Abstract: Among other things, a communication system and technique for transferring information between a stationary unit and a rotating unit of a computed tomography (CT) system is provided. The communication system comprises a transceiver and a contactless data-link comprising at least one physical channel. The transceiver is configured to create at least two logical channels from a single physical channel to provide for transmitting at least two types of information in a single direction and/or to provide for transmitting information bi-directionally. In this manner, an amount of data that can be transmitted over a single physical channel can be increased.

Abstract: One or more techniques and/or systems are provided for transferring power and/or information between a stator and a rotor. The rotor includes a high voltage rectifier filter and an auxiliary regulator coupled to a power transfer apparatus (e.g., rotary transformer). The high voltage rectifier filter is configured to receive a first electrical signal, associated with a first voltage, from the power transfer apparatus and to generate a second electrical signal, associated with a second voltage, based on a frequency and/or an amplitude of the first electrical signal. The auxiliary regulator is configured to generate a third electrical signal based on the first electrical signal, where a third voltage associated with the third electrical signal is generated independent of the frequency and/or amplitude of the first electrical signal. A single bi-directional data link is used for control and/or communication between the stator and the rotor.

Abstract: Among other things, a communication system and technique for transferring information between a stationary unit and a rotating unit of a computed tomography (CT) system is provided. The communication system comprises a transceiver and a contactless data-link comprising at least one physical channel. The transceiver is configured to create at least two logical channels from a single physical channel to provide for transmitting at least two types of information in a single direction and/or to provide for transmitting information bi-directionally. In this manner, an amount of data that can be transmitted over a single physical channel can be increased.

Abstract: Among other things, a communication system and technique for transferring information between a stationary unit and a rotating unit of a computed tomography (CT) system is provided. A transmitter is configured to map digital data to an analog signal by selecting, from at least three signal configurations, a signal configuration associated with the digital data, and to generate an analog signal according to the selected signal configuration. A receiver of the communication system is configured to decode an analog signal by comparing characteristics of a signal sample to at least three possible signal configurations, and to identify a digital code word that corresponds to a signal configuration (of the at least three possible signal configurations) that matches characteristics of the signal sample. In this way, in a CT application, more than 1-bit of data may be communicated per analog signal, allowing more data to be communicated faster.

Abstract: Among other things, a communication system and technique for transferring information between a stationary unit and a rotating unit of a computed tomography (CT) system is provided. A transmitter is configured to map digital data to an analog signal by selecting, from at least three signal configurations, a signal configuration associated with the digital data, and to generate an analog signal according to the selected signal configuration. A receiver of the communication system is configured to decode an analog signal by comparing characteristics of a signal sample to at least three possible signal configurations, and to identify a digital code word that corresponds to a signal configuration (of the at least three possible signal configurations) that matches characteristics of the signal sample. In this way, in a CT application, more than 1-bit of data may be communicated per analog signal, allowing more data to be communicated faster.

Abstract: A delta-sigma A/D converter includes a delta-sigma modulator having an integrating amplifier dispose within the loop of the modulator so that the input of the modulator can be connected to receive relatively low level input currents, and so as to improve DC stability. The modulator is specifically adapted for IC implementation for use in a DAS of a CT scanner so that the current output of a detector of the scanner can be connected directly to the input of the modulator of the converter. The noise shaping characteristics are shaped so as to provide an improved frequency response with minimal spillover. Noise shaping of the converter is provided throughout the dynamic range of the current outputs of CT scanner detectors so as to compensate for the poorer S/N for low input currents.

Abstract: A delta-sigma A/D converter includes a delta-sigma modulator having an integrating amplifier dispose within the loop of the modulator so that the input of the modulator can be connected to receive relatively low level input currents, and so as to improve DC stability. The modulator is specifically adapted for IC implementation for use in a DAS of a CT scanner so that the current output of a detector of the scanner can be connected directly to the input of the modulator of the converter. The noise shaping characteristics are shaped so as to provide an improved frequency response with minimal spillover. Noise shaping of the converter is provided throughout the dynamic range of the current outputs of CT scanner detectors so as to compensate for the poorer S/N for low input currents.

Abstract: A delta-sigma A/D converter includes a delta-sigma modulator having an integrating amplifier dispose within the loop of the modulator so that the input of the modulator can be connected to receive relatively low level input currents, and so as to improve DC stability. The modulator is specifically adapted for IC implementation for use in a DAS of a CT scanner so that the current output of a detector of the scanner can be connected directly to the input of the modulator of the converter. The noise shaping characteristics are shaped so as to provide an improved frequency response with minimal spillover. Noise shaping of the converter is provided throughout the dynamic range of the current outputs of CT scanner detectors so as to compensate for the poorer S/N for low input currents.

Abstract: An ultrasound beamformer that processes the signals of an array transducer includes a plurality of processing channels, one for each element of the active transducer array. Each channel includes a digitizing element for converting the received signal into digital samples and a delay element for delaying the digitized signal. The delays are chosen so that when the signals from the individual channels are combined, a beam forms in a particular direction. The invention implements sub-sampling period delays in the individual channels with low-complexity digital filters having superior delay characteristics with respect to frequency, but having undesirable attenuation characteristics with respect to frequency. The invention corrects for the undesirable attenuation characteristics via a single digital filter after the signals from the individual channels have been combined.

Abstract: An array transducer ultrasound beamformer includes a plurality of processing channels, one for each active element of the transducer array. Each channel includes a digitizing unit for converting the received signal to digital samples and a time multiplexed delay unit for producing a primary stream of delayed TDM samples corresponding to one or more beams. Within each channel, the primary stream of delayed TDM samples is demultiplexed in order to separate the stream in a plurality of secondary streams of delayed TDM samples, wherein each of the secondary streams corresponds to a portion of a beam or a single beam.

Abstract: Although known because of high packaging inductances and thought to be wholly unsuitable for RF amplifiers, high voltage power switching MOSFETs of the type having coplanar leads having inductances on the order of between 8 nH and 15 nH are used in an RF amplifier. The individual devices operate on a high impedance load line to render the high inductance insignificant. The circuit configuration presents a high impedance to the output, eliminating the need for expensive combiners and low inductance packaging.

Abstract: A converter circuit operable in a current control mode is disclosed. The circuit is of the type including an (1) inductor, (2) a clock for providing a clocking signal so that the circuit operates as a synchronous converter and (3) switching means, responsive to the clocking signal and a threshold current, for controlling the load voltage across the inductor between at least two different levels of voltage as a function of one or more supply voltages so that the inductor conducts (a) increasing inductor current for one level of load voltage from the beginning of each cycle of the clocking signal until the inductor current equals the threshold current during each cycle, and (b) decreasing inductor current for the other level of voltage from the time in each cycle the current equals the threshold current until the end of each said cycle.

Abstract: An autozero compensation system for autozeroing the output of a data conversion circuit comprising a floating point amplifier and an analog-to-digital converter. The autozero compensation system comprises a source for generating a desired offset voltage, a plurality of digital counters, one for each gain setting of the amplifier, for storing values which are functions of the offset voltages for the gain settings, and a comparator for comparing the output of the A/D converter with the desired offset. Periodically, each of the counters in the autozero circuit is updated for each gain setting by setting the analog input of the amplifier to system ground and the gain of the amplifier set to each of the gain settings, so that the output of the comparator is used to update each of the counters. The outputs of the counters are each converted to analog form by a D/A converter and used to provide the offset correction voltage to the floating point amplifier.

Abstract: A process is described for converting an image in one digital format to a second digital format by considering both horizontal and vertical values of pixels to generate output pixels of intermediate value.

Abstract: A loudspeaker system having two angled rear panels with four drivers on each rear panel and a single driver on the front panel has the drivers connected in series between first and second terminals and a third terminal connected to the junction of the front driver and one of the banks of series-connected rear drivers. First and second power amplifiers are connected between the third terminal and the first and second terminals, respectively. A potentiometer is connected between the inputs of the first and second power amplifiers with the potentiometer arm coupled to the third terminal through a capacitor.