I need to design a 55-65MHz quadrature 3dB coupler for my balanced amp,maybe I have to use coax to build the circuit for the low frequency, is there anyone could give me some reference on how to build a low frequency coaxial hybrid?
Building coaxial quadrature hybrid for such a low frequencies will result in a hybrid as big as a lab! You are better off considering lumped circuit version.
Hello!
I am really new to RF,and I can't find any useful information on designing coupler of such a low frequency.
Could you give me some reference?How to do that with lumped elements?
You can build as other people said a Lump element hybrid, at your frequency lump components will work fine.
I attach a pdf that has the equations and circuit diagram for your hybrid. Make sure when u build it u put everything symmetrical and as close as possible. Also better use SMD components for the Cs and Ls. If u want to have coaxial feed, just strip a coaxial line connect the inner core to your input and the cover to the ground and you can then connect it to your amplifier on any other component.
Thank you!
I forgot to tell you that the output power of the amp is 200W,my mistake.
could you give me a circuit built with coaxial line which can withstand the power better?
I've simulated the circuit in ADS,the amplitude unbalance is +-0.7dB, I think this is too high to get a good system performce,do you have a circuit with better amplitude imbalance?
Thank you!
I forgot to tell you that the output power of the amp is 200W,my mistake.
could you give me a circuit built with coaxial line which can withstand the power better?