Sign
Properly, loss quantities, when expressed in decibels, should be positive numbers. However, return loss has historically been expressed as a negative number, and this convention is still widely found in the literature.
Taking the ratio of reflected to incident power results in a negative sign for return loss;
- where RL'(dB) is the negative of RL(dB).
Return loss is identical to the magnitude of Γ when expressed in decibels but of opposite sign. That is, return loss with a negative sign is more properly called reflection coefficient. The S-parameter S11 from two-port network theory is frequently also called return loss, but is actually equal to Γ.
Caution is required when discussing increasing or decreasing return loss since these terms strictly have the opposite meaning when return loss is defined as a negative quantity.
Read more about this topic: Return Loss
Famous quotes containing the word sign:
“If you are to reach masses of people in this world, you must do it by a sign language. Whether your vehicle be commerce, literature, or politics, you can do nothing but raise signals, and make motions to the people.”
—John Jay Chapman (1862–1933)
“When much intercourse with a friend has supplied us with a standard of excellence, and has increased our respect for the resources of God who thus sends a real person to outgo our ideal; when he has, moreover, become an object of thought, and, whilst his character retains all its unconscious effect, is converted in the mind into solid and sweet wisdom,—it is a sign to us that his office is closing, and he is commonly withdrawn from our sight in a short time.”
—Ralph Waldo Emerson (1803–1882)
“Every sign is subject to the criteria of ideological evaluation.... The domain of ideology coincides with the domain of signs. They equate with one another. Wherever a sign is present, ideology is present, too. Everything ideological possesses semiotic value.”
—V.N. (Valintin Nikolaevic)