Patents by Inventor Konstantinos Vavelidis

Konstantinos Vavelidis 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).

  • Patent number: 7715836
    Abstract: A transceiver for transmitting and receiving signals includes a transmitter operative to up-convert baseband signals from a baseband frequency into RF signals at a radio frequency (RF) frequency and output the RF signals, a receiver operative to receive RF signals and down-convert the RF signals into baseband signals having the baseband frequency, and a plurality of calibration paths coupling the transmitter to the receiver. Any of the calibration paths can be selected to be active when calibrating components of the transceiver. Tunable components can use calibration information to optimize transceiver performance.
    Type: Grant
    Filed: September 2, 2003
    Date of Patent: May 11, 2010
    Inventors: Iason Vassiliou, Theodore Georgantas, Akira Yamanaka, Konstantinos Vavelidis, Sofoklis Plevridis
  • Publication number: 20100048196
    Abstract: Methods and systems for a variable system on demand are disclosed. Aspects of the method may include configuring one or more filters in a wireless transmitter and/or receiver for a desired band and standard. The presence of a blocker signal in a receiver may be known and/or determined and the receiver may be configured for mitigating the blocker signal. A desired received signal strength indicator may be compared to a wideband received signal strength indicator. Gain levels may be configured in the receiver based on the comparison. Linearity of the receiver may be configured for blocker signal mitigation. The filters may include baseband filters and/or may be at an output of the receiver. The filters may include a plurality of stages, with one or more of the stages bypassed for filter configuring, and may include a mixer as an input. Capacitors and/or resistors may be configured in the filters.
    Type: Application
    Filed: December 1, 2008
    Publication date: February 25, 2010
    Inventors: Theodore Georgantas, Nikolaos Haralabidis, Spyridon Kavadias, Stamatios Alexandros Bouras, Charalampos Kapnistis, Konstantinos Vavelidis, Ilias Bouras
  • Publication number: 20100040184
    Abstract: Methods and systems for coexistence in a multiband, multistandard communication system utilizing a plurality of phase locked loops (PLLs) are disclosed. Aspects may include determining one or more desired frequencies of operation of a transceiver, determining a frequency of unwanted signals such as spurs, intermodulation, and/or mixing product signals, and configuring the PLLs to operate at a multiple of the desired frequencies while avoiding the unwanted signals. The desired frequencies may be generated utilizing integer, which may include multi-modulus dividers. The wireless standards may include LTE, GSM, EDGE, GPS, Bluetooth, WiFi, and/or WCDMA, for example. The frequencies may be configured to mitigate interference. PLLs may be shared when operating in TDD mode, and used separately operating in FDD mode. One or more digital interface signals, zero exceptions on a transmitter spur emission mask, and sampling clocks for ADCs and/or DACs in the transceiver may be generated utilizing the PLLs.
    Type: Application
    Filed: December 1, 2008
    Publication date: February 18, 2010
    Inventors: Nikolaos Haralabidis, Ioannis Kokolakis, Nikolaos Kanakaris, Konstantinos Vavelidis
  • Publication number: 20090088086
    Abstract: A communication device may include one or more circuits in an integrated transmitter and receiver that includes a transmit path and a receive path. The transmit path may include an I processing baseband transmit path and a Q processing baseband transmit path. The receive path may include an I processing baseband receive path and a Q processing baseband receive path. The one or more circuits may enable sharing a first common filter by the I processing baseband transmit path and the I processing baseband receive path. The one or more circuits may also enable sharing a second common filter by the Q processing baseband transmit path and the Q processing baseband receive path. The first common filter and the second common filter are independently programmable to adjust a phase and/or a gain of the said first common filter, and/or a phase and/or a gain of the second common filter.
    Type: Application
    Filed: December 8, 2008
    Publication date: April 2, 2009
    Inventors: Iason Vassiliou, Nikos Haralabidis, Theodore Georgantas, Akira Yamanaka, Konstantinos Vavelidis, Sofoklis Plevridis
  • Patent number: 7463864
    Abstract: A dual band direct conversion architecture for both the receive (RX) and transmit (TX) path of a communications transceiver that minimizes the transceiver area by sharing common circuits used in both RX and TX paths is disclosed. The transceiver also allows the use of extensive digital calibration in order to achieve performance adequate to support high bit rate modulation schemes.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: December 9, 2008
    Assignee: Broadcom Corporation
    Inventors: Iason Vassiliou, Nikos Haralabidis, Theodore Georgantas, Akira Yamanaka, Konstantinos Vavelidis, Sofoklis Plevridis
  • Publication number: 20070207760
    Abstract: A method and system for filter calibration using fractional-N frequency synthesized signals are presented. Aspects of the method may include generating an LO signal by a PLL circuit within a chip. A reference signal may be generated based on the generated LO signal and a synthesizer control signal. A frequency response for a filter circuit integrated within the chip may be calibrated by adjusting parameters associated with the filter circuit based on the generated LO signal. Aspects of the system may include a single-chip multi-band RF receiver that enables generation of a LO signal by a PLL circuit within the single-chip, and enables calibration of a frequency response for a filter circuit integrated within the chip. A reference signal may be generated based on the generated LO signal and a synthesizer control signal. The frequency response may be calibrated by adjusting the filter based on the generated reference signal.
    Type: Application
    Filed: May 11, 2006
    Publication date: September 6, 2007
    Inventors: Spyridon Kavadias, Konstantinos Vavelidis, Nikolaos Haralabidis
  • Publication number: 20070207759
    Abstract: Aspects of a method and system for an RF front-end calibration scheme using signals from a fractional-N frequency synthesized and received signal strength indicator (RSSI) are provided. A frequency synthesizer within a wireless receiver may generate a signal for dynamically modifying a gain in an integrated low-noise amplifier (LNA) for each selected receiver channel. The frequency-synthesized signals may be applied to at least one tunable load communicatively coupled to the LNA. The tunable load may be an input load or an output load. The signal generated by the frequency synthesizer may be sequentially applied to the input load and the output load. A logarithmic amplifier may generate an RSSI signal from the LNA output during the calibration process. The RSSI signal may be utilized for controlling a tunable load coupled to the LNA and optimize the tuning of the LNA in a desired channel by adjusting the tunable load.
    Type: Application
    Filed: May 11, 2006
    Publication date: September 6, 2007
    Inventors: Konstantinos Vavelidis, Charalampos Kapnistis, Iason Vassiliou
  • Publication number: 20070066272
    Abstract: Aspects of a method and system for a multi-band direct conversion CMOS mobile television tuner are provided. A single-chip multi-band RF receiver in a mobile terminal comprising UHF and L-band front-ends receives and amplifies an RF signal utilizing an LNA integrated into the front-end that corresponds to the type of signal received. A received signal strength indicator (RSSI) value may be determined for the amplified signal within the single-chip receiver and may be utilized to adjust a gain of the LNA. The adjustment may be made via on-chip or off-chip processing of the RSSI value. The single-chip receiver may directly convert the amplified signal to a baseband frequency signal and generate in-phase and quadrature components. The components of the baseband frequency signal may be filtered and/or amplified via programmable devices within the single-chip receiver. Circuitry within the single-chip receiver may be controller via an on-chip digital interface.
    Type: Application
    Filed: March 21, 2006
    Publication date: March 22, 2007
    Inventors: Iason Vassiliou, Konstantinos Vavelidis, Stamatios Bouras, Spyridon Kavadias, Ioannis Kokolakis, Georgios Kamoulakos, Aristeidis Kyranas, Charalampos Kapnistis, Nikolaos Haralabidis
  • Publication number: 20070066271
    Abstract: Certain aspects of a method and system for programmable biasing mechanism for a mobile digital television environment are disclosed. Aspects of one method may include controlling a bias of components within each of a plurality of radio frequency (RF) front-ends that comprise low noise amplifiers (LNAs) integrated within a single chip multi-band RF receiver, and of components within each of a plurality of baseband processors integrated within the single chip multi-band RF receiver. The controlling of the bias is based on signal power measurements within the integrated RF front-ends and within the baseband processors, and each of the plurality of RF front-ends handles processing of at least one of: a received UHF signal and a received L-band signal.
    Type: Application
    Filed: March 21, 2006
    Publication date: March 22, 2007
    Inventors: Konstantinos Vavelidis, Iason Vassiliou
  • Publication number: 20070064843
    Abstract: Aspects of a method and system for a mobile cellular television tuner utilizing current-steering variable gain at radio frequency are provided. A control signal may be generated in a LNA integrated within a single-chip multi-band RF receiver based on a gain signal. Adjusting a current flow through circuitry in an input stage within the LNA via the control signal may control a gain for the integrated LNA. A replica circuit within the LNA may be utilized to generate the control signal. A transconductor within the LNA may be utilized to convert the gain signal from a voltage to a current for generating the control signal. The gain signal may be generated on-chip or off-chip. A switched capacitor bank within the LNA may be adjusted to control the input scattering parameter. At least one bias voltage within the LNA may be adjusted during operation of the single-chip multi-band RF receiver.
    Type: Application
    Filed: March 21, 2006
    Publication date: March 22, 2007
    Inventors: Konstantinos Vavelidis, Aristeidis Kyranas
  • Publication number: 20060178165
    Abstract: A dual band direct conversion architecture for both the receive (RX) and transmit (TX) path of a communications transceiver that minimizes the transceiver area by sharing common circuits used in both RX and TX paths is disclosed. The transceiver also allows the use of extensive digital calibration in order to achieve performance adequate to support high bit rate modulation schemes.
    Type: Application
    Filed: April 11, 2005
    Publication date: August 10, 2006
    Inventors: Iason Vassiliou, Nikos Haralabidis, Theodore Georgantas, Akira Yamanaka, Konstantinos Vavelidis, Sofoklis Plevridis
  • Publication number: 20040106380
    Abstract: A transceiver for transmitting and receiving signals includes a transmitter operative to up-convert baseband signals from a baseband frequency into RF signals at a radio frequency (RF) frequency and output the RF signals, a receiver operative to receive RF signals and down-convert the RF signals into baseband signals having the baseband frequency, and a plurality of calibration paths coupling the transmitter to the receiver. Any of the calibration paths can be selected to be active when calibrating components of the transceiver. Tunable components can use calibration information to optimize transceiver performance.
    Type: Application
    Filed: September 2, 2003
    Publication date: June 3, 2004
    Inventors: Iason Vassiliou, Theodore Georgantas, Akira Yamanaka, Konstantinos Vavelidis, Sofoklis Plevridis