Correct Answer - Option 4 : Half-wave dipole antenna
Hertz antenna is a dipole antenna of length equal to half of the wavelength of transmitted EM wave.
\(\therefore l = \frac{\lambda }{2} = \frac{\nu }{{2f}}\)
λ/2 Dipole or Half-wave dipole:
- Length of dipole = λ/2
- Directivity = 1.64 or 2.15 dBi
- Impedance for half-wave dipole antenna in free space is 73 Ω
- Half power beamwidth = 78°
- The frequency is related to the wavelength by the relation c = νλ
