λ/4 directional coupler (dc) vs directional coupler (dc)

[robismyname]

https://en.wikipedia.org/wiki/Power_dividers_and_directional_couplers

As per wikipedia explanation of the above subject. I have a few questions.

For the λ/4 dc (Figure 4 of the provided link), the signal from P1 that is coupled onto P3 is going in the opposite direction than the signal going from P1 to P2? If so what makes the λ/4 dc do this?

Suppose for the λ/4 dc i have Transmitter on P1 and a antenna on P2 and there is reflected power. will that reflected power go into P1 or P3?

I understand for the directional coupler (Figure 1 of the provided link) a small amount of P1 signal goes to P3 and the rest of P1 goes to P2. But suppose there is reflected power coming back from poor mismatch from P2 where will the reflected power from P2 go?

 

[FvM]

I don't understand the "versus" in your question. Figure 1 and Figure 4 have the same port naming. Figure 4 shows a physical implementation of a DC and Figure 1 a schematic symbol. It turns out that the coupled wave actually travels in opposite direction on a transmission line coupler. The ports in figure 4 are named respectively.

You'll need to study transmision line operation (EM theory) to understand why is it so. I suggest to take it is a fact for the time being.

Reflected waves will be treated by the DC according to the arrows shown in figure 1 and the S parameter matrice in the same link. Ideally it's only transmitted to P1 and coupled to to P4.

 

[biff44]

why do u keep saying "(dc)"???