Basic Modular Certification Class Changes under FCC Rules
FCC rule changes governing modular radios demand precise classification of trace, antenna, and proximity shifts to prevent illegal radiated emissions.
Harmonics Measurement
Meaning
Radio frequency testing procedures measure the power levels of emissions generated at integer multiples of the fundamental carrier frequency. These tests ensure that non-linearities in the transceiver chain do not create interference that disrupts other services. Engineers perform these sweeps in both conducted and radiated test environments to satisfy international compatibility standards.
Emission Suppression
Linearity assessment of the transmitter front-end is essential to identify the source of unwanted high-frequency energy. During harmonics measurement, the spectrum analyser sweeps up to ten times the operating frequency to find unwanted peaks. Finding high emissions at these multiples indicates that the output filter or matching network requires optimization.
Regulatory Testing
Compliance with international emissions standards must be verified before any radio device enters the commercial market. If harmonics measurement reveals levels that exceed regional limits, the device cannot receive certification. Regulatory limits are extremely strict to protect other communication bands.
Equipment Calibration
Shielded chamber test configurations require high-performance low-pass filters to prevent test equipment non-linearities from masking the true device emissions. In a harmonics measurement scenario, an external filter is often inserted to block the fundamental carrier, preventing the spectrum analyser from generating its own internal harmonic signals. The resulting logs ensure that the collected data reflects only the device under test.