unbalanced loads can lead to a degraded output spectrum.
I have 50Ohm loads connected to the J3, J4, J5. J2 is connetected to the Spectrum A.
I try to use the chip in integer-N as you can see from the registers.
The second eval board behaves in the same way, so it shouldn't be an hardware problem.
Any further suggestions?
May be there are overload with 50 load at the J3... and + 50 ohms at Spectrum A?
There must be a reflective load somewhere. These can drive the output stage into saturation leading to a degraded RF output.
Try using a smaller output power setting to see if the spectrum clears up.
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