Patents by Inventor Per Löwenborg
Per Löwenborg has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10192017Abstract: Each realization of an electric circuit design defines a frequency response. For a test lot of the design, frequency responses are measured, each at a stable value of an environment parameter, wherein the totality of the values are distributed over a parameter range. Based on the measurements, a design-specific model is defined that describes a frequency response of the design in dependence of the environment parameter. For a unit in a main lot of realizations of the design, a unit-specific frequency response is measured at a stable value of the environment parameter; the model is fitted to the response, whereby a unit-specific model is obtained; data representing the unit-specific model is stored in association with the unit; and the unit is operated in conjunction with a compensation stage configured to determine a present value of the environment parameter and compensate drift in relation to a parameter-independent reference frequency response.Type: GrantFiled: April 28, 2015Date of Patent: January 29, 2019Assignee: Teledyne Signal Processing Devices Sweden ABInventors: Frida Bref, Mikael Gustavsson, Per Löwenborg, Martin Olsson
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Publication number: 20180157780Abstract: Each realization of an electric circuit design defines a frequency response. For a test lot of the design, frequency responses are measured, each at a stable value of an environment parameter, wherein the totality of the values are distributed over a parameter range. Based on the measurements, a design-specific model is defined that describes a frequency response of the design in dependence of the environment parameter. For a unit in a main lot of realizations of the design, a unit-specific frequency response is measured at a stable value of the environment parameter; the model is fitted to the response, whereby a unit-specific model is obtained; data representing the unit-specific model is stored in association with the unit; and the unit is operated in conjunction with a compensation stage configured to determine a present value of the environment parameter and compensate drift in relation to a parameter-independent reference frequency response.Type: ApplicationFiled: April 28, 2015Publication date: June 7, 2018Inventors: Frida ENG, Mikael GUSTAVSSON, Per LÖWENBORG, Martin OLSSON
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Patent number: 8307248Abstract: A method and a module for estimating a plurality of relative channel-error for at least one signal with respect to a reference signal. The signals and are produced by an analog-to-digital module including parallel and time interleaved analog-to-digital converters and are received by an estimation module. The method is performed by the estimation module and includes defining a function representing a relationship between the reference signal and an arbitrary signal in the group of signals, selecting a first reference signal in the group of signals, selecting a second signal from the remaining signals in the group, optimizing the function so as to obtain an estimate of the plurality of relative channel-error, and repeating the selecting a second signal and optimizing the function for each remaining signal.Type: GrantFiled: June 30, 2006Date of Patent: November 6, 2012Assignee: Signal Processing Devices Sweden ABInventors: Håkan Johansson, Per Löwenborg
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Patent number: 8009070Abstract: A method for the compensation of frequency-response mismatch errors in M-channel time-interleaved ADCs. The compensation is done through an M-periodic time-varying filter hn(k)=hn mod M(k) (2), or, equivalently, a set of M time-invariant filters hn(k), n=0, 1, . . . , M?1. The overall compensation system is constructed by determining the M filter impulse responses hn(k) through M separate matrix inversions, where the size of the matrices equals the filter impulse response length. Also, a compensated M-channel time-interleaved ADC based on and performing the method.Type: GrantFiled: June 21, 2007Date of Patent: August 30, 2011Assignee: Signal Processing Devices Sweden ABInventors: Håkan Johansson, Per Löwenborg
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Publication number: 20100182174Abstract: A method for the compensation of frequency-response mismatch errors in M-channel time-interleaved ADCs. The compensation is done through an M-periodic time-varying filter hn(k)=hn mod M(k) (2), or, equivalently, a set of M time-invariant filters hn(k), n=0, 1, . . . , M?1. The overall compensation system is constructed by determining the M filter impulse responses hn(k) through M separate matrix inversions, where the size of the matrices equals the filter impulse response length. Also, a compensated M-channel time-interleaved ADC based on and performing the method.Type: ApplicationFiled: June 21, 2007Publication date: July 22, 2010Applicant: SIGNAL PROCESSING DEVICES SWEDEN ABInventors: Håkan Johansson, Per Löwenborg
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Patent number: 7741982Abstract: A method for estimating a relative time difference vector in a group of digitized signals from a time interleaved analog-to-digital module having a plurality of parallel and time interleaved analog-to-digital converters. The method comprises the steps of selecting (S1) one of said digitized signals as a reference signal, calculating (S2-S3) an actual time delay between each of the remaining signals and said reference signal, and subtracting (S4), for each of said remaining signals, an intended interleaving time delay from said time delay. In order for this method to provide the correct estimate, the signal must be bandlimited, not only to the system bandwidth, but to the bandwidth of one ADC. However, given this bandwidth limitation, the estimation is very precise, and therefore enables reconstruction of the digitized signal without feedback.Type: GrantFiled: February 4, 2005Date of Patent: June 22, 2010Assignee: Signal Processing Devices Sweden ABInventors: Håkan Johansson, Per Löwenborg
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Publication number: 20100049483Abstract: A method and a module for estimating a plurality of relative channel-error for at least one signal with respect to a reference signal. The signals and are produced by an analog-to-digital module including parallel and time interleaved analog-to-digital converters and are received by an estimation module. The method is performed by the estimation module and includes defining a function representing a relationship between the reference signal and an arbitrary signal in the group of signals, selecting a first reference signal in the group of signals, selecting a second signal from the remaining signals in the group, optimizing the function so as to obtain an estimate of the plurality of relative channel-error, and repeating the selecting a second signal and optimizing the function for each remaining signal.Type: ApplicationFiled: June 30, 2006Publication date: February 25, 2010Applicant: SIGNAL PROCESSING DEVICES SWEDEN ABInventors: Håkan Johansson, Per Löwenborg
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Patent number: 6476754Abstract: The present invention refers to a method and apparatus for reconstruction of a nonuniformly sampled bandlimited analog signal xa(t), said nonuniformly sampled signal comprising N subsequences xk(m), k=0, 1, . . . , N−1, N≧2, obtained through sampling at a sampling rate of 1/(MT) according to xk(m)=xa(nMT+tk), where M is an integer, and tk=kMT/N+&Dgr;tk, &Dgr;tk being different from zero. The invention comprises forming a new sequence y(n) from said N subsequences xk(m) such that y(n) at least contains the same information as x(n)=xa(nT), i.e. xa(t) sampled with a sampling rate of 1/T, in a frequency region lower than &ohgr;0, &ohgr;0 being a predetermined limit frequency, by means of (i) upsampling each of said N subsequences xk(m), k=0, 1, . . . , N−1, by a factor M, M being a positive integer; (ii) filtering each of said upsampled N subsequences xk(m), k=0, 1, . . .Type: GrantFiled: October 1, 2001Date of Patent: November 5, 2002Assignee: Telefonaktiebolaget L M Ericsson (publ)Inventors: Per Löwenborg, Håkan Johansson