Before revision: thumbnail|300px|Figure 2: Possible equivalent signal-flow graph for the asymptotic gain model Definition of terms As follows directly from limiting cases of the gain expression, the asymptotic gain G∞ is simply the gain of the system when the return ratio approaches infinity: while the direct transmission term G0 is the gain of the system when the return ratio is zero: Advantages This model is useful because it completely characterizes feedback amplifiers, including loading effects and the bilateral properties of amplifiers and feedback networks.
After revision: thumbnail|300px|Figure 2: Possible equivalent signal-flow graph for the asymptotic gain model As follows directly from limiting cases of the gain expression, the asymptotic gain G∞ is simply the gain of the system when the return ratio approaches infinity: while the direct transmission term G0 is the gain of the system when the return ratio is zero: Advantages This model is useful because it completely characterizes feedback amplifiers, including loading effects and the bilateral properties of amplifiers and feedback networks.