GB584769A - Improvement in low-pass network - Google Patents

Improvement in low-pass network

Info

Publication number
GB584769A
GB584769A GB23737/44A GB2373744A GB584769A GB 584769 A GB584769 A GB 584769A GB 23737/44 A GB23737/44 A GB 23737/44A GB 2373744 A GB2373744 A GB 2373744A GB 584769 A GB584769 A GB 584769A
Authority
GB
United Kingdom
Prior art keywords
band
frequency
frequencies
filter
output
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.)
Expired
Application number
GB23737/44A
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.)
Marconis Wireless Telegraph Co Ltd
BAE Systems Electronics Ltd
Original Assignee
Marconis Wireless Telegraph Co Ltd
Marconi Co Ltd
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 Marconis Wireless Telegraph Co Ltd, Marconi Co Ltd filed Critical Marconis Wireless Telegraph Co Ltd
Publication of GB584769A publication Critical patent/GB584769A/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • H03H7/01—Frequency selective two-port networks
    • H03H7/17—Structural details of sub-circuits of frequency selective networks
    • H03H7/1741—Comprising typical LC combinations, irrespective of presence and location of additional resistors
    • H03H7/1775—Parallel LC in shunt or branch path
    • 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
    • H03H7/01—Frequency selective two-port networks
    • H03H7/0115—Frequency selective two-port networks comprising only inductors and capacitors
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J1/00—Frequency-division multiplex systems
    • H04J1/02—Details
    • H04J1/04—Frequency-transposition arrangements
    • H04J1/045—Filters applied to frequency transposition

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Transmitters (AREA)

Abstract

584,769. Low-pass filtering systems. MARCONI'S WIRELESS TELEGRAPH CO. Ltd. Nov. 28, 1944, No. 23737. Convention date, Nov. 29, 1943. [Class 40 (iv)] [Also in Group XL] In a variable cut-off low-pass filtering system, a carrier frequency having side-bands equal to the required band-width is obtained in two stages, by modulating a first variable frequency with the input frequencies, filtering to restrict one side band, and using the resulting frequencies to modulate another variable carrier frequency and filtering to restrict the other side band, the final output being then rectified. By this means fixed band pass filters of simple construction may be utilized. In the filter, Fig. 1, designed to have a cut-off frequency f2, an input band of frequencies 0-f1 modulates a carrier frequency fc1 and the band pa.ss filter 1 restricts the output to frequencies below fc2+f2. The output of filter 1 modulates a higher frequency fc2 and band pass filter 2 restricts the output to frequencies above fc1+fc2-f2, thereby producing a frequency fc1+fc2 with two side bands of width f2 which on detection produces a frequency band 0-f2. The cut-off frequency can be varied by simultaneously varying the frequencies of the oscillators 1 and 2, to restrict both side bands appropriately. The filter networks may also be made adjustable if desired.
GB23737/44A 1943-11-29 1944-11-28 Improvement in low-pass network Expired GB584769A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US512115A US2472798A (en) 1943-11-29 1943-11-29 Low-pass filter system

Publications (1)

Publication Number Publication Date
GB584769A true GB584769A (en) 1947-01-22

Family

ID=24037728

Family Applications (1)

Application Number Title Priority Date Filing Date
GB23737/44A Expired GB584769A (en) 1943-11-29 1944-11-28 Improvement in low-pass network

Country Status (2)

Country Link
US (1) US2472798A (en)
GB (1) GB584769A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2635143A (en) * 1948-02-24 1953-04-14 Marconi S Wireless Telegrpah C Variable electrical filter
US2923887A (en) * 1955-11-29 1960-02-02 Ross Radio Corp Electronic circuit arrangement for the controlled amplification of a desired signal
US2951206A (en) * 1957-11-15 1960-08-30 Rca Corp Variable delay line
NL153401B (en) * 1966-11-19 1977-05-16 Philips Nv DEVICE FOR FAITHFULLY SELECTING A CHARACTERISTIC COMPONENT FROM A FREQUENCY SPECTRUM.
US6061551A (en) 1998-10-21 2000-05-09 Parkervision, Inc. Method and system for down-converting electromagnetic signals
US7515896B1 (en) 1998-10-21 2009-04-07 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US6694128B1 (en) 1998-08-18 2004-02-17 Parkervision, Inc. Frequency synthesizer using universal frequency translation technology
US6091940A (en) 1998-10-21 2000-07-18 Parkervision, Inc. Method and system for frequency up-conversion
US7295826B1 (en) 1998-10-21 2007-11-13 Parkervision, Inc. Integrated frequency translation and selectivity with gain control functionality, and applications thereof
US6813485B2 (en) 1998-10-21 2004-11-02 Parkervision, Inc. Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same
US6061555A (en) * 1998-10-21 2000-05-09 Parkervision, Inc. Method and system for ensuring reception of a communications signal
US7236754B2 (en) 1999-08-23 2007-06-26 Parkervision, Inc. Method and system for frequency up-conversion
US6049706A (en) 1998-10-21 2000-04-11 Parkervision, Inc. Integrated frequency translation and selectivity
US6370371B1 (en) 1998-10-21 2002-04-09 Parkervision, Inc. Applications of universal frequency translation
US7027786B1 (en) 1998-10-21 2006-04-11 Parkervision, Inc. Carrier and clock recovery using universal frequency translation
US6542722B1 (en) 1998-10-21 2003-04-01 Parkervision, Inc. Method and system for frequency up-conversion with variety of transmitter configurations
US6560301B1 (en) 1998-10-21 2003-05-06 Parkervision, Inc. Integrated frequency translation and selectivity with a variety of filter embodiments
US7039372B1 (en) 1998-10-21 2006-05-02 Parkervision, Inc. Method and system for frequency up-conversion with modulation embodiments
US6804825B1 (en) * 1998-11-30 2004-10-12 Microsoft Corporation Video on demand methods and systems
US7006805B1 (en) 1999-01-22 2006-02-28 Parker Vision, Inc. Aliasing communication system with multi-mode and multi-band functionality and embodiments thereof, such as the family radio service
US6704549B1 (en) 1999-03-03 2004-03-09 Parkvision, Inc. Multi-mode, multi-band communication system
US6704558B1 (en) 1999-01-22 2004-03-09 Parkervision, Inc. Image-reject down-converter and embodiments thereof, such as the family radio service
US6873836B1 (en) 1999-03-03 2005-03-29 Parkervision, Inc. Universal platform module and methods and apparatuses relating thereto enabled by universal frequency translation technology
US6879817B1 (en) 1999-04-16 2005-04-12 Parkervision, Inc. DC offset, re-radiation, and I/Q solutions using universal frequency translation technology
US6853690B1 (en) 1999-04-16 2005-02-08 Parkervision, Inc. Method, system and apparatus for balanced frequency up-conversion of a baseband signal and 4-phase receiver and transceiver embodiments
US7110435B1 (en) 1999-03-15 2006-09-19 Parkervision, Inc. Spread spectrum applications of universal frequency translation
US7693230B2 (en) 1999-04-16 2010-04-06 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US7110444B1 (en) 1999-08-04 2006-09-19 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations
US7065162B1 (en) 1999-04-16 2006-06-20 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same
US7054296B1 (en) 1999-08-04 2006-05-30 Parkervision, Inc. Wireless local area network (WLAN) technology and applications including techniques of universal frequency translation
US7072390B1 (en) 1999-08-04 2006-07-04 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
US8295406B1 (en) 1999-08-04 2012-10-23 Parkervision, Inc. Universal platform module for a plurality of communication protocols
US7082171B1 (en) 1999-11-24 2006-07-25 Parkervision, Inc. Phase shifting applications of universal frequency translation
US6963734B2 (en) 1999-12-22 2005-11-08 Parkervision, Inc. Differential frequency down-conversion using techniques of universal frequency translation technology
US7292835B2 (en) 2000-01-28 2007-11-06 Parkervision, Inc. Wireless and wired cable modem applications of universal frequency translation technology
US7010286B2 (en) 2000-04-14 2006-03-07 Parkervision, Inc. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US7554508B2 (en) 2000-06-09 2009-06-30 Parker Vision, Inc. Phased array antenna applications on universal frequency translation
US7010559B2 (en) 2000-11-14 2006-03-07 Parkervision, Inc. Method and apparatus for a parallel correlator and applications thereof
US7454453B2 (en) 2000-11-14 2008-11-18 Parkervision, Inc. Methods, systems, and computer program products for parallel correlation and applications thereof
US7085335B2 (en) 2001-11-09 2006-08-01 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US7072427B2 (en) * 2001-11-09 2006-07-04 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US6975848B2 (en) 2002-06-04 2005-12-13 Parkervision, Inc. Method and apparatus for DC offset removal in a radio frequency communication channel
US7321640B2 (en) 2002-06-07 2008-01-22 Parkervision, Inc. Active polyphase inverter filter for quadrature signal generation
US7379883B2 (en) 2002-07-18 2008-05-27 Parkervision, Inc. Networking methods and systems
US7460584B2 (en) 2002-07-18 2008-12-02 Parkervision, Inc. Networking methods and systems

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1361488A (en) * 1920-03-31 1920-12-07 American Telephone & Telegraph Plural modulation system
US1830896A (en) * 1928-01-19 1931-11-10 American Telephone & Telegraph Adjustable electric filter system
US1905714A (en) * 1931-04-10 1933-04-25 Bell Telephone Labor Inc Signaling system
US2339633A (en) * 1942-03-23 1944-01-18 Bell Telephone Labor Inc Variable selective system

Also Published As

Publication number Publication date
US2472798A (en) 1949-06-14

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