| Summary: | In this paper, an analytical formulation of the infinite dipole array scan impedance is presented. The primary contribution of this work is the introduction of a lossy transmission line analogue which simultaneously models the Floquet modal impedances as well as the reactive properties of the dipole’s physical geometry. A scan dependent line inductance is implemented, resulting in accurate impedance predictions at extreme scan angles. The model accurately predicts the input scan impedance of tightly-coupled arrays and connected arrays for a variety of element geometries. Ground planes, substrates, superstrates, and feed structures are also incorporated in the model. Calculated impedances are compared to full-wave electromagnetic models, demonstrating high accuracy predictions from broadside to near 90° in each scan plane. Finally, an array which scans to 60° in each scan plane is rapidly optimized using only the transmission line model and compared to full-wave simulations, achieving a 3:1 VSWR over a 6.1:1 bandwidth, demonstrating the value of the model as a starting point for array design.
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