This is probably in dBc for DC offset, which is very like independent of sample rate.
The RF performance of the system is utterly dominated by the performance of the AD9361 chip, so you should also consult the Ad9361 data sheet. Sent from my iPhone > On Jun 6, 2020, at 5:21 AM, guowang qiu via USRP-users > <[email protected]> wrote: > > > Hi all, > > Does anyone know the definition of DC offset， which is plotted in > https://kb.ettus.com/images/c/cb/B200_RF_Performance.pdf, page 282? What is > the unit of DC offset? dB, dBc or dBm? What are the test conditions for this > performance test report? What is the sampling rate? How to test it? > We are still trying to solve this LO leakage issue. > >> On Fri, 29 May 2020 at 02:14, guowang qiu <[email protected]> wrote: >> Hi Marcus, >> >> Thank you for your reply. >> We have tried to set the magnitude of the modulating baseband signal from >> 0.1 to 0.6, it only affects the single tone signal strength and has no >> effect on the LO leakage. >> >> Best regards, >> Damon >> >>> On Fri, 29 May 2020 at 02:03, Marcus D Leech <[email protected]> >>> wrote: >>> Have you tried adjusting the magnitude of the modulating baseband signal? >>> Does that make a difference. >>> >>> My guess is that the leakage path isn’t through the VGA but rather through >>> something else in the package. In which case, no amount of software mods >>> will reduce it. >>> >>> Sent from my iPhone >>> >>> > On May 28, 2020, at 1:50 PM, guowang qiu via USRP-users >>> > <[email protected]> wrote: >>> > >>> > >>> > Hi all, >>> > >>> > We use USRP b210 as a signal generator, and adjust the tx gain to make >>> > the tx power from - 90dbm to 0dbm. USRP b210 works fine in 2.4GHz >>> > frequency band, but it has a very strong LO signal leakage at frequencies >>> > higher than 5GHz. >>> > In my test, the frequency of baseband (cos signal source) is set to >>> > 1MHz, so LO signal leakage and single tone signal can be easily >>> > distinguished. When the tx gain is set from 0 to 30 db, the strength of >>> > the LO signal hardly changes, and it is higher than the strength of the >>> > single tone signal. With the increase of tx gain, the strength of single >>> > tone signal will increase obviously. It seems that the local oscillator >>> > signal generated by the PLL in ad9361 bypasses the internal adjustable >>> > gain power amplifier and leaks directly to the antenna port. >>> > Is it possible to reduce the local leakage by modifying the UHD source >>> > code? >>> > >>> > Best regards, >>> > Damon >>> > _______________________________________________ >>> > USRP-users mailing list >>> > [email protected] >>> > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > _______________________________________________ > USRP-users mailing list > [email protected] > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
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