Co-Design of Low-Profile Linear Microstrip Arrays With Wideband Spatial Filtering Capabilities

The design of low-profile linear microstrip arrays with wideband spatial filtering capabilities is dealt with. An innovative architecture, leveraging the angular selectivity of offset stacked patch (OSP) radiators, is proposed to implement phased arrays (PAs) with interelement spacing larger than half-wavelength that feature remarkable grating lobes (GLs) suppression properties and an enhanced gain within a nonnegligible down-looking scanning angular range. The PA layout is then obtained by optimizing the optimal microscale geometrical descriptors of the radiating elements so that the macroscale electromagnetic (EM) features of the arising finite-size PA fulfill the user-defined requirements. A set of numerical test cases, concerned with a variation of the array size and its polarization, is presented to assess the capabilities, the flexibility, and the potentialities of the proposed spatial filtering technique (SFT) also in comparison with competitive state-of-the-art alternatives. The performance of a printed circuit board (PCB)-manufactured prototype is experimentally assessed, as well.