Right 180nm us a good choice for what you want to do.
Europractice also offers a miniasic version for most of their shuttles. The miniasic
allows smaller block sizes than the regular MPW shuttle. For TSMC180nm-MS/RF the
miniasic blk size is 1.66mm x 1.66mm ~2.755mm^2 and the cost for ~40 bare dies
is 3100euro. Which is ~$3,750 US dollars. So that comes out to about $1,360 for
40 bare dies. And you can order 40 extra dies for a another $1-2K. The regular
TSMC180-MS/RF shuttle is 5mm x 5mm and that would run about
The TSMC180 MS/RF PDK comes with std-cell and IO libraries, so is suitable for the
mixed signal design you mentioned. See the Europractice 2020 prices and schedule at:
https://europractice-ic.com/schedules-prices/
They have also posted their 2021 schedule, but not the prices at:
https://europractice-ic.com/schedules-prices/schedules-2021-2
Muse semiconductor and MOSIS also have TSMC180-MS/RF shuttles and miniasics.
Respond if you need more information, I have run shuttles and miniascis with all three
of these aggregators.
-steve