High-Resolution and Broadband Aperiodic Time-Modulated Arrays for Multi-Beam Applications

This work introduces a probabilistic approach for aperiodic time-modulated arrays tailored to simultaneous multi-beam applications. Specifically, they include on-off RF switches that contribute to amplitude tapering, as in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">“classic”</i> time-modulated arrays, while the spacing is aperiodic, so it is possible to obtain large distances between the elements, in terms of wavelength, without the appearance of grating lobes. The significant spacing allows also a reduction of the deleterious impact of mutual coupling. The proposed aperiodic time-modulated arrays are broadband in the sense that the carrier frequency can potentially span a wide bandwidth without the appearance of grating lobes, independently on the element placement, and they are high-resolution in the sense that the array aperture can be made <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">“electrically”</i> very large regardless the number of elements. The array factor can be controlled simultaneously and independently via switching timing and element positioning. In addition, the proposed arrays are reconfigurable in the sense that a change in the duty cycles of the switches can relatively easily change the shape of the radiation pattern. Furthermore, the presented mathematical modeling allows for obtaining simultaneous beams.