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resources:eval:user-guides:ad-fmcomms5-ebz:phase-sync [28 Oct 2019 16:58]
Travis Collins Add section on external vs internal LO
resources:eval:user-guides:ad-fmcomms5-ebz:phase-sync [14 Jan 2021 05:11]
Robin Getz user interwiki links
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 ==== Theory of Operation ==== ==== Theory of Operation ====
  
-The AD9361 transceiver has no built-in functionality to provide phase synchronization,​ but through external equipment and additional software and HDL phase alignment can be achieved across multiple transceiver chips. The calibration process is documented on this [[https://​wiki.analog.com/​resources/​eval/​user-guides/​ad-fmcomms5-ebz/​multi-chip-sync#​rf_phase_difference|wiki page]] and as well in this {{ :​resources:​tools-software:​linux-software:​doa_whitepaper.pdf|whitepage}} in the "Phase Alignment"​ discussion.+The AD9361 transceiver has no built-in functionality to provide phase synchronization,​ but through external equipment and additional software and HDL phase alignment can be achieved across multiple transceiver chips. The calibration process is documented on this [[/​resources/​eval/​user-guides/​ad-fmcomms5-ebz/​multi-chip-sync#​rf_phase_difference|wiki page]] and as well in this {{ :​resources:​tools-software:​linux-software:​doa_whitepaper.pdf|whitepage}} in the "Phase Alignment"​ discussion.
  
 The calibration procedures are implemented in both IIO-Scope and in a C library libad9361. It can be useful to see how they are implemented,​ or if end-users want additional debug to be extracted start at the following linked lines: The calibration procedures are implemented in both IIO-Scope and in a C library libad9361. It can be useful to see how they are implemented,​ or if end-users want additional debug to be extracted start at the following linked lines:
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 </m> </m>
  
-where <​m>​phi</​m>​ is the phase difference in degrees, <​m>​D</​m>​ is the distance in meters, <​m>​f</​m>​ is the frequency in hertz, and <​m>​c</​m>​ is the speed of light through a specific medium in meters per second. For FMComms5 <​m>​c=15 cm/​nsec</​m>​ which is in reference to FR4. Grab the [[https://​wiki.analog.com/​resources/​eval/​user-guides/​ad-fmcomms5-ebz/​hardware|board files]] for your specific revision to get the actual trace lengths for specific channels, which will determine <​m>​D</​m>​. Below is a plot of possible offsets across frequency and trace distance deltas.+where <​m>​phi</​m>​ is the phase difference in degrees, <​m>​D</​m>​ is the distance in meters, <​m>​f</​m>​ is the frequency in hertz, and <​m>​c</​m>​ is the speed of light through a specific medium in meters per second. For FMComms5 <​m>​c=15 cm/​nsec</​m>​ which is in reference to FR4. Grab the [[/​resources/​eval/​user-guides/​ad-fmcomms5-ebz/​hardware|board files]] for your specific revision to get the actual trace lengths for specific channels, which will determine <​m>​D</​m>​. Below is a plot of possible offsets across frequency and trace distance deltas.
 {{ :​resources:​tools-software:​linux-software:​phasediff.png?​nolink&​600 |Phase difference over frequency and distance}} {{ :​resources:​tools-software:​linux-software:​phasediff.png?​nolink&​600 |Phase difference over frequency and distance}}
  
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 </​code>​ </​code>​
  
-These phase estimates can be used to correct for trace mismatches, which can be applied through internal phase shifters with the HDL reference designs'​ [[https://​wiki.analog.com/​resources/​tools-software/​linux-drivers/​iio-adc/​axi-adc-hdl?​s[]=calibphase#​driver_testing|ADC]] and [[https://​wiki.analog.com/​resources/​tools-software/​linux-drivers/​iio-dds/​axi-dac-dds-hdl?​s[]=calibphase#​driver_testing|DAC cores]] by the calibphase properties.+These phase estimates can be used to correct for trace mismatches, which can be applied through internal phase shifters with the HDL reference designs'​ [[/​resources/​tools-software/​linux-drivers/​iio-adc/​axi-adc-hdl?​s[]=calibphase#​driver_testing|ADC]] and [[/​resources/​tools-software/​linux-drivers/​iio-dds/​axi-dac-dds-hdl?​s[]=calibphase#​driver_testing|DAC cores]] by the calibphase properties.
  
 ==== Phase Performance:​ Rev B vs. Rev C ==== ==== Phase Performance:​ Rev B vs. Rev C ====
resources/eval/user-guides/ad-fmcomms5-ebz/phase-sync.txt · Last modified: 14 Jan 2021 05:11 by Robin Getz