PSO-aided ILA methodology for hemispherical beam coverage and scan loss mitigation

This paper proposes an accurate and efficient integrated lens antenna (ILA) concept and design methodology for extraordinary beam coverage and scan loss mitigation at millimeter-wave spectrum. The geometry of the proposed ILA consists of inhomogeneous curvatures and internal center offset, where multiple parameters have high order and non-linear relations. Relying entirely on conventional full-wave simulation becomes realistically unviable. Based on geometrical optics, twodimensional ray tracing model calculates refractions on the arbitrarily-curved boundaries. The preliminary geometry of the proposed ILA is determined by a novel particle swarm optimization (PSO) algorithm, significantly enhancing the entire efficiency of the design procedure. With the integration of 8×16 phased array antenna, the devised ILA exceeds the conventional beam scanning limitations by 93%, achieving a main beam scanning range of 174 and scan loss of 2.2 dB for both vertical and horizontal polarizations and broad operational bandwidth. This method is estimated to alleviate the mmWave 5G antenna CAPEX (capital expenditure) by more than 50%.