DPD at 225 MHz

We have a radio application at 225 MHz, so we are externally down-converting the 9375 Tx to 225 MHz, and we are upconverting the radio's Rx to to the 9375 Rx (and ORx) input. Due do some frequency planning reasons, we chose to have the 9375 Tx output frequency different than the 9375 Rx input frequency, so the 9375 Tx and Rx LO frequencies are different. Considering that the Tx and ORx LO frequencies are different, will we have any issues implementing DPD on our transmitter? I figured I'd better ask this question in case there are some unforeseen "gotchas" that might restrict us with the DPD implementation given these circumstances.

Thank you,

Chris

  • 0
    •  Analog Employees 
    on Apr 9, 2021 2:16 PM

    Why are you implementing external up/down converters for down converting to 225MHz? You can use the transceiver to directly convert to 225MHz. Can you share a block diagram showing the up/down conversion? If the TX and ORX LO are set to different frequencies, then the data reaching the baseband will not be able to correlate between the TX and ORX samples. You can test that by checking the DPD performance.