Patent ID: 6202485
Filing Date: 2001-03-20
Classification: G01F,H01Q

Abstract:
Level measuring instrument which operates with microwaves, havinga housing section,which is designed as a waveguide short-circuited at one side and one end by a rear wall,which is virtually completely filled with an insert made of a dielectric,an exciter element,which projects into the housing section andwhich is connected to a microwave source,an antenna, adjoining the housing section, for transmitting and/or receiving microwaves, anda gap arranged in the insert between the exciter element and the antenna,which gap forms a filter which is essentially non-transparent to higher modes of the waveguide, wherein the gap runs parallel to a longitudinal axis of the housing section and has a length equal to a quarter wavelength of a fundamental mode of the waveguide having the gap and the dielectric.