I was taught in class that 2 port RF networks have the following structure below, where V2+ is the reflected wave if load at end of port 2 does not match the characteristic impedance of lines at port 2:
Let's take a simple circuit that we can make practically, it consists of 2 ports where input is being applied at port 1. The network consists of a single resistor whose value may not match with characteristic impedance of either lines resulting in reflection:
What I want to understand: If frequency of source is so low such that wavelength of input wave is much greater than L1 and L2 then the circuit doesn't need reflection consideration. What I mean is it would be like a 10 Hz source powering an appropriate load of wire length say 5 cm. This means voltage at load and source vary exactly as each other.
Statement 1: So, in above case, when we reduce it to simple network theory and we say that the current will travel thru Path 1 and return thru Path 2 (which we usually call ground path).
Statement 2: When we increase frequency such that wavelength is comparable to network, then also current should return thru Path 2. But according to first diagram, the reflected voltage/current returns thru path 2.
So, my confusion is does the reflected current wave, I1- (according to first diagram) returns on path 1 or path 2. If it returns on path 2, then does it add with the returning I1+?