ADRF6755 RF output

Hi, 

After setting the attenuation value to 0 dBm, I am getting -24dBm for 1GHz.I have attached schema and other details. If any suggestion you have, let me know.

1)REFF input CLK And PFD set -40Mhz (/2,bubbler&5bit Rdivider all are disabled.)

2)output frequency range-950Mhz to 2150Mhz

3)loop filter values same as ADRF EVM 

4)Register CR9[7:4] = 0xF (5mA cp output current setted)