90 hybrid transformer

you may refer Pozar's microwave engineering book for detail.

Nope, only transmission line hybrids in there.

For the 180 degree you can use a transformer with the secondary center tap grounded. The two outside winding terminals are 180 degrees apart.

Ferroxcube has on their web site a 150+ page application handbook that discusses such things. Also the book Transmission Line Transformers by Jerry Sevick covers this.

For the 90 degree type the topology is a 1:1 transformer with one side of each winding being the two inputs (call these terminals 1 and 2) and the other side of the two windings being the outputs (call these terminals 3 and 4.) To increase the bandwidth a capacitor is placed across terminals 1 and 2 and another capacitor is placed across terminals 3 and 4. Each of these terminals is driven or loaded with respect to a common ground node that is the same ground for all four terminals.

You may want to play with some SPICE simulations for the 90 degree case and see how the various parameters (primary and secondary inductance, coupling coefficient, and capacitor values) affect the performance.