A parasitic three-element superdirective electrically small antenna array

This paper presents a parasitic three-element superdirective electrically small antenna array based on very small printed loop antenna (unit-element). The unit-element dimensions are 24 × 20mm
²
corresponding to λ/14 × λ/17relative to its resonance frequency of 900MHz. The array has been designed for an interelement distance of 21.5mm. Its total dimensions are 63 × 24mm
²
, and it presents a simulated directivity of 9dBi. The array optimization has been performed using an ad-hoc procedure based on spherical wave expansion.