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university:tools:pluto:users:non_quad [25 Jul 2019 22:58] – fix Robin Getz | university:tools:pluto:users:non_quad [26 Jul 2019 17:14] – [UHD] Robin Getz | ||
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===== Sending the data ===== | ===== Sending the data ===== | ||
- | We can send that out the RF, by disabling loopback and setting the Rx and Tx LO to the same value. The results shown during the receiving section are RF loopback (The BIST Loopback setting is set to '' | + | We can send that out the RF, by disabling loopback and setting the Rx and Tx LO to the same value. The results shown during the receiving section are RF loopback (The BIST Loopback setting is set to '' |
====== Receiving a " | ====== Receiving a " | ||
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| {{: | | {{: | ||
- | Its easier to look at this in the time domain. Here the amplitude difference between I & Q is random based on the random difference between the phase of the Rx and Tx PLL. This is indeed completely random, and will change any time either PLL settings are touched. Moving one LO to a different | + | Its easier to look at this in the time domain. Here the amplitude difference between I & Q is random based on the random difference between the phase of the Rx and Tx PLL. This is indeed completely random and will change any time either PLL settings are touched. Moving one LO to a different |
^ Analog Loopback, Time Domain, I & Q Data, ACG On, Quadrature tracking On | ^ Analog Loopback, Time Domain, I & Q Data, ACG On, Quadrature tracking On | ||
| {{: | | {{: | ||
- | You can change this magnitude difference digitally by post processing the sampled data, by using the Phase Rotation control in IIO oscilloscope. It doesn' | + | You can change this magnitude difference digitally by post-processing the sampled data, by using the Phase Rotation control in IIO oscilloscope. It doesn' |
^ Analog Loopback, Time Domain, I & Q Data ^ | ^ Analog Loopback, Time Domain, I & Q Data ^ | ||
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| {{ : | | {{ : | ||
- | Here the green signal is the '' | + | Here the green signal is the '' |
The first step is to understand that the ACG is reacting to magnitude changes caused by the Quadrature tracking corrections. Turning the ACG to manual mode can help isolate the effects of the IQ Correction. Here is a picture of the same setup with the ACG set to manual mode. | The first step is to understand that the ACG is reacting to magnitude changes caused by the Quadrature tracking corrections. Turning the ACG to manual mode can help isolate the effects of the IQ Correction. Here is a picture of the same setup with the ACG set to manual mode. | ||
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For those using a National Instruments USRP Radio, this can be controlled via '' | For those using a National Instruments USRP Radio, this can be controlled via '' | ||
+ | ===== SDRangel ===== | ||
+ | |||
+ | SDRAngel also can turn on/off Quadrature tracking with it's Hardware control buttons. | ||
+ | |||
+ | {{: | ||
+ | |||
+ | * '' | ||
+ | * '' | ||
+ | * '' | ||
===== Scope ===== | ===== Scope ===== | ||
This issue will exist on all integrated devices which have some sort of Quadrature tracking feature, including all hardware based on ADI and [[https:// | This issue will exist on all integrated devices which have some sort of Quadrature tracking feature, including all hardware based on ADI and [[https:// |