Meaning
Motorized 360-degree orientation of a device under test in a horizontal plane presents all emission angles to a fixed measurement antenna inside anechoic test chambers. Controlled turntable rotation enables automated test software to record radiated field strength as a function of azimuth angle. This rotational movement ensures comprehensive capture of narrow directional signal lobes and spurious electromagnetic emissions.
Azimuthal Control
Precision stepper motors drive the test platform at programmatically controlled angular velocities. During turntable rotation, optical shaft encoders monitor position accuracy to within fractions of a degree. Smooth acceleration profiles prevent mechanical vibration from shifting portable test items or dislodging unfastened internal cables during continuous scanning runs.
Data Synchronisation
Automated test execution links table angle positions directly with receiver frequency spectrum sweeps. Executing turntable rotation in synchronization with measurement software creates complete three-dimensional field intensity maps. Step-and-dwell rotation protocols pause motion at defined angular increments to allow receiver spectrum analyzer sweeps to finish before advancing to the next bearing.
Test Validation
Compliance testing standards mandate full spatial coverage around the entire azimuth perimeter during radiated interference measurements. Combining turntable rotation with vertical antenna height sweeps identifies the maximum absolute field strength emitted by the equipment under test. Cabling routed through central slip rings prevents wire twisting during continuous multi-turn scanning routines, ensuring uninterrupted power delivery and signal integrity throughout qualification testing.
