EP0097112A1 - Transformateur d'adaptation HF - Google Patents

Transformateur d'adaptation HF Download PDF

Info

Publication number
EP0097112A1
EP0097112A1 EP83710019A EP83710019A EP0097112A1 EP 0097112 A1 EP0097112 A1 EP 0097112A1 EP 83710019 A EP83710019 A EP 83710019A EP 83710019 A EP83710019 A EP 83710019A EP 0097112 A1 EP0097112 A1 EP 0097112A1
Authority
EP
European Patent Office
Prior art keywords
conductor
hollow cylinder
matching transformer
transformer according
diameter
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
EP83710019A
Other languages
German (de)
English (en)
Other versions
EP0097112B1 (fr
Inventor
Wolfram Dr. Schminke
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.)
BBC Brown Boveri AG Switzerland
Original Assignee
BBC Brown Boveri AG Switzerland
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
Application filed by BBC Brown Boveri AG Switzerland filed Critical BBC Brown Boveri AG Switzerland
Publication of EP0097112A1 publication Critical patent/EP0097112A1/fr
Application granted granted Critical
Publication of EP0097112B1 publication Critical patent/EP0097112B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P5/00—Coupling devices of the waveguide type
    • H01P5/04—Coupling devices of the waveguide type with variable factor of coupling

Definitions

  • the invention relates to an RF matching transformer according to the preamble of claim 1.
  • Such a matching transformer is known in practice as a two-stage t / 4 transformer. It consists of a waveguide, the total length of which is equal to half the wavelength of the operating frequency ⁇ o. It is divided into two ⁇ o / 4 long conductor sections, the different wave resistances of which are determined by the connection impedances at the input and output, between which the adjustment is to be made. Since the length of this transformer is directly linked to the operating frequency, its dimensions can only be used for an operating frequency within a narrow frequency band. In addition, as with a coaxial line, for example, the wave resistances are also predetermined by the geometry, so that differently designed transformers are also required for different adaptation cases.
  • the present invention is therefore based on the object of providing an HF matching transformer whose operating frequency and transmission ratio can be set continuously without changing the installation dimensions of the transformer.
  • the matching transformer according to the invention is preferably designed as a coaxial line, which consists of an outer conductor with a constant inner diameter and an inner conductor with stepped outer diameters, a conductive hollow cylinder with correspondingly stepped diameters being displaceable in the direction of the conductor axis, and attached to the inner conductor on the inner conductor is at least short-circuited in terms of radio frequency.
  • the matching transformer according to the invention has the advantage that its operating frequency can be changed without changing the overall length of the waveguide and thus the installation dimensions.
  • a particular transmission ratio is linked to the respective working frequency, so that there is a continuous, characteristic-like relationship between frequency and transmission ratio in the adjustable working range of the transformer.
  • This characteristic can be designed by a suitable choice of the geometric parameters so that it is adapted to the characteristics of other RF circuit elements. In this way, for example, a continuously tunable HF generator can be set up if the impedance curve of the transmitter tube used corresponds to the characteristic curve of the connected transformer.
  • FIG. 1 The equivalent circuit diagram of the RF matching transformer according to the invention is shown in FIG.
  • a waveguide W of length L is divided into at least two conductor sections W and W 2 with different wave resistances Z 1 and Z 2 .
  • the lengths L 1 and L 2 of the conductor sections can be adjusted in such a way that their sum L I + L 2 remains constant, ie the first length decreases by exactly the amount by which the second increases, and vice versa.
  • the transformer is loaded by a real terminating impedance Z A during operation. This terminating impedance is transformed into a real input impedance Z E. This transformation takes place in several stages, according to the different ladder sections.
  • the conductor section W 2 first converts the real terminating impedance Z A into a generally complex intermediate impedance Z M , which in turn is transformed by the conductor section W 1 into the real input impedance Z E. Since the transmission can be assumed to be damping-free in the first approximation, it obeys the transformation equation known from line theory which describes the connection of the terminating impedance Z A with the intermediate impedance Z M through the conductor section W 2 with the wave resistance Z 2 and the length L 2 .
  • the quantity ⁇ is equal to 2 ⁇ / 2 with the wavelength ⁇ in the line section under consideration and therefore detects the influence of the operating or working frequency on the transformation behavior.
  • An analogous equation applies to the relationship between Z E , Z M , Z 1 and L 1 . If the value Z M obtained from the above equation is inserted into this analog equation, the requirement for a vanishing imaginary part of Z E results in an equation for those wavelengths at which the transformation from a real value Z A back to a real value Z E leads.
  • a coaxial line is provided as the waveguide, which consists of an outer conductor 1 with a constant inner diameter D 1 and an inner conductor 2 with stepped outer diameters d 1 and d 2 .
  • a conductive hollow cylinder 3 is attached to the inner conductor 2.
  • the hollow cylinder 3 is displaceable in the direction of the conductor axis and graduated in diameter in the same way as the inner conductor 2. Its wall thickness is preferably chosen to be so small compared to the other dimensions of the conductor that the properties of the inner conductor 2 with respect to the wave propagation are only slightly disturbed .
  • the hollow cylinder 3 can be made of thin sheet metal, for example, and can be coated with a highly conductive layer. It is particularly advantageous in terms of weight to use metallized plastics on the basis of, for example, glass fiber-reinforced epoxy resins for the hollow cylinder but also for the other conductors.
  • the hollow cylinder is preferably conductively connected to the inner conductor 2 at its ends via sliding contacts and thus forms a view Lich the wave propagation in the coaxial line a movable step on the inner conductor.
  • transmission ratios result in the transformer which no longer correspond to conductor sections with lengths L 1 and L 2 , but rather conductor sections with the new lengths L 1 'and L 2 ', with both the wave resistances Z 1 and Z 21 as well as the total length L remain unchanged.
  • the wave resistances Z 1 and Z 2 of the conductor sections also result from the diameters D 1 , d 1 and d 2 . according to the formula known for the coaxial line whereby the influence of a possible dielectric between outer and inner conductors is taken into account by the relative dielectric constant i.
  • FIG. 3 Another exemplary embodiment of the matching transformer according to the invention is shown in FIG. 3.
  • the inner conductor 2 of the coaxial arrangement is in turn designed with stepped outer diameters d 1 and d 2 .
  • the outer conductor 1 also has graduated inner diameters D and D 3.
  • the diameter of the displaceable hollow cylinder 3 is adapted to the outer conductor 1 and short-circuited with it at least in terms of radio frequency, and thus forms a stepped outer conductor with a displaceable edge. This results in a coaxial line with at least three different conductor sections W 1 , W 2 and W 3 with the corresponding lengths L 1 , L 2 and L 3 and wave resistances Z 1 , Z 2 and Z 3 .
  • each conductor section requires an impedance transformation, a further degree of freedom is obtained compared to the exemplary embodiment shown in FIG. 2 for the implementation of the desired transformation characteristics.
  • the hollow cylinder 3 can be moved from the outside without disturbing the wave propagation, for example by leading out an operating element rigidly connected to the hollow cylinder 3 through a narrow slot in the outer conductor 1 and actuating it by a drive mechanism arranged outside the outer conductor 1.
  • a corresponding operating mechanism can also be in the in Fig . 4 shown embodiment are provided, in which the coaxial line is composed of an inner conductor .2 with stepped outer diameter d 1 and d 2 and an outer conductor 1 with a constant inner diameter D 1 .
  • the hollow cylinder 3 is adapted with its larger diameter to the inner diameter D 1 of the outer conductor 1 and is provided with a smaller diameter D 4 , the size of which lies between the inner diameter D 1 of the outer conductor 1 and the largest outer diameter d 1 of the inner conductor. It is short-circuited to the outer conductor, at least in terms of radio frequency, and together with it forms an outer conductor with two edges which can be displaced in the same direction.
  • the coaxial line is divided into four conductor sections W 1 , W 2 , W 3 and W 4 with the lengths L 1 , L 2 , L 3 and L 4 and the characteristic impedances Z 1 , Z 2 , Z 3 and Z 4 .
  • the lengths of the conductor sections will be changed by moving the hollow cylinder 3 depending on each other, the length L of the hollow cylinder 3 and the total length L of the coaxial line remain constant.
  • the high-frequency short circuit between the hollow cylinder 3 and the adjacent conductor surface is not mediated in this exemplary embodiment by sliding contacts, but by a thin, dielectric film covering 5, which lies between the hollow cylinder 3 and the adjacent conductor surface.
  • the film covering 5 which consists, for example, of Teflon or Kapton, enables on the one hand an almost friction-free sliding of the displaceable hollow cylinder in the outer conductor 1.
  • the hollow cylinder and outer conductor together with the hollow cylinder and outer conductor, it forms coaxial line pieces 6 with a very low impedance. It should be noted that the electrical length of the coaxial line pieces 6 is less than 1/4 of the corresponding wavelengths at the highest operating frequency.
  • FIG. 5 shows the characteristic field of an adaptation transformer according to the invention in accordance with the exemplary embodiment shown in FIG. 2.
  • the pair of characteristics R 3 , f 3 is of particular importance for the application. It shows that the adaptation transformer according to the invention can be continuously tuned over a large frequency range of over 150 MHz if the transformation ratio is changed only slightly by changing the length L 2 .
  • Corresponding characteristic curve fields also describe the operating behavior of the exemplary embodiments according to FIGS. 3 and 4.
  • the characteristic curve curve shown in FIG. 6 results.
  • matching transformers can be constructed according to the invention by suitable selection of the geometric and electrical parameters as well as by combining several movable and fixed diameter stages on the outer and / or inner conductors, the characteristics of which optimally correspond to the respective use in an HF circuit, and the characteristics of the operating frequency and Transmission ratio can be changed continuously over a wide range without having to remove and install the transformer itself.
  • the matching transformer according to the invention with the corresponding changes can also be used in waveguide and stripline systems.

Landscapes

  • Waveguides (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Electrotherapy Devices (AREA)
  • Burglar Alarm Systems (AREA)
EP83710019A 1982-06-04 1983-04-11 Transformateur d'adaptation HF Expired EP0097112B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH346682 1982-06-04
CH3466/82 1982-06-04

Publications (2)

Publication Number Publication Date
EP0097112A1 true EP0097112A1 (fr) 1983-12-28
EP0097112B1 EP0097112B1 (fr) 1987-03-18

Family

ID=4256559

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83710019A Expired EP0097112B1 (fr) 1982-06-04 1983-04-11 Transformateur d'adaptation HF

Country Status (4)

Country Link
US (1) US4532483A (fr)
EP (1) EP0097112B1 (fr)
JP (1) JPS58220501A (fr)
DE (1) DE3370411D1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5545949A (en) * 1994-07-29 1996-08-13 Litton Industries, Inc. Coaxial transmissioin line input transformer having externally variable eccentricity and position
US7604633B2 (en) 1996-04-12 2009-10-20 Cytyc Corporation Moisture transport system for contact electrocoagulation
US6508815B1 (en) * 1998-05-08 2003-01-21 Novacept Radio-frequency generator for powering an ablation device
US8551082B2 (en) 1998-05-08 2013-10-08 Cytyc Surgical Products Radio-frequency generator for powering an ablation device
US6664881B1 (en) 1999-11-30 2003-12-16 Ameritherm, Inc. Efficient, low leakage inductance, multi-tap, RF transformer and method of making same
US8486060B2 (en) 2006-09-18 2013-07-16 Cytyc Corporation Power ramping during RF ablation
US8558637B2 (en) * 2010-05-12 2013-10-15 Mediatek Inc. Circuit device with signal line transition element

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1928408A (en) * 1931-11-24 1933-09-26 Int Communications Lab Inc Shield for leads from micro-ray tubes
CH233273A (de) * 1942-05-12 1944-07-15 Telefunken Gmbh Hochfrequenzleitung.
US2408745A (en) * 1941-11-11 1946-10-08 Gen Electric Co Ltd Variable impedance transformer
FR958201A (fr) * 1950-03-06
CH281296A (fr) * 1948-06-16 1952-02-29 Wallauschek Richard Transformateur d'impédances à rapport de transformation réglable.
DE945261C (de) * 1942-03-11 1956-07-05 Elektronik Ges Mit Beschraenkt Einrichtung zur Einstellung der Phasenlage einer elektromagnetischen Schwingung in einem Hohlleiter
DE969343C (de) * 1943-12-25 1958-05-22 Funkstrahl Ges Fuer Nachrichte Anordnung zur einstellbaren Anpassung eines frequenzabhaengigen Abschlusswiderstandeseiner Ultrahochfrequenzenergieleitung an den Wellenwiderstand derselben
CA853353A (en) * 1967-12-27 1970-10-06 Her Majesty The Queen In Right Of Canada As Represented By The Minister Of National Defence Of Her Majesty's Canadian Government Differential microwave phase shifter

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1927393A (en) * 1931-07-10 1933-09-19 Int Communications Lab Inc Transmission system for ultrashort waves
US2463415A (en) * 1943-08-26 1949-03-01 Westinghouse Electric Corp Shorting bar for concentric lines
US2900610A (en) * 1955-05-19 1959-08-18 Richard W Allen Variable impedance transformer

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR958201A (fr) * 1950-03-06
US1928408A (en) * 1931-11-24 1933-09-26 Int Communications Lab Inc Shield for leads from micro-ray tubes
US2408745A (en) * 1941-11-11 1946-10-08 Gen Electric Co Ltd Variable impedance transformer
DE945261C (de) * 1942-03-11 1956-07-05 Elektronik Ges Mit Beschraenkt Einrichtung zur Einstellung der Phasenlage einer elektromagnetischen Schwingung in einem Hohlleiter
CH233273A (de) * 1942-05-12 1944-07-15 Telefunken Gmbh Hochfrequenzleitung.
DE969343C (de) * 1943-12-25 1958-05-22 Funkstrahl Ges Fuer Nachrichte Anordnung zur einstellbaren Anpassung eines frequenzabhaengigen Abschlusswiderstandeseiner Ultrahochfrequenzenergieleitung an den Wellenwiderstand derselben
CH281296A (fr) * 1948-06-16 1952-02-29 Wallauschek Richard Transformateur d'impédances à rapport de transformation réglable.
CA853353A (en) * 1967-12-27 1970-10-06 Her Majesty The Queen In Right Of Canada As Represented By The Minister Of National Defence Of Her Majesty's Canadian Government Differential microwave phase shifter

Also Published As

Publication number Publication date
JPH0158681B2 (fr) 1989-12-13
JPS58220501A (ja) 1983-12-22
DE3370411D1 (en) 1987-04-23
US4532483A (en) 1985-07-30
EP0097112B1 (fr) 1987-03-18

Similar Documents

Publication Publication Date Title
DE818384C (de) Filter zur UEbertragung eines Bandes in Hohlleitern gefuehrter elektrischer Mikro-Wellen
DE3433068C2 (fr)
DE3871961T3 (de) Entstörfilter mit verteilten Konstanten.
EP0440661B1 (fr) Filtre passe-bande haute frequence
DE3685553T2 (de) Pin-dioden-daempfungsglieder.
DE2837817C3 (de) Hochfrequenz-Breitbandverstärker
DE933515C (de) Schaltungsanordnung fuer die Benutzung bei Elektronenroehren fuer ultrakurze Wellen
DE2403056A1 (de) Einstellbare verzoegerungsleitung und verfahren zu deren betrieb
EP0097112B1 (fr) Transformateur d'adaptation HF
EP0063819A2 (fr) Circuit mélangeur symétrique à micro-onde réalisé en micro-bande
DE69924618T2 (de) Wellenleiterserienresonanzhohlraum zur verbesserung der effizienz und der bandbreite in einer linearstrahlrohre
DE2910813C2 (de) Rundstrahlende J-Antenne
DE3044379C2 (fr)
DE2352712A1 (de) Wellenleitung mit sperrkondensator
DE10316047A1 (de) Richtkoppler in koplanarer Wellenleitertechnik
EP0418630A2 (fr) Coude dans le plan E pour un guide d'ondes rectangulaire
DE2642335C2 (de) Vorrichtung zum kontinuierlichen dielektrischen Erwärmen mittels Mikrowellenenergie
EP1250721A1 (fr) Circuit pour diviser ou reunir des puissances haute frequence
EP1495513A1 (fr) Reseau d'adaptation electrique pourvu d'une ligne de transformation
DE2431278C2 (de) Vierpol-Filter
DE2015579B2 (de) Halterung und anschlussvorrichtung fuer einen halbleiter-mikrowellenoszillator
DE2056845C2 (de) Verlustbehafteter aperiodischer Lastwiderstand
EP0044909B1 (fr) Dispositif répartiteur multiple pour signaux à hautes fréquences
DE3208655C2 (de) Koppelvorrichtung mit variablem Koppelfaktor für einen supraleitenden Hohlraumresonator
WO2005038976A1 (fr) Reseau d'adaptation electrique comprenant une ligne de transformation

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

Designated state(s): CH DE FR GB IT LI

17P Request for examination filed

Effective date: 19840218

17Q First examination report despatched

Effective date: 19860127

R17C First examination report despatched (corrected)

Effective date: 19860325

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

ITF It: translation for a ep patent filed
AK Designated contracting states

Kind code of ref document: B1

Designated state(s): CH DE FR GB IT LI

REF Corresponds to:

Ref document number: 3370411

Country of ref document: DE

Date of ref document: 19870423

ET Fr: translation filed
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: GB

Payment date: 19920316

Year of fee payment: 10

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19920620

Year of fee payment: 10

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

Ref country code: CH

Payment date: 19920710

Year of fee payment: 10

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

Ref country code: FR

Payment date: 19930317

Year of fee payment: 11

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

Ref country code: GB

Effective date: 19930411

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

Ref country code: LI

Effective date: 19930430

Ref country code: CH

Effective date: 19930430

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

Effective date: 19930411

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

Ref country code: DE

Effective date: 19940201

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

Ref country code: FR

Effective date: 19941229

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST