Pulse Generation and Transmission Based on Switched Coupling Between Electrically Small Antennas and Resonant Circuits

A scheme of generating and radiating pulse signals via switched coupling between electrically small antennas and resonators is presented. In this scheme, the electrically small antenna with a matching capacitor/inductor forms a secondary resonator having the same resonant frequency as a primary LC resonator. Initially, the primary resonator is preexcited by a sinusoidal source while the secondary resting in the zero state is isolated by a switch. After the switch changes state, a Gaussian- shaped pulse is produced at the input of the antenna while the energy in the primary resonator is coupled to the secondary. Part of the pulse energy is radiated from the antenna, and the rest returns to the primary resonator. In the end of the pulse, the switch changes back to its initial state, which completes the transmission of the pulse with little ringing effect. A typical design for electrically small dipole antennas (with dimension smaller than 1/10 of the wavelength) is implemented. Simulation and measured results are provided demonstrating that pulse signals can be successfully generated and transmitted using the proposed scheme, with performance mainly limited by the quality of the switches and nonidealities of other components.