ANTENNA CHARACTERIZATION IN A WAVEGUIDE

• US 20120146861A1
• Filed: 08/10/2010
• Published: 06/14/2012
• Est. Priority Date: 08/14/2009
• Status: Active Grant

• Current Assignee: Rosenberger Hochfrequenztechnik GmbH & Company KG (Rosenberger Technology (Kunshan) Co., Ltd.)
• Original Assignee: Rosenberger Hochfrequenztechnik GmbH & Company KG (Rosenberger Technology (Kunshan) Co., Ltd.)
• Inventors: Sczyslo, Sebastian, Armbrecht, Gunnar, Dortmund, Sven, Thye, Holger
• Granted Patent: US 9,279,845 B2
• Time in Patent Office: Days
• US Class Current: 343/703
• CPC Class Codes: G01R 29/0828 TEM-cells
• CPC Class Codes: G01R 29/105 using anechoic chambers; Chambers or open field sites used therefor test sites used for measuring on other objects than aerials G01R29/0828; wave absorbing devices H01Q17/00

Abstract

A method for determining at least one characteristic of an antenna requiring: a) positioning an antenna in a space surrounded by a waveguide; b) feeding an electric excitation signal (u_tx(t)) into a feed connection of the waveguide; c) receiving the electric response signal (u_rx(t)) emitted by the antenna resulting from the excitation signal (u_tx(t)); d) determining at least one characteristic of the antenna from a portion of the response signal (u_rx(t)) and a corresponding portion of the excitation signal (u_tx(t)), where the portion of the response signal (u_rx(t)) is evaluated in the time domain and satisfies the following conditions: (i) only one or more waves of the electromagnetic field caused by the excitation signal (u_tx(t)) and running from the feed connection towards the antenna exist at the location of the antenna; and (ii) the electromagnetic field at the location of the antenna is a TEM field.

Claims

1. Method for determining at least one characteristic of an antenna comprising the steps:

positioning an antenna of which said at least one characteristic is to be determined, in a space surrounded by a waveguide;

feeding an electric excitation signal (u_tx(t)) into a feed connection of the waveguide;

receiving the electric response signal (u_rx(t)) emitted by the antenna as a result of the excitation signal (u_tx(t));

determining said at least one characteristic of the antenna from at least one portion of the response signal (u_rx(t)) and a corresponding portion of the excitation signal (u_tx(t)), wherein the portion of the response signal (u_rx(t)) is a time segment evaluated in the time domain which satisfies the following conditions;

i) only one or several waves of the electromagnetic field caused by the excitation signal (u_tx(t)) and running from the feed connection towards the antenna exist at the location of the antenna; and

ii) the electromagnetic field at the location of the antenna is a TEM field.

2. The method of claim 1 including a high frequency bandwidth excitation pulse used as the excitation signal (u_tx(t)).

3. The method of claim 2 wherein the response signal (u_rx(t)) is recorded in the time domain.

4. The method of claim 1 including a frequency domain signal used as the excitation signal (u_tx(t)).

5. The method of claim 4 including recording the response signal (U_rx(t)) in phase in the frequency domain.

6. The method of claim 1 including determining frequency domain characteristics of the antenna from the response signal (u_rx(t)).

7. The method of claim 1 including determining transmission properties of the antenna from the response signal (u_rx(t)).

8. The method of claim 1 including the frequency bandwidth of the excitation signal (u_tx(t)) being equal to or greater than the frequency bandwidth the antenna.

9. The method of claim 1 wherein a characteristic (h_rx(t)) proportional to the de-convolution of the response signal (u_rx(t)), determined with the excitation signal (u_tx(t)), is a characteristic of the antenna.

10. The method of claim 1 wherein the waveguide comprises a TEM waveguide.

11. The method of claim 1 wherein the antenna includes an ultra-wideband antenna.

12. The method of claim 1 wherein the antenna is arranged in the waveguide, movable in at least one spatial dimension or at least one axis of rotation, and a first value of a characteristic of the antenna is determined in a first antenna position and at least a second value of the characteristic in a second antenna position.

13. The method of claim 1 wherein the dimensions of the waveguide, the positioning of the antenna in the waveguide in the longitudinal direction of the waveguide, or both, are chosen as a function of the duration of the response signal (u_rx(t)) necessary in order to determine the desired characteristic or the size of the antenna.

14. The method of claim 1 wherein the antenna is positioned in the waveguide such that the ratio between relatively orthogonal components of the electric field strength and the magnetic field strength of a Cartesian 2-component TEM field, wherein both components are orthogonal to the main direction of propagation of the electromagnetic field in the waveguide, is approximately the free space intrinsic impedance.

15. The method of claim 1 wherein the characteristic data of the waveguide are determined through measurement and the characteristic is determined from the response signal (u_rx(t)), mathematically corrected by the characteristic data of the waveguide.

16. A measuring device for determining at least one characteristic of an antenna, wherein the measuring device is set up to perform a method according to claim 1.

17. The method of claim 2 wherein said high frequency bandwidth excitation pulse comprises a Gaussian pulse shape.

18. The method of claim 2 including using a frequency domain signal as the excitation signal (u_tx(t)).

19. The method of claim 3 including using a frequency domain signal as the excitation signal (u_tx(t)).

20. The method of claim 17 including using a frequency domain signal as the excitation signal (u_tx(t)).

21. The method of claim 17 including recording the response signal (U_rx(t)) in phase in the frequency domain.

22. The method of claim 3 including determining frequency domain characteristics of the antenna from the response signal (u_rx(t)).

23. The method of claim 17 including determining frequency domain characteristics of the antenna from the response signal (u_rx(t)).

24. The method of claim 6 wherein said frequency domain characteristics of the antenna include gain, directional characteristic, efficiency, or any combination thereof.

25. The method of claim 23 wherein said frequency domain characteristics of the antenna include gain, directional characteristic, efficiency, or any combination thereof.

26. The method of claim 6 including the frequency bandwidth of the excitation signal (u_tx(t)) being equal to or greater than the frequency bandwidth the antenna.

27. The method of claim 23 including the frequency bandwidth of the excitation signal (u_tx(t)) being equal to or greater than the frequency bandwidth the antenna.

28. The method of claim 23 wherein a characteristic (h_rx(t)) proportional to the de-convolution of the response signal (u_rx(t)), determined with the excitation signal (u_tx(t)), is a characteristic of the antenna.

29. The method of claim 24 wherein a characteristic (h_rx(t)) proportional to the de-convolution of the response signal (u_rx(t)), determined with the excitation signal (u_tx(t)), is a characteristic of the antenna.

30. The method of claim 11 including said ultra-wideband antenna having at least 500 MHz frequency bandwidth.

31. The method of claim 10 wherein the waveguide comprises a TEM cell or a GTEM cell.