Question

Relation between SWR ‘S’ and reflection coefficient ‘ρ’ is given by _________

(a) \(S=\frac{1+ρ}{1-ρ}\)

(b) \(S=\frac{1-ρ}{1+ρ}\)

(c) \(S=\frac{1+ρ}{ρ}\)

(d) \(S=\frac{ρ}{1-ρ}\)

This question was addressed to me by my college professor while I was bunking the class.

Origin of the question is Standing Wave Ratio Method topic in section Modern Antennas & Antenna Measurements of Antennas

Answer 1

Right choice is (a) \(S=\frac{1+ρ}{1-ρ}\)

Explanation: Standing waves occur when there is mismatch or reflection due to uneven surfaces. The standing wave ratio is defined as the maximum voltage to minimum voltage and its relation with the reflection coefficient is given as

\(S=\frac{V_{max}}{V_{min}} =\frac{1+ρ}{1-ρ}.\)