Famous Patents
The ice cream cone was invented at the St. Louis Worlds Fair by Ernest Hamwi in 1904. His waffle booth was next to an ice cream vendor who ran short of dishes. Hamwi rolled a waffle to hold ice cream and the cone was born.
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 7152084 | Parallelized infinite impulse response (IIR) and integrator filters A digital parallelized Infinite Impulse Response (IIR) integrator filter comprising a first channel having a first input and second channel having a second input, a first adder to add the two channel inputs, an integrator to integrate the added channel inputs to pro... | 12/19/2006 |
| 7099420 | Block interpolation filter structure using lookup table The present invention based on the LUT enables to perform a filtering at a low speed on a place where a high-speed process is necessary. Particularly, the LUT structure having a block structure is advantageous for filtering at a low speed, and for decreasing memory ... | 08/29/2006 |
| 7085793 | Method and system for efficient and accurate processing of a discrete time input signal A method and system of accurately processing a discrete time input signal having a first clock rate into a discrete time output signal having a second clock rate is presented. The method includes delta filtering the input signal to produce an intermediate signal hav... | 08/01/2006 |
| 7034728 | Bandpass delta-sigma modulator with distributed feedforward paths A delta-sigma modulator. The novel delta-sigma modulator includes one or more filter stages arranged in cascade, wherein each filter stage includes a first circuit for generating a first output signal and second circuit for generating a second output signal; and a s... | 04/25/2006 |
| 6912474 | Method and apparatus for high-speed synchronous digital acquisition derived in real -time from analog samples A method and apparatus for real-time derivation of precise digital clock edges and synchronous logic samples from a digital signal having a clock channel and at least one data channel acquires a plurality of temporally offset analog samples during each of a sequence... | 06/28/2005 |
| 6907374 | Self-calibrating sigma-delta analog-to-digital converter A self-calibrating sigma-delta converter (SCADC) functions in a calibration mode and in an operational mode. In the calibration mode, a test circuit of the SCADC generates test signals that are periodic rectangular voltage waveforms. Each test signal has a dc compon... | 06/14/2005 |
| 6868431 | Circuit and method for processing data A Finite Impulse Response (FIR) filter circuit (60) includes delay elements (63, 64, 66), multipliers (71, 72, 73, 74), a summing device (78), and a digital integrator (69) at the output of the FIR filter circuit (60). A met... | 03/15/2005 |
| 6546408 | Sinc filter using twisting symmetry A sinc filter is implemented by partitioning 1 bit wide incoming data into multibit words. The multibit words are multiplied by respective coefficient sets. Some multibit words are twisted by inverting the bit order and the multiplied using the same coeff... | 04/08/2003 |
| 6408031 | Single bit Sigma Delta filter with input gain A digital system for filtering a single bit input signal according to the transfer function H(z), wherein H(z) has a gain G, a pole at location b0, and a zero at location a0. The digital system filters the single bit input signal wit... | 06/18/2002 |
| 6396880 | π/4 DQPSK encoder and modulator A π/4 DQPSK modulator includes a rotated and offset π/4 encoder that provides encoded I, Q constellation indices values using positive integers. The positive integer I and Q values are input to a digital filter that provides filtered I, Q constellation ... | 05/28/2002 |
| 6286020 | Signal processor delta-sigma modulator stage A 1-bit nth order Delta Sigma Modulator where n is at least one comprises a linear signal processing section (50) which processes the 1-bit signal and produces a p bit output, a filter (52) which filters the p bit signal, an adder (53) a quantizer Q coupl... | 09/04/2001 |
| 6202074 | Multiplierless digital filtering Digital filtering is performed by receiving an L-bit block of 1-bit data samples, wherein L is greater than 1, and using the L-bit block of 1-bit data samples to select a corresponding one of 2L filter output values. Selection may be accomplish... | 03/13/2001 |
| 6041080 | Signal processing system and method for digitally mixing a plurality of analog input signals A signal processing system receives and mixes a plurality of analog input signals having a maximum frequency. Each analog input signal is connected to an input of a modulator producing a high frequency oversampled digital signal. Each high frequency overs... | 03/21/2000 |
| 6023718 | High speed interpolation filter and a method thereof A filter system that filters a digital signal to produce a filtered digital signal where the digital signal has alternating first data values and second data values. The filter system includes a demultiplexer that produces a first signal that includes the... | 02/08/2000 |
| 5768315 | Band-pass sigma-delta converter and commutating filter therefor A communication receiver (600) utilizes a band-pass sigma-delta converter (100) for receiving a radio signal. The band-pass sigma-delta converter (100) includes a comparator (106) coupled to an adder-filter (101) for making a comparison between a predeter... | 06/16/1998 |
| 5557642 | Direct conversion receiver for multiple protocols A novel direct conversion receiver utilizing a sample and hold circuit for subsampling the input signal. The output of the sample and hold circuit is applied to a sigma-delta loop to provide a high speed low resolution data stream which in turn is applied... | 09/17/1996 |
| 5461641 | Decimation filter for a sigma-delta converter and A/D converter using the same A Decimation filter for converting a train of sigma-delta pulses S(i) in synchronism with a sigma-delta clock (fs) into a train of Pulse Coded Modulation (PCM) samples in accordance with the formula ##EQU1## where Cn is the sequence of the coefficien... | 10/24/1995 |
| 5329553 | Decimation filter for a sigma-delta converter and data circuit terminating equipment including the same A decimation filter for converting a received train of sigma-delta pulses in synchronism with a sigma-delta clock (fs) into a train of Pulse Code Modulation (PCM) samples having a PCM clock in accordance with the formula ##EQU1## includes a computer ... | 07/12/1994 |
| 5181033 | Digital filter for filtering and decimating delta sigma modulator output signals An oversampled interpolative delta sigma analog-to-digital converter including a delta sigma modulator is provided with a cascade of bit-slice elements at the output of the modulator to form a filter/decimator. Each bit-slice element includes a filter cir... | 01/19/1993 |
| 5140613 | Baseband modulation system with improved ROM-based digital filter In a conventional ROM-based digital filtering methodology, N past samples of M-bit input symbols are used to address a memory containing a desired filtered output signal. This memory must have an address space of 2M*N. According to the present ... | 08/18/1992 |
| 5053983 | Filter system having an adaptive control for updating filter samples An adaptive filter system is provided to improve filtering operations. Adaptive logic monitors filtered information to determine when sufficient filtering has been performed to perform outputting, further processing, or other operations. In addition, satu... | 10/01/1991 |
| 4972360 | Digital filter for a modem sigma-delta analog-to-digital converter Digital filter used in a sigma-delta decoder wherein each input sample is involved in the computation of three consecutive pulse coded modulation (PCM) output samples. During one sigma-delta sampling period, the filter performs three parallel operations b... | 11/20/1990 |
| 4944036 | Signature filter system A filtering system is provided for acquiring and processing signals using a sampled filter for signal separation and signal enhancement; such as for determing locations, distances, and times in a geophysical exploration system. Signature signals permit mi... | 07/24/1990 |
| 4792916 | Digital signal processing device working with continuous bit streams A device which can be used for digital signal processing, e.g. filtering of digital signals in the form of continuous bit streams that are linear digital representations of analogue signals. The device is composed by cascading individual filter sections. ... | 12/20/1988 |
| 4646323 | Method and system for digital data transmission A system and method for digital transmission of pulses of a predetermined duration includes a transmitter (30) and a receiver (40). A data stream (ai) is transformed into a narrow band signal spectrum and following transmission is demodulated t... | 02/24/1987 |
| 4646322 | Adaptive delta modulation codec An ADM codec includes CVSD encoder and decoder circuitry having a syllabic filter responsive to the binary state of the ADM bit samples for changing the quantization step amplitude at a rate of change directly proportional to the rate of change of slope o... | 02/24/1987 |
| 4553221 | Digital filtering system A digital filtering system is provided for acquiring and processing signals using a digital filter for signal separation and signal enhancement. A digital correlator is provided for generating high resolution output data in response to low resolution inpu... | 11/12/1985 |
| 4520491 | Transmission system using differential pulse code modulation with adaptive prediction In this transmission system using differential PCM, the local decoder, inporated in the loop of the encoder, and the remote decoder comprise identical filters (5) and (15) each constituted by a cascade arrangement of several filtering sections (F1 | 05/28/1985 |
| 4361893 | Transmission system using differential pulse code modulation This system comprises an encoder in which the differential PCM signal to be transmitted is formed as the difference between the incoming linear PCM signal and a prediction signal produced by a prediction filter comprising a local decoder receiving the sai... | 11/30/1982 |
| 4136398 | Digital filter having coefficient number generator A digital filter for generating digital output signals from information signals in accordance with a predetermined transfer characteristics includes a coefficient number generator for supplying digital numbers which indicate the values of coefficients whi... | 01/23/1979 |
| 4016410 | Signal processor with digital filter and integrating network System comprising an integrating digital signal processing device to which input signal samples x(nT) are supplied with a period T and which supplies output signal samples z(mrT) with a period rT. To this end in this integrating signal processing device c... | 04/05/1977 |
| 3988606 | Digital filter device for processing binary-coded signal samples A digital filter is described in which the filter coefficients which differ from zero are coded in unequal numbers of multipliers which are equal to 2n and in which immediately after each multiplication of a given signal sample by the multiplie... | 10/26/1976 |
| 3983382 | Adder with fast detection of sum equal to zeroes or radix minus one Logic circuits in an adder for use in data processing for the detection of a sum of all ZEROES together with the mathematics upon which the circuits are based. Circuits and mathematics are also disclosed for a detection of a sum of all digits equal to the... | 09/28/1976 |
| 3976860 | Method and arrangement for conversion of a digital measured value A method for the conversion of a constantly occurring measured value in digital form into a filtered digital value comprises comparing the instantaneous measured value with a digital value determined by previous measurements, evaluating the difference Ɗ ... | 08/24/1976 |
| 3968354 | Transversal digital filter for delta coded signals A transversal digital filter including a shift register provided with a number of stages to which level control devices are connected by means of taps, the level control devices being connected to a feedback circuit which is connected through a combinatio... | 07/06/1976 |
| 3965338 | Apparatus for achieving a predetermined transfer characteristic A pulse switched digital multiplier for matching transfer characteristics of digital processes having a plurality of pulse switch positions, and a pulse switch setting circuit which, under the control of a setting code from a setting program, sets the pul... | 06/22/1976 |
| 3963911 | Hybrid sample data filter A sample data filter using a delta modulator to feed a shift register of which selected outputs are pulsewidth weighted. Each of the coefficient multipliers include a flip-flop fed by one of the taps of the shift register and triggered by a clock. A synch... | 06/15/1976 |
| 3959637 | Digital filter A digital filter for a plural digitally expressed pulse code modulated (PCM) signal utilizes a storage register to retain several samples of the signal and obviates the need for digital multiplication circuits by using a delta coding for the filter coeffi... | 05/25/1976 |
