Question

Dissipation factor for the dielectric is Df= ____

(a) \(1.8×10^6  \frac{σ}{f(MHz)}\)

(b) \(1.8 \frac{σ}{f(MHz)}\)

(c) \(1.8×10^6\frac{σ}{f(GHz)}\)

(d) \(1.8×10^3  \frac{σ}{f(MHz)}\)

The question was posed to me by my college director while I was bunking the class.

This intriguing question originated from Radio Wave Propagation topic in portion Radio Wave Propagation of Antennas

Answer 1

Right choice is (a) \(1.8×10^6  \frac{σ}{f(MHz)}\)

For explanation: Dissipation factor for the dielectric is Df = \(1.8×10^6  \frac{σ}{f(MHz)}\), σ is the conductivity of earth. This is used to calculate the phase constant for the surface wave given by \(b=tan^{-1}(\frac{ϵ+1}{D_f})\)