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Tom,<br>
Thanks for writing. I've looked at the AD9361 and didn't think that
approach was really appropriate. I suppose at the heart of the
question is the architecture. At this point I'm rather presuming
that for some sufficiently high frequency/short wavelength we simply
have to face the fact that it is going to be an analog process. 12
bits seems quite a compromise and since it isn't it doesn't
represent a wideband approach, I think I tend to rule it out. This
is why I was thinking of converting the SDR to a high side fixed IF
and then filtering/converting with a clean, stepping LO. This could
be quite high performance, very fast (at least if a sufficiently
good varactor oscillator were used, of which Hittite offers some
possibilities) and also a reasonable price/cost point. My personal
interest is in having an all-band station with an SDR core that
could also be useful as instrumentation - but as a secondary
feature.<br>
<br>
I do think that agreement about an architecture might be the hardest
part since there can easily be different opinions, each justified on
some grounds, about this. I previously presented an "all band"
architecture and approach with transverter example at 10 GHz in an
old Ham Radio Magazine (see my web page for a bad copy of that
series of articles <a class="moz-txt-link-freetext" href="http://www.sonic.net/~n6gn">http://www.sonic.net/~n6gn</a>) article but I don't
think I'd want to do it that way again.<br>
<br>
For someone considering this sort of thing, how does it work, do
those interested go off on a private mailing or does some of the
early work go on within this list? I'm a total newbie here and have
never worked on a distributed, Open Source hardware project before.
Please redirect me if I'm being inappropriate.<br>
<br>
Glenn n6gn<br>
<br>
<br>
<div class="moz-cite-prefix">On 04/18/2015 06:14 PM, Tom McDermott
wrote:<br>
</div>
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cite="mid:CACO3nRQOm4ObZsnO4Sq7YB9GD4Mb0QZYiyV4smTGYxAgHmSmCA@mail.gmail.com"
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<div>
<div>Hi Glenn,<br>
<br>
</div>
I've not worked on this, but there are several ASICs that
provide bits-to-VHF/UHF and VHF/UHF-to-bits functions<br>
</div>
<div>for Software Defiend Radios.The Analog Devices AD9361 is
used on the Ettus B200 series SDR modules, has frequency<br>
coverage of 70 MHz to 6 GHz. It has 12-bit I & Q ADC's
and 12-bit I & Q DACs. The Rev E datasheet can be
downloaded<br>
from the AD webpage. It's in a 144-ball-grid array package.<br>
</div>
<br>
The LimeMicro LMS6002D is used on Nuand BladeRF 300 MHz to 3.8
GHz, and also has 12-bit ADCs and DACs.<br>
Lime micro has a newer chip planned (LMS8001 but not yet
released according to their webpage) which is planned<br>
to cover 100 KHz to 12 GHz. The Lime micro site doesn't have
information (that I can find) about the ADC / DAC sizes,<br>
nor can I find how to download those datasheets.<br>
</div>
<div><br>
</div>
<div>Whether the synthesizers are sufficiently clean, or the
DACs good enough would depend on the application of course.<br>
<br>
</div>
<div>-- Tom, N5EG<br>
<br>
</div>
<div><br>
<br>
</div>
<div><br>
<br>
<br>
</div>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Sat, Apr 18, 2015 at 2:50 PM, Glenn
Elmore <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:n6gn@sonic.net" target="_blank">n6gn@sonic.net</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">***** High
Performance Software Defined Radio Discussion List *****<br>
<br>
I'm a total newbie on this list. I hope this is an
appropriate posting.<br>
<br>
I'm wondering who might have worked on, or be working on,
frequency extensions for OpenHPSDR. Specifically, it seems
to me that an effort to extend the range of OpenHPSDR to
include 50 MHz - 6 GHz or higher must have been considered
if not attempted or accomplished by someone by this time.
Who has done this or might be interested in discussing it?<br>
<br>
I'm asking because, although new to OpenHPSDR with an
Angelia just freshly boxed up and working, I already see the
desirability of having coverage of 144,220,432,900,1296 and
2304. It seems to me that it would be a shame to limit this
to a conventional banded transverter approach and that doing
a conversion to a higher fixed IF followed by a down
conversion to cover,say 50 MHz to 6 GHz with a clean LO
up/down converter is an obvious choice. Allow this is a
"radio" project, continuous coverage would allow extension
of signal analyzer and vector network analysis throughout
this range and should be a pretty useful capability.<br>
<br>
Is this already being done by someone?<br>
<br>
Glenn Elmore<br>
n6gn<br>
<br>
<br>
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