Executing Class Two Permissive Changes for Substituted Host Antennas
Substituted host antennas qualify for Class II Permissive Changes only when peak gain stays below certified limits and radiative physical structure remains identical.
Equivalent Antenna Type
Meaning
A specific hardware classification identifies an antenna configuration that outputs identical electromagnetic radiation patterns and impedance characteristics to a primary reference unit. This equivalent antenna type functions as a direct substitute within a radio frequency subsystem when the original component becomes unavailable or fails to meet procurement timelines. Certification bodies maintain these classifications to ensure signal propagation remains within predefined regulatory masks despite physical changes at the module level.
Performance Equivalence
Data sheets for these components detail gain values and beamwidths that remain consistent across the operating frequency band. Engineers evaluate these metrics against a controlled reference model to confirm that the substitute maintains the link budget without modification to the power amplifier or filter stages. Testing occurs in an anechoic chamber where spatial distribution of the field strength defines the operational similarity.
Mechanical Compatibility
Physical dimensions and mounting interfaces follow standardized footprints to facilitate installation into existing chassis enclosures. Thermal dissipation paths remain identical between the original part and the listed substitute so that internal housing temperatures do not exceed established safety thresholds. A successful substitution requires that the connector type and the coaxial routing geometry occupy the same spatial volume as the legacy design.
Regulatory Compliance
Authorities govern these substitutions by verifying that the radiated emissions profile stays within the bounds established during the initial equipment authorisation. Manufacturers submit test reports documenting how the substitute maintains the side lobe levels and polarization purity specified for the certification of the host device. Field deployment of such parts requires no additional hardware filing because the substitution maintains the spectral footprint of the previously approved configuration.
Modular Wireless Certification Class Changes under FCC Rules
FCC modular class changes require Class I audit logs for minor zero-increase emissions shifts and Class II filings for higher gain, host SAR, or altered spurious profiles.