WO2002082580A1 - Tuneable dielectric resonator - Google Patents
Tuneable dielectric resonatorInfo
- Publication number
- WO2002082580A1 WO2002082580A1 PCT/GB2002/001572 GB0201572W WO02082580A1 WO 2002082580 A1 WO2002082580 A1 WO 2002082580A1 GB 0201572 W GB0201572 W GB 0201572W WO 02082580 A1 WO02082580 A1 WO 02082580A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- resonator
- frequency
- piezoelectric element
- dielectric
- tuning
- Prior art date
Links
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
Definitions
- the present invention relates to an improved tuneable dielectric resonator.
- DRs Dielectric resonators
- Q resonator quality factors
- Ceramic dielectric materials are used to form thermally stable DRs as key components in a number of microwave subsystems which are used in a range of consumer and commercial market products. These products range from Satellite TV receiver modules (frequency converter for Low Noise Broadcast (LNB), Cellular Telephones, PCN's. (Personal Communication Networks Systems) and VSAT (Very Small Aperture Satellite) systems for commercial application to emerging uses in transportation and automobile projects, such as sensors in traffic management schemes and vehicle anti-collision devices. Dielectric Resonators may be used to determine and stabilise the frequency of a microwave oscillator or as a resonant element in a microwave filter. New systems of satellite TV transmission based on digital encoding and compression of the video signals determine the need for improved DR components. The availability of advanced materials will also enable necessary advances in the performance of DRs used for these and other purposes.
- Satellite TV receiver modules frequency converter for Low Noise Broadcast (LNB), Cellular Telephones, PCN's. (Personal Communication Networks Systems) and VSAT (Very Small A
- dielectric loss materials are highly desirable, for example in the base stations required for mobile communications.
- Dielectric resonators using dielectric sintered ceramics are commonly used and the dielectric materials used are often complex mixtures of elements.
- One of the earliest resonator materials was Barium Titanate (BaTiO 3 or BaTi O 9 see for example T. Negas et al American Ceramic Society Bulletin vol 72 pp 80-89 1993).
- the dielectric loss of a material is referred to as the tan delta and the inverse of this quantity is called the Q (Quality Factor).
- the Q factor of a resonator is determined by choosing a resonance and then dividing the resonant frequency by the bandwidth 3dB below the peak.
- Ferrite tuning has generally considered to be unsatisfactory as the losses introduced by the ferrite material are too high and the devices are rather large with high power consumption.
- Ferroelectric/paraelectric tuning Materials with a ferroelectric/paraelectric phase transition below room temperature (paraelectric) can be used to tune filters using the principal that, as an electric field is applied, the relative permittivity changes and thus the frequency changes. In this method the tuning of the frequency is adjusted electronically by means of a ferroelectric/paraelectric element. This means that there is a second (linked) materials problem which is to discover far lower loss ferroelectric/ paraelectrics. This has been researched extensively in the system Ba-Sr-Ti-O (BST) but the problem here is that the loss of BST is, at present, far too high at around tan ⁇ ⁇ 5x10 "3 at room temperature.
- Optical tuning Jianping Gan and Deming Xu. Elec Lett 34(22) (1998). This uses the application of a laser to a semiconductor in the tuning microstrip to change the reactance. Although it is fast, a great disadvantage is the loss due to the semiconductor.
- Varactor tuning This is an option for electrically tuning a circuit.
- Virdee et al (BS Virdee Elec Lett 33(4 ) (1997) have shown that tuning of 1.6% can be achieved.
- the integration of semiconductor varactors in a multipole filter is not useful because it requires coupling of the DR to a microstrip resonator. This is expected to be extremely difficult for mutually coupled DRs in a multipole filter structure.
- a method of tuning a dielectric resonator which method comprises changing the frequency of the resonator by of means a frequency changing means which is operated using a piezoelectric element.
- the invention also provides a tunable dielectric resonator in which there is a frequency changing means which is operated by a piezoelectric element.
- a typical resonator cavity has a substantially cylindrical side wall, a flat top wall and a flat base and a dielectric such as a dielectric disc is mounted within the cavity.
- the frequency of the dielectric resonator can be changed by changing the volume of the resonator cavity. This can be achieved by moving a moveable top plate to decrease or increase the volume of the resonator or moving a platform on which the dielectric is mounted. Alternatively the frequency can be changed by moving a conductive element such as a rod, screw etc. into the cavity. Any combination of these methods can be used together. In the present invention these movements are caused by a piezoelectric element which is connected to the component which is moved.
- the piezoelectric element When a voltage is applied to a piezoelectric element the element will change its dimensions and, by coupling the piezoelectric element to a moveable component, the component can be moved and, by using the TM and HE modes, only a very small movement in the piezoelectric is necessary to provide the required tuning.
- the piezoelectric element is a bimorph.
- the bimorph can be in a rectangular plate or disc geometry. Two thin slabs of piezoelectric material are joined together so that their poling directions oppose each other. On the application of a voltage, the piezoelectric effect constricts one element and extends the other causing a substantial movement.
- a 25mm long cantilever is capable of a deflection of well over lOOmicrometres at 100V and around 14micrometres at 14V. This can be sufficient to effect the tuning required but this is also dependent on the force required to cause the tuning. Thus there is a balance to be determined between the force required to move the tuning component and the voltage available to effect the movement.
- Bimorphs are described in Carmen P. Germano "Flexure mode piezoelectric transducers" IEEE Trans Audio and Electroacoustics vol AU-19 6-11 (1970). The achievement of greater tuning is straightforward. Either different modes can be used in the resonant structure or higher voltages can be used or larger bimorphs can be used. There is no reason why tuning of over 25% and indeed up to 100% cannot be achieved by these methods by judicious choice of mode and piezoelectric arrangement.
- the present invention enables an effective range of tuning to be achieved for example tuning of up to 5% of the centre frequency and the invention provides a dielectric resonator structure capable of tuning of up to 5% of the centre frequency.
- the present invention can be used with any cavity mode of the resonator and the invention provides a piezoelectrically tuneable dielectric resonator capable of using different cavity modes.
- the tuning can be very rapid and can be effected so that the tuning does not substantially reduce or degrade the Q of the resonant structure.
- Figure 1 is a schematic diagram of a bimo ⁇ h
- FIGS. 2 to 5 are schematic drawings of different tuning schemes
- bimo ⁇ h comprises two piezoelectric elements (31) and (32) which move in the directions of the arrows when an electric filed is applied across them so that the bimo ⁇ h will change shape.
- a copper cavity (8) has a dielectric (1) mounted on a copper plate (2), there is a piezoelectric disc bimo ⁇ h (3), mounted on supports (4) via quartz spacer (6) and there are coupling loops (7).
- a voltage can be applied to the bimo ⁇ h from (5).
- a voltage can be applied across bimo ⁇ h (3) which will change dimensions and will cause the copper plate to be moved and so vary the size of the cavity and hence the frequency.
- a voltage can be applied to rectangular to bimo ⁇ h (9), which will cause the movement of top plate (11) and so vary the size of the cavity and the frequency.
- the change in dimensions of the biomo ⁇ h and hence change in the frequency of the resonator can rapidly and precisely be achieved to tune the resonator.
- a copper cavity (15) has a dielectric (16) mounted on quartz spacer (17).
- the rod (18) is connected to rectangular bimo ⁇ h (20).
- the change in dimensions of the biomo ⁇ h and hence change in the frequency of the resonator can rapidly and precisely be achieved to tune the resonator.
- a copper cavity was used to carry out the experiments. Inside the cavity was placed a dielectric resonator of TiO 2 , which had a resonant frequency of approximately 3 GHz, and a Q of 10,000 and a relative permittivity of 100.
- a schematic drawing of the cavity is shown in figs. 2 and 3. First the resonant frequency was varied by the circular bimo ⁇ h alone (fig. 2) and then the resonant frequency was altered using the rectangular bimo ⁇ h and then a combination of the two was used (fig. 3).
- V input Volts
- GHz Resonance Resonance Resonance Resonance frequency
- GHz frequency
- GHz frequency
- a copper cavity shown in figs. 2 and 3 was used to carry out the experiments. Inside the cavity was placed a dielectric resonator of Al 2 O 3 which had a resonant frequency of approximately 9GHz and a Q of 40,000 000 and a relative permittivity of 9. First the resonant frequency was varied by the circular bimo ⁇ h alone (fig. 2) and then the resonant frequency was altered using the rectangular bimo ⁇ h and then a combination of the two was used (figs. 2 and 3.)
- V input Volts
- GHz Resonance Resonance Resonance Resonance frequency
- GHz frequency
- GHz frequency
- a copper cavity shown in figs. 2 and 3 was used to carry out the experiments. Inside the cavity was placed a dielectric resonator of NdCaAlTiO x which had a resonant frequency of approximately 5GHz and a Q of 8,000 and a relative permittivity of 44. First the resonant frequency was varied by the circular bimo ⁇ h alone (fig. 2) and then the resonant frequency was altered using the rectangular bimo ⁇ h and then a combination of the two was used (fig. 3)
- V input Volts
- GHz Resonance Resonance Resonance Resonance frequency
- GHz frequency
- GHz frequency
Abstract
Tuneable dielectric resonator structure in which piezoelectric materials are used to effect the tuning.
Description
Tuneable Dielectric Resonator
The present invention relates to an improved tuneable dielectric resonator.
Dielectric resonators (DRs) are key elements for filters, low phase noise oscillators and frequency standards in current microwave communication technology. DRs possess resonator quality factors (Q) comparable to cavity resonators, strong linearity at high power levels, weak temperature coefficients, high mechanical stability and small size.
Ceramic dielectric materials are used to form thermally stable DRs as key components in a number of microwave subsystems which are used in a range of consumer and commercial market products. These products range from Satellite TV receiver modules (frequency converter for Low Noise Broadcast (LNB), Cellular Telephones, PCN's. (Personal Communication Networks Systems) and VSAT (Very Small Aperture Satellite) systems for commercial application to emerging uses in transportation and automobile projects, such as sensors in traffic management schemes and vehicle anti-collision devices. Dielectric Resonators may be used to determine and stabilise the frequency of a microwave oscillator or as a resonant element in a microwave filter. New systems of satellite TV transmission based on digital encoding and compression of the video signals determine the need for improved DR components. The availability of advanced materials will also enable necessary advances in the performance of DRs used for these and other purposes.
In DRs in the areas of communications over a wide frequency range, low dielectric loss materials are highly desirable, for example in the base stations required for mobile communications. Dielectric resonators using dielectric sintered ceramics are commonly used and the dielectric materials used are often complex mixtures of elements. One of the earliest resonator materials was Barium Titanate (BaTiO3 or BaTi O9 see for example T. Negas et al American Ceramic Society Bulletin vol 72 pp
80-89 1993).
The dielectric loss of a material is referred to as the tan delta and the inverse of this quantity is called the Q (Quality Factor). The Q factor of a resonator is determined by choosing a resonance and then dividing the resonant frequency by the bandwidth 3dB below the peak.
In many applications the ability to tune resonators is advantageous but the currently used methods suffer from disadvantages.
Mechanical methods based on stepper motors are conventionally used as described in D.P.Howson and B.M. Sani Elec Lett 31 (19) 1652 (1995), however these methods are slow and unreliable.
Non mechanical methods of tuning which have been proposed are
a) Ferrite tuning: Ferrite tuning has generally considered to be unsatisfactory as the losses introduced by the ferrite material are too high and the devices are rather large with high power consumption.
b) Ferroelectric/paraelectric tuning: Materials with a ferroelectric/paraelectric phase transition below room temperature (paraelectric) can be used to tune filters using the principal that, as an electric field is applied, the relative permittivity changes and thus the frequency changes. In this method the tuning of the frequency is adjusted electronically by means of a ferroelectric/paraelectric element. This means that there is a second (linked) materials problem which is to discover far lower loss ferroelectric/ paraelectrics. This has been researched extensively in the system Ba-Sr-Ti-O (BST) but the problem here is that the loss of BST is, at present, far too high at around tan δ ~ 5x10"3 at room temperature.
c) Optical tuning: Jianping Gan and Deming Xu. Elec Lett 34(22) (1998). This uses the application of a laser to a semiconductor in the tuning microstrip to change the reactance. Although it is fast, a great disadvantage is the loss due to the semiconductor.
d) Varactor tuning: This is an option for electrically tuning a circuit. Virdee et al (BS Virdee Elec Lett 33(4 ) (1997) have shown that tuning of 1.6% can be achieved. However, the integration of semiconductor varactors in a multipole filter is not useful because it requires coupling of the DR to a microstrip resonator. This is expected to be extremely difficult for mutually coupled DRs in a multipole filter structure.
We have devised an improved mechanical method of tuning dielectric resonators which overcomes these difficulties.
According to the invention there is provided a method of tuning a dielectric resonator which method comprises changing the frequency of the resonator by of means a frequency changing means which is operated using a piezoelectric element.
The invention also provides a tunable dielectric resonator in which there is a frequency changing means which is operated by a piezoelectric element.
A typical resonator cavity has a substantially cylindrical side wall, a flat top wall and a flat base and a dielectric such as a dielectric disc is mounted within the cavity.
The frequency of the dielectric resonator can be changed by changing the volume of the resonator cavity. This can be achieved by moving a moveable top plate to decrease or increase the volume of the resonator or moving a platform on which the dielectric is mounted. Alternatively the frequency can be changed by moving a conductive element such as a rod, screw etc. into the cavity. Any combination of these methods can be used together.
In the present invention these movements are caused by a piezoelectric element which is connected to the component which is moved.
When a voltage is applied to a piezoelectric element the element will change its dimensions and, by coupling the piezoelectric element to a moveable component, the component can be moved and, by using the TM and HE modes, only a very small movement in the piezoelectric is necessary to provide the required tuning. Preferably the piezoelectric element is a bimorph. The bimorph can be in a rectangular plate or disc geometry. Two thin slabs of piezoelectric material are joined together so that their poling directions oppose each other. On the application of a voltage, the piezoelectric effect constricts one element and extends the other causing a substantial movement. For example a 25mm long cantilever is capable of a deflection of well over lOOmicrometres at 100V and around 14micrometres at 14V. This can be sufficient to effect the tuning required but this is also dependent on the force required to cause the tuning. Thus there is a balance to be determined between the force required to move the tuning component and the voltage available to effect the movement. Bimorphs are described in Carmen P. Germano "Flexure mode piezoelectric transducers" IEEE Trans Audio and Electroacoustics vol AU-19 6-11 (1970). The achievement of greater tuning is straightforward. Either different modes can be used in the resonant structure or higher voltages can be used or larger bimorphs can be used. There is no reason why tuning of over 25% and indeed up to 100% cannot be achieved by these methods by judicious choice of mode and piezoelectric arrangement.
The present invention enables an effective range of tuning to be achieved for example tuning of up to 5% of the centre frequency and the invention provides a dielectric resonator structure capable of tuning of up to 5% of the centre frequency.
The present invention can be used with any cavity mode of the resonator and the invention provides a piezoelectrically tuneable dielectric resonator capable of using
different cavity modes.
It is a feature of the invention that the tuning can be very rapid and can be effected so that the tuning does not substantially reduce or degrade the Q of the resonant structure.
Embodiments of the invention are illustrated in the drawings in which: -
Figure 1 is a schematic diagram of a bimoφh and
Figures 2 to 5 are schematic drawings of different tuning schemes
Referring to fig. 1 a bimoφh comprises two piezoelectric elements (31) and (32) which move in the directions of the arrows when an electric filed is applied across them so that the bimoφh will change shape.
Referring to fig. 2 a copper cavity (8) has a dielectric (1) mounted on a copper plate (2), there is a piezoelectric disc bimoφh (3), mounted on supports (4) via quartz spacer (6) and there are coupling loops (7). A voltage can be applied to the bimoφh from (5).
Referring to fig. 3 there is in addition a rectangular piezoelectric bimoφh (9) connected by a thin wire (10) to top plate (11).
In use, to tune the resonator a voltage can be applied across bimoφh (3) which will change dimensions and will cause the copper plate to be moved and so vary the size of the cavity and hence the frequency. In fig. 3 a voltage can be applied to rectangular to bimoφh (9), which will cause the movement of top plate (11) and so vary the size of the cavity and the frequency. By varying the applied voltage the change in dimensions of the biomoφh and hence change in the frequency of the resonator can rapidly and precisely be achieved to tune the resonator. Referring to fig. 4 a copper cavity (15) has a dielectric (16) mounted on quartz spacer
(17). There is adjustable top plate (21) and coupling loops (20). There is a metal rod (18) connected to disc bimoφh (19) and, by applying a voltage across bimoφh (19), the rod (18) can be lowered or raised and thus tuning the resonator.
In fig. 5 the rod (18) is connected to rectangular bimoφh (20). As above by varying the applied voltage the change in dimensions of the biomoφh and hence change in the frequency of the resonator can rapidly and precisely be achieved to tune the resonator.
In the examples given below bimoφhs have been used and
Example 1
A copper cavity was used to carry out the experiments. Inside the cavity was placed a dielectric resonator of TiO2, which had a resonant frequency of approximately 3 GHz, and a Q of 10,000 and a relative permittivity of 100. A schematic drawing of the cavity is shown in figs. 2 and 3. First the resonant frequency was varied by the circular bimoφh alone (fig. 2) and then the resonant frequency was altered using the rectangular bimoφh and then a combination of the two was used (fig. 3).
The results are shown in Table 1
Table 1
V input (Volts) Resonance Resonance Resonance frequency (GHz) frequency (GHz) frequency (GHz)
Circular bimoφh Rectangular Both bimoφhs bimoφh
0 2.9609 2.9907 2.9916
50 2.9606 2.9909 2.9923
100 2.9603 2.9913 2.9931
150 2.9601 2.9919 2.9941
200 2.9600 2.9927 2.9952
250 2.9599 2.9936 2.9966
300 2.9598 2.9945 2.9977
350 2.9598 2.9955 2.9992
A graph showing the results is shown in fig. 6.
Example 2
A copper cavity shown in figs. 2 and 3 was used to carry out the experiments. Inside the cavity was placed a dielectric resonator of Al2O3 which had a resonant frequency of approximately 9GHz and a Q of 40,000 000 and a relative permittivity of 9. First the resonant frequency was varied by the circular bimoφh alone (fig. 2) and then the resonant frequency was altered using the rectangular bimoφh and then a combination of the two was used (figs. 2 and 3.)
The results are shown in Table 2
Table 2
V input (Volts) Resonance Resonance Resonance frequency (GHz) frequency (GHz) frequency (GHz)
Circular bimoφh Rectangular Both bimoφhs bimoφh
0 9.0775 9.2527 9.2522
50 9.0779 9.2536 9.2523
100 9.0779 9.2569 9.2548
150 9.0780 9.2604 9.2605
200 9.0781 9.2646 9.2665
250 9.0782 9.2689 9.2730
300 9.0789 9.2736 9.2795
350 9.0795 9.2788 9.2870
The results are shown graphically in figure 6.
Example 3
A copper cavity shown in figs. 2 and 3 was used to carry out the experiments. Inside the cavity was placed a dielectric resonator of NdCaAlTiOx which had a resonant frequency of approximately 5GHz and a Q of 8,000 and a relative permittivity of 44. First the resonant frequency was varied by the circular bimoφh alone (fig. 2) and then the resonant frequency was altered using the rectangular bimoφh and then a combination of the two was used (fig. 3)
The results are shown in Table 3
Table 3
V input (Volts) Resonance Resonance Resonance frequency (GHz) frequency (GHz) frequency (GHz)
Circular bimoφh Rectangular Both bimorphs bimoφh
0 4.6808 4.5645 4.5635
50 4.6823 4.5652 4.5637
100 4.6840 4.5660 4.5649
150 4.6858 4.5669 4.5666
200 4.6877 4.5682 4.5682
250 4.6895 4.5692 4.5700
300 4.6910 4.5706 4.5719
350 4.6930 4.5720 4.5739
The results are shown graphically in figure 7.
Claims
1. A method of tuning a dielectric resonator which method comprises changing the frequency of the resonator by the operation of a frequency changing means which is operated using a piezoelectric element.
2. A method as claimed in claim 1 in which the frequency changing means comprises a moveable top plate mounted in the resonator, which plate is connected to the piezoelectric element and which plate, when moved, decreases or increases the volume of the resonator.
3. A method as claimed in claim 1 in which the frequency changing means comprises a moveable platform on which the dielectric is mounted which platform is connected to the piezoelectric element.
4. A method as claimed in claim 1 in which the frequency changing means comprises a conductive element or rod moveably mounted so that it enters the resonator which element or rod is connected to the piezoelectric element.
5. A method as claimed in any one of claims 1 to 5 in which the piezoelectric element is a bimorph.
6. A tuneable dielectric resonator which comprises a cavity within which is mounted a dielectric and which incoprorates a resonator frequency changing means which is operated by a piezoelectric element,
7. A tuneable dielectric resonator as claimed in claim 6 in which the frequency changing means comprises a moveable top plate mounted in the resonator, which plate is connected to the piezoelectric element and which platform, when moved, decreases or increases the volume of the resonator.
8. A tuneable dielectric resonator as claimed in claim 6 in which the frequency changing means comprises a moveable platform on which the dielectric is mounted which platform is connected to the piezoelectric element.
9. A tuneable dielectric resonator as claimed in claim 6 in which the frequency changing means comprises a conductive element or rod moveably mounted so that it enters the resonator which element or rod is connected to the piezoelectric element.
10. A tuneable dielectric resonator as claimed in any one of claims 6 to 9 in which the piezoelectric element is a bimoφh.
11. A tuneable dielectric resonator as claimed in any one of claims 6 to 10 in which the piezoelectric element comprises a plurality of piezoelectric elements.
12. A tuneable dielectric resonator as claimed in any one of claims 6 to 11 in which the piezoelectric element is capable of tuning up to 5% of the centre frequency of the dielectric resonator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0108256A GB0108256D0 (en) | 2001-04-03 | 2001-04-03 | Tuneable dielectric resonators |
| GB0108256.9 | 2001-04-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2002082580A1 true WO2002082580A1 (en) | 2002-10-17 |
Family
ID=9912099
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/GB2002/001572 WO2002082580A1 (en) | 2001-04-03 | 2002-04-03 | Tuneable dielectric resonator |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB0108256D0 (en) |
| WO (1) | WO2002082580A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006059159A1 (en) * | 2004-12-01 | 2006-06-08 | South Bank University Enterprises Ltd. | Tunable or re-configurable dielectric resonator filter |
| EP2013939A1 (en) * | 2006-04-27 | 2009-01-14 | Powerwave Comtek Oy | Tuning element and tunable resonator |
| CN103311604A (en) * | 2012-03-15 | 2013-09-18 | 成都赛纳赛德科技有限公司 | Tuning structure |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4692727A (en) * | 1985-06-05 | 1987-09-08 | Murata Manufacturing Co., Ltd. | Dielectric resonator device |
| JPS63299604A (en) * | 1987-05-29 | 1988-12-07 | Murata Mfg Co Ltd | Dielectric resonator device |
| JPH05110337A (en) * | 1991-10-14 | 1993-04-30 | Nec Corp | Microwave oscillator |
-
2001
- 2001-04-03 GB GB0108256A patent/GB0108256D0/en not_active Ceased
-
2002
- 2002-04-03 WO PCT/GB2002/001572 patent/WO2002082580A1/en not_active Application Discontinuation
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4692727A (en) * | 1985-06-05 | 1987-09-08 | Murata Manufacturing Co., Ltd. | Dielectric resonator device |
| JPS63299604A (en) * | 1987-05-29 | 1988-12-07 | Murata Mfg Co Ltd | Dielectric resonator device |
| JPH05110337A (en) * | 1991-10-14 | 1993-04-30 | Nec Corp | Microwave oscillator |
Non-Patent Citations (3)
| Title |
|---|
| GHOSH I S ET AL: "Temperature compensated high-Q dielectric resonators for long term stable low phase noise oscillators", FREQUENCY CONTROL SYMPOSIUM, 1997., PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL ORLANDO, FL, USA 28-30 MAY 1997, NEW YORK, NY, USA,IEEE, US, 28 May 1997 (1997-05-28), pages 1024 - 1029, XP010257402, ISBN: 0-7803-3728-X * |
| PATENT ABSTRACTS OF JAPAN vol. 013, no. 136 (E - 737) 5 April 1989 (1989-04-05) * |
| PATENT ABSTRACTS OF JAPAN vol. 017, no. 466 (E - 1421) 25 August 1993 (1993-08-25) * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006059159A1 (en) * | 2004-12-01 | 2006-06-08 | South Bank University Enterprises Ltd. | Tunable or re-configurable dielectric resonator filter |
| GB2436493A (en) * | 2004-12-01 | 2007-09-26 | South Bank Univ Entpr Ltd | Tunable or re-configurable dielectric resonator filter |
| EP2013939A1 (en) * | 2006-04-27 | 2009-01-14 | Powerwave Comtek Oy | Tuning element and tunable resonator |
| EP2013939A4 (en) * | 2006-04-27 | 2012-12-26 | Powerwave Comtek Oy | Tuning element and tunable resonator |
| CN103311604A (en) * | 2012-03-15 | 2013-09-18 | 成都赛纳赛德科技有限公司 | Tuning structure |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0108256D0 (en) | 2001-05-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Fiedziuszko et al. | Dielectric materials, devices, and circuits | |
| Mansour | High-Q tunable dielectric resonator filters | |
| US7119641B2 (en) | Tuneable dielectric resonator | |
| US7135940B2 (en) | Tunable filter and portable telephone | |
| US7449980B2 (en) | Discrete voltage tunable resonator made of dielectric material | |
| Hill et al. | Perspective on ceramic materials for 5G wireless communication systems | |
| Wakino | Recent development of dielectric resonator materials and filters in Japan | |
| US6686817B2 (en) | Electronic tunable filters with dielectric varactors | |
| EP1217685B1 (en) | Ring resonator and antenna | |
| US4998077A (en) | VCO having tapered or stepped microstrip resonator | |
| US20060152303A1 (en) | Electrically tunable notch filters | |
| US20070109078A1 (en) | Tunable MMIC (monolithic microwave integrated circuit) waveguide resonators | |
| Poplavko et al. | Frequency-tunable microwave dielectric resonator | |
| WO1998000881A1 (en) | Near resonant cavity tuning devices | |
| Cruickshank | 1–2 GHz dielectrics and ferrites: overview and perspectives | |
| EP1236240A1 (en) | Microstrip tunable filters tuned by dielectric varactors | |
| US5589440A (en) | Ferroelectric RF limiter | |
| WO2002082580A1 (en) | Tuneable dielectric resonator | |
| Lim et al. | The design of a temperature-stable stepped-impedance resonator using composite ceramic materials | |
| Kalkur et al. | Tunable and switchable resonators and filters based on ferroelectric BST thin films for wireless communications | |
| De Flaviis et al. | High purity ferroelectric materials by sol-gel process for microwave applications | |
| GB2380069A (en) | Dielectric resonator with ferroelectric tuner | |
| US6570460B1 (en) | Voltage-tunable oscillator with dielectric resonator including a ferroelectric ceramic material | |
| KR20210076894A (en) | Solid State Tunable Ion Oscillator Dielectric Materials and Resonant Devices | |
| Eriksson et al. | Two-pole tunable bandpass filter based on YBCO plated single crystal KTO disk resonators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
| 122 | Ep: pct application non-entry in european phase | ||
| NENP | Non-entry into the national phase |
Ref country code: JP |
|
| WWW | Wipo information: withdrawn in national office |
Country of ref document: JP |