Hi all!
As far as I understand, the IF frequency should be 360
MHz as the UmSEL
uses
the TB0130A IF SAW filter. Its center frequency
is 360 MHz.
Yes, IF freq can be 360MHz (TB0130A) or 400MHz (TB0448A), matching
components there is for both variants (C32/C38, C46/C51).
By the way,
why do you say it would be a problem if IF was above 380 MHz
?
Because of interferences ? In this case, would it
still be problem if we
install the UmTRX + UmSEL boards inside an enclosure ?
Well, the original question was from Harald, but the concern was with
interference, yes.
I thought about these well known problems like strong mirror (image) freq's
with their interfer's, direct passthrough, LO-ANT emission and so on.
So, month ago I made measures of RF SAW filter TA1003A (see pics here).
Actually, I chose quite typical method - additional highpass filter (Z6 -
HFCN-740+).
I hope it can help to avoid most of those low-frequencies problems.
It will be much better if Taiyo Yuden RF filters would be used (those
filters also known as Fujitsu brand).
I think it depends on the type of enclosure we use.
Andrey should be
able to comment here.
Yes, of course, tower-mounted enclosures should be not only IP65, but also
EMI isolated.
Best regards,
Andrey Sviyazov.