Ultra wide band sensor unit i.e. low chip rate-antenna unit, for use in radar device for detecting pipe in e.g. wall, has substrate with dielectric whose effective dielectric constant is spatially inhomogeneous

摘要

The sensor unit (14) has a planar radiating element and a substrate arranged in near field to the radiator element. The substrate forms a dielectric whose effective dielectric constant is spatially inhomogeneous. The substrate is arranged below and/or above the radiator element. Dielectric properties of the substrate are continuously changed. The substrate is made of different materials with different dielectric constants, and comprises openings that perforate the materials. The openings are densely and differently distributed over a surface of the substrate. An independent claim is also included for a handheld electrical device i.e. radar device, comprising a housing.