SPRACP3D November   2019  – August 2026 AWR6843 , AWR6843AOP , IWR1443 , IWR1642 , IWR6443 , IWR6843 , IWR6843AOP

 

  1.   1
  2.   Trademarks
  3. 1Introduction
  4. 2Typical Certification Procedure
  5. 3Regulatory Compliance Overview
    1. 3.1 European Union Regulations: Radio Equipment Directive (RED)
      1. 3.1.1 Short Range Radar (EN 305 550)
      2. 3.1.2 Short Range Level Probing Radar (EN 302 729)
        1. 3.1.2.1 Permitted Frequency Ranges and Operating Bandwidth
        2. 3.1.2.2 Antenna Requirements
      3. 3.1.3 RF Exposure Limit - EN 62311
      4. 3.1.4 Electrical Safety - EN 62368
      5. 3.1.5 Electromagnetic Compatibility (EMC) - EN 301 489
    2. 3.2 Federal Communications Commission (FCC)
      1. 3.2.1 End Equipment and FCC Clause
      2. 3.2.2 60GHz Radar Operation (47 CFR § 15.255)
        1. 3.2.2.1 Fundamental Emission Levels, BWs, and Max Duty Cycle
        2. 3.2.2.2 Spurious Emissions
        3. 3.2.2.3 Frequency Stability
        4. 3.2.2.4 FCC Waiver and Other Relevant Information
      3. 3.2.3 Level Probing Radar (47 CFR § 15.256)
        1. 3.2.3.1 Usage Limitations
        2. 3.2.3.2 Fundamental Emissions, BWs
        3. 3.2.3.3 Antenna Restrictions
        4. 3.2.3.4 Unwanted Emissions
      4. 3.2.4 Modular Approval (47 CFR § 15.212)
      5. 3.2.5 Radiation Exposure Requirement
    3. 3.3 Japan Radio Law
      1. 3.3.1 BW, Designated Frequency, and Tolerances
      2. 3.3.2 Out of Band and Spurious Emissions
      3. 3.3.3 Controller Functions
    4. 3.4 Wireless Planning and Coordination Wing (WPC)
      1. 3.4.1 Permitted Frequency of Operations and Approval
      2. 3.4.2 Equipment Type Authorization
    5. 3.5 Federal Telecommunications Institute (IFT)
      1. 3.5.1 Fundamental Emission Levels and BWs
    6. 3.6 National Telecommunications Agency (ANATEL)
      1. 3.6.1 Fundamental Emissions Levels, BWs, and Max Duty Cycle
      2. 3.6.2 Licenses
    7. 3.7 Ministry of Transport and Communications (MTC)
    8. 3.8 National Communications Entity (ENACOM)
  6. 4Applicable Terms and Equations
    1. 4.1 Duty Cycle Factor
    2. 4.2 Effective Isotropic Radiated Power (EIRP)
    3. 4.3 Friis Equation
    4. 4.4 Far-Field Boundary
  7. 5Tools and Setup
    1. 5.1 Hardware Setup
    2. 5.2 Internal Laboratory Test Setup
      1. 5.2.1 Near-Field Circuit Probing
      2. 5.2.2 Occupied Bandwidth Testing
      3. 5.2.3 Radiation Pattern Measurement
    3. 5.3 MMWAVESTUDIO
      1. 5.3.1 Running LUA Scripts
    4. 5.4 mmWave Visualizer
    5. 5.5 IWR6843ISK-ODS Test Case
  8. 6Common Issues and Resolutions
    1. 6.1 Peak Power
    2. 6.2 Occupied Bandwidth
    3. 6.3 Spurious Emissions
      1. 6.3.1 14.4GHz Harmonics
      2. 6.3.2 Suggested Resolution
        1. 6.3.2.1 Hardware Measures
        2. 6.3.2.2 Software Measures
          1. 6.3.2.2.1 APLL Duty Cycling
          2. 6.3.2.2.2 APLL VCO RTRIM Setting in BSS Firmware
    4. 6.4 Overshoot
    5. 6.5 Frequency Stability
      1. 6.5.1 Generating CW Signal
      2. 6.5.2 Frequency Stability Over Temperature and Voltage Range
    6. 6.6 EIRP Spiking and Spectrum Analyzer BW
  9. 7References
  10. 8Revision History

5.2.1 Near-Field Circuit Probing

If an emission is detected, it can sometimes prove difficult to locate the source of the emission. One technique which can assist is called near-field probing. Also known as "sniffing", near-field probing involves using specifically sized probe antennas to track down the source of a radiated emission. Typically the following equipment would be used:

  • Probe antennas
    • The antennas must be tuned or sized to detect a particular range of frequencies, specifically those of interest
  • Cables
  • Spectrum Analyzer
    • The frequency range of the analyzer must be greater than the signal of interest
  • Shield Chamber or Anechoic chamber
    • Chosen to prevent other outside signals from interfering with the measurement

The process is typically as follows:

  • The EUT, SA, antennas and supporting equipment are loaded into the chamber. Electronics other than the EUT and SA are left outside the chamber to prevent contamination of the measurement.
  • The SA is set to have its trace in Max Hold mode with the peak detector. This causes the SA to hold the highest power spike detected on its screen.
  • The probe antenna is then slowly and systematically passed over the whole of the EUT, not making contact with the components or the platter, but rather staying approximately 1 to 2 centimeters above them.
  • Upon finding a spike, the screen can be cleared and reset to confirm the location of the emission

Once an emissions source is located, it is then possible to intuit the source origin based on the location of the radiation and it's frequency. This can be done by considering the length of a trace or the size of populated metallic components. As their size approaches one-quarter wavelength of the emission, they begin to act effectively as antennas.

While this technique is helpful for finding emissions, it is important to realize that not all near-field emissions result in a far-field emission. Thus, not all near-field emissions present EMC issues. For this reason, it is often best used as a reactive or debug exercise. While this section has discussed manual techniques for measurement, there are automated test solutions that are available at some cost.