Coupler with waveguide transition for an antenna in a radar-based level measurement system

摘要

A mechanism for coupling a coaxial waveguide to another waveguide. The mechanism includes a lower or matching waveguide and an impedance transformer. A coaxial port couples the coaxial waveguide to the matching waveguide. The matching waveguide has a waveguide impedance which is close to the impedance of the coaxial waveguide. This arrangement allows matching between the coaxial waveguide and the matching waveguide over a wider frequency band. The impedance transformer couples the matching waveguide to the other waveguide. The impedance transformer comprises a single-stage, double-stage, or multi-stage transformer. The mechanism is suitable for coupling an antenna to a coaxial cable interface in a radar or microwave based level measurement or time of flight ranging systems.