Horn antenna with a composite emitter for a radar-based level measurement system

• US 20070008212A1
• Filed: 06/13/2006
• Published: 01/11/2007
• Est. Priority Date: 06/13/2005
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens Milltronics Process Instruments, Inc. (Siemens AG)
• Inventors: Serban, Gabriel, Singh, Baljinder
• Granted Patent: US 7,602,330 B2
• Time in Patent Office: Days
• US Class Current: 342/124
• CPC Class Codes: H01Q 1/225 used in level-measurement devices, e.g. for level gauge measurement
• CPC Class Codes: H01Q 13/02 Waveguide horns
• CPC Class Codes: H01Q 13/24 constituted by a dielectric or ferromagnetic rod or pipe H01Q13/28 takes precedence

Abstract

A horn antenna suitable for use with a level measurement device and having a composite emitter structure. The emitter structure or assembly comprises an emitter and a plug. The emitter provides the process interface and is formed from a material having properties which include microwave transparency, chemical resistance and/or mechanical strength. The plug is isolated or partitioned from the process interface. The plug is formed from a material different from the emitter and exhibits the properties of microwave transparency and/or mechanical strength. According to another aspect, the level measurement device includes a coupling mechanism which allows the removal of the horn antenna independently of the emitter.

Claims

1-19. -19. (canceled)

20. An antenna structure for use in a level measurement device for measuring a level of a material held in a container, comprising:

a horn antenna;

an emitter assembly comprising;

a plug including a port for coupling to a waveguide from the level measurement device, and

an emitter having a surface for interfacing with a corresponding surface on the plug; and

a coupler for coupling the horn antenna to the level measurement device,

wherein at least a portion of the emitter assembly arranged in the horn antenna.

21. The structure as claimed in claim 20, wherein the coupler comprises:

a first mechanism for coupling the horn antenna to the level measurement device, and

a second mechanism for coupling the emitter assembly to the level measurement device,

wherein the first mechanism independently operable of the second mechanism.

22. The structure as claimed in claim 21,

wherein the first mechanism couples the horn antenna to the level measurement device indirectly via the second mechanism.

23. The structure as claimed in claim 21, wherein the second mechanism comprises a retaining ring having:

a recess for supporting one end of the emitter, and

a plurality of fasteners for securing the retaining ring to the level measurement device.

24. The structure as claimed in claim 23, wherein the first mechanism comprises a fastener for connecting the horn antenna to the retaining ring.

25. The structure as claimed in claim 23, wherein the emitter includes a tip section and a constant diameter section, the constant diameter section having a diameter corresponding substantially to the diameter of the recess.

26. The structure as claimed in claim 25, wherein the plug comprises:

a tip section providing a waveguide coupling port, and

a conical section having a surface for interfacing with the emitter.

27. The structure as claimed in claim 26, wherein the level measurement device includes a mounting collar having an internal chamber having a substantially reciprocal conical recess for receiving the conical section of the plug.

28. The structure as claimed in claim 20, wherein the emitter is formed from a material having a property selected from the group consisting of microwave transparency, chemical resistance, mechanical strength, and combinations thereof.

29. The structure as claimed in claim 28, wherein the material for the emitter comprises a chemically inert polymeric material.

30. The antenna as claimed in claim 29, wherein the plug is formed from a material having a property selected from the group consisting of mechanical strength, microwave transparency, and combinations thereof.

31. The structure as claimed in claim 30, wherein the material for the plug is selected from the group consisting of polymers, ceramics and glass.

32. The structure as claimed in claim 21, wherein the coupler further comprising a barrier member between the emitter and the plug.

33. The structure as claimed in claim 32, wherein the barrier member comprising an O-ring formed from a material selected from the group consisting of PTFE, Viton and Karlez.

34. A level measurement apparatus for determining a distance for material contained in a vessel, the level measurement apparatus comprising:

a housing;

an antenna;

a coupler for coupling the antenna to the housing, the coupler comprising;

a first mechanism for coupling the antenna to the housing, and

a second mechanism for coupling the emitter assembly to the housing;

a controller having a receiver module and a transmitter module, the controller having a bidirectional port for coupling to a waveguide; and

an emitter assembly comprising;

a plug including a port for coupling to the waveguide to the controller, and

an emitter having a service for interfacing with a corresponding surface on the plug,

wherein at least a portion of the emitter assembly is positioned in the antenna, and

wherein the first mechanism independently operable of the second mechanism.

35. The apparatus as claimed in claim 34,

wherein the emitter is formed from a first material having a chemical resistance;

and

wherein the plug is formed from a second material having a mechanical strength.

36. The apparatus as claimed in claim 34, wherein the second mechanism comprises a retaining ring, the retaining ring having:

a recess for supporting one end of the emitter, and

a plurality of fasteners for securing the retaining ring.

37. The level measurement apparatus as claimed in claim 36, wherein the emitter comprises:

a tip section, and

a constant diameter section having a diameter corresponding substantially to the diameter of the recess.

38. The apparatus as claimed in claim 37, wherein the plug comprises:

a tip section providing a waveguide coupling port, and

a conical section having a surface for interfacing with the emitter.

39. The apparatus as claimed in claim 38, further comprises:

a mounting collar including an internal chamber having a substantially reciprocal conical recess for receiving the conical section of the plug.