EP0871235A2 - Microwave filter with coupling elements - Google Patents
Microwave filter with coupling elements Download PDFInfo
- Publication number
- EP0871235A2 EP0871235A2 EP98400865A EP98400865A EP0871235A2 EP 0871235 A2 EP0871235 A2 EP 0871235A2 EP 98400865 A EP98400865 A EP 98400865A EP 98400865 A EP98400865 A EP 98400865A EP 0871235 A2 EP0871235 A2 EP 0871235A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- opening
- coupling
- cavities
- probe
- microwave filter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/20—Frequency-selective devices, e.g. filters
- H01P1/207—Hollow waveguide filters
- H01P1/208—Cascaded cavities; Cascaded resonators inside a hollow waveguide structure
Definitions
- the present invention refers to a microwave filter and, in particular, to a microwave filter with multiple resonant cavities for use in communication systems, as applied especially, but not exclusively, to satellite communications.
- Microwave filters with multiple resonant cavities which include specific coupling elements are known, for instance, through the patent application WO 95/27317, "DIELECTRIC RESONATOR FILTER" which, being referred to in the present patent application, is included in it.
- a monomode microwave filter with multiple resonant cavities which includes two rows of resonant cavities is described, the electromagnetic energy between successive or adjacent cavity resonators being coupled by means of slots -in the walls that separate said cavities, or by means of probes located in said walls; the purpose of said couplings is to obtain a filter-type response of determined characteristics.
- the probe is usually situated in an opening made in a wall that separates two cavities by means of an insulating material which serves as a mechanical support and at the same time prevents electrical contact between the wall and the probe.
- an insulating material which serves as a mechanical support and at the same time prevents electrical contact between the wall and the probe.
- the coupling produced by the slot is mathematically defined as positive, usually the coupling is made through the probe of the opposite sign.
- the sign and the coupling value that correspond to the probe depend on its length, geometry and relative position with respect to the electromagnetic fields within the resonant cavities.
- the adjustment of the coupling value produced by a probe is complicated since the effect produced by said probe cannot easily be formulated as a mathematical model. Therefore, the filter adjustment process requires several probes to be tested in order to obtain the desired output characteristics. Consequently, the microwave filter adjustment process requires a long time and this process is expensive.
- One object of the invention is to provide a microwave filter with multiple resonant cavities which features couplings between adjacent cavities, so that the process for obtaining the output characteristics of said filter is simple, fast and easily repeatable. Consequently, the cost of the process for adjusting the microwave filter is reduced.
- the microwave filter with multiple resonant cavities of the invention is made up of resonant cavities delimited by conducting walls, said resonant cavities being arranged in such a way that they are ordered consecutively.
- At least two adjacent cavities are coupled by means of a coupling element comprising at least one first opening in a common wall to said two adjacent cavities, producing a coupling that is mathematically defined as positive; a probe that is placed in said first opening which produces a coupling of opposite sign to that defined by said first opening and, also, includes movable adjustment means which penetrate in the first opening and whose function is to adjust the overall value of the coupling produced by the combination of said first opening and said probe.
- Figure 1 shows a plan view of the body 11 of a microwave filter with multiple resonant cavities according to the invention, in which the cover of said filter has been removed, so that six consecutively arranged cavities 14,15,16,17,18,19, which are delimited by conducting walls, may be distinguished.
- the microwave filter with six cavities 14 to 19 will be used, the cavities being arranged for instance, in two rows as an example for describing a preferred embodiment of the invention, without this restricting the use of same to said filter with six resonant cavities.
- the signal which is filtered by the microwave filter is applied to an input terminal 12 and the filtered signal is available at an output terminal 13 of said filter.
- the cavities 14 to 19 arranged in two rows, have common conducting walls so that in a conducting wall that is common to the two adjacent and consecutive cavities 14, 15 there is one slot 21 respectively, said slot 21 producing a coupling between the same, and said coupling being mathematically defined as positive.
- a cross-coupling is one that is produced between two cavities, for example 15 and 18, which are attached but non-consecutive. Accordingly, the combination of positive and negative couplings together with the existence of cross-coupling produces zeros in transmission or equalization zeros, and thus the microwave filter with resonant cavities features a complex transfer function.
- the cross-coupling between at least two adjacent non-consecutive cavities, for example 15, 18, is produced by means of a coupling element which comprises at least one first opening 22 which produces a coupling that is, for instance, mathematically defined as positive.
- Said first opening 22 is carried out in a conducting wall 20 that is common to said cavities 15, 18.
- said first opening 21 is centered in the conducting wall 20; however, in other embodiments it may be moved in relation to the centre of said conducting wall 20.
- the insulating material 24 serves as a mechanical support and at the same time prevents electrical contact between the conducting wall 20 and said probe 23.
- the probe 23 produces a coupling of opposite sign to that produced by the first opening 22.
- movable adjustment means 33 for example a screw, which penetrates said opening 22, so that by moving them the overall value of the coupling is adjusted (see figures 2 and 3).
- Said movable adjustment means 33 are accessible from outside the microwave filter body 11. Moreover, when moved in order to adjust the output characteristics of the filter, said movable adjustment means 33 can penetrate into the insulation material 24 through a hole 34.
- the probe 23 is usually made of conductive materials and the coupling value produced by the same is a function of its geometry (symmetrical or asymmetrical) and of its physical dimensions (length).
- the process for obtaining the output characteristics of the microwave filter will be carried out by moving the adjustable coupling means 33, which is a simple and easily repeatable operation as said means are accessible from outside the filter. Consequently, during the process of adjusting the filter, it will not be necessary to change the probe 23 which is defined theoretically in the design process of said microwave filter.
- the insulating material 24 which serves as a mechanical support for the probe 23 has a perforation 34 which passes completely through it and in which said probe 23 is housed, protruding on both sides of said insulating material 23 (see figure 3).
- the movable adjustment means 33 will change not only the overall value of the coupling, but also the sign of the same.
- the couplings respectively produced by the first opening 22 and the probe 23 must be nearly equal.
- the cross-coupling may be obtained as a combination of two openings, containing for instance, the first opening 22, the probe 23 with the adjustable coupling means 33 being placed in the second opening, or in the two openings, respectively. Therefore, said two openings will usually be moved in relation to the centre of the conducting wall 20 that is common to the two adjacent cavities 15, 18.
- the coupling element will be situated, for instance, in the conducting wall that is common to the two adjacent and consecutive cavities 14, 15, producing a negative coupling, said conducting wall not presenting the slot 21.
- the first opening 22 of the coupling element will usually be moved in relation to the centre of the conducting wall that is common to the two adjacent and consecutive cavities 14, 15.
- the described coupling element has means for adjusting the overall value and the coupling sign it produces; positive and negative couplings may thus be obtained with said coupling element.
Landscapes
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
Description
- figure 1 shows a plan-view of a microwave filter body with multiple resonant cavities, according to the invention,
- figure 2 shows a perspective view of a conducting wall which is common to two attached and non-consecutive cavities, according to the invention, and
- figure 3 shows a perspective view of a coupling element, according to the invention.
Claims (4)
- MICROWAVE FILTER with multiple resonant cavities, said cavities being delimited by conducting walls and at least two adjacent cavities (15, 18) being coupled by a coupling element, characterized in that said coupling element comprises:at least one first opening (22) in a conducting wall (20) that is common to said adjacent and non-consecutive cavities (15, 18) which produces a coupling,at least one probe (23) positioned in said first opening (22), producing a coupling of opposite sign to that produced by said first opening (22),at least one movable adjustment means (33) which penetrates into said first opening (22) in such a way that it adjusts the overall value of the coupling produced by said first opening (22) and said probe (23).
- MICROWAVE FILTER according to claim 1, characterized in that said coupling element is located in a conducting wall that is common to two adjacent and consecutive cavities (15, 16).
- MICROWAVE FILTER according to claim 1, characterized in that the first opening (22) and the probe (23) have such dimensions that their couplings compensate respectively in such a way that by varying the position of the movable adjustment means (33), as many coupling values with positive sign as with negative sign are obtained.
- MICROWAVE FILTER according to claim 1, characterized in that the coupling element also includes a second opening in which the movable adjustment means (33) penetrate, and the probe (23) is situated in the first opening (22), thus obtaining a certain range of coupling values.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ES9700777 | 1997-04-11 | ||
ES9700777 | 1997-04-11 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0871235A2 true EP0871235A2 (en) | 1998-10-14 |
EP0871235A3 EP0871235A3 (en) | 1999-03-24 |
Family
ID=8298927
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP98400865A Withdrawn EP0871235A3 (en) | 1997-04-11 | 1998-04-09 | Microwave filter with coupling elements |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0871235A3 (en) |
CA (1) | CA2231033A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6228870B1 (en) | 1998-11-10 | 2001-05-08 | Merck & Co., Inc. | Oxazolidinones useful as alpha 1a adrenoceptor antagonists |
US6319932B1 (en) | 1998-11-10 | 2001-11-20 | Merck & Co., Inc. | Oxazolidinones useful as alpha 1A adrenoceptor antagonists |
WO2023005651A1 (en) * | 2021-07-29 | 2023-02-02 | 中兴通讯股份有限公司 | Multimode dielectric filter |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0075498A1 (en) * | 1981-09-04 | 1983-03-30 | Thomson-Csf | Cavity filter with coupling between non-adjacent cavities |
WO1996029754A1 (en) * | 1995-03-23 | 1996-09-26 | Bartley Machine & Manufacturing Company, Inc. | Dielectric resonator filter |
EP0759645A2 (en) * | 1995-08-21 | 1997-02-26 | Murata Manufacturing Co., Ltd. | Dielectric resonator apparatus |
-
1998
- 1998-04-06 CA CA 2231033 patent/CA2231033A1/en not_active Abandoned
- 1998-04-09 EP EP98400865A patent/EP0871235A3/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0075498A1 (en) * | 1981-09-04 | 1983-03-30 | Thomson-Csf | Cavity filter with coupling between non-adjacent cavities |
WO1996029754A1 (en) * | 1995-03-23 | 1996-09-26 | Bartley Machine & Manufacturing Company, Inc. | Dielectric resonator filter |
EP0759645A2 (en) * | 1995-08-21 | 1997-02-26 | Murata Manufacturing Co., Ltd. | Dielectric resonator apparatus |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6228870B1 (en) | 1998-11-10 | 2001-05-08 | Merck & Co., Inc. | Oxazolidinones useful as alpha 1a adrenoceptor antagonists |
US6319932B1 (en) | 1998-11-10 | 2001-11-20 | Merck & Co., Inc. | Oxazolidinones useful as alpha 1A adrenoceptor antagonists |
WO2023005651A1 (en) * | 2021-07-29 | 2023-02-02 | 中兴通讯股份有限公司 | Multimode dielectric filter |
Also Published As
Publication number | Publication date |
---|---|
CA2231033A1 (en) | 1998-10-11 |
EP0871235A3 (en) | 1999-03-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1024548B1 (en) | Dielectric filter | |
Fiedziuszko | Dual-mode dielectric resonator loaded cavity filters | |
US4216448A (en) | Microwave distributed-constant band-pass filter comprising projections adjacent on capacitively coupled resonator rods to open ends thereof | |
Wang et al. | Dielectric combline resonators and filters | |
EP1414103B1 (en) | Dielectric mono-block triple-mode microwave delay filter | |
EP0856902B1 (en) | Dielectric filter and dielectric duplexer | |
US4142164A (en) | Dielectric resonator of improved type | |
EP1411582B1 (en) | Canonical general response bandpass microwave filter | |
EP0657954B1 (en) | Improved multi-cavity dielectric filter | |
US4990870A (en) | Waveguide bandpass filter having a non-contacting printed circuit filter assembly | |
US6611183B1 (en) | Resonant coupling elements | |
EP1570541B1 (en) | Bandpass filter with pseudo-elliptic response | |
US4902991A (en) | Radio frequency signal combining/sorting device | |
US6975181B2 (en) | Dielectric resonator loaded metal cavity filter | |
EP1220351B1 (en) | High performance microwave filter | |
EP0871235A2 (en) | Microwave filter with coupling elements | |
EP0930666B1 (en) | Dielectric filter and dielectric duplexer | |
JP2001257511A (en) | Resonator, filter duplexer and communication equipment | |
EP1079457A2 (en) | Dielectric resonance device, dielectric filter, composite dielectric filter device, dielectric duplexer, and communication apparatus | |
US6201456B1 (en) | Dielectric filter, dielectric duplexer, and communication device, with non-electrode coupling parts | |
EP1218959B1 (en) | Filter utilizing a coupling bar | |
CA2392275C (en) | Asymmetric response bandpass filter having resonators with minimum couplings | |
Yu et al. | A dual mode filter with trifurcated iris and reduced footprint | |
Wang et al. | Conductor loaded resonator filters with wide spurious-free stopbands | |
GB2305547A (en) | Temperature compensation using a composite resonator in a coaxial cavity signal transmission filter |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): DE ES FR GB IT |
|
AX | Request for extension of the european patent |
Free format text: AL;LT;LV;MK;RO;SI |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
RAP3 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: ALCATEL |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
|
AX | Request for extension of the european patent |
Free format text: AL;LT;LV;MK;RO;SI |
|
RAP3 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: ALCATEL |
|
17P | Request for examination filed |
Effective date: 19990924 |
|
AKX | Designation fees paid |
Free format text: DE ES FR GB IT |
|
17Q | First examination report despatched |
Effective date: 20040603 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20041014 |