RE: Dual-Frequency simultaneously receiver using one USRP 2901

[address@hidden]

Yes and no.  Yes, you can receive two different channels, but in this device they have a common frequency synthesizer, so you have to tune between the two signals.  In your case the frequency difference is much more than the capture bandwidth.  There is a note in the data sheet:

NoteThe USRP-2901 has two local oscillators, one for the transmit (Tx) channels and one for the receive (Rx) channels. While different frequencies can be used for the Tx and Rx channels, the two Tx channels are locked to the same frequency, and the two Rx channels are locked to the same frequency.

 

 

 

From: discuss-gnuradio-bounces+kent.torell=gd-ms.com@gnu.org <discuss-gnuradio-bounces+kent.torell=gd-ms.com@gnu.org> On Behalf Of claudio.franchini@tlrnet.eu
Sent: Thursday, January 26, 2023 7:02 AM
To: 'David Dima' <daviddimavd@gmail.com>
Cc: discuss-gnuradio@gnu.org
Subject: RE: Dual-Frequency simultaneously receiver using one USRP 2901

 

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Hi, David,

the USRP 2901 is a dual channel RTX, so it can definitely receive two different channels at the same time, i.e. two different (carrier) frequencies. We just have to see the management through GNURadio, but here I refer to those who are more experienced than me with the software.

In principle you can put a split downstream of the antenna and then go on the two channel inputs, however keep in mind that with the splitter you introduce a signal loss that can go from 3.5dB to 5dB or more, depending on the splitter (3dB is anyway theoretical and unavoidable). This means that, not only do you have the loss value of the splitter on the signal level, but even more marked the fact that it worsens the noise figure by the same amount. If the dynamics is enough it's fine, otherwise it would be better to use separate antennas. Be careful not to go into transmission on a channel if you use a splitter and a single antenna!

 

Claudio

 

From: discuss-gnuradio-bounces+claudio.franchini=tlrnet.eu@gnu.org <discuss-gnuradio-bounces+claudio.franchini=tlrnet.eu@gnu.org> On Behalf Of David Dima
Sent: Thursday, January 26, 2023 9:33 AM
To: discuss-gnuradio@gnu.org
Subject: Dual-Frequency simultaneously receiver using one USRP 2901

 

Hi,

I am trying to simultaneously receive two signals from Galileo at different frequencies (1176.45 MHz and 1575.42 MHz) using a single antenna, a USRP 2901, and the GNU Radio Companion (GRC) software. I would like to know if it is possible to do this with a single USRP, that is, is the USRP able to receive two different frequencies at the same time?

In the affirmative case, is it ok to just split the incoming signal from the antenna with a splitter and connect it to two ports the USRP?

Many thanks in advance,

David