Methods of transmitting a wideband signal through an electrically small antenna

in this paper, two different methods are introduced to radiate a wideband signal through an electrically small antenna. One method shifts the resonant frequency of the antenna and radiates a frequency modulated signal while the other presents a feeding mechanism to radiate an amplitude modulated signal. Both methods are categorized under antenna direct modulation and take advantage of transient properties of electrically small antennas. It is shown that the bandwidth of the radiated signal can be independent of the bandwidth of the antenna.