On Thu, Jul 28, 2011 at 6:02 PM, Matt Ettus <m...@ettus.com> wrote: > On 07/28/2011 02:58 AM, Gaetano Mendola wrote: >> Hi all, >> I'm transmitting my signal with 5Mhz bandwidth with a carrier of 70Mhz, >> analyzing output spectrum I see some "replicas" outside the bandwidth >> (see attached image). >> I'm using a WBX, will the uhd::usrp::multi_usrp::set_tx_bandwidth remove >> those >> replicas? I don't see any filter after the I/Q modulator (ADL5386). >> >> Is this intended ? > > > Those are odd harmonics, which are expected. In any application where > you are transmitting over the air with significant power, you will need > to filter out the odd-order harmonics. > > The WBX has such wide frequency coverage that it is impractical to have > enough filters to do this for the whole range. This is why we have the > grand-daughterboard -- you can either modify the filter on there > (minicircuits has a whole range of filters to cover the band), or make a > custom filter board for your specific needs.
Thank you for the explanation, I did immagine that seeing that there is no filter after the I/Q modulator I did ask just to be sure. Regards Gaetano -- cpp-today.blogspot.com _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio