Abstract: Described herein are rotary transformers for coupling signals between components that rotate relative to one another. In an exemplary embodiment, a rotary transformer comprises a rotary shaft, a first magnetic core on the rotary shaft, and a first winding wound around the first magnetic core. The rotary transformer farther comprises a hollow second magnetic core, and a second winding wound along the inner wall of the second magnetic core. During operation, the first winding on the rotary shaft rotates within the second winding with the magnetic cores magnetically coupling signals between the two windings. Also, the first and second windings are closely spaced to provide capacitive coupling between the windings that extends the frequency response of the transformer. In one embodiment, the windings comprises substantially flat conductors wound in the shape of the windings. In another embodiment, each of the windings comprises circular loops connected by jogs.

Abstract: Described herein are rotary transformers for coupling signals between components that rotate relative to one another. In an exemplary embodiment, a rotary transformer comprises a rotary shaft, a first magnetic core on the rotary shaft, and a first winding wound around the first magnetic core. The rotary transformer further comprises a hollow second magnetic core, and a second winding wound along the inner wall of the second magnetic core. During operation, the first winding on the rotary shaft rotates within the second winding with the magnetic cores magnetically coupling signals between the two windings. Also, the first and second windings are closely spaced to provide capacitive coupling between the windings that extends the frequency response of the transformer. In one embodiment, the windings comprises substantially flat conductors wound in the shape of the windings. In another embodiment, each of the windings comprises circular loops connected by jogs.

Abstract: Described herein are rotary transformers for coupling signals between components that rotate relative to one another. In an exemplary embodiment, a rotary transformer comprises a rotary shaft, a first magnetic core on the rotary shaft, and a first winding wound around the first magnetic core. The rotary transformer further comprises a hollow second magnetic core, and a second winding wound along the inner wall of the second magnetic core. During operation, the first winding on the rotary shaft rotates within the second winding with the magnetic cores magnetically coupling signals between the two windings. Also, the first and second windings are closely spaced to provide capacitive coupling between the windings that extends the frequency response of the transformer. In one embodiment, the windings comprises substantially flat conductors wound in the shape of the windings. In another embodiment, each of the windings comprises circular loops connected by jogs.

Abstract: The use of any micro-mechanical component in an ultrasound system is disclosed. In particular, the use of micro-relays, micro-switches and inductors in the transducer probe head, in the transducer connector, coupled with the system transducer connector(s) or anywhere else in the system. In an ultrasound system, micro-mechanical components such as micro-fabricated switches, relays and inductors permit impressive size reduction, cost reduction, signal-integrity enhancement and improved operational flexibility.

Abstract: The use of any micro-mechanical component in an ultrasound system is disclosed. In particular, the use of micro-relays, micro-switches and inductors in the transducer probe head, in the transducer connector, coupled with the system transducer connector(s) or anywhere else in the system. In an ultrasound system, micro-mechanical components such as micro-fabricated switches, relays and inductors permit impressive size reduction, cost reduction, signal-integrity enhancement and improved operational flexibility.

Abstract: The use of any micro-mechanical component in an ultrasound system is disclosed. In particular, the use of micro-mechanical ultrasound transducers, micro-relays, micro-switches and inductors in the transducer probe head, in the transducer connector, coupled with the system transducer connector(s) or anywhere else in the system. In an ultrasound system, micro-mechanical components such as micro-mechanical ultrasound transducers, micro-fabricated switches, relays and inductors permit impressive size reduction, cost reduction, signal-integrity enhancement and improved operational flexibility.

Abstract: The use of any micro-mechanical component in an ultrasound system is disclosed. In particular, the use of micro-relays, micro-switches and inductors in the transducer probe head, in the transducer connector, coupled with the system transducer connector(s) or anywhere else in the system. In an ultrasound system, micro-mechanical components such as micro-fabricated switches, relays and inductors permit impressive size reduction, cost reduction, signal-integrity enhancement and improved operational flexibility.

Abstract: The use of any micro-mechanical component in an ultrasound system is disclosed. In particular, the use of micro-relays, micro-switches and inductors in the transducer probe head, in the transducer connector, coupled with the system transducer connector(s) or anywhere else in the system. In an ultrasound system, micro-mechanical components such as micro-fabricated switches, relays and inductors permit impressive size reduction, cost reduction, signal-integrity enhancement and improved operational flexibility.

Abstract: A method and system for obtaining ultrasound data is provided. Different aperture techniques are used for transmit than on receive. The various techniques include synthetic aperture, shorting elements, skipping elements, sliding apertures and combinations thereof. The techniques used may also vary as a function of the depth of field.

Abstract: A three-state, pulse width modulated, bipolar waveform is constructed by summing a first component with an inverted, time-shifted version of the first component. By properly selecting the time interval for the time shift of the second component, frequency filtering benefits can be obtained. The three-state waveform is generated by a switched voltage source that provides a low, constant source impedance for all three voltage states.

Abstract: A medical diagnostic ultrasonic imaging method and system subdivide the transmit aperture into two or more subapertures, each subaperture having at least four adjacent transducer elements. The subapertures are phased differently with respect to one another to selectively reduce either fundamental components or harmonic components of echoes from tissue. These techniques can be used to improve contrast agent harmonic imaging as well as tissue harmonic imaging, depending upon the phase shift selected.

Abstract: An improvement to the method for harmonic imaging including the steps of (a) transmitting ultrasonic energy at a fundamental frequency and (b) receiving reflected ultrasonic energy at a harmonic of the fundamental frequency is provided. The transmitting step includes the step of: applying the plurality of waveforms to a respective plurality of transducer elements, a first waveform of the plurality of waveforms characterized by a first value of a harmonic power ratio, waveforms transmitted from the transducer elements and corresponding to the plurality of waveforms summing as an acoustic waveform substantially at the point, the acoustic waveform characterized by a second value of the harmonic power ratio less than the first value. The imaging method can also include a step for subdividing the transmit aperture into two or more subapertures, each subaperture having at least four adjacent transducer elements.

Abstract: A method and system for obtaining ultrasound data is provided. Two or more transducer elements are shorted or connected to the same transmit or receive channel for a single transmit or receive event. The affect of any grating lobes generated from shorting the transducer elements are minimized by receiving acoustic energy and then obtaining ultrasound data at a harmonic of a fundamental transmit frequency. No contrast agent is added during imaging. A multiplexer with a limited number of switches is used to short pairs of transducer elements together. Alternatively, a multiplexer with a limited number of switches is used to transmit or receive from spaced apertures, such as by connecting a channel to every second transducer element.

Abstract: An improvement to the method for harmonic imaging including the steps of (a) transmitting ultrasonic energy at a fundamental frequency and (b) receiving reflected ultrasonic energy at a harmonic of the fundamental frequency is provided. For the improvement, the transmitting step includes the step of transmitting a uni-polar waveform or a waveform characterized by an amplitude change rate of 8 or fewer times pre carrier cycle, said waveform comprising an envelope shape rising gradually to a respective maximum value and falling gradually from the respective maximum value.

Abstract: An improvement to the method for harmonic imaging including the steps of (a) transmitting ultrasonic energy at a fundamental frequency and (b) receiving reflected ultrasonic energy at a harmonic of the fundamental frequency is provided. The transmitting step includes the step of transmitting a waveform comprising at least a sequence of at least a first and second pulse characterized by first and second pulse durations, respectively, where the second pulse duration is different than the first duration. This arrangement can reduce harmonic energy in the waveform.

Abstract: A phase shifter providing constant group delay and a wide instantaneous bandwidth is taught. In one embodiment, an input port is connected to an output port with a power splitter formed of a transformer connected between the input port and the output port, and having a center tap serving as a sum port. An impedance, such as a resistor, is connected in parallel with the transformer between the input port and the output port. A reactive network is connected between the sum port and ground, including one or more variable reactance device, such as a varactor, which alter the reactance of the reactive network in response to a control signal. Additional reactive elements are included in the reactive network to provide additional poles and zeros which change frequency in response to the variable reactance elements, in order to provide a group delay which is constant for various reactance values provided by the reactive network between the lowest frequency of interest and a higher frequency of interest.

Abstract: A fast switching broadband signal synthesizer method and structure are provided which not only has the ability to change frequency and amplitude quickly, but with a minimal dwell time required before switching can again take place. A signal translator can also be constructed in accordance with this invention in order to convert the output frequency of a companion signal source to any desired frequency while retaining the fast switching speed and switching rate of the signal synthesizer. Amplitude, phase, and frequency modulation of the companion signal are preserved during the translation process. A direct frequency synthesizer is provided wherein internal signals which are combined to generate any output frequency are derived from a single fixed frequency oscillator. By utilizing a single reference frequency oscillator in accordance with this invention, the amount of circuitry required to construct a direct frequency synthesizer is greatly reduced.

Abstract: A method and structure is provided for phase locking an output signal having, for example, a desired frequency of 2.sup.C Hz with a reference signal having a frequency of 2.sup.A.5.sup.B Hz. The phase comparison is performed at a high frequency in order to minimize phase noise and spurious signals.

Abstract: A circuit in a synchronous detector system is provided to minimize and compensate for the errors induced by phase modulation and additive noise in the system. In one embodiment a first-order correction of such errors is achieved by equipping the synchronous detector system with a constant loop filter noise bandwidth and an RMS detector. A resolution filter passing the detected system signal to the RMS detector for correction is made to have a noise bandwidth identical to the loop filter noise bandwidth.