Question

Many circles are drawn in a Smith chart used for transmission line calculations. The circles shown in the figure represent

(A) unit circles.

(B) constant resistance circles.

(C) constant reactance circles. 

(D) constant reflection coefficient circles.

Answer 1

Correct option (B) constant resistance circles.

Explanation:

Given figure is shown below, 

The circle represents constant resistance circle with radius 1/(1 + r) and centre at (r/(1 + r), 0)

General expression for constant resistance circle is given by,

(u - r/(1 + r))² + v² = (1/(1 + r))²