Which of the following increases the resonant frequency of a dipole antenna?
Lengthening it
Inserting coils in series with radiating wires
Shortening it✓Bonne réponse
Adding capacitive loading to the ends of the radiating wires
Explication
A dipole resonates where its length is about half a wavelength, and shorter wavelengths correspond to higher frequencies, so cutting the antenna shorter raises its resonant frequency. Lengthening it, or adding series inductance or end capacitance, all lower the resonant frequency instead.