Meaning
Symmetrical radio frequency radiators consisting of two equal conductive elements are used as reference sources for system validation. A dipole antenna with a known gain and impedance is used to verify the calibration of absorption measurement systems. This validation step is performed before every compliance test sequence to ensure test bench accuracy.
Reference Standard
Regulatory bodies define the exact dimensions and return loss requirements for these standard radiators across each supported band. The physical length of the arms is matched to one-half of the wavelength at the target frequency. This precision allows laboratories to compare their results against established baseline values.
Radiation Pattern
Omnidirectional field distribution of the device produces a predictable energy deposition inside the phantom model. This torus-shaped pattern is symmetric around the axis of the conducting arms. This symmetry simplifies the positioning of the source relative to the liquid container.
Impedance Match
Balun structures integrated into the feed point convert the unbalanced coaxial signal to a balanced signal for the arms. This conversion maintains the symmetry of the current distribution and minimizes common-mode currents on the feed cable. When the match is optimized, the return loss exceeds twenty decibels, ensuring that almost all the applied power is radiated into the test environment rather than being reflected back to the signal generator.
