EP0373028A1 - Passives Bandpassfilter - Google Patents

Passives Bandpassfilter Download PDF

Info

Publication number
EP0373028A1
EP0373028A1 EP89403257A EP89403257A EP0373028A1 EP 0373028 A1 EP0373028 A1 EP 0373028A1 EP 89403257 A EP89403257 A EP 89403257A EP 89403257 A EP89403257 A EP 89403257A EP 0373028 A1 EP0373028 A1 EP 0373028A1
Authority
EP
European Patent Office
Prior art keywords
impedance
filter
microstrips
microstrip
input
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.)
Granted
Application number
EP89403257A
Other languages
English (en)
French (fr)
Other versions
EP0373028B1 (de
Inventor
Henri Budan
Patrick Algani
Alain Grosjean
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thomson Hybrides
Original Assignee
Thomson Hybrides
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from FR8815664A external-priority patent/FR2639776B1/fr
Application filed by Thomson Hybrides filed Critical Thomson Hybrides
Publication of EP0373028A1 publication Critical patent/EP0373028A1/de
Application granted granted Critical
Publication of EP0373028B1 publication Critical patent/EP0373028B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01P1/20336—Comb or interdigital filters

Definitions

  • the present invention relates to a passive bandpass filter, produced using hybrid circuit technology.
  • the structure of this passive filter makes it possible to adapt it, in the microwave domain, to the desired central frequency with a good rate of rejection of the lower frequencies. It is produced in the form of microstrips on a ceramic substrate.
  • FIG. 1 An example is given in FIG. 1, on which two combs of interdigitated microstrips 1 and 2 are deposited on a substrate 3.
  • the microstrips have a length ⁇ g / 4, ⁇ g being the wavelength guided in a microstrip, and their point common is joined to the ground plane which is on the rear face of the substrate 3.
  • the signal input E is applied to a free end of the first microstrip of a first comb, and the filtered output S is collected at one end free from the last microstrip of a second comb.
  • These known filters have two types of drawbacks. First, they occupy a relatively important place.
  • hybrid circuit techniques are influenced by the density of integrated circuits which are reported on a hybrid circuit substrate, especially VLSIs with very high integration density, and the components reported on a hybrid circuit must also be densified, especially if they operate at microwave frequencies.
  • the passive bandpass filter according to the invention eliminates these two drawbacks. It occupies only a small surface on a dielectric substrate, and its response curve is clear: outside the bandwidth, it virtually cuts the outside frequencies, especially the lower frequencies.
  • microstrip line It consists of a plurality of microstrip lines, mutually parallel, all the ends of which on the same side are joined to the ground plane carried by the opposite face of the dielectric substrate.
  • the signal input E is applied to the first microstrip and the output S of the filtered signal is collected on the last microstrip.
  • at least two non-neighboring microstrip lines therefore not coupled by electromagnetism, are coupled by an impedance, self or capacitance, reported on the substrate.
  • the distances from the ground points, to which the input, output and impedance connections are connected, allow you to adjust the input and output impedances and to modify the shape of the filter response curve. .
  • This type of bandpass filter makes it possible to obtain a response curve for the passband whose flanks are relatively steep, because the coupling impedance cancels a term from the denominator of the equation of transfer through the filter.
  • a first improvement to this bandpass filter consists in providing it with an additional impedance, at its input, which cancels a second term in the transfer equation, and makes the flanks of the response curve more abrupt.
  • a second improvement consists in folding the band-pass filter over itself, in the same way as one closes a book. This makes it a smaller component, the dimensions of which are in accordance with its environment of integrated circuits or miniaturized components.
  • the invention relates to a passive bandpass filter, produced by means of microstrips deposited on one face of a dielectric substrate, characterized in that it comprises at least three microstrips, parallel to each other, one end of which is joined by means appropriate to the ground plane carried by the second face of the substrate, at least two of the said microstrips, not neighboring on the substrate, being coupled by a coupling impedance Z, which is a self or a capacitance .
  • the passive filter according to the invention is supported by a substrate 4, one face of which is metallized at 5 to form a ground plane.
  • This substrate is made of ceramic, alumina or materials with a high dielectric constant (9 ⁇ ⁇ ⁇ 100), and its thickness is between 0.3 and 1 mm approximately.
  • microstrip lines On the non-metallized face of this substrate 4 are deposited a plurality of microstrip lines, parallel to each other. At least three microbands 6,7,8 are necessary so that at least two of them are not neighboring. By one of their ends, but on the same side for all the microstrip lines, these are joined to the ground plane 5: in the figure, this connection is made by means of metallized holes 9, but other known means are possible.
  • These microstrip lines are produced either by thick film technology, by screen printing, or by thin film technology, by vacuum evaporation.
  • the input E of the signal to be filtered is applied laterally to the first strip 6 of the series by means of a metallization 10 which, generally, is oriented towards the edge of the substrate 4, or towards the signal generator if the latter is integrated on the same substrate.
  • the filtered output signal S is collected on a metallization 11, lateral on the last strip in the series.
  • the metallizations 10 and 11 are, respectively, at distances x1 and x2 from the ends to the mass of the two microstrip lines considered.
  • two non-neighboring microstrip lines are coupled by an impedance Z 12, joined by two wires or metallizations 13 and 14 at two points, respectively, of the first strip 6 and the second band 8 not neighboring.
  • the impedance Z is either a self or a capacitor, deposited on the substrate 4 in the form of a discrete component or in the form of thick layers.
  • the wires or metallizations 13 and 14 are fixed on the two non-neighboring microstrip lines at distances x3 and x4, respectively, from the ends to ground of the two microstrip lines considered.
  • the displacement of the input metallization 10, by varying x1, makes it possible to adapt the impedance to 75 or 100 ohms, or to some other value.
  • the distance x2 makes it possible to adjust the output impedance of the passive filter.
  • the central frequency of the bandpass filter is adjusted by the length L of the microstrip lines.
  • the bandwidth of the filter is adjusted by the width "l" of the lines, and by the spacing "d” between lines.
  • the spacing "d” plays the same role as the width "l” but more important.
  • microstrips and / or narrow spacings give wide bandwidths and low TOS.
  • Narrow microstrips and / or wide spacings give narrow bandwidths and high TOS.
  • the distances x3 and x4 make it possible to optimize the coupling between two non-neighboring microstrips: they define the input impedance and the output impedance linked to the capacitance or self Z 12, and are calculated according to the specifications required for the filtered.
  • a filter according to the invention which includes a coupling impedance Z 12 has a response curve (S 21) as a function of the frequency F: - which approximates curve 15 of FIG. 3 when the value of Z increases: this filter cuts the frequencies higher than the central frequency well - which on the contrary approaches curve 16 when the value of Z decreases: this filter has better rejection of the lower frequencies.
  • a filter according to the invention of one or more uncoupled microstrips improves the rejection of frequencies outside the central frequency, and makes the response curve more "square"".
  • a filter according to the invention can comprise more than three microstrips as shown in FIG. 2. Let us take the case of a filter with 4 microstrips, which will be called A, B, C, D. Different couplings can be carried out: A-D coupling or A-C and B-D coupling. The choice is made according to the specifications imposed on the filter.
  • FIG. 4 A first improvement to the filter according to the invention is shown in FIG. 4. They consist in adding to the input E of the filter a double impedance Z1 and Z2.
  • the impedance Z1 is provided by a microstrip 17, finer and of higher impedance than the microstrips 6,7,8 of the filter. Typically, it is about 200 micrometers wide, and a length equal to ⁇ / 4. Unlike other microstrips, it has no end joined to the ground plane 5.
  • this impedance Connected in parallel on the input circuit, this impedance resonates for the rejection frequency. It cancels a second term in the filter transfer equation, which completes the action of the impedance 12 of the filter, which cancels a first term.
  • Impedance 17 can also be achieved by a line and a capacity.
  • Impedance Z2 corrects the deterioration of the input impedance, brought by Z1. Placed in series between the input E of the filter, and the connection point on the first microstrip 6, it can be carried out either by a line 18, or by a line and a capacitor.
  • the characteristic impedances of 17 and 18 are interactive, and calculated to obtain the desired slope and rejection level, on the response curve of the filter.
  • the second improvement makes it possible to produce a bandpass filter even smaller than that of the main invention.
  • a filter according to the invention only the substrate 4 is reported with its ground plane 5, and three microstrips 6,7,8 with an input E and an output S.
  • this filter could comprise more than three bands , and the impedances 17 and 18 of the first improvement.
  • the second improvement consists in cutting the filter along a line 19 which, perpendicular to the microstrips 6,7,8, separates it into two equal parts, in the direction of the length of the substrate 4. The two parts are then, as shown on the right of the figure, brazed one on the other, by their faces supporting the ground plane 5.
  • microstrips 6,7,8, the halves of which are now carried by the upper and lower faces of a sandwich including in its center a ground plane 5, are reformed by means of jumpers or metallizations 20, on the side of the sandwich: the electrical continuity of each microstrip is thus ensured.
  • microstrips must be slightly shorter in length than ⁇ g / 4: the length of the jumpers 20, equal to twice the thickness of the substrate 4, reduces this length to ⁇ g / 4.
  • jumpers 21, or other suitable external connections are fixed to the edges of the sandwich.
  • a minimum of three jumpers 21 is required, corresponding to the input E, the output S and the ground plane 5.
  • These jumpers are provided with means 22 for either implanting the component in the holes of a substrate, or mounting it in SMD (surface mountable components).
  • SMD surface mountable components
  • This type of passive filter is used in information processing systems, for example in radio telephones, in the range 0.5 to 10 GHz, with a bandwidth of 0.9 to 1 GHz.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Filters And Equalizers (AREA)
  • Networks Using Active Elements (AREA)
EP89403257A 1988-11-30 1989-11-24 Passives Bandpassfilter Expired - Lifetime EP0373028B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FR8815664A FR2639776B1 (fr) 1988-11-30 1988-11-30 Filtre passif passe-bande
FR8815664 1988-11-30
FR898908017A FR2648641B2 (fr) 1988-11-30 1989-06-16 Filtre passif passe-bande
FR8908017 1989-06-16

Publications (2)

Publication Number Publication Date
EP0373028A1 true EP0373028A1 (de) 1990-06-13
EP0373028B1 EP0373028B1 (de) 1994-05-18

Family

ID=26227020

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89403257A Expired - Lifetime EP0373028B1 (de) 1988-11-30 1989-11-24 Passives Bandpassfilter

Country Status (6)

Country Link
EP (1) EP0373028B1 (de)
AT (1) ATE105976T1 (de)
CA (1) CA2004184A1 (de)
DE (1) DE68915408T2 (de)
FI (1) FI895714A0 (de)
FR (1) FR2648641B2 (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2669476A1 (fr) * 1990-11-21 1992-05-22 Valtronic France Filtre passif passe-bande.
DE19652799A1 (de) * 1996-12-18 1998-06-25 Siemens Ag Mikrowellenfilter
ES2143964A1 (es) * 1998-09-15 2000-05-16 Univ Catalunya Politecnica Diplexor dual para telefonia celular gsm y dcs.
EP1235297A2 (de) * 2001-02-26 2002-08-28 Samsung Electronics Co., Ltd. Kammfilter
US10862185B2 (en) 2017-12-01 2020-12-08 Semiconductor Components Industries, Llc Integrated circuit with capacitor in different layer than transmission line

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1906059A1 (de) * 1969-02-07 1970-08-13 Licentia Gmbh Kammfilter
FR2222767A1 (de) * 1973-03-19 1974-10-18 Fujitsu Ltd
DE2407313A1 (de) * 1974-02-15 1975-08-21 Kathrein Werke Kg Resonatoranordnung
US4253073A (en) * 1978-08-17 1981-02-24 Communications Satellite Corporation Single ground plane interdigital band-pass filter apparatus and method
FR2570884A1 (fr) * 1984-09-22 1986-03-28 Smiths Industries Plc Procede pour accorder un dispositif a microlame, notamment une antenne
EP0193162A1 (de) * 1985-02-27 1986-09-03 Alcatel Transmission Par Faisceaux Hertziens A.T.F.H. Mikrowellenbandpassfilter
US4721931A (en) * 1986-05-02 1988-01-26 Murata Manufacturing Co., Ltd. Stripline filter
US4740765A (en) * 1985-09-30 1988-04-26 Murata Manufacturing Co., Ltd. Dielectric filter
EP0285503A1 (de) * 1987-03-31 1988-10-05 Thomson-Csf Filter mit Elementen mit verteilten Parametern, wobei zwei Arten von Kopplungsvorrichtungen vorhanden sind

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1906059A1 (de) * 1969-02-07 1970-08-13 Licentia Gmbh Kammfilter
FR2222767A1 (de) * 1973-03-19 1974-10-18 Fujitsu Ltd
DE2407313A1 (de) * 1974-02-15 1975-08-21 Kathrein Werke Kg Resonatoranordnung
US4253073A (en) * 1978-08-17 1981-02-24 Communications Satellite Corporation Single ground plane interdigital band-pass filter apparatus and method
FR2570884A1 (fr) * 1984-09-22 1986-03-28 Smiths Industries Plc Procede pour accorder un dispositif a microlame, notamment une antenne
EP0193162A1 (de) * 1985-02-27 1986-09-03 Alcatel Transmission Par Faisceaux Hertziens A.T.F.H. Mikrowellenbandpassfilter
US4740765A (en) * 1985-09-30 1988-04-26 Murata Manufacturing Co., Ltd. Dielectric filter
US4721931A (en) * 1986-05-02 1988-01-26 Murata Manufacturing Co., Ltd. Stripline filter
EP0285503A1 (de) * 1987-03-31 1988-10-05 Thomson-Csf Filter mit Elementen mit verteilten Parametern, wobei zwei Arten von Kopplungsvorrichtungen vorhanden sind

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 7, no. 182 (E-192)[1327], 11 août 1983; & JP-A-58 85 601 (NIPPON DENKI K.K.) 23-05-1983 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2669476A1 (fr) * 1990-11-21 1992-05-22 Valtronic France Filtre passif passe-bande.
EP0487396A1 (de) * 1990-11-21 1992-05-27 Valtronic France Passives Bandpassfilter
DE19652799A1 (de) * 1996-12-18 1998-06-25 Siemens Ag Mikrowellenfilter
WO1998027607A1 (de) * 1996-12-18 1998-06-25 Siemens Aktiengesellschaft Mikrowellenfilter
DE19652799C2 (de) * 1996-12-18 1999-05-20 Siemens Ag Mikrowellenfilter
ES2143964A1 (es) * 1998-09-15 2000-05-16 Univ Catalunya Politecnica Diplexor dual para telefonia celular gsm y dcs.
EP1235297A2 (de) * 2001-02-26 2002-08-28 Samsung Electronics Co., Ltd. Kammfilter
EP1235297A3 (de) * 2001-02-26 2003-10-08 Samsung Electronics Co., Ltd. Kammfilter
US10862185B2 (en) 2017-12-01 2020-12-08 Semiconductor Components Industries, Llc Integrated circuit with capacitor in different layer than transmission line

Also Published As

Publication number Publication date
DE68915408D1 (de) 1994-06-23
FR2648641A2 (fr) 1990-12-21
FR2648641B2 (fr) 1994-09-09
DE68915408T2 (de) 1994-09-08
ATE105976T1 (de) 1994-06-15
FI895714A0 (fi) 1989-11-29
EP0373028B1 (de) 1994-05-18
CA2004184A1 (en) 1990-05-31

Similar Documents

Publication Publication Date Title
EP0285503B1 (de) Filter mit Elementen mit verteilten Parametern, wobei zwei Arten von Kopplungsvorrichtungen vorhanden sind
EP2345104B1 (de) Differenz-dipolantennensystem mit einer koplanaren strahlungsstruktur und sender-/empfängereinrichtung
EP2184803B1 (de) Coplanare Differenzial-Zweiband-Verzögerunsleitung, Differenzialfilter höherer Ordnung und Filterantenne mit einer solchen Leitung
FR2578104A1 (fr) Filtre passe-bande pour hyperfrequences
EP1368895A1 (de) Oberflächenwellenfilter
EP0373028B1 (de) Passives Bandpassfilter
FR2535547A1 (fr) Resonateurs bi-rubans et filtres realises a partir de ces resonateurs
FR2510325A1 (fr) Filtre hyperfrequence de petites dimensions, a resonateurs lineaires
EP0424255B1 (de) Filtereinheit und entsprechender Filter
EP0649571B1 (de) Bandpassfilter mit gekoppelten resonatoren
EP0487396A1 (de) Passives Bandpassfilter
EP0141704B1 (de) Miniatur-UHF-Filter bestehend aus resonierenden Sperrkreisen und Kupplungskapazitäten
EP2688137B1 (de) Hyperfrequenzresonator mit Impedanzsprung, insbesondere für Hyperfrequenz-Bandsperrfilter oder -Bandpassfilter
EP0337825B1 (de) Mikrowellensperrfilter in Mikrostreifenausführung
FR2639776A1 (fr) Filtre passif passe-bande
EP0983616B1 (de) Verfahren und vorrichtung zum verbinden zweier millimeterelemente
FR2675638A1 (fr) Dispositif resonateur dielectrique.
EP0064458A1 (de) Bandpassfilter, ausgeführt in Rechteckhohlleitertechnik, mit hoher Selektivität
FR2626716A1 (fr) Filtre a resonateurs plans
EP0576340B1 (de) Oberflächenwellenfilter mit reflektierenden Gittern
EP0780973B1 (de) Kerbfilter mit passiven Elementen
EP1568098B1 (de) Breitband-mikrowellenbandtrenneinrichtung
FR2539933A1 (fr) Filtre commutable pour micro-ondes
FR2704984A1 (fr) Filtre passe-bande à lignes couplées dissymétriques.
FR2820885A1 (fr) Filtre dielectrique, duplexeur dielectrique et dispositif de telecommunications

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE GB IT LI NL SE

17P Request for examination filed

Effective date: 19900618

17Q First examination report despatched

Effective date: 19920805

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE GB IT LI NL SE

REF Corresponds to:

Ref document number: 105976

Country of ref document: AT

Date of ref document: 19940615

Kind code of ref document: T

ITF It: translation for a ep patent filed

Owner name: JACOBACCI CASETTA & PERANI S.P.A.

REF Corresponds to:

Ref document number: 68915408

Country of ref document: DE

Date of ref document: 19940623

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19940609

EAL Se: european patent in force in sweden

Ref document number: 89403257.2

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19961129

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19971013

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19971014

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19971016

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19971017

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19971028

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19971031

Year of fee payment: 9

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971124

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981124

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981125

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981130

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981130

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981130

BERE Be: lapsed

Owner name: THOMSON HYBRIDES

Effective date: 19981130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990601

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19981124

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

EUG Se: european patent has lapsed

Ref document number: 89403257.2

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19990601

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990901

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20051124