Metallised plastic antenna funnel for a fill level radar

• US 7,872,610 B2
• Filed: 11/17/2006
• Issued: 01/18/2011
• Est. Priority Date: 11/24/2005
• Status: Active Grant

• Current Assignee: VEGA Grieshaber KG (Grieshaber Verwaltungsgesellschaft mbH)
• Original Assignee: VEGA Grieshaber KG (Grieshaber Verwaltungsgesellschaft mbH)
• Inventors: Motzer, Juergen, Kienzle, Klaus, Sum, Christian, Fehrenbach, Josef
• Primary Examiner(s): Ho; Tan
• Application Number:
  US11/601,228
• Publication Number:
  US 20070115196A1
• Time in Patent Office: 1,523 Days
• Field of Search: 343/785, 343/786, 343/841
• US Class Current: 343/785
• CPC Class Codes: G01F 23/284 Electromagnetic waves
• 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 13/0208 Corrugated horns waveguide mouth antenna with corrugated flange H01Q13/065; manufacturing details H01Q13/0283
• CPC Class Codes: H01Q 19/062 for focusing

Abstract

A metalized plastic antenna includes a plastic antenna body with metallization on the inside. In this arrangement metallization is used for conducting electromagnetic waves. Furthermore, metallization may be implemented as a protective coating so that chemical resistance of the plastic antenna may be ensured even in the case of corrosive environmental conditions.

Claims

1. A metallised plastic antenna for a fill level radar, comprising:

an antenna body made of a plastic material; and

a collar having a connection region,

wherein an inside of the antenna body includes metallisation adapted for conducting electromagnetic waves, and

wherein the connection region of the collar includes a first angle in relation to the longitudinal axis of the collar such that the connection region can be placed against a waveguide so as to provide a seal.

2. The metallised plastic antenna according to claim 1, wherein the inside of the antenna body forms a hollow space;

wherein the hollow space comprises an aperture; and

wherein the hollow space is filled at least in part with a filler that closes off the aperture of the hollow space.

3. The metallised plastic antenna according to claim 1, wherein the filler comprises a dielectric material.

4. The metallised plastic antenna according to claim 1, wherein the frequency of the electromagnetic waves is between 50 gigahertz and 100 gigahertz.

5. The metallised plastic antenna according to claim 1, wherein the frequency of the electromagnetic waves is between 75 gigahertz and 85 gigahertz.

6. The metallised plastic antenna according to claim 1, wherein the frequency of the electromagnetic waves is between 5 gigahertz and 30 gigahertz.

7. The metallised plastic antenna according to claim 1, wherein the plastic antenna is designed as one of a horn antenna and as a parabolic antenna.

8. The metallised plastic antenna according to claim 1, wherein the antenna body comprises glass-fibre reinforced plastic.

9. The metallised plastic antenna according to claim 1, wherein the antenna body comprises polybutylene therapthalate and glass fibre.

10. The metallised plastic antenna according to claim 8, wherein the glass fibre content in the antenna body is between 25% and 35%.

11. The metallised plastic antenna according to claim 1, wherein metallisation of the inside of the antenna body comprises a varnish coating that has been enriched with conductive elements.

12. The metallised plastic antenna according to claim 11, wherein the varnish coating comprises a metal-filled conductive varnish.

13. The metallised plastic antenna according to any one of the preceding claims, wherein metallisation of the inside of the antenna body has been applied as a high vacuum vapour-deposit layer.

14. The metallised plastic antenna according to claim 1, wherein metallisation of the inside of the antenna body has been applied as a chemical electroplating layer.

15. The metallised plastic antenna according to claim 1, further comprising:

an encapsulation for closing off the aperture of the hollow space;

wherein the encapsulation serves to provide chemical protection to the inside of the antenna body from external influences.

16. The metallised plastic antenna according to claim 15, wherein encapsulation is designed as a lens for focussing the electromagnetic waves.

17. The metallised plastic antenna according to claim 1, wherein the connection region of the plastic antenna is rotationally symmetrical in relation to the longitudinal axis of the collar.

18. The metallised plastic antenna according to claim 1, further comprising a second layer;

wherein the second layer is arranged between the metallisation and the antenna body.

19. The metallised plastic antenna according to claim 1, further comprising a third layer;

wherein the third layer is arranged on the metallisation.

20. A fill level radar for determining the fill level in a tank, comprising:

a plastic antenna according to claim 1 for at least one of transmitting receiving electromagnetic waves; and

a waveguide feeding the electromagnetic waves to the antenna,

wherein the waveguide includes a region for connecting the waveguide to the connection region of the plastic antenna;

wherein the region of the waveguide in the connected state includes a second angle in relation to the longitudinal axis of the collar of the plastic antenna;

wherein the connection region of the plastic antenna includes a first angle in relation to the longitudinal axis of the collar of the lastic antenna which first angle is larger than the second angle; and

wherein the connection region of the plastic antenna can be placed against the region of the waveguide so as to provide a seal.

21. The use of a plastic antenna according to claim 1 for fill level measuring.

22. A method for producing a plastic antenna according to claim 1, comprising the steps of:

providing an antenna body from a plastic, with an inside;

metallisation of the inside of the antenna body for conducting electromagnetic waves.

23. The method according to claim 22, further comprising the step of:

plasma activation of the inside prior to metallisation;

wherein metallisation involves a step selected from the group comprising varnish coating, high-vacuum vapour depositing, and chemical electroplating.

24. The method according to claim 22, further comprising the step of:

applying a second layer to the inside of the antenna body prior to metallisation.

25. The method according to claim 22, further comprising the step of:

applying a third layer to the metallisation of the antenna body.