Topband: The Magic-T

[Richard (Rick) Karlquist]

The 90 degree hybrid is a third type of hybrid combiner,
distinct from the 0 degree and 180 degree types.  It
is typically used for 4 square phasing.  All 3 combiners
basically have a 3 dB insertion loss for signals having
appropriate phase conditions.

What you say is true to the extent that using a 90
degree combiner for two signals that are in phase
will result in a 3 dB loss.  You would not normally
want to do that.

Rick N6RK



On 2/10/2021 2:25 PM, P H via Topband wrote:
> My impression is that a hybrid combiner, which introduces 90 degree shift (hence two identical signals of amplitude A fed to its inputs will give in total a signal with the amplitude of 1.41*A) is 3dB less efficient in comparison to a simple combiner where A+A gives 2*A at the output.
> Do you have any thoughts on this?
> A loss of 3 dB may be like "to be or not to be" of a QSO on 160 meters.
> Regards
> Piotr, SP2BPD
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