GB2367952A - Microwave dual mode dielectric resonator - Google Patents
Microwave dual mode dielectric resonator Download PDFInfo
- Publication number
- GB2367952A GB2367952A GB0025158A GB0025158A GB2367952A GB 2367952 A GB2367952 A GB 2367952A GB 0025158 A GB0025158 A GB 0025158A GB 0025158 A GB0025158 A GB 0025158A GB 2367952 A GB2367952 A GB 2367952A
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- Prior art keywords
- resonator
- coupling
- element according
- irregularity
- dielectric
- 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.)
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Links
- 230000009977 dual effect Effects 0.000 title description 9
- 230000008878 coupling Effects 0.000 claims abstract description 46
- 238000010168 coupling process Methods 0.000 claims abstract description 46
- 238000005859 coupling reaction Methods 0.000 claims abstract description 46
- 230000001939 inductive effect Effects 0.000 claims abstract description 17
- 239000003989 dielectric material Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 6
- 239000000843 powder Substances 0.000 claims description 6
- 239000000919 ceramic Substances 0.000 claims description 4
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 description 11
- 238000000034 method Methods 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 9
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 6
- 230000008901 benefit Effects 0.000 description 5
- 210000000554 iris Anatomy 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 210000000887 face Anatomy 0.000 description 3
- 229910052709 silver Inorganic materials 0.000 description 3
- 239000004332 silver Substances 0.000 description 3
- 229960005363 aluminium oxide Drugs 0.000 description 2
- FFTDWVOLFHWSSJ-UHFFFAOYSA-N barium(2+);oxygen(2-);titanium(4+) Chemical group [O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Ti+4].[Ti+4].[Ti+4].[Ba+2] FFTDWVOLFHWSSJ-UHFFFAOYSA-N 0.000 description 2
- 229910010293 ceramic material Inorganic materials 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 239000010432 diamond Substances 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 230000017525 heat dissipation Effects 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000003467 diminishing effect Effects 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P7/00—Resonators of the waveguide type
- H01P7/10—Dielectric resonators
- H01P7/105—Multimode resonators
-
- 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
- H01P1/2084—Cascaded cavities; Cascaded resonators inside a hollow waveguide structure with dielectric resonators
- H01P1/2086—Cascaded cavities; Cascaded resonators inside a hollow waveguide structure with dielectric resonators multimode
Landscapes
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
A dielectric resonator element suitable for a microwave filter or duplexer comprises a metallised dielectric block 10 of substantially square cross-section, but with an irregularity such as a planar cut 14 or a protrusion in a corner thereof. The irregularity promotes coupling between two orthogonal modes without needing a coupling screw. The block may comprise an iris 20 at each end to allow coupling with adjacent elements via a coupling element 30 (see figures 4, 5). The coupling element 30 comprises a dielectric sheet with a centrally arranged inductive loop (36, see figure 4) on each side. The inductive loop is formed from two conductive posts (38, see figure 4) connected to a conductive strip (40, see figure 4) folded into a loop.
Description
MICROWAVE DUAL MODE RESONATOR The present invention relates to a microwave dual mode resonator for use in microwave filters and duplexers, wherein transmission through the resonator takes place in two or more modes.
Microwave resonators are known using dielectric elements of high dielectric constant for miniaturising the resonator."800 MHz band high-power band pass filter using TM, 10 mode dielectric resonators for cellular base stations"Nishikawa et al, 1988 IEEE MTT-S Digest, page 519 discloses a resonator comprising a solid dielectric core which functions as the resonator, being silver-plated on the outside for shielding. The silver-plating also serves to conduct heat away efficiently from the dielectric core. Resonant frequency is adjusted by moving a dielectric tuning rod in a through hole in the core.
"800 MHz high-power duplexer using TM dual mode dielectric resonators"Ishikawa, et al, 1992 IEEE MTT-S Digest, page 1617 discloses a resonator unit having a dielectric core of high dielectric constant, and being of cruciform shape. Recesses were created in two opposite comers of the cruciform shape. This created a perturbation in the electrical transmission characteristics, and hence a degree of coupling between two orthogonal modes of transmission. This results in two resonant frequencies, and enables the resonator to be used as a duplexer. Tuning was achieved by insertion of a dielectric tuning rod. This device has the difficulty that it is in practice difficult to form the recesses to obtain accurately and repeatable electrical characteristics.
"Dual mode coupling by square cut in resonators and filters"Zaki et al, IEEE Transactions on
Microwave Theory and Techniques, Volume 40, Number 12, December 1992, page 2294 discloses a simple rectangular waveguide cavity having along one edge of the cavity, a square comer cut to produce a recess of rectangular form along the edge. This recess creates an electrical coupling between two orthogonal modes propagating through the cavity. The advantage of this method is that the electrical characteristics of the effects of the recess can accurately be calculated in advance by numerical techniques.
Whilst the disclosure of Zaki is principally concerned with air filled cavities, the results are applicable to cavities filled with dielectric material of high dielectric constant. This comer cut technique is intended to avoid the need for a final tuning of the resonator by means of tuning aids such as coupling screws. However, in the case of high dielectric constant materials, these are usually powder ceramic materials, where square recesses present difficulties in manufacture and life-expectancy of the manufacturing tools.
Summary of the Invention
It is an object of the invention to provide a resonator for microwave filters or duplexers which avoids or reduces the above noted problems.
In a first aspect, the present invention provides a resonator element for a microwave filter or duplexer, the element being formed of dielectric material of tubular form having a cross section such as to enable electromagnetic propagation in two orthogonal modes, and the surface of the tubular member having an irregularity comprising a recess or protrusion extending along the length of the tubular member such as to enable coupling between said two orthogonal modes, and wherein the surface of the irregularity is continuous and without discontinuity.
In accordance with the invention it has been realised that, particularly in the case of powder ceramic high dielectric constant material, irregularities formed without discontinuities, e. g.sharp comers, are easier to manufacture and are more stable and therefore have more predictable characteristics with the added benefit of a longer life expectancy of the manufacture tool.
For the purposes of the present specification"continuous"is used in the mathematical sense of being constant or varying over an extent smoothly and without a discontinuity in value at any point, e. g. a sharp edge. It has been realised that such irregularities are susceptible to mathematical analysis by numerical techniques, to give a desired degree of accuracy in the calculation of the anticipated effect of the irregularity on the electrical characteristics of the resonator.
The cross sectional shape of the tubular resonator element may be of any desired form as long as it supports two orthogonal modes of transmission, for example diamond, rhomboid, cruciform, square, circular or elliptical. If the two orthogonal modes are required to resonate at different resonant frequencies, this may lead to an asymmetrical cross-section.
The position and range of shapes of the surface irregularity will be constrained by the crosssectional shape of the resonator element. Thus, with a shape having comers or extremities, it may be convenient to position the irregularity at a comer or extremity for maximum effect. In the case of a square or rectangular cross-section, a recess is preferably formed along a comer of the cross sectional shape ; alternatively recesses may be formed in two or more comers.
As preferred, recesses are employed rather than protrusions, for convenience in assembly with other components. The recesses may have any desired form, but a preferred form is a simple slope between the edges of the recess, having a plane surface extending from one edge to the other. This has the advantage of simplicity of manufacture. Alternatively, other shapes of recess may be envisaged, for example an outwardly rounded surface, which would have the advantage for powder ceramic material that the rounded exterior surface provides improved long-term stability.
The desired material of the powder ceramic of the dielectric element is barium tetratitanate or zirconium tetratitanate, having a dielectric constant between 36 and 45. This enables maximum miniaturisation of the size of the dielectric element. If miniaturisation is not an overriding requirement, then material of a smaller dielectric constant may be used, for example aluminiumoxide. aluminium oxide.
As preferred, axially movable rods, coupling screws or such like are provided for moving in and out of bores in the resonator element for final adjustment of the Q values.
As preferred, a silver coating on the exterior surface of the resonator element prevents field leakage and serves as a heat sink.
It is necessary to provide a means of coupling electrical signals into and out of the resonator element. It is preferred in accordance with the invention to provide at the two axial ends of
the tubular member, an iris or recess which provides a cavity for inductive coupling of the end with a subsequent signal processing stage. It is common to provide a plurality or multiplicity of the resonator elements positioned end to end in sequence to give a desired filter characteristic with the desired number of poles and zeros, in which case two adjacent recesses of adjacent resonator elements will be positioned face to face.
The size of the recesses in relation to the size of the resonator element will be determined by the desired characteristics of the resonator, in particular the unloaded quality factor-Qo value. The Qo value will be determined by the reciprocal of the sum of the reciprocals of the dielectric quality factor-d and the quality factor of the waveguide operating in its fundamental TE mode.
It is preferred to provide in such co-operating recesses an inductive loop comprising as preferred a single turn of an electrical conductor for improving the coupling. As preferred, adjusting screws are provided for adjusting the positions of the inductive coupling loop within the recesses for final tuning. The inductive loop is mounted in an intermediate coupling element comprising a sheet of dielectric material, for positioning between adjacent resonator elements in a filter structure.
In a further aspect, the invention provides a coupling element for a microwave filter or duplexer comprising a plurality of resonator elements positioned end to end to give a desired filter characteristic, the coupling element being intended for positioning between adjacent resonator elements, and comprising a sheet of dielectric material, having extending from a central area thereof on each side an inductive loop, each inductive loop comprising two conductive posts extending from the dielectric sheet, with their free ends connected to a conductive element in a loop form.
The preferred method of computing the electrical characteristics of the resonator element is by numerical analysis. This involves, in known manner, "discretising"the structure into small cubes (elements) thus forming a virtual structure which has been made discrete in space. Each element then takes incident impulse data from adjacent connecting elements and upon each iteration, scatters these impulses in a manner relating to the physical properties of that space. This process generates reflected impulses which, upon, each iteration, become
incident impulses to the adjacent ; connected elements. This process of scattering on each iteration makes the virtual structure discrete in time forming a time step. Relating the size of each element to time step yields velocity information. After a desired number of iterations, the characteristics of the resonator element are provided to a desired degree of accuracy.
Brief Description of the Drawings
A preferred embodiment of the invention will now be described with reference to the accompanying drawings wherein :
Figure 1 is a schematic cross sectional view of two known resonator elements for microwave filters ;
Figure 2 is a schematic cross sectional view of a resonator element in accordance with the invention for use in a microwave filter or duplexer ;
Figure 3 is a perspective view of the resonator element of Figure 2 ;
Figure 4 is a perspective view of an intermediate coupling element for coupling together two elements of Figure 3, when placed end to end;
Figure 5 is a schematic view of a filter formed by a plurality of elements of Figures 3 and 4 placed end to end ; and
Figure 6 and 7 are experimental results obtained from a filter employing elements as shown in Figure 3.
Description of the Preferred Embodiment
The problem in at least a preferred form of the invention is to develop a low cost, high-power and high performing duplexer for use in mobile communication base This technology may also apply to any equipment which relies on microwave filters.
The solution in accordance with the preferred form of the invention is to provide a dual TE mode dielectric loaded waveguide resonator of rectangular cross-section with a surface irregularity at one or more comers to create coupling between the two orthogonal TE modes.
The result is a dual mode resonator structure which performs two requirements whilst being very simple which allows for the realisation of an inexpensive microwave filter.
Microwave filters and duplexers are used extensively in communications systems to multiplex signals and protect against interference-typically, these devices are bulky and expensive. There are several solutions to this problem. Previous examples which are in this category are shown in Figure 1. In Figure la a metallic rectangular waveguide cavity 2 has dielectric loading 4 contained within it, comprising an element of cruciform cross-section and extending along the length of the cavity. An internal perturbation 6, comprising a drilled recess in one comer of the cruciform shape creates intermode coupling between the two orthogonal modes of transmission, one mode having the electric vector oscillating in the two vertical arms of the cruciform, and the other mode having the electric vector oscillating in the two horizontal arms of the cruciform. In Figure lb, a metallic cavity 2 has a dielectric loading 4 having a cross-section of a regular diamond shape. A tuning screw 8 extends through one comer of the cavity in a direction along a diagonal of the cavity towards one face of the dielectric loading, so as to create a degree of coupling between the two modes of electromagnetic transmission, one mode having the electric vector in a perpendicular direction, and the other mode having the electric vector in a horizontal direction.
The problem with the examples of Figures la and lb is that they are complicated, expensive, and difficult to manufacture, with a lower heat dissipation than desired. A simple dielectric structure capable of providing the required"dual field"loading and maximum heat dissipation would be a cube shaped piece of dielectric. Previously, in order to provide coupling between the two orthogonal fields a tuning screw would be needed. This would involve the drilling of an internal perturbation, usually a hole, into the dielectric at a difficult angle, which is costly.
The invention provides a surface irregularity to create orthogonal mode coupling in the dielectric loading of a waveguide resonator. The advantage of this is that the manufacturing tolerance for the coupling is tied in with that for the resonant frequency, i. e. -the resonator element. This reduces the cost of the cavity while at the same time, reducing the tuning range needed to correct for errors introduced during complicated manufacturing requirements.
Whereas the prior art uses a right-angled notch or rebate, the inter-mode coupling is achieved in accordance with the preferred form of the invention by using a 450 angled recess - using this angle makes construction easier and hence, more accurate as well as less costly.
The dielectric structure of the invention is simple and so lends itself to simple manufacture and low cost. It is also capable of conducting high-power because there is a large surface area
connecting with the cavity wall. There is good unloaded Q, comparable with other structures of this nature. It is simple, easier to make, tune and is comparatively easier to temperature stabilise.
Referring now to Figures 2 and 3, a preferred embodiment comprises a resonator element 10 comprising a tubular dielectric loading 12 having a generally square cross-section, but with one comer being cut away to provide an irregularity 14 comprising a recess which has a plane surface extending at an angle of 450 from one surface of the element to an adjacent surface.
The material of the resonator element is a powder ceramic barium tetratitanate having a dielectric constant of about 45. The exterior surfaces 16 of the element are coated with silver to seal the transmitted electromagnetic waves within the element. In addition, the front and rear faces or edges 18 have silver coats. The front and rear faces are each formed with a recess or iris 20 which provides a cavity for coupling the element to an adjacent element
Electromagnetic transmission takes place in the resonator element in two modes, a first with the electric vector vertical as seen in Figure 2, and the second with the electric vector horizontal as seen in Figure 2. Recess 14 acts to rotate the electric fields together, out of the right angle so that they interact, "pushing and pulling"on each other. The depth of the recess 14 determines the degree of interaction or coupling coefficient. The effect of this is to create two resonant frequencies for transmission, with a frequency difference between them determined by the coupling coefficient.
The electrical characteristics of the resonator element are computed by numerical analysis.
This involves, in known manner,"discretising"the structure into small cubes (elements) thus forming a virtual structure which has been made discrete in space. Each element then takes incident impulse data from adjacent connecting elements and upon each iteration, scatters these impulses in a manner relating to the physical properties of that space. This process generates reflected impulses which, upon, each iteration, become incident impulses to the adjacent; connected elements. This process of scattering on each iteration makes the virtual structure discrete in time forming a time step. Relating the size of each element to time step yields velocity information. After a desired number of iterations, the characteristics of the resonator element are provided to a desired degree of accuracy.
Figure 6 is an example of a practical resonator which has been tested, wherein the resonant frequencies have values of 2. 014 GHz and 2. 045 GHz with a difference of 0. 031 GHz or 31 MHz. Figure 7 shows a typical electric field distribution for the dual mode structure, with maximum field intensity occurring at the centre and diminishing towards the edges.
It should be noted that the modes of transmission discussed herein are fundamental modes of transmission, and higher order transmission modes may occur upon appropriate excitation.
Referring now to Figures 4 and 5, there is shown in Figure 4 a coupling element 30 for coupling one resonator element 10 to a second resonator element 10 in an end to end structure as shown in Figure 5, forming a composite microwave filter or duplexer with a desired number of poles and zeros and desired filter characteristic. The coupling element 30 comprises dielectric material of the same type as that of element 10 formed as a thin sheet with a cross-sectional shape similar to that of element 10. The dielectric element 30 is silvered on all sides except that the area 32 corresponding to iris 20 is left unsilvered. At the centre of the element, on each side, is disposed an inductive loop 36. Each loop 36 is formed as two tubular posts 38 upstanding from sheet 30 and having their ends soldered thereto at 34, and a metal strip 40 having its ends soldered to the upper ends of rods 38 to complete the loop. In an alternative construction, rods 38 may extend through sheet 30, through holes drilled in the sheet to form the posts for the inductive loop on the other side of the sheet. In addition, adjusting screws 42 are provided for providing an adjustment of the inductive coupling of the loops. These are mounted in the faces 16 of resonator element 10, and project into irises 20 so as to contact the coupling loop, so as to distort the loop a certain amount 10 provide a degree of adjustment of the inductive coupling.
In addition, further adjustment screws 48 are provided which are screwed into bores 50 to adjust the dielectric loading of the resonator element.
Claims (18)
- Claims 1. A resonator element for a microwave filter or duplexer, the element being formed of a dielectric material of tubular form having a cross section such as to enable electromagnetic propagation in two orthogonal modes, and the surface of the tubular member having an irregularity extending along the length of the tubular member such as to enable coupling between said two orthogonal modes, and wherein the surface of the irregularity is continuous and without discontinuity.
- 2. An element according to claim 1, wherein the element has a rectangular cross sectional shape.
- 3. An element according to claim 1 or 2, wherein the irregularity is disposed across a comer or extremity of the cross-sectional shape of the tubular form.
- 4. An element according to any preceding claim, wherein the irregularity comprises a recess or protrusion.
- 5. An element according to claim 4, wherein the irregularity comprises a recess comprising a plane surface extending from one edge of the recess to the other.
- 6. An element according to claim 5, wherein the tubular form is rectangular in cross section, and the recess comprises a plane surface extending across one comer of the rectangle at an angle to adjacent edges of the rectangle.
- 7. An element according to any preceding claim, wherein external faces of the resonator element have a conductive coating formed thereon.
- 8. An element according to any preceding claim, wherein an end of the tubular form has a recess formed therein, for forming a cavity for coupling the resonator element with adjacent structures.
- 9. An element according to any preceding claim, wherein the material of the resonator element is a powder ceramic.
- 10. An element according to any preceding claim, including an adjustment screw mounted in bores within the resonator element for axial movement in order to adjust the Q value of the resonator element.
- 11. An element according to any preceding claim, forming part of a microwave filter or duplexer, and including a coupling element positioned at an end face of the resonator element, the coupling element comprising a sheet of dielectric material, having extending from a central area thereof on each side an inductive loop, each inductive loop comprising two conductive posts extending from the dielectric sheet, with their free ends connected to a conductive element in a loop form.
- 12. A coupling element for a microwave filter or duplexer comprising a plurality of resonator elements positioned end to end to give a desired filter characteristic, the coupling element being intended for positioning between adjacent resonator elements, and comprising a sheet of dielectric material, having extending from a central area thereof on each side an inductive loop, each inductive loop comprising two conductive posts extending from the dielectric sheet, with their free ends connected to a conductive element in a loop form.
- 13. A resonator element or coupling element according to claim 11 or 12, including an adjustment screw for adjusting the position of an inductive loop within an iris.
- 14. A resonator element or coupling element according to claim 11,12 or 13, wherein the conductive element comprises a conductive strip.
- 15. A resonator element or coupling element according to any of claims 11 to 14, wherein the sheet of dielectric material has a conductive coating formed thereon.
- 16. A resonator element as claimed in claim 1 and substantially as described with reference to the accompanying drawings.
- 17. A coupling element according to claim 12 and substantially as described with reference to the accompanying drawings.
- 18. A microwave filter or duplexer for a base station of a mobile telecommunications system, and including an element according to any preceding claim.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0025158A GB2367952A (en) | 2000-10-13 | 2000-10-13 | Microwave dual mode dielectric resonator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0025158A GB2367952A (en) | 2000-10-13 | 2000-10-13 | Microwave dual mode dielectric resonator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0025158D0 GB0025158D0 (en) | 2000-11-29 |
| GB2367952A true GB2367952A (en) | 2002-04-17 |
Family
ID=9901248
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0025158A Withdrawn GB2367952A (en) | 2000-10-13 | 2000-10-13 | Microwave dual mode dielectric resonator |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2367952A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009038200A1 (en) * | 2007-09-19 | 2009-03-26 | Ngk Spark Plug Co., Ltd. | Dielectric resonator, dielectric resonator filter and method for controlling dielectric resonator |
| JP2009095011A (en) * | 2007-09-19 | 2009-04-30 | Ngk Spark Plug Co Ltd | Dielectric resonator filter |
| JP2009095010A (en) * | 2007-09-19 | 2009-04-30 | Ngk Spark Plug Co Ltd | Dielectric resonator and method for controlling dielectric resonator |
| JP2009095009A (en) * | 2007-09-19 | 2009-04-30 | Ngk Spark Plug Co Ltd | Dielectric resonator and method for controlling dielectric resonator |
| JP2009111981A (en) * | 2007-10-11 | 2009-05-21 | Ngk Spark Plug Co Ltd | Multimode dielectric resonator and adjustment method thereof |
| GB2465522A (en) * | 2007-09-19 | 2010-05-26 | Ngk Spark Plug Co | Dielectric resonator, dielectric resonator filter and method for controlling dielectric resonator |
| US9077062B2 (en) | 2012-03-02 | 2015-07-07 | Lockheed Martin Corporation | System and method for providing an interchangeable dielectric filter within a waveguide |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112928406A (en) * | 2019-12-06 | 2021-06-08 | 薛冰 | Dielectric filter with novel negative coupling structure |
-
2000
- 2000-10-13 GB GB0025158A patent/GB2367952A/en not_active Withdrawn
Non-Patent Citations (2)
| Title |
|---|
| Awai et al, "Procs of 25th European Microwave Conf. Bologna Italy", 1995 Swanley UK, p533-537, vol 1 * |
| Liang et al, "Microwave Symposium Digest", 1995, IEEE MTT-S Digest, vol 2, pp 509-512 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009038200A1 (en) * | 2007-09-19 | 2009-03-26 | Ngk Spark Plug Co., Ltd. | Dielectric resonator, dielectric resonator filter and method for controlling dielectric resonator |
| JP2009095011A (en) * | 2007-09-19 | 2009-04-30 | Ngk Spark Plug Co Ltd | Dielectric resonator filter |
| JP2009095010A (en) * | 2007-09-19 | 2009-04-30 | Ngk Spark Plug Co Ltd | Dielectric resonator and method for controlling dielectric resonator |
| JP2009095009A (en) * | 2007-09-19 | 2009-04-30 | Ngk Spark Plug Co Ltd | Dielectric resonator and method for controlling dielectric resonator |
| GB2465522A (en) * | 2007-09-19 | 2010-05-26 | Ngk Spark Plug Co | Dielectric resonator, dielectric resonator filter and method for controlling dielectric resonator |
| CN101803107A (en) * | 2007-09-19 | 2010-08-11 | 日本特殊陶业株式会社 | Dielectric resonator, dielectric resonator filter and method for controlling dielectric resonator |
| GB2465522B (en) * | 2007-09-19 | 2012-02-15 | Ngk Spark Plug Co | Dielectric resonator, dielectric resonator filter and method for controlling dielectric resonator |
| US8410873B2 (en) | 2007-09-19 | 2013-04-02 | Ngk Spark Plug Co., Ltd. | Dielectric resonator having a dielectric resonant element with two oppositely located notches for EH mode coupling |
| JP2009111981A (en) * | 2007-10-11 | 2009-05-21 | Ngk Spark Plug Co Ltd | Multimode dielectric resonator and adjustment method thereof |
| US9077062B2 (en) | 2012-03-02 | 2015-07-07 | Lockheed Martin Corporation | System and method for providing an interchangeable dielectric filter within a waveguide |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0025158D0 (en) | 2000-11-29 |
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| Date | Code | Title | Description |
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| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |