A deterministic procedure to design a nonperiodic planar array radiating a rotationally symmetric pencil beam pattern with an adjustable sidelobe level is proposed. The elements positions are derived by modifying the peculiar locations of the sunflower seeds in such a way that the corresponding spatial density fits a Taylor amplitude tapering law which guarantees the pattern requirements in terms of beamwidth and sidelobe level. Different configurations, based on a Voronoi cell spatial tessellation of the radiative aperture, are presented, having as a benchmark the requirements for a typical multibeam satellite antenna.

Abstract-An effective and robust strategy for concurrently designing the transmit and receive antennas of a frequency-modulated, continuoswave radar is discussed. The aperture architecture is based on the use of non-periodic, interleaved sub-arrays. Deterministic element placement is employed for ensuring design efficiency. The procedure yields controllable sub-array radiation patterns and two-way side-lobe levels below 30 dB, that are also stable over a wide frequency range.

[1] A method for ensuring polarization agility in conjunction with beam steering in planar array antennas is proposed. It relies on interleaving two subarrays with orthogonal, linear polarizations that, together, can generate arbitrary polarization states: adjustable linear, elliptical, and left-or right-handed circular. The complexity of the resulting system is comparable with that of standard, fully populated array antennas consisting of identical, linearly polarized elements. By dynamically controlling the amplitude and the phase of the signals fed to the subarrays, a stable polarization state can be maintained during beam steering. The concept is validated by numerically investigating an architecture obtained by interleaving nonuniform subarrays designed by means of a deterministic placement strategy. The effects of the mutual coupling between the different radiating elements are modeled and discussed.Citation: Simeoni, M., I. E. Lager, C. I. Coman, and A. G. Roederer (2009), Implementation of polarization agility in planar phased-array antennas by means of interleaved subarrays, Radio Sci., 44, RS5013,

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Pulse-shape models are presented that furnish the tools for analyzing a number of aspects of the performance of microelectronic circuits. Model pulse shapes are provided and their properties are analyzed in detail. Applications that are covered include the replication of measured pulses that are of relevance for inter-and intra-chip interconnects and, concurrently, examples of passive circuits that generate them. The pulses are appropriate as input to time-domain electromagnetic simulation. They are also instrumental to microelectronic performance prediction protocols and measurement equipmentaspects that are of crucial importance to integrated circuit packaging.