Patent ID: 6684697
Filing Date: 2004-02-03
Classification: G01F,H01Q

Abstract:
Radar antenna (1) for the transmission and reception of radar waves (4) for measuring the level of a surface of a liquid enclosed in a tank, wherein the radar antenna (1) is arranged above the surface (3a) of the liquid and substantially directed downwards towards said surface and said level determined based on said radar waves being transmitted from the radar antenna (1) and reflected back from the surface (3a) of the liquid and wherein said radar antenna (1) has a front surface (1a) from which said radar waves, in operation, leave the antenna (1) and which front surface the radar waves approaches, when reflected by the liquid of the surface (3a), characterized by that said antenna (1) is a planar antenna having a sheet arranged on the front surface (1a), wherein said sheet has a sheet surface (1b) between said antenna front surface (1a) and the surface (3a) of the liquid and said sheet surface (1b) being arranged in a predetermined angle &agr; being greater than 0Â° in relation to the horizontal plane H, whereby a fluid occurring on the surface (1b) of the sheet is drained off by means of gravity.