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Transition time

Category: Hardware
Product Number: ADRV9002
Software Version: Argo Navis 0.23.1

Is it possible to minimize transition time if only tx/rx switch is performed (without frequency switch)?

PLL Retune with hop table real-time process is used (Table 45. Frequency Hopping Modes of Operation, Reference Manual ADRV9001). 

Frequency Hopping Table Index is selected by DGPIO.

  • Hi GregTyma,

    It sounds like you're using the frequency hopping mode, but you are asking about not hopping frequencies. Can you please elaborate on your use-case?

    Kind Regards,
    Michał

  • Cześć Michał,

    1.) I would like to make several cycles rx/tx wihout  frequency hop.

    2.) Then frequency hop will be performed and adrv goto 1.)

    Pozdrawiam,

    Grzegorz

  • Hi Grzegorz,

    The short answer is no.

    When using the Frequency Hopping mode, the Rx Enable and Tx Enable signals change function and are referred to as Rx Setup and Tx Setup. These signals are sampled at a Hop Edge to determine which channel will be prepared for the next frame. If the hop edge is never provided, Rx/Tx Setup signals are never sampled, and so nothing will happen when they are toggled.

    One of the functions of the hop signal is to trigger the retuning of the LO for an upcoming frame, and since the ADRV9002 does not have internal logic to compare frequencies in the hopping table, it will always retune at a hop edge - even if the frequency is the same.

    Since you need a hop edge to switch between Rx and Tx, and the hop edge always causes the LO to re-tune (regardless of frequency), the transition time is an ever-present limitation in the Frequency Hopping mode, even when there's no real transition taking place.

    Kind Regards,
    Michał