Swept-Frequency Directivity; Figure 2-1 Typical Coupling Variation With Frequency - Keysight 778D Operating And Service Manual

Figure 2-1

Swept-Frequency Directivity

Directivity (in dB) is equal to:
where
P = Power
aux = auxiliary arm
main = main arm
The power input to the main arm is the same for both measurements.
NOTE
Keysight 778D Operating and Service Manual
Typical coupling variation with frequency
( P aux
10 log - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
P aux
(
) when Pmain flows forward
) when Pmain flows reversed
Specifications 2
17