Question

Which of the following is true about normal mode of radiation?

(a) The dimensions of the antenna are small compared to the wavelength

(b) The radiation is along the axis of the antenna

(c) It has high radiation efficiency

(d) It has broad bandwidth

I have been asked this question at a job interview.

I want to ask this question from Frequency Independent Antenna topic in section Frequency Independent Antenna of Antennas

Answer 1

Right answer is (a) The dimensions of the antenna are small compared to the wavelength

To elaborate: The normal mode of radiation depends on the size of the antenna. Its critical dependency on dimensions of antenna which has to be less than the wavelength is difficult and so it causes for narrow bandwidth and low radiation efficiency. Radiation is normal to the direction of axis.