Patents Assigned to Atheros Communications
  • Multiple Antennas Having Good Isolation Disposed In A Limited Space
    Publication number: 20070229364
    Abstract: An apparatus and method are taught for instantiation of a plurality of high-frequency antennas in a limited space in a manner that provides good isolation. The instantiation may include relative rotations of linear conductors, mirror images, as well as horizontally and vertically polarized antennas. In one embodiment, the antennas may be multi-band antennas.
    Type: Application
    Filed: March 14, 2007
    Publication date: October 4, 2007
    Applicant: Atheros Communications, Inc.
    Inventor: Arie Shor
  • System and method of conforming wireless devices to worldwide regulations
    Patent number: 7274911
    Abstract: Countries or regions of the world can have different regulations governing wireless devices. A client product advantageously conforms to any regulatory environment, thereby allowing the client product to operate permissibly in any wireless network. The client product scans all frequencies at a predetermined interval for explicit information on regulation-conformant methods of operation, including frequencies and output power levels. If the client product receives a beacon, then the client product extracts relevant information from the beacon. Based on the relevant information, the client product operates in either the infrastructure mode or the ad hoc mode. On the other hand, if the client product does not receive explicit information, the client product detects other types of information and implicitly derives methods of operation in both infrastructure and ad hoc modes that conform to local regulations.
    Type: Grant
    Filed: September 6, 2005
    Date of Patent: September 25, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: Sheung L. Li
  • Reducing power consumption in embedded systems by controlling voltage based on system state and partition designation
    Patent number: 7257723
    Abstract: An embedded system optimally operates with minimal power consumption without sacrificing performance. Power consumption can be reduced by independently and dynamically controlling multiple power partitions, wherein components within a partition can have the same power profile. States of operation can be programmably defined in a table and enforced using hardware. Voltages in the table can be dynamically updated during a runtime of the system using a timing feedback module, which is connected to a critical path in a partition. The timing feedback module can output a vector that indicates the timing margin for that critical path. Using this timing margin, software can increase or decrease the voltage to optimize power consumption of that partition.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: August 14, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: Mike Galles
  • Dual frequency band wireless LAN
    Patent number: 7251459
    Abstract: A dual band radio is constructed using a primary and secondary transceiver. The primary transceiver is a complete radio that is operational in a stand alone configuration. The secondary transceiver is a not a complete radio and is configured to re-use components such as fine gain control and fine frequency stepping of the primary transceiver to produce operational frequencies of the secondary transceiver. The primary transceiver acts like an intermediate frequency device for the secondary transceiver. Switches are utilized to divert signals to/from the primary transceiver from/to the secondary transceiver. The switches are also configured to act as gain control devices. Antennas are selected using either wideband or narrowband antenna switches that are configured as a diode bridge having high impedance at operational frequencies on control lines that bias the diodes.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: July 31, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: William J. McFarland, Keith Onedera, Arie Shor, David Su, Manolis Terrovitis, John Thomson, Masoud Zaragari
  • Method and system for noise floor calibration and receive signal strength detection
    Patent number: 7245893
    Abstract: A system for detecting the level of the noise floor due to circuit noise as seen at the ADC for a wireless receiver. The system measures power after digitizing and filtering, and subtracts off any variable gain used in the analog front end to determine differentially the size of the signal at the antenna. The system further differentially detects the signal size of any incoming signal at the antenna in a similar fashion, and determines its size relative to the measured noise floor. If the level of the circuit noise of the receiver is known absolutely, the absolute signal size of the incoming signal can likewise be determined with this inventive method and system.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: July 17, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: Paul J. Husted, William J. McFarland
  • Rekey operation with multiplexing capability
    Patent number: 7245724
    Abstract: A method of providing a protocol for rekeying between two stations is disclosed. The method can include providing a first set of messages for computing a new key and reserving an auxiliary storage area for the new key. The first set of messages comprises an enable exchange. The method also includes providing a second set of messages to obsolete an old key and switch to the new key. The second set of messages comprises a transition exchange. In one embodiment, the protocol includes rekeying between multiple stations, and the rekey coordinator sends the first set of messages to a plurality of rekey participants. The auxiliary storage area allows multiplexing in both the enable and transition exchanges, thereby facilitating an efficient and safe rekey operation.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: July 17, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: Greg Chesson, Nancy Cam-Winget
  • Method and apparatus for a signal selective RF transceiver system
    Patent number: 7245882
    Abstract: Method and apparatus to dynamically configure the signal reception selectivity of a plurality of transceivers is described. In one embodiment, a transceiver includes a receiver circuit having two or more filter circuits. Each of the filter circuits is configured to pass RF signals from a different portion of an overall receiver bandwidth. When two or more receivers in proximity to one another are simultaneously operating, the filter circuits of the respective receiver are dynamically configured to different RF frequency passbands to minimize interference and cross talk between receivers and transmitters.
    Type: Grant
    Filed: July 17, 2003
    Date of Patent: July 17, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: William J. McFarland
  • Inductor layout using step symmetry for inductors
    Patent number: 7242274
    Abstract: A differential circuit layout can advantageously use step symmetry for inductors and mirror symmetry for the rest of the circuit. Interconnect segments can be used to connect the terminals of the inductors to other components in the circuit. These interconnect segments facilitate the transition from the step symmetry of the inductors to the mirror symmetry of the other components. To provide this transition, the terminals of an inductor and its associated interconnect segments are formed on a middle axis of the inductor. This mixed symmetry can advantageously cancel the common-mode magnetic field, reduce the parasitic inductor coupling, and balance parasitic wiring capacitances between the two sides of the differential circuit.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: July 10, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: Manolis Terrovitis
  • Transistor biasing independent of inductor voltage drop
    Patent number: 7233205
    Abstract: A differential amplifier can include input transistors for receiving a differential input signal and an inductor connected to the input transistors. The inductor can protect a voltage supply from radio frequency in the differential input signal. The accuracy of this differential amplifier can be significantly improved by including a bias network. This bias network advantageously allows a bias current in the input transistors to be set independently of a voltage drop across the inductor.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: June 19, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: Keith K. Onodera
  • Cable having embedded access points
    Patent number: 7231224
    Abstract: A cable has miniaturized, low-cost, highly-integrated wireless network access points embedded in the cable at periodic intervals along the length of the cable. Power conductors that run the length of the cable supply each of the access points with electrical power. Each access point has an antenna for receiving and transmitting radio signals. The antenna of an access point is encapsulated, along with the rest of the access point circuitry, underneath an insulating protective outer sheath of the cable. The cable includes conductors that are usable for a purpose other than deploying a wireless network. When the cable is physically installed (for example, in the wall or ceiling of a building) for the other purpose, the access points are simultaneously physically installed. The access points so installed can then be activated and used as part of a wireless network.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: June 12, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: Gregory Lawrence Chesson
  • Method and apparatus for signal power loss reduction in RF communication systems
    Patent number: 7212788
    Abstract: Multiple power amplifiers in an RF front end are coupled to multiple antennas without diversity switching between the PAs and antennas. Diversity switches direct signals to broadcast by a selected antenna to a PA coupled to the selected antenna. Multiple LNAs are similarly coupled to the diverse antennas. Having one PA and LNA set for each antenna removes the need for diversity switching between the PA/LNAs and each antenna improving signal reception. In one embodiment, a single external PA performs broadcast functions and plural on-chip LNAs are used for reception. In another embodiment, phase shifters are coupled to each PA and LNA, which provide beam forming capability for broadcasts, and in phase signal combinations for received signals.
    Type: Grant
    Filed: August 13, 2002
    Date of Patent: May 1, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: David Weber, Manolis Terrovitis, David Su
  • Method and system to implement non-linear filtering and crossover detection for pilot carrier signal phase tracking
    Patent number: 7203255
    Abstract: Systems and methods for correcting phase ambiguity in a total pilot phase value are presented. Examples include comparing and correcting total pilot phase values having different pilot frequencies within the same sampling interval, such as the same data symbol. Another example includes correcting a total pilot phase value for one sampling interval and corresponding to one pilot frequency using nonlinear filtering of values of the total pilot phase for prior sampling intervals at the same pilot frequency.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: April 10, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: Yi-Hsiu Wang, Teresa H. Meng
  • Efficient pilot tracking method for OFDM receivers
    Patent number: 7184495
    Abstract: A method for maintaining an accurate channel estimate. The method includes providing a reference channel estimate based on at least one long training symbol, and generating a frequency domain representation of a first data symbol including a plurality of pilots. The method then includes tracking phase change in the plurality of pilots of the first data symbol relative to pilots of the at least one long training symbol to produce correction factors, and adjusting the reference channel estimate based upon the correction factors.
    Type: Grant
    Filed: February 14, 2002
    Date of Patent: February 27, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: John Thomson, Teresa Meng
  • Look up table based upsampling and digital filtering
    Patent number: 7185036
    Abstract: A system and method are disclosed for processing a signal that includes receiving encoded data including a plurality of input symbols; generating an input symbol set from the plurality of input symbols; looking up a plurality of output samples for the input symbol set; and outputting the plurality of output samples.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: February 27, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: Yi-Hsiu Wang, John Thomson
  • Key caching system
    Patent number: 7185196
    Abstract: A key-caching system retrieves actively used keys from a relatively fast cache memory for fast processing of wireless communications. Additional keys are stored in relatively slow system memory that has high storage capacity. As keys become needed for active use, the keys are retrieved from the system memory and stored in the cache memory. By using active memory for keys actively being used, system performance is enhanced. By using system memory for keys not being used, a greater number of keys are available for transfer to the cache and subsequent active use.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: February 27, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: Jeffrey Scott Kuskin, Tao-Fei Samuel Ng, Deepak Prabhakar Dhamdhere, Fiona J. Cain, Andrew M. Davidson
  • Method and apparatus for a transceiver having a constant power output
    Patent number: 7170953
    Abstract: The present invention includes a transceiver and a method of operating the same that includes in the transmitter a power control circuit that operates on an analog differential signal containing data packets individually. The power control circuit initially transmits a series of data symbols with known values, periodically strobes the transceiver system for correct power levels and incrementally increases the power level of the transceiver until the optimal gain is reached, without exceeding the maximum output power.
    Type: Grant
    Filed: December 1, 2005
    Date of Patent: January 30, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: Brian J. Kaczynski
  • Method and apparatus for a gain controlled mixer
    Patent number: 7171184
    Abstract: A gain controlled mixer for an integrated CMOS transceiver. Accuracy of the controlled gain may be relatively invariant over temperature, manufacturing process, and other variations attendant to circuit realizations in a CMOS transceiver, and other realizations. A plurality of substantially matched circuit elements are instantiated and disposed similarly within the gain controlled mixer, enhancing the gain accuracy of selectable gain control states. Matching gain and other functions between circuit elements is further enhanced by appropriately controlling DC operating point conditions.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: January 30, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: Hirad Samavati
  • Modified start frame delimiter detection
    Patent number: 7161955
    Abstract: A modified approach to detecting the start frame delimiter (SFD) is disclosed. A receiving system scans a decoded but not yet de-scrambled received signal for a scrambled version of the SFD associated with the preamble format being used. Using this approach, it is not necessary to use any bits intended for use in synchronization to initialize a de-scrambler so as to be able to de-scramble the SFD portion of the preamble for detection. The bits that otherwise would have been dedicated to initializing the de-scrambler may then be used for synchronization, as intended. Detecting fewer than all bits comprising a start frame delimiter is described. Bits not used for SFD detection may be used for other purposes, such as synchronization.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: January 9, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: Chaohuang Zeng, William McFarland
  • Systems and methods to provide wideband magnitude and phase imbalance calibration and compensation in quadrature receivers
    Patent number: 7158586
    Abstract: Systems and methods for passively calibrating and correcting for I/Q mismatch in a quadrature receiver without the necessity of modifying the analog portion of the receiver by adding calibration signals or correction circuitry are presented. The passive I/Q mismatch calibration system proceeds using normally received incoming transmitted data signals to obtain statistical information on which to base I/Q mismatch compensation factors. The I/Q mismatch compensation factors can be used to adjust the magnitude and phase response in the time domain or the frequency domain, the analog or the digital portion of the receiver. Depending on the embodiment, the passive I/Q mismatch calibration system can calibrate frequency dependent gain or magnitude imbalance, frequency independent magnitude imbalance, frequency dependent phase imbalance, and frequency independent phase imbalance or combinations or these.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: January 2, 2007
    Assignee: Atheros Communications, Inc.
    Inventor: Paul J. Husted
  • Dynamic preamble detection
    Patent number: 7158542
    Abstract: A system and method are disclosed for dynamic preamble detection. A subset of the bits comprising the synchronization portion of the preamble are decoded, de-scrambled, and analyzed to determine dynamically which preamble format is being used. The source data values for the synchronization bits for a first preamble format are different than the source data values for the synchronization bits for a second preamble format and the receiving system uses the difference to determine which preamble format has been used. The information concerning which format has been used may be used to extend a synchronization operation.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: January 2, 2007
    Assignee: Atheros Communications, Inc.
    Inventors: Chaohuang Zeng, William J. McFarland