Q9Electromagnetics Waves
Question
9. Write one equation of Maxwell for the dynamic electric field.
Answer
On a Smith chart, the centre point (Γ = 0) is the common centre of all constant-VSWR circles; it represents a perfectly matched load (Z = Z0), and each constant-VSWR circle is centred there with radius |Γ| = (VSWR−1)/(VSWR+1).
The Smith chart is a polar plot of the complex reflection coefficient Γ = |Γ|∠θ inside the unit circle |Γ| ≤ 1. Because VSWR depends only on the magnitude |Γ| (VSWR = (1+|Γ|)/(1−|Γ|)) and not on its phase angle θ, every point on the chart with the same |Γ| — regardless of angle — has the same VSWR; the locus of all such points is a circle of radius |Γ| centred exactly at the chart's origin, the point Γ = 0. This origin point itself corresponds to |Γ| = 0, i.e., VSWR = 1, the ideal matched condition Z = Z0. Thus the centre of every constant-VSWR circle on a Smith chart is the same fixed point: the chart's geometric centre, representing the matched load, and larger-VSWR circles are simply concentric circles of larger radius drawn about this same centre.