ok i tried what you suggested to me and here i upload the results , so what do you think guys about this results in compare with the first ones!
S(1,1) at the upper freq=-13.54 db
S(4,1) at the upper freq=-13.00 db
are this results good?
because i read somewhere that we must always have S(1,1) and the isolated port S(4,1) <14.6 db
I made a quick simulation and will attach the results. Branchline hybrid with one section is a liitle bit too narrow for this wide 250 MHz band. You should add one branchline section more.
Basically this kind of optimization is very trivial to be made in ADS and you will find the optimization goals I was using in the schematic. I hope you will get some advise you asked.
I added the FR-4 board dielectric loss to the MSub properties, please use the data according to manufactur data. Isolation is better than 19 dB over the 250 MHz band with matching better than 18dB at all ports. By adding some more elements to the circuit broader bandwidth can be met but that is another story.