242results about "Transmission noise reduction" patented technology

An apparatus and method is disclosed which allow a limited energy source (such as a low voltage battery stack or a low current computer auxiliary device power connection) to charge a high performance capacitive device, which in turn powers a low duty-cycle, high power load circuit (such as a packet-switched radio data transmitter).

Methods and devices are described for reducing transmit RF signal loss in a bi-directional RF transmit/receive system with a duplexer circuit. In one case a filter in a transmit path is used such as to reduce amplified noise in a receive frequency band.

An apparatus and method for minimizing electromagnetic interference in a microcomputing system. The apparatus and method of the present invention are based on the fundamental aspect of providing an EMI shield specifically dimensioned to receive a microprocessor within the microcomputing system. The apparatus and method of the present invention are further based on the aspect of providing at least one ferrite bead along a power delivery path to attenuate any high-frequency leakage current from the microprocessor that results at the resonant frequencies of the EMI shield.

The invention provides an amplifier circuit of a capacitor microphone of which the noise resistance against noise of a supply voltage is enhanced. In an amplifier circuit of a capacitor microphone of the invention, while a noise component of a supply voltage is applied to one inversion input terminal of an operational amplifier of an amplification portion through a parasitic capacitor existing between an external power supply wiring and an external wiring that are adjacent to each other, the problem noise component of the supply voltage is applied to the other non-inversion input terminal by capacitive coupling to an internal power supply wiring. Therefore, the noise component is cancelled at the operational amplifier.

Methods and devices are described for increasing RF throughput in a multiple RF paths RF transmit/receive system with a plurality RF transmit/receive systems. In one case a tunable notch filter is used to reduce channel interference between the plurality of RF transmit/receive systems.

A method for controlling interference in a Near Field Communication (NFC) network including a plurality of connections for direct communication between terminals is provided. The method includes receiving a signal transmitted by a first terminal through a first connection for direct communication with the first terminal, and measuring received power for the signal, measuring received power for each of interference signals upon receiving the interference signals caused by communication through connections other than the first connection among the plurality of connections, calculating a first Signal-to-Interference Ratio (SIR) using the received power for the signal and the received power for each of interference signals, and determining to one of maintain and release setup for each of the connections other than the first connection, if the first SIR is less than a threshold.

A radio reception device for vehicle 100 (200) includes a variable phase shifter 22, an amplitude regulator 23, and an adder 24, and has an arrangement in which a signal of an RF, IF, or baseband stage of a radio receiver mixed with a noise is added to a phase-inverted component of the noise to remove only the noise. Therefore, sound distortion due to loss of sound information does not occur so that a quality sound can be provided.

A charging circuit for charging/biasing high impedance loads such as capacitive loads. The circuit comprises an input for connecting to a voltage/charge source and an output for connecting to the load. A capacitor is connected between the output and a reference voltage such as ground and a reverse bias diode is connected between the input and the output terminals. The reverse bias diode is arranged to allow a reverse current to pass which is sufficient to compensate for current leakage at the output terminal or other parts of the circuit. The reverse bias diode is conveniently a polysilicon diode. The diode may be connected in parallel with a shunt device to allow for rapid charging during start up.

A mechanism is provided for selecting IDLE patterns based on data being transmitted on the different ports of a wide lane serial attached small computer system interface cable. The mechanism examines the frequency content of the data bearing lanes and selects a DWORD to transmit for an IDLE that has a different frequency content to reduce spikes in electromagnetic interference emissions at a given frequency.

A method and system configures operating parameters associated with an operation of a connected accessory or second device in order to mitigate harmonic interference within an operating frequency band of a wireless communication device (WCD). In response to a connection between the WCD and the second device via a physical communications interface, Accessory Authentication and Configuration (AAC) logic of the WCD receives device identifying information about the second device. The AAC logic determines candidate values for each operating parameter, based on the device identifying information. The AAC logic dynamically selects a particular candidate value for each operating parameter, based on a current operating frequency band of the WCD, and an expected level of harmonic interference. The AAC logic automatically configures each operating parameter with the corresponding selected candidate value to enable proper operation of the second device while mitigating harmonic interference within the operating frequency band of the WCD.

A radio system comprises a power source and a power amplifier circuit coupled to the power source on a power line. The radio system also comprises an active cancellation circuit. The active cancellation circuit comprises a bi-directional DC-DC converter. The active cancellation circuit is configured to cancel low-frequency emissions from the power amplifier circuit on the power line.

A frequency jittering circuit modulates a hysteretic band of an oscillator such that the clock generated by the oscillator has a jitter frequency, and thus a switching mode power supply operative on the clock will have a jittering switching frequency.

In aspect, the disclosure includes a method of configuring a MIMO wideband receiver. The method would include estimating, on a SISO basis, a set of post-processing parameters for a plurality of receiver channels; receiving, by each of the plurality of receiver channels, a first test signal which is transmitted from a first transmitter channel on a MIMO basis; calculating a first set of crosstalk parameters in response to receiving the first test signal; receiving, by each of the plurality of receiver channels, a second test signal which is transmitted from a second transmitter channel on the MIMO basis; calculating a second set of crosstalk parameters in response to receiving second test signal; and calculating the set of post-processing parameters based on the first set of crosstalk parameters and the second set of crosstalk parameters by cancelling a crosstalk interference among plurality of receiver channels.

The invention relates to a method and a filter for distinguishing signal components from one another, whereof at least one comprises a periodic signal sequence. In the solution samples are taken during several signal sequences (300) and a signal sequence model is formed by arranging the samples taken from several signal sequences (300) together so that the samples represent a single signal sequence (300) model and the signal sequence model is specified by filtering.

A power supply noise sensor includes a noise sensing section A to sense impulse noise applied to a power supply line and an output holding section B to hold a sense output from the noise sensing section A. The noise sensing section A includes a time constant circuit to gradually vary a power supply voltage including impulse noise. When a peak value of the impulse noise reduces after the peak value exceeds a predetermined value, a direction of a current flowing through the time constant circuit is inverted to hold a noise output from the output holding section B also after the impulse noise disappears. Therefore, the impulse noise in the forward direction and the impulse noise in the reverse direction superimposed onto the power supply system of the sensor can be sensed in a simple configuration.

A method, including receiving an input analog signal containing noise at a specific noise frequency and digitizing the input analog signal to form a digitized signal. The method also includes recovering a first amplitude and a first phase of the noise from the digitized signal, and generating an analog correction signal at the specific noise frequency. The analog correction signal has a second amplitude equal to the first amplitude and a second phase opposite to the first phase. The method further includes summing the input analog signal with the analog correction signal to generate an output analog signal.

In accordance with one embodiment, a method for a health scanning system is disclosed. The method includes receiving at least one electrical physiological data signal (PDS); suppressing a Direct Current (DC) signal component of the PDS to emphasize the Alternating Current (AC) signal component of the PDS; isolating the signal noise in the AC signal component of the PDS; and extracting a noise signature from the signal noise in the PDS. The noise signature, after calibration, can be used to uniquely identify a known user from other users.

An electronic apparatus comprising a radio transmitter is disclosed. In a computer system (1) having a radio transmission circuit (3) of a phase modulation type supplied with power from a power supply (4) of a switching type, the switching frequency of the power supply (4) is determined based on the comparison frequency for the sampling operation of a PLL circuit (10) of the radio transmitter, thereby removing the power noises generated from the switching regulator of the radio transmitter of a phase modulation type.

A microphone microchip for a voice communication device. The microchip receives and processes an audio signal from a microphone. The microchip incorporates an RF filter that substantially attenuates noise signals at RF frequencies, while passing audio signals, substantially unattenuated. The filter is inserted between ports through which RF carrier signal noise can enter the microchip and internal elements of the microchip that provide a nonlinear response. Thus, modulated RF carrier noise is attenuated before this noise can interact with the nonlinear elements to convert the modulated carrier noise to audible interference. Corruption of microphone signals is thereby avoided.

The present invention discloses a parameter tuning approach for bypass damping filter to suppress subsynchronous resonance in power systems, namely determining the parameters of capacitor, inductor and damping resistor in BDF. Using this approach, the parameters of capacitor and inductor in BDF can be adjusted, so that the frequency where the negative electrical damping of generator reaches minimum can be away from the frequency range of low frequency oscillation mode and typical frequencies of each torsional mode; the parameter of damping resistor in BDF can be further adjusted so that the minimum value of negative electrical damping is in reasonable range. The application of BDF with parameters tuned by the present invention contributes to the suppression of both the torsional interaction effect and the transient torque amplification effect.

The invention provides a headset interface and GPIO (General Purpose Input/Output) interface multiplex circuit structure. A host base band or host audio codec comprises a low dropout linear regulator, a programmable grain amplifier, a first power amplifier, a second power amplifier and a grounding terminal, wherein the output end of the low dropout linear regulator, the input end of the programmable grain amplifier and a first general input/output interface are connected in parallel and then the paralleled integrated body is connected with a microphone interface; the grounding terminal of the host base band is connected with a grounding port; the output end of the first power amplifier is connected with a second general input/output interface in parallel and is then is connected with a left channel headset interface; and the output end of the second power amplifier is connected with a third general input/output interface in parallel and is then is connected with a right channel headset interface. According to the headset interface and GPIO interface multiplex circuit structure disclosed by the invention, the connection between the host and headset equipment can be realized, the connection between the host and data interface equipment can be realized and the functions of the headset interface are expanded.