356 results about "Phase response" patented technology

A CDMA modem includes a modem transmitter having: a code generator which provides an associated pilot code signal and which generates a plurality of message code signals; a spreading circuit which produces a spread-spectrum message signal by combining each of the information signals with a respective one of the message code signals; and a global pilot code generator that provides a global pilot code signal to which the message code signals are synchronized. The CDMA modem also includes a modem receiver having an associated pilot code generator and a group of associated pilot code correlators for correlating code-phase delayed versions of the associated pilot signal with a receive CDM signal to produce a despread associated pilot signal. The code phase of the associated pilot signal is changed responsive to an acquisition signal value until a pilot signal is received. The associated pilot code tracking logic adjusts the associated pilot code signal in phase responsive to the acquisition signal so that the signal power level of the despread associated pilot code signal is maximized. Finally, the CDMA modem receiver includes a group of message signal acquisition circuits, each including a plurality of receive message signal correlators which correlate respective local received message code signal to the CDM signal to produce a respective despread received message signal.

Cardiac methods and devices that separate signals using at least two composite signals acquired at least at two input impedances. A target source impedance may be selected, and a cardiac signal may be separated from composite signals using the selected target source impedance. Medical systems include a cardiac device having a housing that provides amplification circuitry configured to have a first amplifier input impedance and a second amplifier input impedance, such as using two separate circuits or switching between two input impedances. One or more electrode assemblies are coupled to the amplification circuitry. A signal processor is provided in the housing configured to separate a source signal using a first composite signal detected at the first input impedance and a second composite signal detected at the second input impedance. The phase response of the first input amplifier circuit is about equal to that of the second input amplifier circuit.

A method and apparatus for reducing crosstalk between sensors in an inline Fabry-Perot (FP) sensor array. The inline FP sensor array comprises a plurality of fiber Bragg gratings arranged periodically along an optical fiber. The sensors are formed between each of the Bragg gratings. A light source provides multiplexed pulses as interrogation pulses for the array. The light pulses are applied to one end of the sensor array and a light detector detects reflected pulses. The detected pulses comprise a composite of reflections from all the Bragg gratings along the fiber. The apparatus processes the detected signals using an inverse scattering algorithm to detect an accurate phase response from each of the Bragg sensors while reducing crosstalk from other Bragg sensors within the array. One form of inverse scattering algorithm is a layer-peeling algorithm.

The location of a physical disturbance along an optical waveguide is determined by measuring different propagation times for the resulting phase variation to propagate to phase responsive receivers at ends of bidirectional signal paths. Each receiver can have a coupler that functions as a beam combiner and as a beam splitter inserting the opposite signal. On each receiving end, the coupler provides one or more detectors with signals from which phase related independent variable values are taken, processed and mapped to phase angles. Relative phase angle versus time is derived for each opposite signal pair and correlated at a time difference, i.e., a difference in propagation time from which the location of the disturbance is resolved. Polarization sensitive and polarization insensitive examples are discussed with various optical fiber arrangements.

Embodiments described in the present disclosure relate to an array microphone apparatus for generating a beam forming signal. The apparatus includes first, second, and third omni-directional microphones, each converting an audible signal into a corresponding electrical signal. The three microphones are arranged in a horizontal coplanar alignment, and the second microphone is disposed between the other two microphones. The apparatus includes a first directional microphone forming device to jointly output a first directional microphone signal with a first bi-directional pattern, and a magnitude and phase response handler device to output a second directional microphone signal with an omni-directional pattern shifted by a prefixed value with respect to first directional microphone signal. The apparatus further includes a combining device receiving the first and second directional microphone signals and outputting a combined directional microphone signal with a combined beam pattern correlated to the first bi-directional and second omni-directional patterns, the combined directional microphone signal being perpendicular to the horizontal coplanar alignment of the first, second, and third omn-directional microphones.