Effective Isotropic Sensitivity (EIS)
EIS is the Effective Isotropic Sensitivity.
In antenna measurements, the measured sensitivity in a single direction (that is, for a fixed
and ) is known as the EIS.|
Typically, for an antenna system (antenna + transmission line + receiver + associated electronics) sensitivity measurement, if a single value of EIS is given, this will be the minimum value of the EIS over all measured angles.
If the EIS value was measured for an antenna system with an isotropic antenna, then the EIS would be the same as the Total Isotropic Sensitivity (TIS).
Total (full 3D) Measurements from a Single-Point (single-direction) Measurement
If the minimum EIS and the directivity (D) are known for an antenna, then the TIS can be found from the equation:
In this manner, if the directivity and peak angle for an antenna are known in advance, the measurement time can be greatly reduced by using equation . This is particularly important for sensitivity measurements, which take much longer than power measurements.