I have an eval for the ADF4371 and I'm using an HMC1031 eval to lock the 100MHz ref to a precision 10MHz OCXO. I am generating an 18GHz LO. As seen here:
The problem here is measured PN at 100Hz offset. With the on-board crystal reference PN @ 100Hz = -87dBc/Hz. With HMC1031 PN @ 100Hz = -67dBc/Hz.
Notable design parameters:
- HMC1031 Loop BW set to 10Hz as outlined in the spec sheet page 12. www.analog.com/.../hmc1031.pdf
- 100MHz VCXO, CVHD-950, CMOS output
- The measure slew rate from the HMC1031/CVHD-950 better than on board 100MHz reference.
Thanks in advance!
Adding part number to title for searching purposes
[edited by: aandrews at 9:32 AM (GMT -4) on 12 Oct 2020]