MAC Technology, Inc. - Definitions
diagram
Coupling: The difference in power level measured at the coupled port relative to the power level applied at the input port (unless noted). Coupling tolerances are specified including frequency sensitivity and therefore indicate the maximum range for the measured coupling level.

Frequency Sensitivity: The maximum variation in coupling level as measured over the specified frequency band.

True Insertion Loss: The difference in the measured power level at the output port relative to the power level applied at the input port with all other ports properly terminated.

Insertion Loss (Excluding Coupled Power): A calculated value indicating power dissipation within the device and not including power routed to other outputs. Typically given for reference only.

Directivity: The difference of coupled power levels obtained after applying power through the coupler in both the forward and reverse directions with all other ports properly terminated.

Isolation: The amount of power reduction measured at any output port with respect to the power level applied at any other output port with all other ports properly terminated.

Amplitude Balance: The maximum difference of output power levels measured at any given frequency in the specified operating band.

Phase Balance: The maximum difference in output phase levels measured at any given frequency in the specified operating band.

Average Power: The maximum calculated average or CW power level which may be applied at the input of a device without potentially resulting in damage to the device.

Reverse Power: The maximum calculated average or CW power level which may be applied at the output of a device without potentially resulting in damage to the device.

Peak Power: The maximum peak power level which may be applied at the input of a device without potentially resulting in damage to the device. Note: The average power level (determined by duty cycle) of a peak power signal must not exceed the "Average Power" rating of the device.