Question

How to find return loss at port 1 when port 2 is short circuited?

Answer 1

If short circuit is mentioned
Port 1 = 20 log (1/|τin|)
Port 2 = 20 log (1/|τout|) τ = tau

τin = S22 - (S12×S21)/(1+S11)
τout = S11 - (S12×S21)/(1+S22)