WO2000001062A2 - Frequency offset image rejection - Google Patents
Frequency offset image rejection Download PDFInfo
- Publication number
- WO2000001062A2 WO2000001062A2 PCT/IB1999/001182 IB9901182W WO0001062A2 WO 2000001062 A2 WO2000001062 A2 WO 2000001062A2 IB 9901182 W IB9901182 W IB 9901182W WO 0001062 A2 WO0001062 A2 WO 0001062A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- signal
- phase
- shifted
- image
- frequency
- Prior art date
Links
- 230000010363 phase shift Effects 0.000 claims abstract description 23
- 239000003990 capacitor Substances 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 8
- 230000002238 attenuated effect Effects 0.000 claims 1
- 238000013459 approach Methods 0.000 abstract description 12
- 238000006243 chemical reaction Methods 0.000 abstract description 5
- 238000004891 communication Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- 238000010897 surface acoustic wave method Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
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
- H03D7/18—Modifications of frequency-changers for eliminating image frequencies
-
- 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
- H03D7/165—Multiple-frequency-changing at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/16—Circuits
- H04B1/26—Circuits for superheterodyne receivers
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
- H03D2200/00—Indexing scheme relating to details of demodulation or transference of modulation from one carrier to another covered by H03D
- H03D2200/0041—Functional aspects of demodulators
- H03D2200/0066—Mixing
- H03D2200/0078—Mixing using a switched phase shifter or delay line
Definitions
- the invention relates to signal processing, and more specifically, to image rejection in signal down converters.
- Image rejection in receivers has traditionally been provided by passive filters. More recently, image rejection is being implemented in receiver down converters to ease the rejection requirements of preceding passive filters. As is well known in the art, receiver down converters process a received signal and generate a down-converted signal having a lower frequency. A conventional receiver down converter is described with reference to HGS. 1, 2A and 2B.
- FIG. 1 is a block diagram illustrating a conventional image reject down converter arrangement 100.
- a received signal s(t) ⁇ is processed by a passive filter 102 that removes undesirable information from signal s(t) ⁇ and provides a filtered signal s(t) ⁇ '.
- a passive filter that is typically used for passive filter 102 is a surface acoustic wave (SAW) filter.
- Filtered signal s(t) ⁇ ' is provided to an automatic gain controller (AGC) 106 that adjusts the gain of signal s(t)' to provide an output signal s(t) ⁇ ".
- AGC automatic gain controller
- the gain of signal s(t) ⁇ " provided by AGC 106 is selected to be compatible with, i.e.
- Signal s(t) ⁇ is provided to an image reject mixer 107.
- image reject mixer 107 signal s(t) ⁇ " is provided to a mixer 108 along with a signal S LO generated by a local oscillator 110 and having a frequency of f L o- Mixer 108 generates a signal W .
- Signal S LO is also provided to a phase shifter 112 that generates a phase shifted signal S LO ' that is ninety (90) degrees out of phase with respect to signal S LO -
- Multiple phase shifters are sometimes employed to provide the signals S LO and S O ' so long as the total phase shift between signals S LO and S LO ' is ninety (90) degrees.
- two phase shifters providing phase shifts of plus forty five (+45) degrees and minus forty five (-45) degrees may be employed.
- a mixer 114 combines signal s(t) ⁇ " with phase shifted signal S O ' and generates a signal V Q '.
- Signal V is ninety (90) degrees out of phase with respect to signal V Q '.
- Signal V ⁇ ' is processed by a phase shifter 116 that generates a signal Vj that is forty five (45) degrees out of phase with respect to signal V .
- a phase shifter 118 processes signal V Q ' and provides a signal V Q that is one hundred thirty-five (135) degrees out of phase with respect to signal V Q '.
- phase shifters 116 and 118 provide an additional ninety (90) degrees of phase shift of the unwanted image information contained in signals Vi and V Q .
- image rejection at f] is different (asymmetric) from the image rejection at f 2 .
- the worst case image rejection is often unacceptable for certain applications.
- the worst case image rejection is typically less than seventy (70) decibels (dB) at fj, which is unsuitable for many communication systems, such as wireless telephony. Therefore, the conventional approach for providing image rejection in signal down converters does not provide adequate image rejection for down-converted signals having relatively low center frequencies (frp).
- FIG. 3 is a graph illustrating the frequency response of the image rejection filter and image rejection down converter of FIG. 1 ;
- Circuit 500 is an all-pass network that includes a resistor 502 connected between an INPUT and a node 504.
- a capacitor 506 is connected between node 504 and a ground 508.
- Another capacitor 510 is connected between INPUT and a node 512.
- a resistor 514 is connected between node 512 and the ground 508.
- All-pass network 500 also includes a buffer 516 that is preferably a unity gain buffer, having a non-inverting (+) input and an inverting (-) input.
- the non-inverting (+) input of buffer 516 is connected to node 512.
- the inverting (-) input of buffer 516 is connected to node 504.
- the output of buffer 516 is connected to the OUTPUT of all-pass network 500.
- the specific component values for resistors 502, 514 and capacitors 506, 510 are selected based upon the particular frequency at which the ninety (90) degree phase shift between signals Vi' and V Q ' is to be provided. According to prior approaches, the component values for safe phase shifters are selected to provide a phase shift around the center frequency of the down-converted signal. However, embodiments of the invention as described herein include selecting the components for phase shifters 416 and 418 so that the additional ninety (90) degrees of phase shift between signals Vf and V Q ' provided by phase shifters 416 and 418 is performed around a frequency other than the center frequency of the down-converted signal. According to an embodiment of the invention, the frequency at which the phase shift is to be centered is defined as follows: where: frp' is the frequency at which the phase shift is to be centered, frp' is the center frequency of the down-converted signal, and
- resistors 502 and 514 and capacitors 506 and 510 for phase shifter 416 are determined by the following equation:
- phase shifter 416 45° phase shift
- phase shifter 418 (135° phase shift) resistors 502 and 514: 100K ohms resistors 502 and 514: 100K ohms capacitors 506 and 510: 12.7 pF capacitors 506 and 510: 73.9 pF
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000557540A JP2002519919A (en) | 1998-06-29 | 1999-06-24 | Frequency offset image rejection |
EP99957671A EP1040566A2 (en) | 1998-06-29 | 1999-06-24 | Frequency offset image rejection |
KR1020007002131A KR20010023486A (en) | 1998-06-29 | 1999-06-24 | Frequency offset image rejection |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/107,186 US6314279B1 (en) | 1998-06-29 | 1998-06-29 | Frequency offset image rejection |
US09/107,186 | 1998-06-29 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2000001062A2 true WO2000001062A2 (en) | 2000-01-06 |
WO2000001062A3 WO2000001062A3 (en) | 2000-04-13 |
Family
ID=22315292
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/IB1999/001182 WO2000001062A2 (en) | 1998-06-29 | 1999-06-24 | Frequency offset image rejection |
Country Status (7)
Country | Link |
---|---|
US (1) | US6314279B1 (en) |
EP (1) | EP1040566A2 (en) |
JP (1) | JP2002519919A (en) |
KR (1) | KR20010023486A (en) |
CN (1) | CN1273708A (en) |
TW (1) | TW439353B (en) |
WO (1) | WO2000001062A2 (en) |
Families Citing this family (42)
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US6694128B1 (en) | 1998-08-18 | 2004-02-17 | Parkervision, Inc. | Frequency synthesizer using universal frequency translation technology |
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 |
US6370371B1 (en) | 1998-10-21 | 2002-04-09 | Parkervision, Inc. | Applications of universal frequency translation |
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 |
US7039372B1 (en) | 1998-10-21 | 2006-05-02 | Parkervision, Inc. | Method and system for frequency up-conversion with modulation embodiments |
US7236754B2 (en) | 1999-08-23 | 2007-06-26 | Parkervision, Inc. | Method and system for frequency up-conversion |
US6560301B1 (en) | 1998-10-21 | 2003-05-06 | Parkervision, Inc. | Integrated frequency translation and selectivity with a variety of filter embodiments |
US6061555A (en) | 1998-10-21 | 2000-05-09 | Parkervision, Inc. | Method and system for ensuring reception of a communications signal |
US6704558B1 (en) | 1999-01-22 | 2004-03-09 | Parkervision, Inc. | Image-reject down-converter and embodiments thereof, such as the family radio service |
US7209725B1 (en) * | 1999-01-22 | 2007-04-24 | Parkervision, Inc | Analog zero if FM decoder 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 |
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 |
JP4284568B2 (en) * | 1999-03-18 | 2009-06-24 | ソニー株式会社 | Receiving apparatus and method, and recording medium |
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 |
US8295406B1 (en) | 1999-08-04 | 2012-10-23 | Parkervision, Inc. | Universal platform module for a plurality of communication protocols |
US7054296B1 (en) * | 1999-08-04 | 2006-05-30 | Parkervision, Inc. | Wireless local area network (WLAN) technology and applications including techniques of universal frequency translation |
US6634555B1 (en) | 2000-01-24 | 2003-10-21 | Parker Vision, Inc. | Bar code scanner using universal frequency translation technology for up-conversion and down-conversion |
US6766148B1 (en) * | 2000-03-21 | 2004-07-20 | Koninklijke Phillips Electronics N.V. | Switched sideband frequency low-IF transmitter |
US7010286B2 (en) | 2000-04-14 | 2006-03-07 | Parkervision, Inc. | Apparatus, system, and method for down-converting and up-converting electromagnetic signals |
US6748220B1 (en) | 2000-05-05 | 2004-06-08 | Nortel Networks Limited | Resource allocation in wireless networks |
US6678503B1 (en) * | 2000-05-17 | 2004-01-13 | Intersil Americas Inc. | Apparatus for radio frequency processing with dual modulus synthesizer |
US6675004B1 (en) * | 2000-08-25 | 2004-01-06 | Interwave Communications International Ltd. | Method and apparatus for receive channel noise suppression |
US6980787B1 (en) * | 2000-09-26 | 2005-12-27 | Ati International Srl | Image rejection mixing in wideband applications |
US7454453B2 (en) | 2000-11-14 | 2008-11-18 | Parkervision, Inc. | Methods, systems, and computer program products for parallel correlation and applications thereof |
US7072427B2 (en) | 2001-11-09 | 2006-07-04 | Parkervision, Inc. | Method and apparatus for reducing DC offsets in a communication system |
US7333791B2 (en) * | 2001-12-11 | 2008-02-19 | Microtune (Texas), L.P. | Use of an image reject mixer in a forward data channel tuner |
JP3586260B2 (en) * | 2002-04-10 | 2004-11-10 | 株式会社東芝 | Semiconductor integrated circuit device |
US7460584B2 (en) | 2002-07-18 | 2008-12-02 | Parkervision, Inc. | Networking methods and systems |
US7379883B2 (en) | 2002-07-18 | 2008-05-27 | Parkervision, Inc. | Networking methods and systems |
US6909886B2 (en) * | 2002-08-30 | 2005-06-21 | Microtune ( Texas), L.P. | Current driven polyphase filters and method of operation |
EP1441437B1 (en) * | 2003-01-21 | 2006-08-09 | CSEM Centre Suisse d'Electronique et de Microtechnique S.A. - Recherche et Développement | Operating frequency controlled quadrature signal generator |
US7362384B2 (en) * | 2004-02-26 | 2008-04-22 | Broadcom Corporation | Apparatus and method for feed-forward image rejection in a dual conversion receiver |
US7375741B2 (en) * | 2005-03-24 | 2008-05-20 | Himax Technologies Limited | Circuit and method for eliminating image interfering with desired channel |
US20090047921A1 (en) * | 2005-11-07 | 2009-02-19 | Matsushita Electric Industrial Co., Ltd. | Image suppression receiver |
US20080111607A1 (en) * | 2006-11-10 | 2008-05-15 | Hart Robert T | Amplitude-linear differential phase shift circuit |
US20090017770A1 (en) * | 2007-07-11 | 2009-01-15 | Broadcom Corporation | Noise cancellation system for transceivers |
CN109150113A (en) * | 2018-08-23 | 2019-01-04 | 西安邮电大学 | A kind of image-reject mixer in radiofrequency signal transceiver chip |
CN111388011B (en) * | 2020-03-26 | 2023-02-21 | 深圳开立生物医疗科技股份有限公司 | Ultrasonic Doppler blood flow imaging method, device, equipment and readable storage medium |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US5140198A (en) * | 1989-08-30 | 1992-08-18 | Seiko Corporation | Image canceling mixer circuit on an integrated circuit chip |
US5678220A (en) * | 1994-06-06 | 1997-10-14 | France Telecom | Device for rejection of the image signal of a signal converted to an intermediate frequency |
GB2321353A (en) * | 1996-12-18 | 1998-07-22 | Plessey Semiconductors Ltd | Image reject mixer arrangements |
Family Cites Families (13)
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US2964622A (en) * | 1957-10-21 | 1960-12-13 | Sylvania Electric Prod | Image suppressed superheterodyne receiver |
US3575660A (en) * | 1968-10-03 | 1971-04-20 | Hazeltime Corp | Electronic image rejection apparatus |
GB2094079A (en) * | 1981-02-20 | 1982-09-08 | Philips Electronic Associated | Fm demodulator |
US4755761A (en) * | 1986-06-26 | 1988-07-05 | General Electric Company | Zero intermediate-frequency demodulator |
GB9017418D0 (en) | 1990-08-08 | 1990-09-19 | Gen Electric Co Plc | Half frequency mixer |
JP2574596B2 (en) * | 1992-06-03 | 1997-01-22 | 松下電器産業株式会社 | Frequency converter |
JPH06334440A (en) * | 1993-03-26 | 1994-12-02 | Sanyo Electric Co Ltd | Double balance mixer circuit |
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US5826180A (en) * | 1994-08-08 | 1998-10-20 | Nice Systems Ltd. | Near homodyne radio frequency receiver |
GB9424056D0 (en) | 1994-11-29 | 1995-01-18 | Sgs Thomson Microelectronics | A satellite tuner stage |
US5912975A (en) * | 1995-06-30 | 1999-06-15 | Philips Electronics North America Corp | Method and circuit for creating phantom sources using phase shifting circuitry |
FR2742620B1 (en) * | 1995-12-15 | 1998-02-20 | Matra Communication | IMAGE FREQUENCY REJECTION MIXER |
JP3336196B2 (en) * | 1996-06-25 | 2002-10-21 | 株式会社ミツトヨ | Amplitude extraction device |
-
1998
- 1998-06-29 US US09/107,186 patent/US6314279B1/en not_active Expired - Fee Related
-
1999
- 1999-06-24 CN CN99801040A patent/CN1273708A/en active Pending
- 1999-06-24 JP JP2000557540A patent/JP2002519919A/en not_active Withdrawn
- 1999-06-24 KR KR1020007002131A patent/KR20010023486A/en not_active Application Discontinuation
- 1999-06-24 WO PCT/IB1999/001182 patent/WO2000001062A2/en not_active Application Discontinuation
- 1999-06-24 EP EP99957671A patent/EP1040566A2/en not_active Withdrawn
- 1999-12-16 TW TW088122116A patent/TW439353B/en not_active IP Right Cessation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5140198A (en) * | 1989-08-30 | 1992-08-18 | Seiko Corporation | Image canceling mixer circuit on an integrated circuit chip |
US5678220A (en) * | 1994-06-06 | 1997-10-14 | France Telecom | Device for rejection of the image signal of a signal converted to an intermediate frequency |
GB2321353A (en) * | 1996-12-18 | 1998-07-22 | Plessey Semiconductors Ltd | Image reject mixer arrangements |
Also Published As
Publication number | Publication date |
---|---|
TW439353B (en) | 2001-06-07 |
EP1040566A2 (en) | 2000-10-04 |
JP2002519919A (en) | 2002-07-02 |
CN1273708A (en) | 2000-11-15 |
US6314279B1 (en) | 2001-11-06 |
WO2000001062A3 (en) | 2000-04-13 |
KR20010023486A (en) | 2001-03-26 |
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