SWRZ162 May   2024 IWR2944

 

  1.   1
  2. 1Introduction
  3. 2Device Nomenclature
  4. 3Device Markings
  5. 4Advisory to Silicon Variant / Revision Map
  6. 5Known Design Exceptions to Functional Specifications
    1.     MSS#25
    2.     MSS#27
    3.     MSS#28
    4.     MSS#29
    5.     MSS#30
    6.     MSS#33
    7.     MSS#40
    8. 5.1  MSS#46
    9. 5.2  MSS#48
    10. 5.3  MSS#49
    11. 5.4  MSS#52
    12. 5.5  MSS#53
    13. 5.6  MSS#54
    14. 5.7  MSS#55
    15. 5.8  MSS#56
    16. 5.9  MSS#57
    17. 5.10 MSS#58
    18. 5.11 MSS#59
    19. 5.12 MSS#60
    20. 5.13 MSS#61
    21. 5.14 MSS#62
    22. 5.15 ANA#12A
    23.     ANA#32A
    24.     ANA#33A
    25.     ANA#34A
    26.     ANA#35A
    27.     ANA#36
    28.     ANA#37A
    29.     ANA#38A
    30.     ANA#39
    31.     ANA#43
    32.     ANA#44
    33.     ANA#45
    34.     ANA#46
    35.     ANA#47
  7.   Trademarks
  8. 6Revision History

ANA#12A

Second Harmonic (HD2) Present in the Receiver

Revision(s) Affected:

IWR2944 ES1.0, ES2.0

Description:

There is a finite isolation between the RF pins/package and the FMCW synthesizer. This can create spurious tones at the synthesizer output and lead to appearance of 2nd order harmonics and inter-modulations of expected IF frequencies at RX ADC output. The amplitude of the 2nd harmonic could be as high as -55 dBc, referenced to the power level of the intended tone at the LNA input.

Workaround(s):

No workaround available at this time. However, in many typical radar use cases the HD2 does not affect the system performance due to two reasons:

  1. Since the HD2 comes from a coupling to the LO signal, there is an inherent suppression of the HD2 level due to the self-mixing effect (that is, phase noise and phase spur suppression effect at the mixer).
  2. In real-life scenarios there is often a double-bounce effect of the radar signal reflected from the target, which leads to a ghost object at twice the distance of the actual object. This effect is often indistinguishable from the effect of HD2 itself.