V.I. Litun, V.N. Mitrokhin

Providing of ultra wide range electrical beam scanning is possible for planar array antenna (AA) by combining with passive divergent dome lens (DL, up to 3/2 of hemisphere [1]). Also DL can be used to protect AA elements from negative environmental conditions [2]. The dome antenna (DA) consists of primary AA (classical, active or digital) and passive DL (fig. 1). Discrete waveguide-based structure (fig. 2) is preferred for electrically big DA of upper cm-band and lower mm-band. Possibility of optimal DL shape approximation by a sphere is shown in [4]. That sphere\'s center is moved along the system axis from AA plane. The geometry of such quasi-optimal DA (fig. 3) can be described by: R - DL inner radius; h - center displacement value; L - DL thickness. Electrical characteristics of DA are scanning angle amplification factor (SAAF) K(θ) (which is the ratio of system\'s scanning angle to primary AA scanning angle) and primary AA phase.