Question

To radiate EM signal of wavelength \( \lambda \) with high efficiency, the antennas should have a minimum size equal to:

• A. 2\(\lambda\)
• B. \(\frac{\lambda}{4}\)
• C. \(\frac{\lambda}{2}\)
• D. \(\lambda\)

Answer 1

The Correct Option is B

For efficient radiation of electromagnetic (EM) waves, the minimum length of an antenna should be proportional to the wavelength of the signal being transmitted. The minimum length of the antenna is given by: \[ \text{Minimum length of antenna} = \frac{\lambda}{4}, \] where \( \lambda \) is the wavelength of the EM signal. Thus, the minimum size of the antenna for efficient radiation is \( \boxed{\frac{\lambda}{4}} \).