Miniaturized Self-Oscillating Active Integrated Antenna with Quasi-Isotropic Radiation

By placing a loop radiator over a truncated ground plane, a self-oscillating active integrated antenna with quasi-isotropic radiation is proposed in this communication. The proposed antenna comprises a loop radiator and an unstable transistor in direct integration. As the radiator is partially shielded, equivalent electric and magnetic dipole moments can be generated simultaneously, therefore giving rise to nearly uniform radiation in terms of the total electric field. The design concept is first introduced, followed by the simulation scheme and experimental results. The measured radiation characteristics support the operational principle of the proposed scheme.