Hi Andrey,
What do you think about Alexander's suggestion ?
If we can find an affordable and convenient solution to connect to the
mezzanine board on the UmTRX, this would be great. It would allow us to
start the production of the first release of the UmTRX while we work on the
mezzanine board design.
If we do not have any other solution than using standard SMA connectors,
it would cost us quite a lot (connectors, balun, matching...) and it might
be a better solution to have the preselecter on the UmTRX PCB.
What do you think ?
:-)
On Sun, Mar 18, 2012 at 6:13 PM, Alexander Chemeris <
alexander.chemeris(a)gmail.com> wrote:
Hi Jean-Samuel and Andrey,
On Sun, Mar 18, 2012 at 18:25, Jean-Samuel Najnudel - BJT PARTNERS
SARL <jsn(a)bjtpartners.com> wrote:
However, I really believe the preselector should
remain on the UmTRX
main
PCB.
If we want to connect the preselector as an external mezzanine board, it
would cost us 5 extra SMA connectors (RX1in, RX1out, RX2in, RX2out,
clock
source), 2 RF switches before the superhet
filtering (to still be able
to
have switched diversity), several GPIO (serial
mixer control, RF
switches
control) and power supply.
This is possible but it would really cost much more than keeping the
preselector on the main PCB, especially as I believe, in practice, we
will
need almsot always this preselector, even not to
pass the GSM spec but
just
to be able to get a reasonably narrow sampling
bandwidth.
I would really suggest to keep the preselector in the main PCB and
populating or not the components (VCO/PLL, mixer and SAW IF).
Could we save on connectors if we use some RF side connector with many
pins? Nothing specific in mind, just thinking out loud.
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru