US3849676A - Phase-corrector - Google Patents

Phase-corrector Download PDF

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Publication number
US3849676A
US3849676A US00406862A US40686273A US3849676A US 3849676 A US3849676 A US 3849676A US 00406862 A US00406862 A US 00406862A US 40686273 A US40686273 A US 40686273A US 3849676 A US3849676 A US 3849676A
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phase
terminal
diodes
linear
corrector
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US00406862A
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English (en)
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C Bareyt
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Thales SA
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Thomson CSF SA
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/18—Networks for phase shifting
    • H03H7/20—Two-port phase shifters providing an adjustable phase shift

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  • Thepresent invention relates to phase-correctors, in particular although not exclusively, for the precorrection of frequency-modulated signals intended for application to a travelling wave tube or to other non-linear devices giving rise to phase and amplitude distortions of the same kind.
  • travellin wave tubes have a phase characteristic (phase lag created as a function of the input power P,) of the kind indicated for example in FIG. 1, which is the characteristic taken from a 25 watt tube operating at a carrier frequency in the order of 6,000 mc/s, the phase lag increasing with input power. This lag d) is given in degrees and the power P in decibels relatively to the reference level of 1 mW.
  • phase characteristic phase lag created as a function of the input power P,
  • FIG. 2 is the characteristic taken from a 25 watt tube operating at a carrier frequency in the order of 6,000 mc/s, the phase lag increasing with input power.
  • This lag d is given in degrees and the power P in decibels relatively to the reference level of 1 mW.
  • These tubes on the other hand have an output power P /input power P characteristic of the kind illustrated in FIG. 2, which is a characteristic taken from the same tube as that of FIG. 1, P and P being given again relatively to the reference level of 1 m
  • phasedistortion is generally the greatest source of nuisance in practical applications, applications such for example as the amplification, by means of a travelling wave tube, of a signal frequency-modulated by a multiplex telephone signal.
  • a phase-correcting device comprising two channels which receive the signal to be corrected with the same amplitude and in phase quadrature, the first of the channels being linear, the'second containing a non-linear device formed by a series of attenuators, each of which is constituted by a PIN diode non-linearly attenuating its input signal in accordance with the law determined by the diode characteristic, and by a variable bias voltage produced by detection of part of this input signal.
  • a phase corrector comprising means, having first ancl second terminals, for applying an input signal in phase quadrature to said first and second terminals, the signal appearing at said first terminal lagging in phase relatively to the signal appearing at said second terminal; a linear attenuator coupled to said first terminal; a non-linear channel coupled to said second terminal and including a non-linear device comprising a d-c series arrangement of two diodes, said two diodes being connected in the same direction relatively to a d-c current applied to said series arrangement, and being coupled in parallel and in reverse directions relatively to the a-c current appearing at said second terminal, means for biasing said diodes by the same d-c voltage value and in the same direction, and an adder for adding together the output signals from said linear attenuator and from said non-linear channel.
  • FIGS. 1 and 2 already described, are graphs showing a pratical example of the phase and amplitude distortions produced by a travelling wave tube.
  • FIG. 3 is a diagram of an embodiment of a phasecorrector in accordance with the invention.
  • FIGS. 4 and 5 are diagrams illustrating the operation of the phase corrector shown in FIG. 3.
  • FIG. 6 is a travelling wave tube amplifier circuit, utilising a phase-corrector device in accordance with the invention.
  • a 3 db coupler 30, that is to say a 3 db coupler whose outputs are in phase-quadrature, is supplied at its input E with the input signal and produces at its two outputs l and 2 two signals, the output 1 delivering a signal lagging in phase by 90 in relation to the signal appearing at the output 2.
  • the output 1 supplies a linear attenuator, preferably an adjustable one.
  • This attenuator in the present example, utilises as an adjustable resistive element, a PIN diode 3 biased by an adjustable constant voltage supplied by a source 21, the diode 3 and the source 21 being connected in parallel between ground and the common terminal M of two capacitors 41 and 42 connected in series, the other terminal of the capacitor 41 forming the input of the linear channel and the other tenninal of the capacitor 42 the output of this channel.
  • the output 2 of the coupler constitutes the input of the non-linear channel. It is connected, respectively, through two capacitors 4 and 5 to the anode of a diode 6 and to the cathode of a diode 7.
  • the diodes 6 and 7 will for example be Schottky diodes.
  • the cathode of the diode 6 and the anode of the diode 7 are connected to the first terminal of a capacitor 8 whose second terminal forms the output of the non-linear channel.
  • a voltage source 20 equipped with an a.c.
  • a d-c potential difference of 2U is applied between the terminal 11, common to the capacitor 4 and the diode 6, and the terminal 12, common to the capacitor 5 and the diode 7; this has the effect of applying a d-c voltage U between anode and cathode of each diode.
  • the output of the non-linear channel and that of the linear channel respectively supply the two inputs of an adder 10 whose output S is the output of the phase-corrector.
  • FIG. 4 a vectorial illustration of the output signals A,, A A and B B and B from the linear and nonlinear channels respectively of the phase-corrector, has been given in respect of three input signals having different amplitudes but the same frequency and the same phase, V V V
  • the corresponding output signals W W and W;, from the phase-corrector have also been shown.
  • the linear attenuator and the non-linear channel have attenuated signal V in the same ratio.
  • the linear channel and the non-linear channel thus, in respect of the signal V produce two signals A and B of the same amplitude, in phase quadrature, the resultant W of which has a phase lead of 45 in relation to the phase of the signals A,, A and A
  • the corresponding output signal W will, in relation to the phase (1),, have a phase lead of less than 45, and if the largest of the three input signals has been less attenuated by the non-linear channel than by the linear channel, it will have a lead of more than 45 in relation to (b More generally, if the non-linear device compresses the low-amplitude signals in relation to the highamplitude ones, or in other words if it behaves as an expander vis-a-vis high amplitudes, at the output of the phase correct
  • FIG. 5 illustrates how this may be done in a simple manner.
  • the curve X which is symmetrical in relation to represents the input voltage U output current I characteristic of the non-linear channel in the absence of application of any bias to the two diodes. If, by means of the source 20, a voltage difference 2 U is applied between the terminals 11 and 12, in
  • the amplitude distortion introduced by the phase-correcting device is in the reverse direction to that introduced by the travelling wave tube.
  • what happens in practice is partial correction and not over-compensation.
  • phase-corrector followed by an amplitudecorrector so that as far as the amplitude is concerned, the superimposed effects of the amplitude distortions introduced by the phase-corrector, the amplitudecorrector and the travelling wave tube, compensate one another in a satisfactory manner. It is possible to utilise, as an amplitude-corrector, a circuit identical to that which constitutes the non-linear channel of the phase-corrector, with an appropriate bias voltage.
  • FIG. 6 illustrates an amplifier device of this kind.
  • the block 100 represents the phase-corrector of FIG. 3, the output of which supplies an amplitude-corrector which is a circuit identical, apart from the value of the bias, to that of the non-linear channel of the phase-corrector device shown in FIG. 3, the corresponding elements being represented by the same reference numbers but increased by 100.
  • the output of the capacitor 108 of the amplitude-corrector is connected to the input of a travelling wave tube 50.
  • the phase-corrector may be improved through forming its non-linear channel by the series arrangement of two or more circuits of the kind constituting the non-linear channel in the phase-corrector shown in FIG. 3; the value of the bias 2 U may then differ for the different circuits.
  • a linear attenuator coupled to said first terminal; a non-linear channel coupled to said second terminal and including a non-linear device comprising a d-c series arrangement of two diodes, said two diodes being connected in the same direction relatively to a dc current applied to said series arrangement, and being coupled in parallel and in reverse directions relatively to the a-c current appearing at said second terminal, means for biasing said diodes by the same d-c voltage value and in the same direction, and an adder for adding together the output signals from said linear attenuator and from said non-linear channel.
  • An amplifying arrangement for a frequency modulated signal comprising, in a series arrangement, two correctors followed and a travelling wave tube, one of said correctors being a phase corrector and the other one being an amplitude corrector, said phase corrector comprising means, having an input and first and second output terminals, for applying an input signal in phase quadrature to said first and second terminals, the signal appearing at said first terminal lagging in phase relatively to the signal appearing at said second terminal; a linear attenuator coupled to said first terminal; a nonlinear channel coupled to said second terminal and including a non-linear device comprising a do series arrangement of two diodes, said two diodes being connected in the same direction relatively to a d-c current applied to said series arrangement, and being coupled in parallel and in reverse directions relatively to the a-c current appearing at said second terminal, means for biasing said diodes by the same d-c voltage value and in the same direction, and an adder for adding together the output signals from said linear attenuator and from
  • said amplitude corrector comprises a dc series arrangement of two diodes, said two diodes being connected in the same direction relatively to a d-c current applied to said series arrangement, and being coupled in parallel and in reverse directions relatively to the a-c current of the input signal, and means for biasing said diodes by the same d-c voltage value and in the same direction.

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  • Amplifiers (AREA)
  • Filters And Equalizers (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
US00406862A 1972-10-20 1973-10-16 Phase-corrector Expired - Lifetime US3849676A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7237262A FR2204334A5 (it) 1972-10-20 1972-10-20

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US3849676A true US3849676A (en) 1974-11-19

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US (1) US3849676A (it)
JP (1) JPS4975050A (it)
DE (1) DE2352569A1 (it)
FR (1) FR2204334A5 (it)
GB (1) GB1405350A (it)
IT (1) IT994459B (it)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4255724A (en) * 1977-12-02 1981-03-10 Thomson-Csf Distortion-corrector for microwave tubes
US4614921A (en) * 1985-08-20 1986-09-30 The United States Of America As Represented By The Secretary Of The Air Force Low pass π section digital phase shifter apparatus
US4752743A (en) * 1986-09-26 1988-06-21 Varian Associates, Inc. Linearizer for TWT amplifiers
US4887043A (en) * 1985-11-15 1989-12-12 Gte Telecomunicazioni, S.P.A. Phase shifter-equalizer circuit
EP0687062A1 (de) * 1994-06-09 1995-12-13 Siemens Aktiengesellschaft Analoger Phasenschieber für kleine Steuerspannungen
US6340917B1 (en) * 1999-03-18 2002-01-22 Alcatel Broad frequency band linearization device
US20070241815A1 (en) * 2004-10-28 2007-10-18 Hifumi Noto Linearizer
US9287846B2 (en) 2011-03-02 2016-03-15 Delphi Deutschland Gmbh Analog phase shifter

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5183758A (ja) * 1975-01-21 1976-07-22 Nippon Electric Co Koshuhazofukuki
JPS51140461A (en) * 1975-05-30 1976-12-03 Nec Corp Linear output amplifier with no distortion at low level of signal
JPS52109434U (it) * 1976-02-17 1977-08-19
DE3306762A1 (de) * 1983-02-25 1984-08-30 Siemens AG, 1000 Berlin und 8000 München Als bodeentzerrer ausgebildeter einstellbarer daempfungsentzerrer
JP4546052B2 (ja) * 2003-07-24 2010-09-15 日本電気株式会社 Ａｍ−ｐｍ歪補償回路および方法
JP2007180915A (ja) * 2005-12-28 2007-07-12 Hitachi Kokusai Electric Inc 歪補償増幅装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2945949A (en) * 1956-12-14 1960-07-19 Fernseh Gmbh Method and arrangement for producing electric advance impulses
US2984799A (en) * 1959-05-18 1961-05-16 Collins Radio Co Broadband-phase r.-c. network
US3148285A (en) * 1962-02-07 1964-09-08 Mcdonnell Aircraft Corp Control circuit with phase lead characteristics
US3532997A (en) * 1965-04-30 1970-10-06 Nouvelle D Electronique Et De Corrective network for servo-systems
US3546636A (en) * 1968-12-20 1970-12-08 Bell Telephone Labor Inc Microwave phase shifter
US3760219A (en) * 1972-04-25 1973-09-18 Us Army Traveling wave device providing prebunched transverse-wave beam

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2945949A (en) * 1956-12-14 1960-07-19 Fernseh Gmbh Method and arrangement for producing electric advance impulses
US2984799A (en) * 1959-05-18 1961-05-16 Collins Radio Co Broadband-phase r.-c. network
US3148285A (en) * 1962-02-07 1964-09-08 Mcdonnell Aircraft Corp Control circuit with phase lead characteristics
US3532997A (en) * 1965-04-30 1970-10-06 Nouvelle D Electronique Et De Corrective network for servo-systems
US3546636A (en) * 1968-12-20 1970-12-08 Bell Telephone Labor Inc Microwave phase shifter
US3760219A (en) * 1972-04-25 1973-09-18 Us Army Traveling wave device providing prebunched transverse-wave beam

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4255724A (en) * 1977-12-02 1981-03-10 Thomson-Csf Distortion-corrector for microwave tubes
US4614921A (en) * 1985-08-20 1986-09-30 The United States Of America As Represented By The Secretary Of The Air Force Low pass π section digital phase shifter apparatus
US4887043A (en) * 1985-11-15 1989-12-12 Gte Telecomunicazioni, S.P.A. Phase shifter-equalizer circuit
US4752743A (en) * 1986-09-26 1988-06-21 Varian Associates, Inc. Linearizer for TWT amplifiers
EP0687062A1 (de) * 1994-06-09 1995-12-13 Siemens Aktiengesellschaft Analoger Phasenschieber für kleine Steuerspannungen
US6340917B1 (en) * 1999-03-18 2002-01-22 Alcatel Broad frequency band linearization device
US20070241815A1 (en) * 2004-10-28 2007-10-18 Hifumi Noto Linearizer
US7557654B2 (en) * 2004-10-28 2009-07-07 Mitsubishi Electric Corporation Linearizer
US9287846B2 (en) 2011-03-02 2016-03-15 Delphi Deutschland Gmbh Analog phase shifter

Also Published As

Publication number Publication date
FR2204334A5 (it) 1974-05-17
DE2352569A1 (de) 1974-05-02
GB1405350A (en) 1975-09-10
JPS4975050A (it) 1974-07-19
IT994459B (it) 1975-10-20

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