Course › Antennas
Resonance and antenna length
What it means for an antenna to be resonant, and how its length sets the frequency.
What you will be able to do
- Define resonance for an antenna
- Say how lengthening or shortening an antenna changes its resonant frequency
Why does the length of an antenna matter?
An antenna works best at one frequency, and its length decides which.
Resonance
An antenna is resonant at a frequency when it is most efficient at radiating or receiving at
that frequency. See Resonance.
Length and frequency
A half-wave dipole and a quarter-wave vertical, each with its length marked
A longer antenna matches a lower frequency, which has a longer wavelength. A shorter antenna
matches a higher frequency.
You now know
Source: RSK Foundation tutorial, KARE 08 §1