System and method for tuning a resonant structure

• US 6,369,585 B2
• Filed: 10/02/1998
• Issued: 04/09/2002
• Est. Priority Date: 10/02/1998
• Status: Expired due to Term

• Current Assignee: Siemens Medical Systems, Inc. (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Yao, Chong Guo
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): Nguyen, Vincent Q.
• Application Number:
  US09/165,523
• Publication Number:
  US 20010013785A1
• Time in Patent Office: 1,285 Days
• Field of Search: 324/636, 324/652, 324/653, 324/71.3, 324/316, 324/318, 324/322, 324/633, 333/17.1, 333/219, 333/227, 333/231, 333/235, 315/5.41, 315/505, 315/507, 250/492.3
• US Class Current: 324/636
• CPC Class Codes: G01R 23/04 adapted for measuring in circuits having distributed constants
• CPC Class Codes: G01R 27/32 in circuits having distributed constants , e.g. having very long conductors or involving high frequencies
• CPC Class Codes: G01R 31/2824 testing of oscillators or resonators
• CPC Class Codes: H05H 7/18 Cavities; Resonators travelling-wave tubes H01J23/18; hyperfrequency cavities in general H01P7/04, H01P7/06

Abstract

An embodiment of the present invention includes the use of a single connection to measure the resonance frequency of main cells or side cells of a resonant structure, such as a linear accelerator cavity structure. Only one antenna is require to perform both the tasks of exciting a cavity structure and picking up the resonant frequency signal. According to an embodiment of the present invention, a first antenna probe is inserted into the main cells of a linear accelerator cavity structure. The first antenna probe includes an antenna window which may be positioned approximately in the center of a main cell adjacent to a target side cell in order to measure the resonance frequency of a target side cell. All non-target side cells adjacent to the main cell aligned with the window antenna are then shorted. For example, the non-target cells may be shorted by metal surrounding the first antenna probe at locations other than the antenna window. A signal is sent and a resonance frequency is noted. In order to measure the resonance frequency of a target main cell according to an embodiment of the present invention, a second antenna probe is inserted into a side cell adjacent to the target main cell. The main cells adjacent to the target main cell are then shorted and side cells adjacent to the target main cell are also shorted. A signal is sent and the resonance frequency of the target main cell is then measured.

Claims

1. A method for determining a resonance frequency of a device including a plurality of cells forming a resonant structure, the method comprising:

using a probe to provide an excite signal in a first cell, wherein the probe includes a signal wire;

receiving a signal through the probe in response to the excite signal, the signal being reflected from a second cell;

shorting a third cell; and

determining a resonance frequency of the second cell based on the reflected signal.

2. The method of claim 1, wherein the probe is a coaxial cable with metal surrounding at least a portion of the signal wire.

3. The method of claim 1, wherein the probe includes an antenna window.

4. The method of claim 1, further comprising shorting the first cell of the system.

5. The method of claim 1, wherein the third cell of the system is adjacent to the first cell of the system.

6. The method of claim 1, wherein the third cell of the system is adjacent to the second cell of the system.

7. The method of claim 1, wherein the system includes a linear accelerator in which a beam passes through cells positioned as main cells and does not pass through cells positioned as side cells.

8. The method of claim 1, wherein the system includes a side coupled cavity structure.

9. The method of claim 1, wherein the first cell is a main cell of the system.

10. The method of claim 9, wherein the second cell is a side cell of the system.

11. The method of claim 1, wherein the first cell is a side cell of the system.

12. The method of claim 11, wherein the second cell is a main cell of the system.

13. A system including a plurality of cells positioned to form a resonant structure, said system further comprising:

a probe providing an excite signal in a first cell wherein the probe includes a signal wire;

the probe receiving a reflected signal in response to said excite signal; and

means for determining a resonance frequency of a second cell based on said reflected signal when a third cell is shorted.

14. The system of claim 13, wherein the probe is a coaxial cable with metal surrounding at least a portion of the signal wire.

15. The system of claim 13, wherein the probe includes an antenna window.

16. A system for determining a resonance frequency of a device including a plurality of cells positioned to form a resonant structure, said system further comprising:

a first cell;

a second cell;

a third cell; and

a probe including a signal wire, wherein the probe is configured to provide an excite signal in the first cell the probe also being configured to receive a reflected signal in response to the excite signal related to a resonance frequency of the second cell, and wherein the third cell is shorted.

17. The system of claim 16, wherein the probe is a coaxial cable with metal surrounding at least a portion of the signal wire.

18. The system of claim 16, wherein the probe includes an antenna window.

19. The system of claim 16, further comprising shorting the first cell.

20. The system of claim 16, wherein the system is a linear accelerator system in which a beam passes through cells positioned as main cells and does not pass through any cells positioned as side cells.

21. The system of claim 16, wherein the system includes a side coupled cavity structure.

22. The system of claim 16, wherein the first cell is a main cell of the system.

23. The system of claim 22, wherein the second cell is a side cell.

24. The system of claim 16, wherein the first cell is a side cell.

25. The system of claim 24, wherein the second cell is a main cell.