A Wideband Electrically Small Transient-State Antenna

A new concept associated with feeding an electrically small antenna is introduced to overcome the fundamental limits of antennas. This new understanding of input impedance allows transmission of an arbitrary waveform using a high quality factor (high-Q) resonant antenna which has been previously impossible. A sample design is introduced and simulated using a full-wave electromagnetic simulator in association with a circuit transient simulator. The basic antenna is able to radiate a double-sideband amplitude-modulated signal. A combination of two orthogonal antennas is used to transmit a circularly polarized quadrature phase shift keying (QPSK)-modulated signal. The simulation and measured results confirm the effectiveness of the new concept.