61
Ka Yin Leung: Digital filter with decimated frequency response. Crystal Semiconductor, Gregory M Howison, J P Violette, December 9, 1997: US05696708 (70 worldwide citation)

A method for changing the frequency of a low-pass Finite Impulse Response (FIR) filter with a fixed frequency clock utilizes a decimation-by-coefficient technique. The decimation-by-coefficient method utilizes a single set of coefficients that are stored in a coefficient Read Only Memory (ROM) (64). ...


62
Croisier Alain, Esteban Daniel J, Levilion Marc E, Riso Vladimir: Digital filter for pcm encoded signals. International Business Machines Corporation, December 4, 1973: US3777130 (70 worldwide citation)

A digital filter either of a recursive or transversal type responsive to successive digitally encoded analog signal samples of m bits each. The filter comprises an accumulator for multiplying and summing a weighted hybrid value obtained from a memory medium addressed by a selected one of the m bits ...


63
Lane Allen Smith: System for digital filtering in a fixed number of clock cycles. Lucent Technologies, William H Bollman, January 16, 2001: US06175849 (70 worldwide citation)

An integrated circuit, e.g. an AC '97 conforming audio codec, includes a digital filter and gain module including multiple channels of gain control and multiple channels of digital filtering. A gain control module includes an overflow check of data samples requiring differing lengths of clampin ...


64
Tsutomu Hamabe, Akio Kinoshita, Kazuhiro Doi, Kenichiro Muraoka, Noriharu Sato: Apparatus for actively reducing noise for interior of enclosed space. Nissan Motor, Hitachi, Lowe Price LeBlanc & Becker, August 9, 1994: US05337365 (69 worldwide citation)

An apparatus for reducing noise for an interior of enclosed space, e.g., a vehicular compartment using an FIR adaptive digital filter is disclosed in which a control circuit is provided which outputs drive signals to a plurality of loud speakers which generate control sounds to interfer with a noise ...


65
Tamal Bose, Howard Vincent Derby, Andrew Keith Levien, Anthony William Pankratz: Method and apparatus for measuring pressure in a coriolis mass flowmeter. Micro Motion, Duft Graziano & Forest P C, March 31, 1998: US05734112 (68 worldwide citation)

A method for determining pressure in an operating Coriolis effect mass flowmeter. The Coriolis flowmeter flow tubes are vibrated in both a bending mode (as is normal for measuring mass flow rate) and in a twisting mode. The ratio of the fundamental frequencies at which the flow tubes vibrate in each ...


66
Yutaka Takahashi: Echo canceler having adaptive digital filter unit associated with delta-sigma modulation circuit. NEC Corporation, Sughrue Mion Zinn Macpeak & Seas, June 22, 1993: US05222084 (67 worldwide citation)

An echo canceler comprises an adaptive digital filter circuit for producing an echo replica signal on the basis of a transmit digital signal and a first digital signal indicative of a far-end signal, and an adder for eliminating the echo signal from a received signal with reference to the echo repli ...


67
Jonathan Herman Fischer, Lane Allen Smith: Recursive digital filter with reset. Lucent Technologies, William H Bollman, December 26, 2000: US06167415 (67 worldwide citation)

An integrated circuit, e.g. an Audio Codec (AC) '97 conforming audio codec, includes a digital filter and gain module including multiple channels of gain control and multiple channels of digital filtering. A gain control module includes an overflow check of data samples requiring differing lengths o ...


68
Heinz Gockler: Digital filter tree. ANT Nachrichtentechnik, Spencer & Frank, June 13, 1989: US04839889 (66 worldwide citation)

The invention relates to a digital filter tree composed of a plurality of digital filter banks arranged in a tree structure one behind the other to branch out in stages with a separation into L.sub..nu. individual signals taking place in each stage and the sampling rate being reduced each time by th ...


69
Koji Takano, Fumiaki Nagao: Digital filters. Sanyo Electric, Cantor Colburn, August 21, 2001: US06279021 (65 worldwide citation)

A digital filter is provided with a plurality of selectors. Switchover from one selector to another switches the digital filter operation between its separation filter function and synthesis filter function. The digital filter is constructed mainly with a multiplier, an accumulator, and an adder-sub ...


70
Kevin T Chan: Adaptive configurable class-A/class-B transmit DAC for transceiver emission and power consumption control. Broadcom Corporation, McAndrews Held & Malloy, July 15, 2003: US06594304 (65 worldwide citation)

A power efficient and reduced electromagnetic interference (EMI) emissions transmitter for unshielded twisted pair (UTP) data communication applications. Transmit data is processed by a digital filter. The digital filter output data is converted to a current-mode analog waveform by a digital-to-anal ...



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