Patent ID: 7265558

Claim:
A radar level gauge for determining a filling level of a filling material contained in a container by transmitting and receiving elliptically polarized waves, comprising: a feeding circuitry for feeding and receiving two essentially orthogonal elliptically polarized waveguide modes, one of said modes for transmission and another mode for reception; an antenna for transmitting said waveguide modes towards said filling material and for receiving signals reflected from said filling material; a waveguide to provide signals between said feeding circuitry and said antenna; wherein said feeding circuitry comprises: a microwave generating unit, a microwave receiving unit; at least three feeding probes at least partly protruding into said waveguide for transmitting and receiving said two essentially orthogonal elliptically polarized waveguide modes; and a coupling circuitry for transferring and feeding signals between each feeding probe and the microwave generating unit and/or the microwave receiving unit.