i'm using HMC 439 for PLL Application.Right now i'm applying REF Frequency :100 MHz and Varying VCO Frequency for testing purpose to check variation in the Tuned voltage.OP-amp that i'm using is THS4031 but problem i'm facing is that voltage is not varying that much. I want to generate frequency at 6.9GHz . right now Frequency getting between 6.97 GHz to 7 GHz. Loop filter is design using ADisim PLL please provide me suggestion how set gain of op-amp. and alternate OP-Amp for it. Below i mentioned tuning voltage requirement at 6.9GHz frequency.It is possible to generate 3.05 V? Please provide suggestion.
Loop Bw: 10MHz
VCO: HMC 505
Tunning voltage at 6.9 GHZ: 3.05 V