Compact broad-band admittance tunnel incorporating Gaussian beam antennas

• US 20080309571A1
• Filed: 12/19/2007
• Published: 12/18/2008
• Est. Priority Date: 12/22/2006
• Status: Active Grant

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Diaz, Rodolfo, Peebles, Jeffrey, Zhang, Zhichao, LeBaron, Richard, Lozano-Plata, Lorena
• Granted Patent: US 7,889,148 B2
• Time in Patent Office: Days
• US Class Current: 343/785
• CPC Class Codes: H01Q 13/0275 Ridged horns slot-line radiating ends H01Q13/085
• CPC Class Codes: H01Q 13/24 constituted by a dielectric or ferromagnetic rod or pipe H01Q13/28 takes precedence

Abstract

A plane wave antenna including: a horn antenna; a waveguide at least partially inside the horn antenna, wherein the waveguide includes: a central dielectric slab increasing in width toward the horn antenna and with a first dielectric constant, an upper slab above the central dielectric slab with a second dielectric constant, and a lower slab below the central dielectric slab with the second dielectric constant; wherein the central dielectric slab has a substantially constant thickness less than a quarter of a wavelength at a highest frequency of operation of the plane wave antenna.

Claims

1. A plane wave antenna comprising:

a horn antenna;

a waveguide at least partially inside the horn antenna, wherein the waveguide comprises;

a central dielectric slab increasing in width toward the horn antenna and with a first dielectric constant,

an upper slab above the central dielectric slab with a second dielectric constant, and

a lower slab below the central dielectric slab with a third dielectric constant;

wherein the central dielectric slab has a substantially constant thickness less than a quarter of a wavelength at a highest frequency of operation of the plane wave antenna.

2. The plane wave antenna of claim 1, further comprising an iris between the waveguide and a test sample, wherein the iris has a serrated edge.

3. The plane wave antenna of claim 1, wherein the central dielectric slab has an arctangent curve shape toward the horn antenna.

4. The plane wave antenna of claim 1, wherein the central dielectric slab has an exponential curve shape toward the horn antenna.

5. The plane wave antenna of claim 1, wherein the central dielectric slab has a polynomial curve shape toward the horn antenna.

6. The plane wave antenna of claim 1, wherein each of the upper slab and the lower slab has an ellipsoid shape.

7. The plane wave antenna of claim 6, wherein each of the upper slab and the lower slab has a thickness of about 1/10th of its length and a width of about ½

of its length.

8. The plane wave antenna of claim 6, wherein the upper slab and the lower slab are each spaced apart from the central dielectric slab with an air gap therebetween.

9. The plane wave antenna of claim 8, wherein the air gap is about 0.09 inches.

10. The plane wave antenna of claim 1, wherein the first dielectric constant is higher than the second dielectric constant, and wherein the third dielectric constant is substantially the same as the second dielectric constant.

11. The plane wave antenna of claim 1, wherein the upper slab and the lower slab are spaced apart from the central dielectric slab.

12. The plane wave antenna of claim 1, wherein the horn antenna is a broadband double-ridged horn antenna.

14. The sample evaluating system of claim 10, wherein the waveguide comprises:

a central dielectric slab increasing in width toward the horn antenna and with a first dielectric constant,

an upper slab above the central dielectric slab with a second dielectric constant, and

a lower slab below the central dielectric slab with a third dielectric constant;

wherein the central dielectric slab has a substantially constant thickness less than a quarter of a wavelength at a highest frequency of operation of the plane wave antenna.

15. The sample evaluating system of claim 11, wherein the central dielectric slab has an arctangent curve shape toward the horn antenna or an exponential curve shape toward the horn antenna or a polynomial curve shape toward the horn antenna.

16. The sample evaluating system of claim 11, wherein the upper slab and the lower slab have an ellipsoid shape.

17. The sample evaluating system of claim 11, wherein the first dielectric constant is higher than the second dielectric constant, and wherein the third dielectric constant is substantially the same as the second dielectric constant.

18. The sample evaluating system of claim 11, wherein the upper slab and the lower slab are spaced apart from the central dielectric slab.

19. The sample evaluating system of claim 11, wherein the horn antenna is a broadband double ridged horn antenna.

21. The waveguide of claim 19, wherein the central dielectric slab has an arctangent curve shape toward the horn antenna.

22. The waveguide of claim 19, wherein the central dielectric slab has an exponential curve shape toward the horn antenna.

23. The waveguide of claim 19, wherein the central dielectric slab has a polynomial curve shape toward the horn antenna.

24. The waveguide of claim 19, wherein the upper slab and the lower slab have an ellipsoid shape

25. The waveguide of claim 19, wherein the first dielectric constant is higher than the second dielectric constant.

27. The method of claim 25, further comprising forming an iris between the waveguide and a test sample, wherein the iris has a serrated edge.

28. The method of claim 25, wherein the central dielectric slab is formed to have an arctangent curve shape toward the horn antenna or an exponential curve shape toward the horn antenna or a polynomial curve shape toward the horn antenna.

29. The method of claim 25, wherein the upper slab and the lower slab form an ellipsoid shape.

30. The method of claim 25, wherein the first dielectric constant is higher than the second dielectric constant, and wherein the third dielectric constant is substantially the same as the second dielectric constant.

31. The method of claim 25, wherein the upper slab and the lower slab are spaced apart from the central dielectric slab.

32. The method of claim 25, wherein the horn antenna is formed to be a broadband double-ridged horn antenna.

13. A sample evaluating system comprising:

a transmitter for transmitting an evaluation signal, the transmitter comprising

a horn antenna and

a waveguide at least partially inside the horn antenna,

a receiver for receiving the evaluation signal; and

a sample holder between the transmitter and the receiver, the sample holder comprising an iris having a serrated edge.

20. A waveguide comprising:

a central dielectric slab increasing in width toward the horn antenna and with a first dielectric constant,

an upper slab above the central dielectric slab with a second dielectric constant, and

a lower slab below the central dielectric slab with the second dielectric constant;

wherein the central dielectric slab has a substantially constant thickness less than a quarter of a wavelength at a highest frequency of operation of the plane wave antenna.

26. A method of manufacturing a plane wave antenna, the method comprising:

forming a waveguide, the method of forming the waveguide comprising;

forming a central dielectric slab with a first dielectric constant, wherein the central dielectric slab is wider at a first end than at a second end,

forming an upper dielectric slab with a second dielectric constant above the central dielectric slab;

forming a lower dielectric slab with a third dielectric constant below the central dielectric slab;

inserting at least a portion of the waveguide into a horn antenna;

wherein the central dielectric slab has a substantially constant thickness less than a quarter of a wavelength at a highest frequency of operation of the plane wave antenna.