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GB2255461A - Active filter circuit - Google Patents

Active filter circuit

Info

Publication number
GB2255461A
GB2255461A GB9212049A GB9212049A GB2255461A GB 2255461 A GB2255461 A GB 2255461A GB 9212049 A GB9212049 A GB 9212049A GB 9212049 A GB9212049 A GB 9212049A GB 2255461 A GB2255461 A GB 2255461A
Authority
GB
United Kingdom
Prior art keywords
bandwidth
filter
filter circuit
passband
communication system
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
GB9212049A
Other versions
GB9212049D0 (en
GB2255461B (en
Inventor
Joseph P Heck
Barry L Jason
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.)
Motorola Solutions Inc
Original Assignee
Motorola Inc
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 Motorola Inc filed Critical Motorola Inc
Priority to GB9503349A priority Critical patent/GB2284718A/en
Publication of GB9212049D0 publication Critical patent/GB9212049D0/en
Publication of GB2255461A publication Critical patent/GB2255461A/en
Application granted granted Critical
Publication of GB2255461B publication Critical patent/GB2255461B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing
    • H03D7/16—Multiple-frequency-changing
    • H03D7/161—Multiple-frequency-changing all the frequency changers being connected in cascade
    • H03D7/163—Multiple-frequency-changing all the frequency changers being connected in cascade the local oscillations of at least two of the frequency changers being derived from a single oscillator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H11/00—Networks using active elements
    • H03H11/02—Multiple-port networks
    • H03H11/04—Frequency selective two-port networks
    • H03H11/0422—Frequency selective two-port networks using transconductance amplifiers, e.g. gmC filters
    • H03H11/0444—Simulation of ladder networks
    • H03H11/045—Leapfrog structures

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Transmitters (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Networks Using Active Elements (AREA)
  • Noise Elimination (AREA)

Abstract

A filter circuit (250) disposed upon a single integrated circuit comprised of active fiter elements including transconductance elements (286-330) for a radiotelephone. The bandwidth of the passband of the filter is variable to pass alternately, signals of either a first bandwidth or a second bandwidth for passing, for example, signals generated in a conventional, cellular communication system, or a cellular communication system of increased capacity. Fine tuning of the bandwidth of the passband of the filter permits blocking of noise signals positioned, in frequency, proximate to a received, information signal.
GB9212049A 1990-10-10 1991-08-19 Active filter circuit Expired - Fee Related GB2255461B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9503349A GB2284718A (en) 1990-10-10 1991-08-19 Adjusting telephone bandwidth using variable integrated transconductance filter

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US59506290A 1990-10-10 1990-10-10
PCT/US1991/005876 WO1992007422A1 (en) 1990-10-10 1991-08-19 Active filter circuit

Publications (3)

Publication Number Publication Date
GB9212049D0 GB9212049D0 (en) 1992-08-12
GB2255461A true GB2255461A (en) 1992-11-04
GB2255461B GB2255461B (en) 1995-06-14

Family

ID=24381563

Family Applications (2)

Application Number Title Priority Date Filing Date
GB9503349A Withdrawn GB2284718A (en) 1990-10-10 1991-08-19 Adjusting telephone bandwidth using variable integrated transconductance filter
GB9212049A Expired - Fee Related GB2255461B (en) 1990-10-10 1991-08-19 Active filter circuit

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB9503349A Withdrawn GB2284718A (en) 1990-10-10 1991-08-19 Adjusting telephone bandwidth using variable integrated transconductance filter

Country Status (8)

Country Link
JP (1) JPH05503409A (en)
AR (1) AR246644A1 (en)
BR (1) BR9106178A (en)
CA (1) CA2069639A1 (en)
DE (1) DE4192545T (en)
GB (2) GB2284718A (en)
MX (1) MX9101511A (en)
WO (1) WO1992007422A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE9703944L (en) * 1997-10-29 1999-04-30 Ericsson Telefon Ab L M Radio communication device and method
US6489847B1 (en) 2000-01-28 2002-12-03 Telefonaktiebolaget Lm Ericsson Low distoration driving amplifier for integrated filters
GB2394133A (en) * 2002-10-17 2004-04-14 Toumaz Technology Ltd Radio receiver with reconfigurable filtering arrangement

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3805091A (en) * 1972-06-15 1974-04-16 Arp Instr Frequency sensitive circuit employing variable transconductance circuit
US4374335A (en) * 1980-05-19 1983-02-15 Precision Monolithics, Inc. Tuneable I.C. active integrator

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB491693A (en) * 1937-01-21 1938-09-07 Hazeltine Corp Improvements in variable selectivity radio receivers
GB856892A (en) * 1957-11-14 1960-12-21 Collins Radio Co Means for reducing the threshold of angular-modulation receivers
US4356658A (en) * 1981-02-11 1982-11-02 Goldfarb Adolph E Multiple and varied motion stage apparatus for doll figure
US4356657A (en) * 1981-02-11 1982-11-02 Adolph E. Goldfarb Toy car wash apparatus and method
CA1190289A (en) * 1981-04-28 1985-07-09 Nippon Hoso Kyokai Fm signal demodulation system
US4531148A (en) * 1981-08-31 1985-07-23 Oki Electric Industry Co., Ltd. High sensitivity FM signal demodulation system
JPS6250030B1 (en) * 1981-08-31 1987-10-22 Oki Electric Ind Co Ltd
IT1212744B (en) * 1983-05-19 1989-11-30 Sogs Ates Componenti Elettroni CIRCUIT FOR THE ATTENUATION OF INTERFERENCE IN A RADIO RECEIVER BY USING AN ADJUSTABLE BANDWIDTH LOW-PASS FILTER.
US4591805A (en) * 1984-05-30 1986-05-27 General Electric Company Adaptive bandwidth amplifier
US4839542A (en) * 1984-08-21 1989-06-13 General Datacomm Industries, Inc. Active transconductance filter device
DE3737581A1 (en) * 1987-11-05 1989-05-18 Grundig Emv DEVICE FOR AUTOMATICALLY APPLYING THE BALANCING VOLTAGE TO THE TUNABLE SWITCHING ELEMENTS OF THE ZF AMPLIFIER OF A TELEVISION RECEIVER
JPH02186723A (en) * 1988-08-25 1990-07-23 Nec Corp Receiver
US5051628A (en) * 1990-01-02 1991-09-24 Motorola, Inc. Integrated filter circuit

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3805091A (en) * 1972-06-15 1974-04-16 Arp Instr Frequency sensitive circuit employing variable transconductance circuit
US4374335A (en) * 1980-05-19 1983-02-15 Precision Monolithics, Inc. Tuneable I.C. active integrator

Also Published As

Publication number Publication date
AR246644A1 (en) 1994-08-31
GB9212049D0 (en) 1992-08-12
BR9106178A (en) 1993-03-16
MX9101511A (en) 1992-06-05
GB2255461B (en) 1995-06-14
JPH05503409A (en) 1993-06-03
CA2069639A1 (en) 1992-04-11
DE4192545T (en) 1992-10-08
GB2284718A (en) 1995-06-14
GB9503349D0 (en) 1995-04-12
WO1992007422A1 (en) 1992-04-30

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19950914