Within this physical description there are two very distinct antenna designs : the small loop ( or `` magnetic loop '' ) with a size much smaller than a wavelength , and the resonant loop antenna with a circumference approximately equal to the wavelength .
Within this physical description two different antenna designs are common : the small loop ( or `` magnetic loop '' ) with a size much smaller than a wavelength , and the resonant loop antenna with a circumference approximately equal to the wavelength .