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AFE7950: TX ERROR

Danilo A.
Mastermind 34030 points

Part Number: AFE7950

Hi Team,

Posting on behalf of our customer.

I'll share this E2E post with our customer so he can reply when needed.

We are currently using the afe7950, and 4GHz 200MHz OFDM communication signals are functioning well for both transmission and reception.

In another project, we are using a 4GHz carrier frequency raised to 4.87GHz.

Since we suspect errors caused by IQ imbalance when raising the frequency to 4.87GHz, we intend to apply both the QMC automatic and manual correction functions.

I am sending this email to request technical support regarding this issue. We have consulted various manuals and attempted different approaches, but we have not been able to find a solution regarding the configuration.

Currently, when demodulating the IQ using a Spectrum IQ Analyzer, the IQ waveform exhibits vertical mirroring, in-phase, and Q-axis disappearance at regular intervals.

Regards,

Danilo

  • 0
    TI__Genius 11115 points

    Hi Danilo, 

    AFE79xx devices are based on RF sampling architecture. In this architecture, RF mixing in done in digital and there would no IQ imbalance. 

    What is the sampling frequency of DAC in this test? Maybe higher Nyquist image is misunderstood as IQ imbalance. 

    Regards,

    Vijay

  • 0 in reply to Vijayendra Varma Siddamsetty
    TI__Mastermind 34030 points

    Hi Vijay,

    Thank you for your response. Please see our customer's follow up inquiry below.

    Since I am not aware of anything right now, please ask about the analysis later. First, please provide the procedures for QMC automatic and manual modes, as well as the SPI address settings. Even if you only use a direct NCO, IQ imbalance can sufficiently occur in the broadband filter.

    Regards,

    Danilo