SPRACV2 November   2020 AWR1843 , AWR2243

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Background – Simple Single-Chip Applications
  3. 2Cascade Incoherence Sources and Mitigation Strategies
    1. 2.1 PCB Routing Imbalances and Device Processes
    2. 2.2 Temperature Drifts
    3. 2.3 Scheduling of Run Time Calibrations
  4. 3Enabling Cascade Coherence and Improved Phase Performance
    1. 3.1 High-Level Summary
      1. 3.1.1 Sequence of Proposed Steps and Introductory Flow Diagrams
    2. 3.2 Saving RF INIT Calibration Results at Customer Factory
      1. 3.2.1 Note on LODIST Calibration
      2. 3.2.2 TX Phase Shifter Calibration and Saving Results at Customer Factory
    3. 3.3 Corner Reflector-Based Offsets Measurement at Customer Factory
      1. 3.3.1 Corner Reflector-Based Inter-Channel Imbalances
      2. 3.3.2 Corner Reflector-Based TX Phase Shifter Errors
    4. 3.4 Restoring Customer Calibration Results In-Field
      1. 3.4.1 Restore RF INIT Calibrations Results In-Field
      2. 3.4.2 Restore TX Phase Shift Calibration Results In-Field
    5. 3.5 Host-Based Temperature Calibrations In-Field
      1. 3.5.1 Disabling AWR Devices’ Autonomous Run Time Calibrations
      2. 3.5.2 Enabling Host-Based Temperature Calibrations of Inter-Channel Imbalances
      3. 3.5.3 Switching of DSP Imbalance Data
      4. 3.5.4 Enabling TX Phase Shifter’s Host-Based Temperature Calibrations
        1. 3.5.4.1 Estimating TX Phase Shift Values at Any Temperature
        2. 3.5.4.2 Temperature Correction LUTs for AWR1843TX Phase Shifter
        3. 3.5.4.3 Temperature Correction LUTs for AWR2243 TX Phase Shifter
        4. 3.5.4.4 Restoring TX Phase Shift Values – Format Conversion
        5. 3.5.4.5 Restoring TX Phase Shift Values – Transition Timing and Constraints
        6. 3.5.4.6 Typical Post-Calibration TX Phase Shifter Accuracies
        7. 3.5.4.7 Correcting for Temperature Drift While Sweeping Across Phase Settings
        8. 3.5.4.8 Amplitude Stability Across Phase Shifter Settings
        9. 3.5.4.9 Impact of Customer PCB’s 20-GHz Sync Path Attenuation on TX Phase Shifters
      5. 3.5.5 Ambient and Device Temperatures
  5. 4Concept Illustrations
  6. 5Miscellaneous (Interference, Gain Variation, Sampling Jitter)
    1. 5.1 Handling Interference In-Field
    2. 5.2 Information on TX Power and RX Gain Drift with Temperature
    3. 5.3 Jitter Between Chirp Start and ADC Sampling Start
  7. 6Conclusion
  8.   A Appendix
    1.     A.1 Terminology
    2.     A.2 References
    3.     A.3 Flow Diagrams for Proposed Cascade Coherence Scheme
    4.     A.4 LUTs for TX Phase Shifter Temperature Drift Mitigation
    5.     A.5 Circular Shift of TX Phase Shifter Calibration Data Save and Restore APIs

5.2 Information on TX Power and RX Gain Drift with Temperature

In general the strategies recommended above keep the RF-analog bias settings constant over large temperature ranges (e.g. ~50C to 140C may use the same TX and RX bias settings). With this, the radar return signal strength varies with temperature, depending on the bias setting choice. This section provides information (nominal AWR2243 design based expectations) regarding how the TX power and RX gain vary with temperature. It is provided as a table for different bias settings, given that the host has API based control on the temperature/bias settings.

Note: This information is from nominal device simulations and there can be some deviation across manufacturing process.
Table 5-1 TX Power versus Device Temperature (use for deriving relative “drift” over temperature)
TX Output Power (dBm)
Temperature -40C Settings 10C Settings 25C Settings 50C Settings 140C Settings
-40 13.11 13.48 13.57 13.77 14.43
-30 13.00 13.38 13.5 13.66 14.41
-20 12.87 13.28 13.41 13.56 14.38
-10 12.71 13.17 13.31 13.46 14.34
0 12.54 13.05 13.2 13.36 14.28
10 12.35 12.93 13.08 13.27 14.21
20 12.14 12.79 12.95 13.17 14.13
30 11.91 12.65 12.8 13.06 14.04
40 11.65 12.50 12.64 12.95 13.94
50 11.38 12.34 12.47 12.83 13.82
60 11.09 12.16 12.29 12.71 13.69
70 10.78 11.96 12.1 12.57 13.55
80 10.45 11.76 11.89 12.43 13.4
90 10.09 11.54 11.67 12.29 13.24
100 9.72 11.26 11.44 12.11 13.06
110 9.33 11.01 11.2 11.94 12.87
120 8.92 10.76 10.95 11.77 12.67
130 8.49 10.48 10.68 11.58 12.46
140 8.03 10.17 10.4 11.36 12.24
Table 5-2 RX Gain Across Temperature for Various Settings
RX Gain (dB)
Temperature -40C Settings 25C Settings 140C Settings
-40 37.53 40.07 43.35
-30 37.09 39.59 42.85
-20 36.65 39.13 42.37
-10 36.24 38.68 41.9
0 35.83 38.24 41.44
10 35.44 37.82 40.99
20 35.06 37.41 40.56
30 34.69 37.01 40.14
40 34.34 36.62 39.73
50 33.99 36.25 39.32
60 33.66 35.89 38.93
70 33.33 35.53 38.55
80 33.01 35.19 38.17
90 32.69 34.85 37.79
100 32.38 34.51 37.42
110 32.07 34.17 37.05
120 31.76 33.84 36.68
130 31.45 33.5 36.31
140 31.14 33.16 35.94