Re: [Discuss-gnuradio] Dealing with TX/RX cross-talk on USRP

[Marcus Müller]

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Hi Ken,

first question: Which USRP/Daughterboard?
Maybe you should be asking this question on the
address@hidden mailing list; I'm going to go ahead and CC:
that list in my reply.

Basically, limited crosstalk is very hard to avoid; especially when
trying to deal with a weak RX while TX'ing high power you'll run into
problems you can't really circumvent due to the fact that RF signals
on the same PCB inevitable leak.

An RX LNA close to the antenna is usually the way to go here, or even
separating RX and TX.

You could try turning off the TX amp (gain to 0 and transmit
complex(0,0)), maybe that might help more than shutting down the flow
graph. If you manage to get success using that way, I'd greatly
appreciate you notifying the list.

Greetings,
Marcus


On 05.04.2014 22:01, Ken Adams wrote:
> I'm looking for tips on how to deal with the USRP TX/RX leakage.
> I'm transmitting with 30db (max) gain while trying to measure RSSI
> on the RX2 channel and experiencing about 40db of energy leakage
> from the TX/RX. My TX and RX chains are separated by 50MHz. Not
> sure how I can filter it out.
> 
> I'm thinking an antenna amp would work, so I could turn down the
> gain on the USRP; however, I want to try and avoid this.
> 
> Is there a fast way to switch between RX/TX channels? I did some
> quick tests with just turning off the TX channel flow graph, but
> the leakage takes a long time to dissipate.
> 
> 
> 
> _______________________________________________ Discuss-gnuradio
> mailing list address@hidden 
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> 
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