AD5933 synchronizing different frequency sweep ranges issue

Hello, everyone, I am using AD5933 with Arduino, I can measure impedance from 47ohm to 1Mohm in the frequency range(10Hz-100kHz). I have measured impedance at different frequency ranges by using different MCLK external programmable oscillator DSL1077. Now I want to measure impedance at whole frequency sweep at a time. I have implemented logarithmic frequency sweep, so for this, I am changing my start frequency register every time for performing logarithmic frequency sweep by setting increment frequency register and number of increment register as zero.
when I have applied from 10Hz-100 kHz I am not getting the accurate result I have uploaded data in terms of real and imaginary (i have measured 47-ohm resistor with 47-ohm RFB). Although the clock frequency is changing with respect to frequency sweep. if I apply each frequency sweep separately like (5kHz-100Khz) OR (10Hz-20) etc, I am getting good results. 

how can I measure whole frequency sweep accurately, do I need to measure gain factor for each sweep separately.?
my output excitation voltage is 1.98Vp-p, and the PGA gain is X1.



add output and feedback resistor value
[edited by: aitzaz at 12:53 AM (GMT 0) on 9 Jul 2019]