SPRACP3C November 2019 – December 2021 AWR6843 , AWR6843AOP , IWR1443 , IWR1642 , IWR6443 , IWR6843 , IWR6843AOP
Problem Statement: Spurious EMI showing at multiples of 14.4 GHz on the non-AOP module
Solution: Use of metal shield or RF absorber.
Deep Dive:
All the clocks in the system are derived from the 14.4-Ghz APLL. Figure 5-1 shows the root clock tree within the radar device. During test and certification, 14.4-GHz peak and harmonics of this frequency may show up as spurious emissions, as shown in Figure 5-2, the 2nd harmonics of 14.4 Ghz (28.8 GHz) causing radiated emission beyond the regulatory limit.
This issue does not apply to the Antenna on Package (AOP) devices and shielding is inapplicable