Could you please help me decide if the HMC984 could be used as a phase detector? If not, are there any other suggestions? I cannot use the AD8302 because of the inability to measure phase near 180 degrees and also near zero degrees. I also do not think I can use the AD9901 because of the limited range of 270° at 70MHz.
Do you require having the phase detector output be analog? If not, have you seen the solution that uses an IQ Demodulator + ADC? There was an Analog Dialogue article written a few years back that shows how to implement this:
RF-to-Bits Solution Offers Precise Phase and Magnitude Data | Analog Devices
The phase detector can be analog or digital. I will be using a XILINX ZYNQ 7000 series system on a chip as a part of this system, which has the capability to do both. I saw that article, but the only problem is that the ADL5380 frequency range is from 400MHz-6GHz, which is above the frequency range I would like to measure.
Plus, I am already planning on using two AD8361s for the impedance magnitude measurement, but I need a solution for phase.
The HMC984 would work but there are a couple of considerations. The datasheet specifies PFD operation down to dc but doesn't mention this assumes square wave inputs. You would need a comparator circuit to perform the sine wave conversion. It gets a bit tricky because the HMC984 VCOp/n input was designed to mate with our companion HMC983 divider output:
The PFD charge pump output must be converted to a voltage for the Zynq A/D converter.
Thank you very much. I will order an HMC984 and a LTC6752-4 comparator to evaluate this solution.