Greetings to all readers!
Many folk will have become familiar in recent years with the 'ZLPLL'
4GHz PLL board designed and sold by Wayne, ZL2BKC. They are rather
good.....provided, of course, that the reference signal is clean.
Well, Wayne has also been on the scent of the ADF5355 trail and has
produced his first (small) batch of what he now calls the '13G ZLPLL'.
Different to the earlier edition, the new design requires an off-board
reference, but like the earlier version it's fully programmable and it
works well way up past 13 GHz. For a digitally generated microwave PLL
at these sorts of frequencies, its PN seems
To generate a 13+ GHz output signal the chip uses a doubler that's
internal to the chip so the PLL 'fundamental' is also present in the
output spectrum, the desired output needing filtering if the F/2
component is a problem.
I have one of Wayne's early batch of 13G ZLPLLs here with me in the UK
and I propose, for possible comparison purposes, to have it with me at
the Crawley RT next month. Or I may be able to show it off to some
other folk between now and then..... (I do also have with me a very
good quality 10 MHz OCXO that is appropriately interfaced to the 13G
ZLPLL, so it can be a plug-and-play comparison.)
It should be interesting to compare the output signal from Wayne's
design, one that uses a reliably genuine chip set, with the Chinese ones
that some folk are obviously acquiring!
Cheers and 73,
--Doug Friend, M/VK4OE