Validating Embedded Transmitter Approvals during Host Entry Audits
Host entry audits validate embedded transmitter grants by cross-referencing host antenna gain, spurious radiation reports, and local regulatory filings.
Turntable Emission Scan
Meaning
Certification testing environments utilize rotating platforms to map the electromagnetic field strength of a device from every angle. Performing a turntable emission scan ensures that the maximum radiated energy is identified regardless of the orientation of the equipment. This data is required by regulatory agencies to prove that the product does not exceed legal limits for radio interference.
Radiation Pattern
Antenna gain and internal shielding create a non-uniform distribution of energy around the chassis. The turntable emission scan captures these variations by taking measurements at specific angular increments. This identifies the worst case direction which is then used for the final compliance evaluation.
Far-field Analysis
Distance between the measurement antenna and the source must be sufficient to ensure stable wave propagation. During a turntable emission scan, the laboratory maintains a fixed distance, typically three or ten meters, to comply with international standards. The height of the receiving antenna is also varied to find the peak signal strength in the vertical plane.
This three dimensional search is necessary to account for reflections from the ground plane in the test chamber. High precision motors and synchronized software allow for the automated collection of thousands of data points in a single session.
Laboratory Compliance
Verified test results from an accredited facility are necessary for a product to enter the global market. A complete turntable emission scan report includes the plots of the energy levels against the frequency limit lines. This documentation provides the evidence that the integration of cells and boards into the final enclosure has not created new interference paths.