Patents by Inventor Stefan Barkarö
Stefan Barkarö 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: 7839993Abstract: In a line driver/receiver circuit where the line driver is connected with its output terminals to a load for supplying a transmit signal thereto and where the receiver is connected with its input terminals to the load for simultaneously receiving a receive signal therefrom, the transmit signal on the input terminals of the receiver is canceled by connecting the output terminals of the line driver to the load via equal complex sense impedances of an impedance value that is much smaller than the impedance value of the load impedance to match the load impedance, connecting the input terminals of the receiver to the load via equal first resistors and to respective output terminal of the line driver via equal second resistors, and providing transconductance amplifiers to sense the voltage across the sense impedances and supply corresponding currents to respective input terminal of the line driver.Type: GrantFiled: April 9, 2004Date of Patent: November 23, 2010Assignee: Lantiq Deutschland GmbHInventors: Stefan Barkarö, Torbjörn Randahl
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Publication number: 20100289523Abstract: In a line driver/receiver circuit where the line driver is connected with its output terminals to a load for supplying a transmit signal thereto and where the receiver is connected with its input terminals to the load for simultaneously receiving a receive signal therefrom, the transmit signal on the input terminals of the receiver is canceled by connecting the output terminals of the line driver to the load via equal complex sense impedances of an impedance value that is much smaller than the impedance value of the load impedance to match the load impedance, connecting the input terminals of the receiver to the load via equal first resistors and to respective output terminal of the line driver via equal second resistors, and providing transconductance amplifiers to sense the voltage across the sense impedances and supply corresponding currents to respective input terminal of the line driver.Type: ApplicationFiled: July 28, 2010Publication date: November 18, 2010Inventors: STEFAN BARKARÖ, TORBJÖRN RANDAHL
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Patent number: 7801296Abstract: at least one self oscillating loop circuit which oscillates with a switching frequency (fs), wherein the self oscillating loop circuit (18, 19, 20) comprises an output driver (19) which is switched with said switching frequency and a loop filter (20) which feeds back an amplified loop signal output by said driver (19) to an input of said self oscillating loop and a trimming circuit (21) for trimming the switching frequency (fs) of said self oscillating loop circuit.Type: GrantFiled: January 27, 2005Date of Patent: September 21, 2010Assignee: Infineon Technologies AGInventors: Karl Stefan Barkarö, Bo Bokinge, Jörg Hauptmann, Karl-Mikael Johanson, Lars Karlsson, Torbjörn Ivar Randahl
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Patent number: 6728366Abstract: For signal level adjustment of a multitone signal received over a transmission line (1) during a training sequence in a DSL system, a programmable high-pass filter (2) is connected to the transmission line (1). A programmable gain control unit (4) is connected between the filter (2) and an A/D converter (5). A digital signal processor (6) is connected with its inputs to the A/D converter (5), with control outputs (7, 9) to control inputs (8, 10) of the filter (2), and with control outputs (11, 13) to control inputs (12, 14) of the gain control unit (4). The processor (6) detects signal level differences between the highest and the lowest tone of the multitone signal and programs the filter (2) to make the signal levels of the highest and the lowest tone equal.Type: GrantFiled: November 22, 2000Date of Patent: April 27, 2004Assignee: Telefonaktiebolaget LM EricssonInventors: Stefan Barkarö, Albin Johansson
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Patent number: 6687370Abstract: To secure an ADSL connection between a first ADSL transceiver (4) in a central office and a second ADSL transceiver (5) on a subscriber's premises on a telephone line (1) between a SLIC (2) in the central office and a telephone (3), a request to the SLIC (2) to apply a ringing signal to the telephone line (1) is detected. In response to such detection, the first ADSL transceiver (4) switches from a normal bit rate to a lower bit rate for the ADSL connection, and orders the second ADSL transceiver (5) to do the same before the ringing signal is applied. In response to an off-hook condition, the lower bit rate is maintained for the ADSL connection. In response to an on-hook condition after the off-hook condition as well as in response to a disappearance of the ringing request without an off-hook condition, the first ADSL transceiver (4) switches back to the normal bit rate and orders the second ADSL transceiver (5) to do the same.Type: GrantFiled: November 22, 2000Date of Patent: February 3, 2004Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Stefan Barkarö, Torbjörn Randahl
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Patent number: 6636605Abstract: At the output of a line driver (1) connected to a long transmission line, signals received on the transmission line are only a fraction of signals transmitted by the line driver on the transmission line. To minimize the transmitted signal with its distortion and noise in the receive path of the line driver, an additional driver (4) having the same voltages and currents in the signal path, is added. The additional driver (4) drives an additional load (Z2). The signal transmitted to the transmission line together with its superimposed received signal, is subtracted from the signal from the additional driver (4), which is not superimposed on any received signal. The resulting signal is reduced from transmitted signal, transmitted distortion and transmitted noise. To minimize die size and power consumption, the additional driver (4) is scaled, but the distortion remains unchanged compared to the “normal” line driver.Type: GrantFiled: December 21, 1999Date of Patent: October 21, 2003Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Torbjörn Randahl, Stefan Barkarö
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Patent number: 6625175Abstract: To secure an ADSL connection to an ADSL transceiver connected to a telephone line to be used also by an associated telephone, the telephone is normally kept disconnected from the telephone line and a predetermined number of bits is allocated to the ADSL connection. Upon an off-hook condition of the telephone in connection with an outgoing call, and upon a presence of a ringing signal on the telephone line or an off-hook condition of the telephone in connection with an incoming call, a predetermined lower number of bits is allocated to the ADSL connection before the telephone is connected to the telephone line.Type: GrantFiled: November 12, 1999Date of Patent: September 23, 2003Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Torbjörn Randahl, Stefan Barkarö
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Patent number: 6542520Abstract: In an arrangement for securing an ADSL connection to an ADSL transceiver connected together with a telephone to a common telephone line; there are devices for setting a first number and a second, lower number, respectively, of bits to be allocated to the ADSL connection. Moreover, there are devices for detecting whether or not a ringing signal is present on the line and whether the telephone is in the off-hook or the on-hook condition. The first number of bits is allocated when neither the ringing signal nor the off-hook condition is detected, and the second, lower number of bits is allocated when the ringing signal and/or the off-hook condition is detected.Type: GrantFiled: May 6, 1999Date of Patent: April 1, 2003Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Stefan Barkarö, Albin Johansson
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Patent number: 6407578Abstract: To reduce power dissipation in a line driver connected to a transmission line for transmitting multitone signals in the form of successive symbols separated by cyclic prefixes and generated by a digital signal processor, a controllable voltage supply is connected with its output terminal to a supply voltage terminal of the line driver. In response to an expected peak-to-peak value of the next symbol to be transmitted, the digital signal processor controls the controllable voltage supply during each cyclic prefix to set an appropriate supply voltage to the line driver.Type: GrantFiled: December 4, 2000Date of Patent: June 18, 2002Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventor: Stefan Barkarö