EMRFD Message Archive 8324
Message Date From Subject 8324 2013-03-10 00:10:01 iami78 Twisted wire quadrature splitter, driving differentially (0+180 degr Smoky (tin flavored) greetings,
Am I totally wrong in thinking that the twisted wire quadrature splitter's (appears ex. on page 3.37 in EMRFD) 50-ohm termination port is 180 degrees, compared to the input port.
Meaning, that if I want to drive it from a differential source, I could feed the input port with 0-degrees and the 50-ohm termination port with 180 degrees (excluding the 50-ohm resistor then, of course)?
The idea is to drive it directly with Si570, differentially.
73 de Janne OH1SDR
8326 2013-03-10 01:22:05 ha5rxz Re: Twisted wire quadrature splitter, driving differentially (0+180 Janne, thanks for an interesting challenge on a wet Sunday morning. I think that you're wrong but I'm willing to be proved otherwise, the best explanation of a ninety degree coupler that I can find is as follows:
"A 3 dB, 90° hybrid coupler is a four-port device that is used either to equally split an input signal with a resultant 90° phase shift between output ports or to combine two signals while maintaining high isolation between the ports. When power is introduced at the IN port, half the power (3dB) flows to the 0° port and the other half is coupled (in the opposite direction) to the 90° port. Reflections from mismatches sent back to the output ports will flow directly to the ISO port or cancel at the input. This is why hybrids are so widely used to split high power signals in applications where unwanted reflections could easily damage the driver device."
So, that fourth port with the fifty ohm terminati
8330 2013-03-10 11:40:20 iami78 Re: Twisted wire quadrature splitter, driving differentially (0+180 Hi Peter!
Thanks for the very clear explanation. I hope this text wasn't picked from EMRFD, because it would just prove that I should read better. Really good explanation! The 50-ohm terminati