Designing 180 degree hybrid only with LC elements
Is it possible to design a 180 degree hybrid just with LC elements, so without any transformer or microstrip structure? Frequency is 30MHz, so TL's are impossible.
Yes. If you are at a fixed frequency you start with an in phase power divider and add enough low pass filter operating well below cutoff to one output to get the extra phase shift.
Lowpass, bandpass, highpass.delay etc. filters would do the trick.
Use Bode Plot drawing to determine Phase shift, poles, zeros and therefore L and C elements. It will be easier if this was a filter. It will become harder because it is not a filter but a filter with LC elements to behave like a 180 degrees coupler.
You have to work out some arraignment in gain of the LC filter so the filter you created works as a coupler too. After Jean Baptiste Fourier is Sir Henry Bode my most favorite guy.
How about a lumped element ratrace. Which is again like a lowpass and highpass as mentioned previously.
Frannk, this is exactly what I was looking for. A hybrid without losses from power splitters! Thanks