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IWR6843ISK-ODS: how to control chirp bandwidth and start frequency by mmwave Studio

Takatoshi Tsuji
Expert 1550 points
Part Number: IWR6843ISK-ODS

Hello ,

I am playing IWR6843ISK-ODS by mmwave Studio, for evaluating RF output by spectrum analyzer. I can see RF level change according to setting of "O/p Pwr Backoff TX0" but bandwidth change is not observed by setting of "Ramp End Time", although bandwith(MHz) on the GUI become half (1788.92 to 899.46). Also, frequency change is not observed by setting of "Start Freq".

Please kindly advise how to contol those RF parameter.

Best regards,

Taka

  • 0
    TI__Mastermind 40495 points

    HI, there:

    The RF bandwidth will not change by RF start frequency setting. But you should see the change on the RF start frequency, right?  Otherwise, I will worry about your system setup.

    Here is a document explain about how to change the profile configuration http://www.ti.com/lit/an/swra553a/swra553a.pdf

    To change the RF bandwidth, you need to change the "frequency slope".  And you can keep the other parameter untouched.

    Best,

    Zigang  

  • 0 in reply to zigang Yang
    Expert 1550 points

    Hello Zigang,

    Thank you for your message. It seems it is not possible to apply 30 usec as "Ramp End Time"  with keeping 29.982MHz as frequency slope and 100usec as Idle time, although 30usec is available at LRR in table 1 Example Chirp Configurations for Typical Applications, according to swra553.pdf.

    Please kindly advise why 30usec & 29.982 MHz is NOT applied.

    Best regards,

    Taka

  • 0 in reply to Takatoshi Tsuji
    TI__Mastermind 40495 points

    Hi, Taka:

    You can not just change the ramp end time, because ramp end time = ADC sampling time + ADC start time + excess time. 

    ADC sampling time = numADCSample / ADCSamplingRate;

    Excess time needs to be larger than 1us. 

    You can find this information in FIgure 7 in the document I sent last time. 

    Best,

    Zigang