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 _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
