SPRZ519 august 2023 IWR2243
20GHz FM_CW_SYNCOUT/CLKOUT to FM_CW_SYNCIN Coupling in Cascade Use Case
IWR2243 ES1.0, ES1.1
There is ~18dB on chip isolation between the 20GHz FM_CW_SYNCOUT/CLKOUT and FM_CW_SYNCIN signals of the master device in cascade configuration. Apart from the stronger FM_CW_SYNCIN signal that is looped back to the master device, there is also a weaker signal coupled from SYNCOUT/CLKOUT directly to SYNCIN. Between the two signals, there is a delay due to PCB routing. This signal delay, caused by PCB routing, could lead to slight smearing of the object peak in the range dimension. The extent of smearing depends on the PCB routing delays of the 20GHz signals.
Keep the PCB routing delay of the 20GHz sync signals lower, to reduce the extent of smearing of the peak.