I am planning to generate a sweep signal 12.5-13GHz using ADF5355 chip. The external reference of the synthesizer is fed by a sweep 125-130MHz generated by AD9910 DDS. This will be divided by 10 and given to PFD(12.5-13MHZ).The VCO output i am expecting a sweep of 12.5-13GHz with 500MHz BW. The problem I am facing is Sweep signal output is getting but the start freq and stop freq are not matching with requirement(ie. i am getting BW always less than 500MHz).I am using evaluation boards of two chips and the default loop BW for ADF5355 is 5KHz ,this i have not changed.Can any body help me to solve this issue.
Is this a correct method to generate 500MHZ signal using ADF5355?