Return Loss - Sign

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:

    The desire to annoy no one, to harm no one, can equally well be the sign of a just as of an anxious disposition.
    Friedrich Nietzsche (1844–1900)

    Impoliteness is frequently the sign of an awkward modesty that loses its head when surprised and hopes to conceal this with rudeness.
    Friedrich Nietzsche (1844–1900)

    A sign, or representamen, is something which stands to somebody for something in some respect or capacity. It addresses somebody, that is, creates in the mind of that person an equivalent sign, or perhaps a more developed sign. That sign which it creates I call the interpretant of the first sign. The sign stands for something, its object. It stands for that object, not in all respects, but in reference to a sort of idea, which I have sometimes called the ground of the representamen.
    Charles Sanders Peirce (1839–1914)