Question

Which of the following statement is false?

(a) LPDA is a frequency independent antenna

(b) In LPDA the lengths of the dipoles increases from the apex of the feed line toward other end

(c) The included angle varies as the length of the dipole changes from the apex of feed line

(d) The spacing between adjacent dipoles and their lengths are in same ratio

This question was addressed to me by my school teacher while I was bunking the class.

This interesting question is from Frequency Independent Antenna topic in division Frequency Independent Antenna of Antennas

Answer 1

The correct answer is (c) The included angle varies as the length of the dipole changes from the apex of feed line

The explanation is: The electrical properties of the LPDA are periodically repeated in terms of logarithmic frequency. The relation between the antenna dipole spacing lengths or adjacent lengths and the scaling factor is given as\(\frac{L_N}{L_{N+1}} =\frac{S_N}{S_{N+1}} = τ.\)  LPDA is a frequency independent antenna and the lengths of the dipoles increases from the apex of the feed line toward other end by maintaining constant included angle.