SPRACP3C November   2019  – December 2021 AWR6843 , AWR6843AOP , IWR1443 , IWR1642 , IWR6443 , IWR6843 , IWR6843AOP

 

  1.   Trademarks
  2. 1Introduction
  3. 2Typical Certification Procedure
  4. 3Regulatory Compliance Overview
    1. 3.1 European Union Regulations - Radio Equipment directive (RED)
      1. 3.1.1 Efficient Use of the Radio Spectrum (EN 305 550)
      2. 3.1.2 RF Exposure Limit - EN 62311
      3. 3.1.3 Electrical Safety - EN 62368
      4. 3.1.4 ElectroMagnetic Compatibility (EMC) - EN 301 489-1
    2. 3.2 Federal Communications Commission (FCC)
      1. 3.2.1 End Equipment and FCC Clause
      2. 3.2.2 Fundamental Emmision levels
      3. 3.2.3 Spurious Emission
      4. 3.2.4 Frequency Stability
      5. 3.2.5 Radiation Exposure Requirement
      6. 3.2.6 FCC Waiver and Other Relevant Information
    3. 3.3 Applicable Terms and Equations
      1. 3.3.1 Duty Cycle Factor
      2. 3.3.2 Effective Isotropic Radiated Power (EIRP)
      3. 3.3.3 Friis Equation
      4. 3.3.4 Far-Field Boundary
  5. 4Tools and Setup
    1. 4.1 Hardware Setup
    2. 4.2 MMWAVESTUDIO
      1. 4.2.1 Running LUA Scripts
    3. 4.3 mmWave Visualizer
    4. 4.4 IWR6843ISK-ODS Test Case
  6. 5Common Issues and Resolutions
    1. 5.1 Peak Power
    2. 5.2 Occupied Bandwidth
    3. 5.3 Spurious Emissions
      1. 5.3.1 14.4-Ghz Harmonics
      2. 5.3.2 Suggested Resolution
        1. 5.3.2.1 Hardware Measures
        2. 5.3.2.2 Software Measures
    4. 5.4 Overshoot
    5. 5.5 Frequency Stability
      1. 5.5.1 Generating CW Signal
      2. 5.5.2 Frequency Stability Over Temperature and Voltage Range
  7. 6References
  8. 7Revision History

5.1 Peak Power

Problem statement: peak power is above the regulatory limit.

Solution: Implement TX power back off

ar1.ProfileConfig (0, 60.25, 7, 5.0, 69.5, TXBO, TXBO, TXBO, 0, 0, 0, 53.265, 1, 256, 4000, 0, 131072, 30)

Power back off, TXBO = 3, 6, 9, 12 … (see SDK Documentation for supported values)

Deep Dive:

  • IWR6843ISK TX Power = 10 dBm/TX antenna
  • TX gain = 8 dBi

For simultaneous 3 TX use case:

Equation 12. TX power = 10log1010 +1010 + 1010
Equation 13. Total TX Power = TX power + TX gain = 14.8 + 8 = 22.8dB

When using the mmWave Visualizer and accompanying config file instead of a LUA script the TX power back-off is specified by setting the TX backoff in the ProfileCFG parameter where each of the 8 bit values corresponds to TX1, TX2 and TX3 respectively.

For example for a 6dB back-off on all TX channels, the TX power control word would be 0x060606 i.e. 394758 (use this decimal value). Here's the corresponding profileCfg command.

profileCfg 0 62.00 30 10 69.72 394758 0 28.42 1 128 2180 0 0 24

This is defined in the mmwavelink html documentation