RF Electronics Chapter 3: Transformers and Hybrids Page 61
2022, C. J. Kikkert, James Cook University, ISBN 978-0-6486803-9-0.
Transmission Line Hybrid with Ferrite Cores
A simple hybrid made using standard 50 Ω transmission line hybrid and ferrite cores is
shown in figures 3.18 to 3.20. If the impedance at A and B is Z
0
then at C the impedance
is ½Z
0
. The impedance seen when B=0 is 2×(½Z
0
)=Z
0
. The power dissipated in the load
resistor is the power associated with the difference in the input signals. For high power
operation, the rating of that resistor must be carefully considered. If the input at A and B
are the same then no power will be dissipated in the load resistor.
Figure 3.18. Hybrid with ferrite cores.
Figure 3.19. Circuit of hybrid in figure 3.18
The realisation of the hybrid is shown in figure 3.19 and the circuit can be analysed using
the circuit representation in figure 3.20. In figure 3.19, the 25 Ω transmission lines are
obtained by having two 50 Ω transmission lines in parallel.
Figure 3.20. Circuit of hybrid in figure 3.18.
RF Electronics: Design and Simulation
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