Meaning
Horizontal rotation of an antenna or sensor during radiation pattern measurement determines the angular distribution of electromagnetic energy in the horizontal plane. Executing an azimuth scan allows the test engineer to capture the signal strength at discrete angular intervals around the device under test. This process maps the radiation characteristics across a complete circle to verify wireless performance.
Angular Sweep
Measurement procedures in anechoic chambers rely on a rotating turntable to systematically alter the angle of the device relative to the measurement antenna. Step size during the azimuth scan dictates the angular resolution of the resulting dataset. High resolution scans require smaller steps but consume more testing time in the chamber.
Antenna Positioning
Accurate alignment of the positioning system ensures that the phase center of the device under test remains at the center of the rotation axis. Deviations from this axis introduce phase errors during the azimuth scan. Cables must be secured to prevent them from exerting torque on the turntable or shifting the alignment of the device during rotation.
Scan Evaluation
Analysis of the captured data reveals the directional properties of the transmitter such as its beamwidth and front to back ratio. The azimuth scan is required for regulatory certification protocols that dictate maximum permissible radiation levels. Engineers compare these results to simulated radiation patterns to validate the antenna integration before mass production begins.
