EP3012902A1 - Résonateur, filtre et procédé de filtrage des fréquences radio - Google Patents

Résonateur, filtre et procédé de filtrage des fréquences radio Download PDF

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Publication number
EP3012902A1
EP3012902A1 EP14290316.0A EP14290316A EP3012902A1 EP 3012902 A1 EP3012902 A1 EP 3012902A1 EP 14290316 A EP14290316 A EP 14290316A EP 3012902 A1 EP3012902 A1 EP 3012902A1
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EP
European Patent Office
Prior art keywords
resonator
posts
wall
post
grounded
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Withdrawn
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EP14290316.0A
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German (de)
English (en)
Inventor
Senad Bulja
Martin Gimersky
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Alcatel Lucent SAS
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Alcatel Lucent SAS
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Publication date
Application filed by Alcatel Lucent SAS filed Critical Alcatel Lucent SAS
Priority to EP14290316.0A priority Critical patent/EP3012902A1/fr
Publication of EP3012902A1 publication Critical patent/EP3012902A1/fr
Withdrawn legal-status Critical Current

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    • 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
    • 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
    • H01P1/201—Filters for transverse electromagnetic waves
    • H01P1/205—Comb or interdigital filters; Cascaded coaxial cavities
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P7/00—Resonators of the waveguide type
    • H01P7/04—Coaxial resonators

Definitions

  • the present invention relates to filters for telecommunications, in particular to radio-frequency filters.
  • Filters are widely used in telecommunications. Applications include base stations for wireless cellular communications, radar systems, amplifier linearization systems, point-to-point radio, and RF signal cancellation systems, to name just a few. Although a specific filter is chosen or designed dependent on the particular application, it is generally desirable for a filter to have low insertion loss in the pass-band and high attenuation in the stop-band. Furthermore, in some applications, the frequency separation (known as the guard-band) between stop-band and pass-band needs to be small, so a filter of a high order is required. Of course as the order of a filter is increased so does its complexity in terms of the number of components the filter requires and hence the filter's size. Furthermore, although increasing the order of a filter increases stop-band attenuation, insertion loss in the pass-band is also thereby increased.
  • Q-Factor Quality factor
  • Q quality factor
  • the Q-factor is defined as the ratio of energy stored in the element to the time-averaged power loss.
  • Q is typically in the range of about 60 to 100.
  • Q is higher and can be as high as several thousands.
  • cavity resonators offer sufficient Q but their relatively large size prevents their use in many applications.
  • the miniaturization problem is especially pressing with the advent of small cell base stations, where the volume of the base station should be minimal, since it is important the base station be as inconspicuous as possible (as opposed to an eyesore).
  • the volume of the base station should be minimal, since it is important the base station be as inconspicuous as possible (as opposed to an eyesore).
  • larger more powerful base stations there is a trend in macrocell base stations towards multiband solutions within a similar mechanical housing to that of previous single-band solutions, so filter miniaturization without sacrificing system performance is becoming important for macrocell base stations too.
  • ceramic mono-block filters with external metallization are used. They offer significant size reduction but have a relatively low Q of a few 100's (up to 500), which is too low for many applications. Additionally, the small size of the filters prevents their use in high-power applications, due to relatively high insertion losses and rather limited power-handling capabilities.
  • filters with ceramic resonators are also offer significant size reductions. Furthermore, these filters offer power-handling capabilities that are much higher than those of mono-block filters. However, cost is the main prohibiting factor for wider deployment of these filters.
  • cavity filters made up of cavity resonators.
  • high-power applications such as those found in mobile cellular communication base stations, there is still no real practical alternative to cavity filters.
  • the standard building block of a cavity filter is a combline resonator, depicted in its basic form in Figure 1 .
  • the combline resonator includes a resonator post in a cavity, and resonates at a frequency where the resonator posts's height is one quarter-wavelength of the electric current, I , induced on the surface of the resonator.
  • a single combline resonator is provided, and as there is no significant capacitive loading at the top of the resonator post, the electrical length of the combline resonator needs to be approximately 90 degrees at the frequency of operation. This electrical length of 90 degrees means that the resonator behaves as an impedance transformer, namely where the resonator post has a short-circuit ended bottom and an open-circuit ended top.
  • a tuning screw extends from the top of the cavity toward the resonator post's ungrounded end so as to effectively balance undesired effects caused by manufacturing tolerances.
  • the tuning screw allows the resonator to be tuned to the resonant frequency for which the resonator was designed.
  • Figure 3 shows the equivalent circuit of each of the resonators shown in Figures 1 and 2 .
  • the known approach to size reduction is to apply a capacitive cap to the resonator post in the cavity, in other words to increase the diameter of the resonator post's top end (which is separated from the cavity surface by a gap).
  • This provides a greater electrical loading and hence lower radio frequency of operation.
  • this must be done with care and only to a moderate level since the Q-factor is reduced in consequence.
  • An example of the present invention is a resonator comprising a resonant chamber, each chamber comprising a first wall, a second wall opposite the first wall, and side walls.
  • the resonant chamber houses three or more resonator posts that are spaced apart, each resonator post being grounded on one of the first wall and the second wall.
  • a first set of the resonator posts is grounded on the first wall so as to extend into the chamber from the first wall.
  • a second set of the resonators is grounded on the second wall so as to extend into the chamber from the second wall.
  • Each resonator post of the first set is for magnetic field coupling in proximity with at least one of the resonator posts of the second set.
  • the first wall may be a top wall and the second wall may be a bottom wall.
  • Some embodiments provide distributed resonator posts within a resonant cavity.
  • the posts can be considered as interdigitated, being alternately grounded on opposite surfaces of the cavity.
  • Some embodiments simultaneously provide cavity filters having reduced dimensions and an extended range of frequency-tunability. This is significant as filters are typically the bulkiest and heaviest subsystems in base stations for mobile cellular telecommunications, rivalled only by power-amplifier heat-sinks, so filter miniaturization is desirable.
  • the greater frequency tunability avoids the need for a network operator to buy replacement known filters for transiting to a new frequency band. Instead with filters according to embodiments, simple retuning is sufficient. Wasteful stockpiling of known cavity filters of different frequency bands is avoided. Opening-up and reconstruction of resonant cavity filters for retuning purposes is also avoided.
  • Some embodiments exploit electromagnetic characteristics that arise when multiple combline resonator posts are placed in the vicinity of one another.
  • Some embodiments will be used in Remote Radio Heads (RRH) where smaller and light-weight filters will cause less stresses due to wind load and reduced requirements for load-bearing on a tower or mast on which the RRH is mounted.
  • RRH Remote Radio Heads
  • Some embodiments provide a reduction in size of the resonant cavity in a filter, as compared to a known filter.
  • An example resonator consisting of a cavity housing eight resonator posts and a tuning screw yields a cavity size reduction of 3.35 as compared to a corresponding resonator having a single resonator post.
  • the same resonator has a frequency tunable range of 15%. This significant frequency range is achieved without the need to open the filter, so there is no practical risk of degradation of radio frequency characteristics by contamination of the filter insides.
  • the present invention in some embodiments allows greater frequency-tunable range and smaller size than an alternative proposal having just two resonator posts in a resonant cavity.
  • the first set comprising one resonator post grounded on the first wall
  • the second set comprising two resonator posts grounded on the second wall.
  • resonator posts there are four or more resonator posts, the first set comprising resonator posts grounded on the first wall, and the second set comprising resonator posts grounded on the second wall, such that in a direction the posts are alternately grounded on the first wall and the second wall.
  • the resonator posts are in a row, and preferably the row is straight or curved, for example semi-circular.
  • the posts are alternately grounded on the first wall and the second wall in the direction along the row.
  • the resonators are disposed in a grid such that, between any two resonator posts of the first set, a resonator post of the second set is provided.
  • the resonator post of the first set or the resonator posts of the first set is/are in an interdigitated configuration with the resonator posts of the second set.
  • At least one resonator post is of adjustable extension into the chamber so as to adjust the resonant frequency of the resonator.
  • the or each resonator post of adjustable extension into the chamber comprises a screw member that extends into the chamber.
  • one resonator post is of adjustable extension and is one that is near or at the centre of the resonator post configuration.
  • Examples of the present invention also relate to corresponding filters and methods of radio frequency filtering.
  • the present invention relates to a radio frequency filter comprising at least one resonator as outlined above.
  • Another example of the present invention relates to a method of radio frequency filtering comprising passing a signal for filtering through at least one resonator, each resonator comprising a resonant chamber, each chamber comprising a first wall, a second wall opposite the first wall, and side walls; in which the resonant chamber houses three or more resonator posts that are spaced apart, each resonator posts being grounded on one of the first wall and the second wall, a first set of the resonator posts being grounded on the first wall so as to extend into the chamber from the first wall; a second set of the resonator posts being grounded on the second wall so as to extend into the chamber from the second wall; wherein each resonator post of the first set is for magnetic field coupling in proximity with at least one of the resonator posts of the second set.
  • the resonator posts of the first set are in an interdigitated configuration with the resonator posts of the second set.
  • the resonators are disposed in a grid such that, between any two resonator posts of the first set, a resonator post of the second set is provided.
  • at least one resonator post is of adjustable extension into the chamber so as to adjust the resonant frequency of the resonator.
  • a resonator structure 2 may be provided in which there are two resonator posts 4, 6, one 4 of which is grounded on the bottom 8 of a resonator cavity 10 and the other 6 of which is grounded on the top 12 of the resonator cavity 10.
  • Figure 5 corresponds to two of the resonators each represented by their own equivalent - parallel LC (inductor-capacitor) - circuit, connected through an admittance transformer, Y t .
  • the inventors then inferred from equation (2) that the first term on the right corresponds to the susceptance of inductor L 0 , while the second term represents the equivalent capacitive susceptance, composed of the susceptance of capacitor C 0 and the susceptance contribution of the second resonator.
  • Equation (5) indicates that the introduction of an admittance transformer, Y t , results in two resonant frequencies: one above and the other below the resonant frequency of an individual resonator.
  • the resonant frequencies of the resonator structure 2 shown in Figure 5 can be adjusted by a selection of the admittance transformer, Y t .
  • Coupled represents the amount of energy that one resonator post intercepts from another resonator post and can be expressed equally well by an equivalent loading "impedance” that one resonator post exhibits when another resonator post is placed in its vicinity.
  • the loading impedance is infinite, no coupling exists between the resonator posts. In practice, this corresponds to the case of infinite physical separation between resonator posts.
  • the resonators are positioned at opposite sides from each other. This means that the directions of the surface currents on the respective resonator posts 4,6 are such that the magnetic fields created by these two currents reinforce each other in the space 16 between the resonators. This implies that the coupling between the two resonator posts 4, 6 is strong, the resonator posts 4,6 exhibit a great deal of influence on each other, and this influence can be controlled by manipulating the amount of coupling between the two resonator posts 4,6. As explained earlier with reference to Figure 5 , coupling can be represented by an equivalent impedance/admittance transformer between the two resonators.
  • this notional impedance/admittance transformer has a tunable electrical length.
  • each individual resonator post has an electrical length of 90° in isolation and that the electrical length of the transformer is adjustable, the overall electrical length of the resonant structure shown in Figure 4 can be arbitrarily long, resulting in reduced frequencies of operation compared to a single resonator in isolation.
  • N is three or more
  • FIG. 8 depicts N (two or more) identical resonator posts of Figure 3 , each represented by their own equivalent - parallel LC (inductor-capacitor) - circuit, connected through an admittance transformer, Y t .
  • the resonant frequency of the circuit of Figure 8 is, similarly, obtained from the condition that the input admittance, Y in , is equal to zero.
  • n number of admittance transformers
  • a resonator structure 19 (sometimes referred to as a resonant structure or the like) may be provided in which there are three resonator posts 20, 22, 24, two 20,24 of which are grounded on the bottom 26 of a resonator cavity 28 and the other 22 of which is disposed between said first two posts 20, 24 and is grounded on the top 30 of the resonator cavity 28.
  • top wall bottom wall, sides walls, is intended to distinguish the walls from each other and resonators may function in any orientation relative to the Earth.
  • the first term on the right corresponds to the susceptance of inductor L 0
  • the second term represents the equivalent capacitive susceptance, composed of the susceptance of capacitor C 0 and the susceptance contribution of the remaining two resonator posts.
  • the first resonant frequency ⁇ 1 is the resonant frequency of a single resonator post alone, while the other two frequencies are positioned above and below the resonant frequency of an individual resonator post, ⁇ 1 .
  • the resonant frequencies given by (11) can be adjusted by a selection of the admittance transformer, Y t .
  • a resonator structure 31 may be provided in which there are four resonator posts 32, 34, 36, 38, two 32,36 of which is grounded on the bottom 40 of a resonator cavity 42 and the other 34,38 of which is grounded on the top 44 of the resonator cavity 42.
  • the resonator posts can be considered as in an interdigitated configuration in that, although not touching each other, along a row or direction the resonator posts are alternately provided from one group (top wall grounded) and then the other group (bottom wall grounded).
  • the term interdigitated is used as this configuration is somewhat analogous to fingers of one hand have been inserted between those of the other hand.
  • ⁇ 2 and ⁇ 4 are of particular importance, since they are lower than the operating frequency of a single resonator, as opposed to ⁇ 1 and ⁇ 3 , which are always higher than the frequency of a single resonator post. Furthermore, it can be shown that ⁇ 2 is, for the same operating conditions (i.e. same resonators and same admittance transformers), always lower than ⁇ 4 . It can be further shown that the resonant frequency of a structure having four resonator posts will resonate with a frequency that is always lower that the lowest frequency of a three-resonator post structure.
  • individual resonator posts and admittance transformers are identical and operate at a frequency of 2 GHz.
  • Figure 9 shows ⁇ 2 of (8), ⁇ 3 of (11) and ⁇ 2 of (13) plotted as a function of the admittance transformer, Y t .
  • the admittance transformer, Y t is allowed to vary from 0.0033 S (equivalent to 300 ⁇ ) to 0.05 S (equivalent to 20 ⁇ ).
  • the frequency of operation of coupled resonant structures is successively decreased as the number of coupled resonator posts increases.
  • the reduction of the operating frequency of coupled resonant structures is not linearly proportional to the number of coupled resonator posts.
  • the input admittance of coupled resonator posts can be expressed in the form of a generalized continued fraction, which does not converge linearly as the number of its constituent elements increases.
  • the rate of convergence of the generalized continued fraction is greatly reduced as the number of its constituent elements increases. Physically, this can be understood, at least to a first-order approximation, in terms of the currents flowing on the resonator surfaces.
  • the inventors realised that it is now possible to increase the number of resonator posts with alternative resonator posts grounded on opposite surfaces of the cavity, so that the frequency of operation is further reduced, in line with the theory presented earlier.
  • the individual resonator posts can be arranged in a row, Fig. 10 , or can be arranged in a circular/semicircular fashion, Fig. 11 .
  • the increase in the number of resonator posts in this fashion does not linearly decrease the frequency of operation.
  • Figure 10 shows a resonant structure 50 comprising a cavity 52 defined by a top wall 54, bottom wall 56, and four side walls 58.
  • the walls are, of course electrically conductive.
  • Each resonator post 60,62,64,66 has a non-grounded end 68 so that an air gap 70is provided between that non-grounded end and the opposite top or bottom wall to the top or bottom wall on which that resonator post is grounded.
  • Figure 11 shows a resonant structure 50a comprising a cavity 52a defined by a top wall 54a, bottom wall 56a, and four side walls 58a.
  • the walls are, of course electrically conductive.
  • Five 61a, 65a, 69a, 73a, 77a of these are grounded on the bottom wall 56a and four 63a, 67a, 71a, 75a are grounded on the top wall 54a in an alternating manner along the row 59a so as to take what may be considered as an inter-digitating configuration.
  • Each resonator post has a non-grounded end so that an air gap is provided between that non-grounded end and the opposite top or bottom wall to the top or bottom wall on which that resonator post is grounded.
  • One such a solution is found by positioning the resonator posts so that they form a rectangular or circular grid.
  • Figures 12 and 13 illustrate two rectangular grid examples, one with four and the other with nine resonator posts, respectively. It is important to state that each of the resonator posts in these two figures couple only to its adjacent neighbours on the vertical and horizontal axes. The resonator posts do not couple to their neighbouring resonator posts on the diagonal axis, since these resonator posts protrude from the same side of the ground plane. For the same reason, the resonator posts along the diagonal axes do not couple to each other.
  • Figure 12 shows a resonant structure 50b comprising a cavity 52b defined by a top wall 54b, bottom wall 56b, and four side walls 58b.
  • the walls are, of course electrically conductive.
  • Each resonator post 60b,62b,64b,66b has a non-grounded end so that an air gap 70b is provided between that non-grounded end and the opposite top or bottom wall to the top or bottom wall on which that resonator post is grounded.
  • Figure 13 shows a resonant structure 50c comprising a cavity 52c defined by a top wall 54c, bottom wall 56c, and four side walls 58c.
  • the walls are, of course electrically conductive.
  • each resonator post has a non-grounded end so that an air gap is provided between that non-grounded end and the opposite top or bottom wall to the top or bottom wall on which that resonator post is grounded.
  • Figure 14 A technique that can be used to facilitate economic manufacture of a filter consisting of any of the structures in Figures 10 to 13 is depicted in Figure 14 , which specifically represents the structure of Figure 13 .
  • Figure 14 can be considered a side-exploded view of the structure of Figure 13 .
  • the resonator structure described above in respect of Figure 13 is assembled from three parts: the bottom wall 56c with resonator posts grounded thereon (left in Figure 14 ), the cavity body made up of the four side walls 58c (centre in the Figure 14 ) and the top wall 54c on which are grounded the other resonator posts (right in the Figure 14 ).
  • top and bottom walls 54c, 56cwith their respective resonators can be fabricated by one of the established dimensionally-stable, highly-repeatable and relatively low-cost large-scale manufacturing processes such as casting.
  • R 4 R 9 R 16 k 0.1 20 60,000 2 10
  • the proposed folding approach can be applied to arrangements where the coupled resonator posts are not arranged in a rectangular grid, but can be arranged in a circular fashion, for example. However, that will require formation of an effective order of the resonator matrix.
  • Figures 10 and 11 represent some embodiments of distributed resonators, so that the reduction in the operating frequency is achieved, while Figures 12 and 13 further refine the distributed-resonator concept.
  • Table 2 compares the resonant frequencies, f 0 , of the four solutions presented in the respective Figures 10 to 13 .
  • the cavity size is identical, 20 x 20 x 40 mm 3 , and the basic resonator element - operating at a frequency of 1693 MHz - is the same.
  • the separation between the identical resonator posts depicted in Figures 10 to 13 is constant and also kept the same, 2.6 mm.
  • the reported resonant-frequency values were obtained by utilizing the full-wave analysis software tool of CST Studio Suite by CST AG www.cst.com/Products/CSTS2 .
  • Table 2 Comparison of resonant frequencies of distributed resonators of Figs. 10 to 13.
  • Resonator type Resonant frequency, f 0 [MHz] Single resonator post 1693 4 resonator posts linear ( Fig. 10 ) 750 4 resonator posts folded ( Fig. 12 ) 680 9 resonator posts curvilinear ( Fig. 11 ) 653 9 resonator posts folded ( Fig. 13 ) 506
  • the middle resonator post of the structures shown in respective Figures 11 and 13 is replaced with a tuning screw 100.
  • the tuning screw 100 is shown diagrammatically in that the screw body portion extending into the cavity is shown, but not the screw head, nor the screw thread on the screw body portion.
  • the tuning screw 100's intrusion into the cavity is made variable.
  • the tuning screw is allowed to intrude into the cavity to a maximum of 39 mm, thus allowing for a gap of 1 mm before the tuning screw would get in contact with the resonator housing.
  • the frequency tunability of the structures of Figures 15 and 16 are compared to the frequency tunability of a resonator having a single resonator post, which is shown in Figure 2 (PRIOR ART).
  • frequency tuning is performed by using a screw positioned at the top of the resonant post. Since in this comparison the resonant post is 39 mm in height and the cavity height is 40 mm, the tuning screw in this Figure 2 (PRIOR ART) case can intrude a maximum of 1 mm before getting in contact with the top of the resonator post.
  • Table 3 Comparison of frequency tunability of resonant structures of Figs. 15 and 16. f 0 (9 resonator posts curvilinear), Fig.15 [MHz] f 0 (9 resonator posts folded), Fig. 16 [MHz] Screw intrusion (0 mm) 742 590 Screw intrusion (39 mm) 653 506 Frequency tunability [%] 12.7 15.3 Table 4: For comparison, frequency tunability of a prior art resonator having a single resonator post. f 0 (single resonator post) [MHz] Screw intrusion (0 mm) 1693 Screw intrusion (0.5 mm) 1596 Frequency tunability [%] 5.8
  • the proposed distributed-resonator structures (seen for example in Figures 10 to 16 ) not only offer a reduction in the frequency of operation, but they also lend themselves to frequency tunability.
  • the arrangement of 9 folded distributed resonators ( Fig. 16 ) has a frequency tunability of over 15 %
  • the curvilinear arrangeent of 9 distributed resonators ( Fig. 15 ) has a tunability of over 12 %. This favourably compares to the frequency tunability of the prior art ( Figure 2 ) resonator having a a single resonator post, which stands at 5.8 %.
  • program storage devices e.g., digital data storage media, which are machine or computer readable and encode machine-executable or computer-executable programs of instructions, wherein said instructions perform some or all of the steps of said above-described methods.
  • the program storage devices may be, e.g., digital memories, magnetic storage media such as a magnetic disks and magnetic tapes, hard drives, or optically readable digital data storage media.
  • Some embodiments involve computers programmed to perform said steps of the above-described methods.

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EP14290316.0A 2014-10-21 2014-10-21 Résonateur, filtre et procédé de filtrage des fréquences radio Withdrawn EP3012902A1 (fr)

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EP14290316.0A EP3012902A1 (fr) 2014-10-21 2014-10-21 Résonateur, filtre et procédé de filtrage des fréquences radio

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EP14290316.0A EP3012902A1 (fr) 2014-10-21 2014-10-21 Résonateur, filtre et procédé de filtrage des fréquences radio

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3285331A1 (fr) * 2016-08-17 2018-02-21 Nokia Technologies Oy Resonateur
EP3301752A1 (fr) * 2016-09-28 2018-04-04 Nokia Technologies Oy Résonateur
EP3333967A1 (fr) * 2016-12-12 2018-06-13 Nokia Technologies OY Résonateur
WO2021213630A1 (fr) * 2020-04-21 2021-10-28 Nokia Technologies Oy Dispositif résonant comprenant des éléments résonants dans une cavité résonante
US11276907B2 (en) 2019-03-26 2022-03-15 Nokia Solutions And Networks Oy Apparatus for radio frequency signals and method of manufacturing such apparatus
CN117374544A (zh) * 2023-12-08 2024-01-09 成都威频通讯技术有限公司 一种交指电容耦合小型化腔体低通滤波器

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0038996A1 (fr) * 1980-04-28 1981-11-04 Oki Electric Industry Company, Limited Filtre aux hautes fréquences
JPS5714201A (en) * 1980-06-30 1982-01-25 Murata Mfg Co Ltd Filter using dielectric resonator
US20040051603A1 (en) * 2002-09-17 2004-03-18 Pance Kristi Dhimiter Cross-coupled dielectric resonator circuit
EP1575118A1 (fr) * 2004-03-12 2005-09-14 M/A-Com, Inc. Méthode et mécanisme pour accorder des circuits de résonateurs diélectriques
WO2007149423A2 (fr) * 2006-06-21 2007-12-27 M/A-Com, Inc. Circuits de résonateurs diélectriques

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0038996A1 (fr) * 1980-04-28 1981-11-04 Oki Electric Industry Company, Limited Filtre aux hautes fréquences
JPS5714201A (en) * 1980-06-30 1982-01-25 Murata Mfg Co Ltd Filter using dielectric resonator
US20040051603A1 (en) * 2002-09-17 2004-03-18 Pance Kristi Dhimiter Cross-coupled dielectric resonator circuit
EP1575118A1 (fr) * 2004-03-12 2005-09-14 M/A-Com, Inc. Méthode et mécanisme pour accorder des circuits de résonateurs diélectriques
WO2007149423A2 (fr) * 2006-06-21 2007-12-27 M/A-Com, Inc. Circuits de résonateurs diélectriques

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3285331A1 (fr) * 2016-08-17 2018-02-21 Nokia Technologies Oy Resonateur
EP3301752A1 (fr) * 2016-09-28 2018-04-04 Nokia Technologies Oy Résonateur
EP3333967A1 (fr) * 2016-12-12 2018-06-13 Nokia Technologies OY Résonateur
US11063335B2 (en) 2016-12-12 2021-07-13 Nokia Technologies Oy Resonator
US11276907B2 (en) 2019-03-26 2022-03-15 Nokia Solutions And Networks Oy Apparatus for radio frequency signals and method of manufacturing such apparatus
WO2021213630A1 (fr) * 2020-04-21 2021-10-28 Nokia Technologies Oy Dispositif résonant comprenant des éléments résonants dans une cavité résonante
CN117374544A (zh) * 2023-12-08 2024-01-09 成都威频通讯技术有限公司 一种交指电容耦合小型化腔体低通滤波器
CN117374544B (zh) * 2023-12-08 2024-02-23 成都威频通讯技术有限公司 一种交指电容耦合小型化腔体低通滤波器

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