I am working on a 45MHz IF carrier recovery circuit using ADF4002. The Ref pin is used as the input of the circuit so the VCO can automatically track the input frequency.
The problem is that, my 45MHz IF is -50dBm and Zo=50ohms. I am currently using a 40dB gain amplifier as the driver for the PLL Ref pin, it works but the IF gain of my receiver become very high now (~80dB). It causes stability problems.
Does anyone have a clever way to do this?