GB584769A - Improvement in low-pass network - Google Patents
Improvement in low-pass networkInfo
- 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
Links
- 238000001914 filtration Methods 0.000 abstract 4
- 238000010276 construction Methods 0.000 abstract 1
- 238000001514 detection method Methods 0.000 abstract 1
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.
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) |
Families Citing this family (45)
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)
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 |
-
1943
- 1943-11-29 US US512115A patent/US2472798A/en not_active Expired - Lifetime
-
1944
- 1944-11-28 GB GB23737/44A patent/GB584769A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US2472798A (en) | 1949-06-14 |
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