Question

Find the radiation resistance of a Hertzian dipole of length 1m and operating at a frequency 1MHz?

(a) 0.08Ω

(b) 8.8mΩ

(c) 8.8Ω

(d) 0.88Ω

The question was posed to me in final exam.

My question is based upon Radiation Resistance topic in portion Antenna Parameters of Antennas

Answer 1

Right option is (b) 8.8mΩ

To elaborate: \(λ=\frac{c}{f}=\frac{3×10^8}{1×10^6}=300m\)

Radiation resistance of a Hertzian dipole is given by \(R=80π^2(\frac{l}{\lambda})^2=80π^2 (\frac{1}{300})^2\)=0.0088Ω