EP0071508A1 - Small-dimensioned microwave filter with linear resonators - Google Patents

Small-dimensioned microwave filter with linear resonators Download PDF

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Publication number
EP0071508A1
EP0071508A1 EP82401307A EP82401307A EP0071508A1 EP 0071508 A1 EP0071508 A1 EP 0071508A1 EP 82401307 A EP82401307 A EP 82401307A EP 82401307 A EP82401307 A EP 82401307A EP 0071508 A1 EP0071508 A1 EP 0071508A1
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Prior art keywords
resonators
filter
capacitors
length
resonator
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EP82401307A
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German (de)
French (fr)
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EP0071508B1 (en
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Patrick Janer
Marie-Christine Henriot
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Thales SA
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Thomson CSF SA
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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
    • H01P1/201—Filters for transverse electromagnetic waves
    • H01P1/203—Strip line filters
    • H01P1/20327—Electromagnetic interstage coupling
    • H01P1/20354—Non-comb or non-interdigital filters
    • H01P1/20372—Hairpin resonators

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  • the present invention relates to filters produced by means of linear resonators open at their two ends, known as hair pin resonators in the Anglo-Saxon literature) or U-shaped resonators.
  • these filters is related to the length of the resonators, but in known filters this length is substantially equal to half the average working wavelength in the filter.
  • these known filters are not tunable: it would indeed be necessary to be able to easily modify the length of the U-shaped resonators which is of course not the case.
  • the object of the present invention is to provide filters with linear U-shaped resonators of dimensions considerably smaller than those of conventional filters of the same type.
  • n linear resonators (n positive integer), open at their two ends and of length 2 ( ⁇ : given length), and which comprises n capacitors connected respectively to the n resonators in order to lower the average working frequency of the filter below the value corresponding, in the filter, to the wavelength equal to ⁇ .
  • FIG. 1 shows a band pass filter with linear U-shaped resonators of the conventional type.
  • this is a filter produced on a wafer, 1, of two times two inches, ie 5.08 x 5.08 cm, having a thickness of 1.27 mm; a graduated scale from 0 to 1 cm is placed next to the plate to show the enlargement ratio of the drawing.
  • the filter according to FIG. 1 comprises, in addition to the plate 1 made of alumina, a ground plane constituted by a gold deposit of 10 lU thickness covering all of that of the two faces of the plate which is not visible on the drawing.
  • a ground plane constituted by a gold deposit of 10 lU thickness covering all of that of the two faces of the plate which is not visible on the drawing.
  • two lines L 1 , L2 are made by depositing gold 10 u thick, and, between these two lines, six U-shaped resonators, H 1 to H 6 .
  • the lines L 1 , L 2 constitute the ports of the filter; they are mutually parallel and parallel to the vertical bars of the U of the resonators.
  • a filter of the type of that according to FIG. 1 is of course with fixed bandwidth since it does not have a tuning element whose characteristic would be easily adjustable.
  • FIG. 2 is a graph which gives, as a function of the frequency F expressed in megahertz, the value of the attenuation A, expressed in decibels, which the filter entails according to FIG. 1.
  • This graph shows that the filter has a band -passing centered on 825 MHz and with a width of 55 MHz at 3dB of the value at 825 MHz; it is for this bandwidth that the filter of Figure 1 was calculated, the U-shaped resonators of which were chosen to be 70 mm long, or , where ⁇ is the wavelength in alumina corresponding to the frequency of 825 MHz.
  • the filter according to FIG. 1 has, as shown in FIG.
  • a passband which can be called “parasitic passband”, and which is due to the harmonic 2 of the U-shaped resonators; this parasitic bandwidth is situated substantially between 1000 and 1400 Hz and, in this bandwidth, the attenuation varies in wave form between -3 and -20 decibels.
  • Figure 3 is the representation of a filter according to the invention; this filter, like the filter according to figure 1, was calculated to present a 55 MHz bandwidth centered on 825 MHz.
  • This filter is produced on an alumina wafer, 1, twice an inch, ie 2.54 x 2.54 cm having a thickness of 1.27 mm; a graduated scale of 0 to 1 cm, placed next to the plate, gives the enlargement ratio of the drawing.
  • the filter according to FIG. 3 comprises a ground plane here consisting of a gold deposit 10 ⁇ m thick and which completely covers all of that of the two faces of the plate which is not not visible in the drawing; on the face of the wafer 1 visible in the drawing, two lines L ′ 1 , L ′ 2 are mutually parallel, and between these lines, five U-shaped resonators, H ' 1 to H I 5 whose vertical bars are parallel to the lines L' 1 , L ' 2 . Between two points located, in the case of FIG.
  • variable capacitors C 1 to C 5 , associated respectively with the resonators H ' 1 to H ' 5 ;
  • these variable capacitors symbolically represented by two parallel bars crossed by an arrow, are miniature commercial capacitors whose capacity can be adjusted between 0.3 and 1.2 picofarads.
  • the length of the U-shaped resonators of FIG. 3 is 40 mm, which, for a half wavelength having this value in alumina, corresponds to a frequency of 1450 MHz; but, as shown in Figure 4, with the filter according to Figure 3 the bandwidth is no longer centered on a frequency whose corresponding half wavelength is equal to the length of the U-shaped resonators.
  • FIG. 4 is a graph which represents, with the same scales on the abscissa and on the ordinate as in FIG. 2, the attenuation as a function of the frequency produced by the filter according to FIG. 3.
  • This graph shows that the filter of FIG. 3 has a bandwidth centered on 825 MHz, almost identical to that of the filter according to FIG. 1.
  • the "parasitic bandwidth" of the filter of FIG. 1 (between 1000 and 1400 MHz) does not exist with the filter.
  • FIG. 5 shows a resonator, H, with the associated capacitor, C, obtained in the manner indicated above.
  • the capacitor C consists of a row of parallel tongues, arranged between the branches of the U of the resonator H, perpendicular to its branches; two successive tongues are respectively integral with the two branches of the U.
  • FIG. 6 represents a notch filter which comprises a single access line, L, the two ends of which constitute the inlet and the outlet of the filter respectively.
  • Three U-shaped resonators, H o ,, H 02 ' H 03 are arranged in the same plane as line L, with their branches parallel to line L and are placed on either side of this line.
  • Variable capacitors C ′ 1 , C ′ 2 , C ′ 3 make it possible to obtain the same advantages as in the case of FIG. 3 but in a transposition to the strip cut function.
  • the coupling between the access line or lines and the resonators can be done by an electrical connection between one of the resonators and the line considered.
  • an access line, or both may be perpendicular to the bars of the U-shaped resonators and terminate in an electrical connection to the resonator; this is how, for example, in FIG. 3 the line L ' 1 can be replaced by a connection starting from the left edge of the plate and ending at a point on the left bar of the resonator H' 1 , this point depending of the input coupling to be performed.
  • filters of which the lines, the resonators and possibly the capacitors consist of metallic deposits on a substrate

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Abstract

1. A microwave filter comprising n linear hair-pin resonators (H'1 -H'5 ), n being a positive integer, characterized in that the length of each resonator is smaller than lambda/2, lambda being the wavelength corresponding to the center frequency of the filter band, and that a capacitor (C1 -C2 ) is branched between the open ends of each resonator, the capacitance of said capacitor being such that a resonance frequency equal to said center frequency of the filter band is obtained in the resonant circuit constituted by said capacitor and the associated resonator.

Description

La présente invention se rapporte aux filtres réalisés au moyen de résonateurs linéaires ouverts à leurs deux extrémités, connus sous le nom de résonateurs en épingle à cheveux (hair pin resonator dans la littérature anglo-saxonne) ou de résonateurs en U.The present invention relates to filters produced by means of linear resonators open at their two ends, known as hair pin resonators in the Anglo-Saxon literature) or U-shaped resonators.

La dimension de ces filtres est liée à la longueur des résonateurs, or dans les filtres connus cette longueur est sensiblement égale à la moitié de la longueur d'onde moyenne de travail dans le filtre. De plus, ces filtres connus ne sont pas accordables : il faudrait en effet pouvoir modifier facilement la longueur des résonateurs en U ce qui n'est bien entendu pas le cas.The size of these filters is related to the length of the resonators, but in known filters this length is substantially equal to half the average working wavelength in the filter. In addition, these known filters are not tunable: it would indeed be necessary to be able to easily modify the length of the U-shaped resonators which is of course not the case.

La présente invention a pour but de proposer des filtres à résonateurs linéaires en U de dimensions nettement inférieures à celles des filtres classiques du même type.The object of the present invention is to provide filters with linear U-shaped resonators of dimensions considerably smaller than those of conventional filters of the same type.

Ceci est obtenu par l'utilisation de condensateurs associés à des filtres à résonateurs en U de type classique.This is obtained by the use of capacitors associated with conventional type U-shaped resonator filters.

Selon l'invention, il est proposé de réaliser un filtre hyperfréquence à n résonateurs linéaires (n entier positif), ouverts à leurs deux extrémités et de longueur 2 (λ: longueur donnée), et qui comporte n condensateurs connectés respectivement sur les n résonateurs afin de descendre la fréquence moyenne de travail du filtre en dessous de la valeur correspondant, dans le filtre, à la longueur d'onde égale à λ.According to the invention, it is proposed to produce a microwave filter with n linear resonators (n positive integer), open at their two ends and of length 2 (λ: given length), and which comprises n capacitors connected respectively to the n resonators in order to lower the average working frequency of the filter below the value corresponding, in the filter, to the wavelength equal to λ.

La présente invention sera mieux comprise et d'autres caractéristiques apparaîtront à l'aide de la description ci-après et des figures s'y rapportant qui représentent :

  • - la figure 1, un filtre selon l'art connu,
  • - la figure 2, un graphique relatif à la figure 1,
  • - la figure 3, un filtre selon l'invention,
  • - la figure 4, un graphique relatif à la figure 3,
  • - la figure 5, une partie d'un filtre selon l'invention,
  • - la figure 6, un schéma d'un filtre selon l'invention.
The present invention will be better understood and other characteristics will appear with the aid of the description below and of the figures relating thereto which represent:
  • FIG. 1, a filter according to the known art,
  • FIG. 2, a graph relating to FIG. 1,
  • FIG. 3, a filter according to the invention,
  • FIG. 4, a graph relating to FIG. 3,
  • FIG. 5, part of a filter according to the invention,
  • - Figure 6, a diagram of a filter according to the invention.

La figure 1 montre un filtre passe-bande à résonateurs linéaires en U de type classique. Dans le cas de l'exemple décrit il s'agit d'un filtre réalisé sur une plaquette, 1, de deux fois deux pouces, soit 5,08 x 5,08 cm, présentant une épaisseur de 1,27 mm ; une échelle graduée de 0 à 1 cm est placée à côté de la plaquette pour montrer le rapport d'agrandissement du dessin.FIG. 1 shows a band pass filter with linear U-shaped resonators of the conventional type. In the case of the example described, this is a filter produced on a wafer, 1, of two times two inches, ie 5.08 x 5.08 cm, having a thickness of 1.27 mm; a graduated scale from 0 to 1 cm is placed next to the plate to show the enlargement ratio of the drawing.

Le filtre selon la figure 1 comporte, outre la plaquette 1 réalisée en alumine, un plan de masse constitué par un dépôt d'or de 10 lU d'épaisseur recouvrant toute celle des deux faces de la plaquette qui n'est pas visible sur le dessin. Sur la face de la plaquette visible sur le dessin sont réalisés, par dépôt d'or de 10 u d'épaisseur, deux lignes L1 , L2 et, entre ces deux lignes, six résonateurs en U, H1 à H6. Les lignes L1 , L2 constituent les accès du filtre ; elles sont parallèles entre elles et parallèles aux barres verticales des U des résonateurs.The filter according to FIG. 1 comprises, in addition to the plate 1 made of alumina, a ground plane constituted by a gold deposit of 10 lU thickness covering all of that of the two faces of the plate which is not visible on the drawing. On the face of the plate visible in the drawing, two lines L 1 , L2 are made by depositing gold 10 u thick, and, between these two lines, six U-shaped resonators, H 1 to H 6 . The lines L 1 , L 2 constitute the ports of the filter; they are mutually parallel and parallel to the vertical bars of the U of the resonators.

Un filtre du type de celui selon la figure 1 est bien entendu à bande passante fixe puisqu'il ne présente pas d'élément d'accord dont la caractéristique serait facilement ajustable.A filter of the type of that according to FIG. 1 is of course with fixed bandwidth since it does not have a tuning element whose characteristic would be easily adjustable.

La figure 2 est un graphique qui donne, en fonction de la fréquence F exprimée en mégahertz, la valeur de l'atténuation A, exprimée en décibels, qu'entraîne le filtre selon la figure 1. Ce graphique montre que le filtre présente une bande-passante centrée sur 825 MHz et d'une largeur de 55 MHz à 3dB de la valeur à 825 MHz ; c'est pour cette bande passante qu'a été calculé le filtre de la figure 1 dont les résonateurs en U ont été choisis d'une longueur égale à 70 mm, soit

Figure imgb0001
, où λ est la longueur d'onde dans l'alumine correspondant à la fréquence de 825 MHz. Il est à noter par ailleurs que, à côté de cette bande passante centrée sur 825 MHz, le filtre selon la figure 1 présente, comme il ressort de la figure 2, une bande passante qui peut être appelée "bande passante parasite", et qui est due à l'harmonique 2 des résonateurs en U ; cette bande passante parasite est située sensiblement entre 1000 et 1400 Hz et, dans cette bande passante, l'atténuation varie de façon ondulatoire entre -3 et -20 décibels.FIG. 2 is a graph which gives, as a function of the frequency F expressed in megahertz, the value of the attenuation A, expressed in decibels, which the filter entails according to FIG. 1. This graph shows that the filter has a band -passing centered on 825 MHz and with a width of 55 MHz at 3dB of the value at 825 MHz; it is for this bandwidth that the filter of Figure 1 was calculated, the U-shaped resonators of which were chosen to be 70 mm long, or
Figure imgb0001
 , where λ is the wavelength in alumina corresponding to the frequency of 825 MHz. It should also be noted that, next to this passband centered on 825 MHz, the filter according to FIG. 1 has, as shown in FIG. 2, a passband which can be called "parasitic passband", and which is due to the harmonic 2 of the U-shaped resonators; this parasitic bandwidth is situated substantially between 1000 and 1400 Hz and, in this bandwidth, the attenuation varies in wave form between -3 and -20 decibels.

La figure 3 est la représentation d'un filtre selon l'invention ; ce filtre, comme le filtre selon la figure 1, a été calculé pour présenter une bande passante de 55 MHz centrée sur 825 MHz. Ce filtre est réalisé sur une plaquette d'alumine, 1, de deux fois un pouce, soit 2,54 x 2,54 cm présentant une épaisseur de 1,27 mm ; une échelle graduée de 0 à 1 cm, placée à côté de la plaquette, donne le rapport d'agrandissement du dessin.Figure 3 is the representation of a filter according to the invention; this filter, like the filter according to figure 1, was calculated to present a 55 MHz bandwidth centered on 825 MHz. This filter is produced on an alumina wafer, 1, twice an inch, ie 2.54 x 2.54 cm having a thickness of 1.27 mm; a graduated scale of 0 to 1 cm, placed next to the plate, gives the enlargement ratio of the drawing.

Comme le filtre selon la figure 1, le filtre selon la figure 3 comporte un plan de masse constitué ici d'un dépôt d'or de 10 µ d'épaisseur et qui recouvre entièrement toute celle des deux faces de la plaquette qui n'est pas visible sur le dessin ; sur la face de la plaquette 1 visible sur le dessin sont réalisés, par un dépôt d'or de 10 µ d'épaisseur, deux lignes L'1, L'2 parallèles entre elles et, entre ces lignes, cinq résonateurs en U, H'1 à HI 5 dont les barres verticales sont parallèles aux lignes L'1 , L'2. Entre deux points situés, dans le cas de la figure 3, au voisinage des extrémités des résonateurs en U, H'1 à H'5, sont branchés cinq condensateurs variables, C1 à C5, associés respectivement aux résonateurs H'1 à H'5 ; ces condensateurs variables, représentés symboliquement par deux barres parallèles traversées par une flèche, sont des condensateurs miniatures du commerce dont la capacité peut être réglée entre 0,3 et 1,2 picofarads.Like the filter according to FIG. 1, the filter according to FIG. 3 comprises a ground plane here consisting of a gold deposit 10 μm thick and which completely covers all of that of the two faces of the plate which is not not visible in the drawing; on the face of the wafer 1 visible in the drawing, two lines L ′ 1 , L ′ 2 are mutually parallel, and between these lines, five U-shaped resonators, H ' 1 to H I 5 whose vertical bars are parallel to the lines L' 1 , L ' 2 . Between two points located, in the case of FIG. 3, in the vicinity of the ends of the U-shaped resonators, H ' 1 to H' 5 , are connected five variable capacitors, C 1 to C 5 , associated respectively with the resonators H ' 1 to H '5; these variable capacitors, symbolically represented by two parallel bars crossed by an arrow, are miniature commercial capacitors whose capacity can be adjusted between 0.3 and 1.2 picofarads.

La longueur des résonateurs en U de la figure 3 est de 40 mm, ce qui, pour une demi longueur d'onde ayant cette valeur dans l'alumine, correspond à une fréquence de 1450 MHz ; mais, comme le montre la figure 4, avec le filtre selon la figure 3 la bande passante n'est plus centrée sur une fréquence dont la demi longueur d'onde correspondante est égale à la longueur des résonateurs en U.The length of the U-shaped resonators of FIG. 3 is 40 mm, which, for a half wavelength having this value in alumina, corresponds to a frequency of 1450 MHz; but, as shown in Figure 4, with the filter according to Figure 3 the bandwidth is no longer centered on a frequency whose corresponding half wavelength is equal to the length of the U-shaped resonators.

La figure 4 est un graphique qui représente, avec les mêmes échelles en abscisse et en ordonnée que sur la figure 2, l'atténuation en fonction de la fréquence que produit le filtre selon la figure 3. Ce graphique montre que le filtre de la figure 3 présente une bande passante centrée sur 825 MHz, quasiment identique à celle du filtre selon la figure 1. Par contre la "bande passante parasite" du filtre de la figure 1 (entre 1000 et 1400 MHz) n'existe pas avec le filtre de la figure 3 ; en effet les condensateurs C1 à C5 ont été réglés pour, dans l'exemple décrit, descendre la fréquence moyenne de la bande passante du filtre d'environ une octave, ce qui entraîne un doublement de la longueur électrique des résonateurs alors que, la longueur physique des résonateurs restant inchangée, le premier harmonique gênant devient l'harmonique quatre (3300 MHz).FIG. 4 is a graph which represents, with the same scales on the abscissa and on the ordinate as in FIG. 2, the attenuation as a function of the frequency produced by the filter according to FIG. 3. This graph shows that the filter of FIG. 3 has a bandwidth centered on 825 MHz, almost identical to that of the filter according to FIG. 1. On the other hand, the "parasitic bandwidth" of the filter of FIG. 1 (between 1000 and 1400 MHz) does not exist with the filter. Figure 3; in fact the capacitors C 1 to C 5 have been adjusted to, in the example described, lower the average frequency of the pass band of the filter by approximately one octave, which results in a doubling of the electrical length of the resonators whereas, the physical length of the resonators remaining unchanged, the first annoying harmonic becomes harmonic four (3300 MHz).

Ainsi d'une façon générale, il y a réduction de la taille du filtre par rapport aux filtres du genre de celui selon la figure 1 ; le condensateur complétant la longueur électrique du résonateur auquel il est associé, il est possible de donner à ce résonateur une longueur physique de l'ordre de 4 comme dans le cas du filtre correspondant à la figure 3 et de régler le condensateur pour donner la courbe de la figure 4. En choisissant convenablement les condensateurs variables il est même possible de donner aux résonateurs en U une longueur inférieure à

Figure imgb0002
.Thus in general, there is a reduction in the size of the filter compared to filters of the kind of that according to FIG. 1; the capacitor completing the electrical length of the resonator with which it is associated, it is possible to give this resonator a physical length of the order of 4 as in the case of the filter corresponding to FIG. 3 and to adjust the capacitor to give the curve of figure 4. By choosing the variable capacitors suitably it is even possible to give the U-shaped resonators a length less than
Figure imgb0002
 .

En faisant varier d'une manière continue la valeur des condensateurs du filtre selon la figure 3, une variation continue de l'accord en fréquence de ce filtre est obtenue.By continuously varying the value of the capacitors of the filter according to FIG. 3, a continuous variation of the frequency tuning of this filter is obtained.

Une autre possibilité de réalisation des condensateurs d'accord du filtre selon l'invention est la réalisation de type circuit gravé. Dans cette réalisation les condensateurs sont obtenus en même temps et de la même façon que les résonateurs : dépôt métallique sur une plaquette ou plaquette métallisée dont une partie de la couche métallique a été retirée par attaque chimique ou mécanique. La figure 5 montre un résonateur, H, avec le condensateur y associé, C, obtenu de la façon indiquée ci-avant. Le condensateur C est constitué d'une rangée de languettes parallèles, disposées entre les branches du U du résonateur H, perpendiculairement à ses branches ; deux languettes successives sont respectivement solidaires des deux branches du U. Il est à remarquer que des filtres réalisés de la sorte ne sont pas réglables mais présentent, par rapport aux filtres à condensateurs variables du genre de celui selon la figure 3, l'avantage d'une épaisseur plus réduite et d'une fabrication plus rapide.Another possibility of producing the tuning capacitors of the filter according to the invention is the realization of the etched circuit type. In this embodiment, the capacitors are obtained at the same time and in the same way as the resonators: metallic deposition on a wafer or metallized wafer from which part of the metallic layer has been removed by chemical or mechanical attack. FIG. 5 shows a resonator, H, with the associated capacitor, C, obtained in the manner indicated above. The capacitor C consists of a row of parallel tongues, arranged between the branches of the U of the resonator H, perpendicular to its branches; two successive tongues are respectively integral with the two branches of the U. It should be noted that filters produced in this way are not adjustable but have, compared to filters with variable capacitors of the kind of that according to FIG. 3, the advantage of '' reduced thickness and faster production.

Différentes variantes aux filtres décrits à l'aide des figures 3 à 5 peuvent être proposées sans sortir du cadre de l'invention. C'est ainsi qu'il est possible de réaliser de la même façon des filtres coupe-bande ; la figure 6 est une vue schématique d'un tel filtre.Different variants of the filters described with the aid of Figures 3 to 5 can be proposed without departing from the scope of the invention. This is how band-cut filters can be made in the same way; Figure 6 is a schematic view of such a filter.

La figure 6 représente un filtre coupe-bande qui comporte une seule ligne d'accès, L, dont les deux extrémités constituent respectivement l'entrée et la sortie du filtre. Trois résonateurs en U, Ho, , H02 ' H03 , sont disposés dans un même plan que la ligne L, avec leurs branches parallèles à la ligne L et sont placés de part et d'autre de cette ligne. Des condensateurs variables C'1 , C'2 , C'3 permettent d'obtenir les mêmes avantages que dans le cas de la figure 3 mais dans une transposition à la fonction coupe-bande.FIG. 6 represents a notch filter which comprises a single access line, L, the two ends of which constitute the inlet and the outlet of the filter respectively. Three U-shaped resonators, H o ,, H 02 ' H 03 , are arranged in the same plane as line L, with their branches parallel to line L and are placed on either side of this line. Variable capacitors C ′ 1 , C ′ 2 , C ′ 3 make it possible to obtain the same advantages as in the case of FIG. 3 but in a transposition to the strip cut function.

Dans d'autres variantes, le couplage entre la ou les lignes d'accès et les résonateurs pourra se faire par une connexion électrique entre l'un des résonateurs et la ligne considérée. De même une ligne d'accès, ou les deux, pourra être perpendiculaire aux barres des résonateurs en U et se terminer par une connexion électrique sur le résonateur ; c'est ainsi que, par exemple, sur la figure 3 la ligne L'1 peut être remplacée par une connexion partant du bord gauche de la plaquette et aboutissant en un point de la barre de gauche du résonateur H'1, ce point dépendant du couplage d'entrée à réaliser.In other variants, the coupling between the access line or lines and the resonators can be done by an electrical connection between one of the resonators and the line considered. Similarly, an access line, or both, may be perpendicular to the bars of the U-shaped resonators and terminate in an electrical connection to the resonator; this is how, for example, in FIG. 3 the line L ' 1 can be replaced by a connection starting from the left edge of the plate and ending at a point on the left bar of the resonator H' 1 , this point depending of the input coupling to be performed.

Par ailleurs, au lieu de réaliser des filtres dont les lignes, les résonateurs et éventuellement les condensateurs sont constitués de dépôts métalliques sur un substrat, il est possible, dans une plaque métallique déposée sur un substrat, de réaliser les lignes, les résonateurs et éventuellement les condensateurs, par enlèvement de métal ; on a alors un filtre à lignes et résonateurs à fente ("slot lines" et "resonant slots" dans la littérature anglo-saxonne).Furthermore, instead of making filters of which the lines, the resonators and possibly the capacitors consist of metallic deposits on a substrate, it is possible, in a metal plate deposited on a substrate, to produce the lines, the resonators and possibly capacitors, by removing metal; we then have a filter with slotted lines and resonators ("slot lines" and "resonant slots" in Anglo-Saxon literature).

Claims (3)

1. Filtre hyperfréquence à n résonateurs (n entier positif) linéaires, ouverts à leurs deux extrémités (H'1 - H'5) et de longueur
Figure imgb0003
(λ : longueur donnée), caractérisé en ce que, afin de descendre sa fréquence moyenne de travail en dessous de la valeur correspondant, dans le filtre, à la longueur d'onde égale à λ, il comporte n condensateurs (C1- C5) connectés respectivement sur les n résonateurs.1. Microwave filter with n linear resonators (n positive integer), open at their two ends (H ' 1 - H' 5 ) and of length
Figure imgb0003
 (λ: given length), characterized in that, in order to lower its average working frequency below the value corresponding, in the filter, to the wavelength equal to λ, it comprises n capacitors (C 1 - C 5 ) connected respectively to the n resonators. 2. Filtre selon la revendication 1, ou les n résonateurs sont des résonateurs en U présentant deux barres sensiblement parallèles, caractérisé en ce que les condensateurs sont des condensateurs variables (C1- C5) dont les deux connexions sont respectivement soudées aux deux barres du U des résonateurs auxquels les condensateurs sont connectés.2. Filter according to claim 1, or the n resonators are U-shaped resonators having two substantially parallel bars, characterized in that the capacitors are variable capacitors (C 1 - C 5 ) whose two connections are respectively welded to the two bars of the U of the resonators to which the capacitors are connected. 3. Filtre selon la revendication 1, caractérisé en ce que les résonateurs étant obtenus par une technique donnée de dépôt métallique sur un substrat (1), les condensateurs (C) sont des condensateurs fixes, déposés, par la technique donnée sur le substrat.3. Filter according to claim 1, characterized in that the resonators being obtained by a given technique of metallic deposition on a substrate (1), the capacitors (C) are fixed capacitors, deposited, by the technique given on the substrate.
EP82401307A 1981-07-24 1982-07-09 Small-dimensioned microwave filter with linear resonators Expired EP0071508B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8114425A FR2510325B1 (en) 1981-07-24 1981-07-24 SMALL DIMENSIONAL MICROWAVE FILTER WITH LINEAR RESONATORS
FR8114425 1981-07-24

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EP0071508A1 true EP0071508A1 (en) 1983-02-09
EP0071508B1 EP0071508B1 (en) 1987-01-21

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JP (1) JPS5816901U (en)
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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2565438A1 (en) * 1984-05-30 1985-12-06 Cepe DIELECTRIC FILTER WITH VARIABLE CENTRAL FREQUENCY.
GB2164804A (en) * 1984-09-17 1986-03-26 Stc Plc Stripline filters for transmission systems
EP0071509B1 (en) * 1981-07-24 1986-08-20 Thomson-Csf Band-pass filter with open-ended linear resonators
US4731596A (en) * 1985-02-27 1988-03-15 Alcatel Thomson Faisceaux Hertziens Band-pass filter for hyperfrequencies
FR2613538A1 (en) * 1987-03-31 1988-10-07 Thomson Csf Microwave filter
EP0326498A1 (en) * 1988-01-29 1989-08-02 France Telecom Resonant circuit and filter using it
US5187460A (en) * 1990-03-09 1993-02-16 Tekelec Airtronic Microstrip line resonator with a feedback circuit
EP0803979A2 (en) * 1996-04-26 1997-10-29 Lk-Products Oy Integrated filter construction
US6313719B1 (en) * 2000-03-09 2001-11-06 Avaya Technology Corp. Method of tuning a planar filter with additional coupling created by bent resonator elements
US7231238B2 (en) 1989-01-13 2007-06-12 Superconductor Technologies, Inc. High temperature spiral snake superconducting resonator having wider runs with higher current density
RU2662058C1 (en) * 2017-06-26 2018-07-23 Российская Федерация, от имени которой выступает Министерство обороны Российской Федерации Microvawe low-pass filter

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2540294B1 (en) * 1983-01-31 1985-10-04 Thomson Csf MICROWAVE FILTER WITH LINEAR RESONATORS
JP2718984B2 (en) * 1989-03-20 1998-02-25 松下電器産業株式会社 Resonator and filter using the resonator

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US3094664A (en) * 1961-11-09 1963-06-18 Bell Telephone Labor Inc Solid state diode surface wave traveling wave amplifier
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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0071509B1 (en) * 1981-07-24 1986-08-20 Thomson-Csf Band-pass filter with open-ended linear resonators
EP0165158A1 (en) * 1984-05-30 1985-12-18 Compagnie D'electronique Et De Piezo-Electricite - C.E.P.E. Dielectric filter with a variable centre frequency
FR2565438A1 (en) * 1984-05-30 1985-12-06 Cepe DIELECTRIC FILTER WITH VARIABLE CENTRAL FREQUENCY.
GB2164804B (en) * 1984-09-17 1989-03-15 Stc Plc Filters for transmission systems
GB2164804A (en) * 1984-09-17 1986-03-26 Stc Plc Stripline filters for transmission systems
US4731596A (en) * 1985-02-27 1988-03-15 Alcatel Thomson Faisceaux Hertziens Band-pass filter for hyperfrequencies
FR2613538A1 (en) * 1987-03-31 1988-10-07 Thomson Csf Microwave filter
EP0326498A1 (en) * 1988-01-29 1989-08-02 France Telecom Resonant circuit and filter using it
FR2626716A1 (en) * 1988-01-29 1989-08-04 France Etat FILTER WITH PLANAR RESONATORS
US7231238B2 (en) 1989-01-13 2007-06-12 Superconductor Technologies, Inc. High temperature spiral snake superconducting resonator having wider runs with higher current density
US5187460A (en) * 1990-03-09 1993-02-16 Tekelec Airtronic Microstrip line resonator with a feedback circuit
EP0803979A2 (en) * 1996-04-26 1997-10-29 Lk-Products Oy Integrated filter construction
EP0803979A3 (en) * 1996-04-26 1999-03-03 Lk-Products Oy Integrated filter construction
US6313719B1 (en) * 2000-03-09 2001-11-06 Avaya Technology Corp. Method of tuning a planar filter with additional coupling created by bent resonator elements
RU2662058C1 (en) * 2017-06-26 2018-07-23 Российская Федерация, от имени которой выступает Министерство обороны Российской Федерации Microvawe low-pass filter

Also Published As

Publication number Publication date
FR2510325B1 (en) 1987-09-04
JPS6329282Y2 (en) 1988-08-08
DE3275253D1 (en) 1987-02-26
EP0071508B1 (en) 1987-01-21
FR2510325A1 (en) 1983-01-28
JPS5816901U (en) 1983-02-02

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