effective isotropic sensitivity (EIS)

Effective Isotropic Sensitivity(EIS) and Total Isotropic Sensitivity(TIS) are two parameters for evaluating the reception sensitivity ofantennas.

When measuring EIS values, which is comparable to measuring Equivalent Isotropically Radiated Power( EIRP), the sensitivity is measured in one direction, over the entire antenna system consisting of antenna, antenna cable and receiver. If only a single EIS value is determined, then this EIS value corresponds to the minimum value for all measured directions.

If the EIS value is measured for an isotropic antenna, then this value corresponds to the Total Isotropic Sensitivity (TIS). There is a direct relationship between the TIS value and the EIS value via the directional factor (D): TIS = EIS + D. If the directional factor is known, then the measurement time for the TIS measurement can be reduced.