| 摘要 |
A radar level gauge (RLG) is provided for determining a filling level of a filling material contained in a container by transmitting and receiving elliptically or circularly polarized waves. The RLG comprises: a feeding circuitry for feeding and receiving two essentially orthogonal elliptically polarized waveguide modes, one of the modes for transmission and another mode for reception; an antenna for transmitting the waveguide modes towards the filling material and for receiving reflected signals; and a waveguide to provide signals between said feeding circuitry and the antenna. Further, the feeding circuitry comprises: a microwave generating unit (TX); a microwave receiving unit (RX); at least three feeding probes being at least partly exposed to the interior of the waveguide; and a coupling circuitry for transferring and feeding signals between each feeding probe and the microwave generating unit and/or the microwave receiving unit. At least the coupling circuitry and the feeding probes are implemented on a common printed circuit board (PCB), and the printed circuit board is arranged transversely over the waveguide.
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