Device for emitting high-frequency signals

• US 20030137447A1
• Filed: 12/09/2002
• Published: 07/24/2003
• Est. Priority Date: 03/04/2000
• Status: Active Grant

• Current Assignee: Endress + Hauser + Co. KG
• Original Assignee: Endress + Hauser + Co. KG
• Inventors: Burger, Stefan
• Granted Patent: US 6,727,845 B2
• Time in Patent Office: Days
• US Class Current: 342/124
• CPC Class Codes: H01P 5/103 Hollow-waveguide/coaxial-line transitions

Abstract

The invention relates to a device for emitting high-frequency signals, comprising a signal generation unit (6), a signalling line (12), an emission cable (16) and an antenna configured as a circular waveguide (10), said antenna being sealed in an end section by a rear wall (15). According to the invention, the signal generation unit (6) creates the high-frequency signals, the signalling line (12) conducts the high-frequency signals along the emission cable (16) and said emission cable (16) projects into the interior of the antenna (10) and is positioned approximately parallel to the rear wall (15). The invention aims to provide a device for emitting electromagnetic waves, which is characterized by optimized emission characteristics. To achieve this, the distance (Z) between the emission cable (16) and the rear wall (15) of the antenna (10) is approximately λ/6, whereby λ is the wavelength of the high-frequency signals borne by the antenna (10).

Claims

1. A device for emitting high-frequency signals, having a signal generation unit, a signal line, an emission cable, and an antenna embodied as a circular waveguide, which is terminated in an end region by a rear wall, wherein the signal generation unit generates the high-frequency signals, and the signal line carries the high-frequency signals to the emission cable of the antenna, and the emission cable protrudes into the circular waveguide and is disposed approximately parallel to the rear wall,

characterized in that

the spacing (Z) between the emission cable (16) and the rear wall (15) of the antenna (10) is approximately lambda/6, where lambda is the wavelength of the high-frequency signals carried in the antenna (10).

2. The device of claim 1,

characterized in that

the emission cable (16) disposed in the interior of the antenna (10) has a length (L), and the length (L) of the emission cable (16) meets the condition L≧

D/2, and at D characterizes the inside diameter of the antenna (10) embodied as a circular waveguide.

3. The device of claim 1 or 2,

characterized in that

a mushroom transmitter (18) is disposed in the region of the free end (17) of the emission cable (16).

4. The device of claim 1, 2 or 3,

characterized in that

a dielectric material (19) is provided, which fills up at least the interior of the antenna (10) in the region of the emission cable (16).

5. The device of claim 4,

characterized in that

a recess (20), into which the emission cable (16) protrudes, is provided in the dielectric material (19).

6. The device of claim 4 or 5,

characterized in that

the dielectric material (19) is polytetrafluoroethylene (PTFE) or aluminum trioxide (Al₂O₃).

7. The device of one or more of claims 1-6,

characterized in that

the device is part of a fill-level measuring instrument (1).