Question

Which of the following is the condition for the Log periodic antenna to be inactive transmission line region?

(a) \(L=\frac{λ}{2} \)

(b) \(L > \frac{λ}{2} \)

(c) \(L < \frac{λ}{2} \)

(d) \(L = \frac{λ}{4} \)

I have been asked this question by my college director while I was bunking the class.

My doubt is from Frequency Independent Antenna topic in division Frequency Independent Antenna of Antennas

Answer 1

The correct answer is (c) \(L < \frac{λ}{2} \)

The explanation is: The LPDA has dipoles of varying length along the axis. The dipole lengths of the LPDA less than half the wavelength belongs to the Inactive transmission line region. \(L < \frac{λ}{2}. \)