Theoretical Study and Systematic Design of Multiport Wire Antenna

This letter presents a systematic study of multiport wire antennas (MPWA) as a step toward reconfigurable radiation apertures, an essential component in modern wireless systems. We predict the surface current distribution of the multiport structure and derive a closed-form relation for the radiation pattern of the aperture as a function of its input port excitations. Based on this, we present a design procedure for optimal selection of port locations and their respective input excitations with a desired radiation pattern in mind. Finally, we develop a computationally efficient method to derive the impedance matrix of the multiport aperture without the need for full-wave simulation. As an example, we used this method to design a 15-port mm-wave antenna. We demonstrate that for a selected aperture size and port locations, and only by adjusting the phases and amplitudes of excitation, we can reconfigure the MPWA to synthesize a desired beam at any frequency within the 20-40 GHz range. There is good agreement between the results predicted by this method and those from EM-based simulations, enabling an efficient and scalable approach for designing multiport radiators.