EP0764996A1
Expired / Lapsed
EP
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Dielectric resonator capable of varying resonant frequency
Assignee: Murata Manufacturing Co Ltd
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Filing: 1996-09-19
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Granted: —
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Expires: 2016-09-19
Abstract
Abstract A dielectric resonator capable of adjusting a resonance frequency, reducing occurrence of a mode jump if it is applied to an oscillator and being manufactured at a low cost. The dielectric resonator has a pair of upper and lower opposing conductive plates (211, 212); a dielectric substrate (3) disposed between the conductive plates (211, 212); a first electrode (1) formed on one surface of the dielectric substrate (3), the first electrode (1) having a first opening (4); a second electrode (2) formed on another surface of the dielectric substrate (3), the second electrode having a second opening (5) corresponding to the first opening (4) so that a resonator is formed by a portion of the dielectric substrate (3) disposed between the first and second openings (4, 5); and a variable capacitor (70, 71; 90a, 90b) located in a portion of the dielectric substrate (3) in which an applied electromagnetic field is confined in and around the resonator.
Inventors
- 👤 Yohei c/o Murata Mfg. Co. Ltd. Ishikawa
- 👤 Toshiro c/o Murata Mfg. Co. Ltd. Hiratsuka
- 👤 Sadao c/o Murata Mfg. Co. Ltd. Yamashita
- 👤 Kenichi c/o Murata Mfg. Co. Ltd. Iio
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 00:39
CPC Classifications
H; H01; H01P; H01P7/00; H01P7/10
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
141 words
A dielectric resonator capable of varying its resonant frequency comprising: a pair of upper and lower opposing conductive plates (211, 212); a dielectric substrate (3) disposed between said conductive plates (211, 212); a first electrode (1) formed on one surface of said dielectric substrate (3), said first electrode (1) having a first opening (4); a second electrode (2) formed on another surface of said dielectric substrate (3), said second electrode (2) having a second opening (5) corresponding to said first opening (4) so that a resonator having a resonant frequency is formed by a portion of said dielectric substrate (3) disposed between said first and second openings (4, 5); a variable capacitor (70, 71; 90a, 90b) for varying said resonant frequency located on a portion of said dielectric substrate (3) corresponding to an electromagnetic field confined in and around said resonator.
Claim 2
Dependent Claim
125 words
A dielectric resonator according to Claim 1 further comprising: a slit (S1; S2) formed in said first electrode (1), said slit (S1; S2) being connected to said resonator; a third electrode (102; 103) disposed in said slot (S1; S2) , said third electrode (102; 103) being insulated from said first and second electrodes (1, 2); wherein one end of said third electrode (102; 103) adjacent to said first opening (4) is connected to said variable capacitor (70, 71; 90a, 90b) for permitting a bias voltage to be applied to said capacitor (70, 71; 90a, 90b) through said third electrode (102; 103) from outside of said dielectric resonator to vary a capacitance of said variable capacitor (70, 71; 90a, 90b) and thereby vary said resonant frequency.
Claim 3
Dependent Claim
28 words
A dielectric resonator according to Claim 2, wherein said third electrode (102; 103) has a widened portion (102b; 103b) which is accessible from outside of said dielectric resonator.
Claim 4
Dependent Claim
25 words
A dielectric resonator according to one of Claims 1 to 3, wherein said variable capacitor (70, 71; 90a, 90b) is formed by a varactor diode.
Claim 5
Dependent Claim
30 words
A dielectric resonator according to Claim 4, further comprising a second varactor diode whose cathode and anode are connected to said first electrode (1) and third electrode (102; 103) respectively.
Claim 6
Dependent Claim
23 words
A dielectric resonator according to one of Claims 1 to 3, wherein said variable capacitor (90a, 90b) is formed by a switching element.
Claim 7
Dependent Claim
23 words
A dielectric resonator according to one of Claims 2 to 6, wherein said slit (S2) is perpendicular to a circumference of said opening.
Claim 8
Dependent Claim
30 words
A dielectric resonator according to Claim 4, wherein a cathode and an anode of said varactor diode are connected to said first electrode (1) and third electrode (102; 103) respectively.
Claim 9
Dependent Claim
20 words
A dielectric resonator according to one of Claims 2 to 8, wherein said third electrode (102) projects into said resonator.
Claim 10
Dependent Claim
26 words
A dielectric resonator according to Claim 9, wherein said first electrode (1) has a projection, which projects into said resonator, along with said third electrode (102).
Claim 11
Dependent Claim
31 words
A dielectric resonator according to Claim 10, wherein said variable capacitor (70, 71) is disposed between said projection of said first electrode (1) and said projection of said third electrode (102).
Claim 12
Dependent Claim
23 words
A dielectric resonator according to one of Claims 2 to 8, further comprising: a sub-slit (25a, 25b) substantially perpendicular to said slit (S2).
Claim 13
Dependent Claim
41 words
A dielectric resonator according to Claim 12, wherein said sub-slit (25a, 25b) is disposed away from said resonator by a spacing of λg1/4, where λg1 is a wavelength of an electromagnetic wave whose frequency is said resonant frequency of said resonator.
Claim 14
Dependent Claim
21 words
A dielectric resonator according to Claim 13, further comprising another sub-slit (26a, 26b) being disposed apart from said resonator by λg1/2.
Claim 15
Dependent Claim
21 words
A dielectric resonator according to one of Claims 12 to 14, wherein said sub-slit (25a, 25b, 26a, 26b) includes a bend.
Claim 16
Dependent Claim
30 words
A dielectric resonator according to Claim 15, wherein a portion from said bend to an end of said sub-slit (25a, 25b, 26a, 26b) is substantially parallel to said slit (S2).
Claim 17
Dependent Claim
25 words
A dielectric substrate according to one of Claims 1 to 16, wherein at least one of said openings (4, 5) has a substantially circular shape.
Claim 18
Dependent Claim
102 words
A dielectric resonator according to one of Claims 1 to 17, wherein a distance between said dielectric substrate (3) and said upper conductive plate (211), a distance between said dielectric substrate (3) and said lower conductive plate (212), a dielectric constant of said dielectric substrate (3), an area of said openings (4, 5), and a thickness of said dielectric substrate (3) are determined so that a standing wave is generated in said resonator when an electromagnetic field having said resonant frequency is applied thereto, and said electromagnetic field is cut off in portions of said dielectric substrate (3) other than said resonator.
Claim 19
Dependent Claim
78 words
A dielectric resonator according to Claim 1, wherein said variable capacitor (90a, 90b) has: a first insulating support; a thin film electrode (92) fixed on said support; a second insulating support; a movable thin film electrode (93) mounted on said second insulating support, for movement to vary a capacitance of said variable capacitor and thereby vary said resonant frequency; wherein said fixed electrode (92) and movable electrode (93) are opposed to each other to form said variable capacitor.
References Cited (Backward Citations)
GB2141880A
Cited
US4812791A
Cited
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