83 results about "Phase cancellation" patented technology

A feedthrough terminal assembly for an active implantable medical device (AIMD) includes a plurality of leadwires extending from electronic circuitry of the AIMD, and a lossy ferrite inductor through which the leadwires extend in non-conductive relation for increasing the impedance of the leadwires at selected RF frequencies and reducing magnetic flux core saturation of the lossy ferrite inductor through phase cancellation of signals carried by the leadwires. A process is also provided for filtering electromagnetic interference (EMI) in an implanted leadwire extending from an AIMD into body fluids or tissue, wherein the leadwire is subjected to occasional high-power electromagnetic fields such as those produced by medical diagnostic equipment including magnetic resonance imaging.

Aspects of the present invention provide for a novel photomask for patterning features for an integrated circuit, the photomask including a first area transmitting light in a first phase surrounded by second area, the second area transmitting light in a second phase, the second phase opposite the first phase. No blocking material separates the first area from the second area. After development of photoresist, the transition between the first and second area causes formation of a residual photoresist feature on the photoresist surface due to phase canceling of light. If the first area is small enough, it is nonprinting, ie., the opposite sides of the residual photoresist feature formed at its perimeter merge, forming a contiguous photoresist feature, and thus a corresponding patterned feature after etch.

A feedthrough terminal assembly for an active implantable medical device (AIMD) includes a plurality of leadwires extending from electronic circuitry of the AIMD, and a lossy ferrite inductor through which the leadwires extend in non-conductive relation for increasing the impedance of the leadwires at selected RF frequencies and reducing magnetic flux core saturation of the lossy ferrite inductor through phase cancellation of signals carried by the leadwires. A process is also provided for filtering electromagnetic interference (EMI) in an implanted leadwire extending from an AIMD into body fluids or tissue, wherein the leadwire is subjected to occasional high-power electromagnetic fields such as those produced by medical diagnostic equipment including magnetic resonance imaging.

An active implantable medical device (AIMD) feedthrough terminal assembly includes a plurality of wires extending from AIMD electronic circuitry, and a lossy ferrite inductor, the wires passing through the A lossy ferrite inductor for increasing the impedance of the wire at a selected RF frequency and reducing the magnetic flux core saturation of the lossy ferrite inductor through phase cancellation of the signal carried by the wire . Also provided is a process for filtering electromagnetic interference (EMI) of implanted leads extending from an AIMD into bodily fluids or tissue, wherein the leads are subjected to occasional high power electromagnetic fields, such as those produced by, for example, magnetic resonance imaging High power electromagnetic fields generated by medical diagnostic equipment.

A dual-frequency coaxial earphone includes a frame, a shared yoke, a high frequency speaker part, and a low frequency speaker part. The high frequency speaker part and the low frequency speaker part are coaxially arranged at inside and outside of the shared yoke, and are coaxial with a central opening of the frame. Further, a permanent magnet of the higher frequency speaker part is contrary, in polarity, to an annular magnet of the low frequency speaker part. Therefore, acoustic frequency of the low frequency speaker part can be phase-countered by passing thereof through an acoustic annular recess, so that the acoustic frequency of the low frequency speaker part has the same phase as the acoustic frequency of the high frequency speaker part and both then are output synchronally. The high frequency speaker part and the low frequency speaker part can then be separated, in acoustic frequency, from each other. This will effectively solve the problem of intermodulation of distortion for the high and low acoustic frequencies, and reduce the size of the earphone to more compact.

A phase cancellation circuit for a cavity filter including a sampler loop assembly arranged to receive an input signal, a variable loop assembly connected to the sampler loop assembly by a cable, wherein the variable loop assembly is arranged to transmit an output signal from cavity filter, wherein the sampler loop assembly samples a cancellation signal at an isolation frequency from the input signal and transmits the cancellation signal to the variable loop assembly via the cable, and, wherein the cable has a length equal to a multiple of a half-wavelength at the desired isolation frequency, wherein the cancellation signal undergoes a 180° phase shift by traveling through the cable, wherein the variable loop assembly combines the cancellation signal with the input signal to cancel the input signal at the isolation frequency due to the 180° phase shift for creating the output signal with a notch at the isolation frequency.

In a multi-phase power converter using a phase-locked loop (PLL) arrangement for interleaving of pulse frequency modulated (PFM) pulses of the respective phases, improved transient response, improved stability of high bandwidth output voltage feedback loop, guaranteed stability of the PLL loop and avoidance of jittering and phase cancellation issues are achieved by anchoring the bandwidth at the frequency of peak phase margin. This methodology is applicable to multi-phase power conveners of any number of phases and any known or foreseeable topology for individual phases and is not only applicable to power converters operating under constant on-time control, but is extendable to ramp pulse modulation (RPM) control and hysteresis control. Interleaving of pulses from all phases is simplified through use of phase managers with a reduced number of PLLS using hybrid interleaving arrangements that do not exhibit jittering even when ripple is completely canceled.

An ultrasonic diagnostic imaging system produces an image with an extended focal range by transmitting a plurality of beams spaced along an array for multiline reception. The receive multilines of a plurality of transmit beams are spatially aligned and are combined with phase adjustment between the respective receive multilines to prevent undesired phase cancellation. The combined multilines produce the effect of an extended transmit focus so that an image produced using the combined multilines exhibits an extended focal range. To prevent motion artifacts the multiline order is adjustable as a function of image motion.

The invention belongs to the technical field of loudspeakers, in particular to a thin type piezoelectric speaker with a novel piezoelectric ceramic wafer structure. The thin type piezoelectric speaker structurally comprises a vibration film, piezoelectric ceramic wafers adhered to the vibration film, electrodes on the surfaces of the piezoelectric ceramic wafers, and electrode leading wires connecting the electrodes with an external circuit, and a frame for restricting the vibration film. With the adoption of structure in which an integral piezoelectric ceramic wafer is changed by a plurality of ceramic wafers distributed regularly, the difficulty in the manufacturing process of the piezoelectric ceramic wafers is reduced, the middle-frequency characteristic of the piezoelectric loudspeaker provided by the invention is adjusted, the distortion of acoustic pressure level is reduced, the phase cancellation of middle-frequency sound radiation in the space is reduced and even eliminated, the levelness of acoustic pressure level frequency response curve of the piezoelectric loudspeaker is greatly improved, and the peaks and valleys of the middle-frequency acoustic pressure level frequency response curve can be eliminated under the situation that the parameters are appropriate. Therefore, the tone quality of the piezoelectric loudspeaker is better.

Conduit spacers useful in preparing duct banks with reduced electromagnetic fields (EMF) are disclosed. The conduit spacers are designed to maximize phase cancellation of EMF from a closely-spaced series of electric power cables placed in conduits supported underground by the conduit spacers. The spacers are also designed to minimize the EMF above ground by reducing the distance needed to bury the cables for a given EMF above ground. In one embodiment, the spacers place conduits adjacent one another for maximum cancellation of a single three-phase cable installation. In another embodiment, the spacers place conduits adjacent one another for maximum cancellation for a dual three-phase cable installation, including cross-phase cancellation, e.g., A-B-C and C-B-A.

Aspects and examples provide improvement in the attenuation level near the passband within the stopband of the bandpass-type filter using a ladder-type circuit formed by a BAW resonator. In one example the filter includes a ladder-type circuit formed by a bulk acoustic wave (BAW) resonator, and a loop circuit connected between two distinct points on a signal path extending from an input to an output of the ladder-type circuit for phase-cancellation of signals at the two distinct points. The two distinct points may be the input and the output of the ladder-type circuit. The loop circuit may include a SAW resonator or a BAW resonator. The BAW resonator may be a film bulk acoustic resonator (FBAR) or solidly mounted resonator (SMR).

The invention provides an open-ended coaxial probe and connection cable for measuring a dielectric spectrum property of biological tissues, and a corresponding instrument calibration method according to high-precision and wide-broadband measurement requirements on the dielectric property of in-vitro or in-vivo biological active tissues which are soft, small in volume and irregular in appearance. The open-ended coaxial probe comprises an inner conductor and an outer conductor which are concentrically arranged; the ratio of the radius of the inner conductor to the radius of the outer conductor is 3: 10; polytetrafluoroethylene is filled between the inner conductor and the outer conductor and a plating layer is arranged on the surface of the outer conductor. The connection cable is mainly composed of an N-type connector and a coaxial cable. The probe is calibrated by utilizing a phase cancellation method and is used for measuring the dielectric property of the biological active tissues at 1-200 MHz. Meanwhile, in order to increase the reliability of measured data, a calibration box which is used with the open-ended coaxial probe is provided; and a method for measuring the dielectric property of the biological tissues can be carried out by using the open-ended coaxial probe.

The invention belongs to the technical field of speakers, particularly relating to a thin piezoelectric speaker with a novel diaphragm structure. The structure of the speaker comprises a diaphragm, a piezoelectric ceramic wafer, an electrode, an electrode leading wire and a edge frame, wherein the piezoelectric ceramic wafer is adhered on the diaphragm; the electrode is arranged on the surface ofthe piezoelectric ceramic wafer; the electrode leading wire is connected with the electrode and an outer circuit; and the edge frame is used for restricting the diaphragm. The characteristics of the medium and low frequency section of the piezoelectric speaker are regulated through introducing single holes, single hole arrays, multiple holes, multiple hole arrays and porous symmetrical structureson the rectangular or round diaphragm, thus the distortion rate is reduced; the phase cancellation of medium-frequency range sound irradiation in space is lowered or eliminated; the evenness of the acoustic pressure level frequency response curve of the piezoelectric speaker is greatly improved; even if the acoustic pressure level at the distortion position is improved by above 25db, which is generated by the fact that the voltage applied on the frequency bandwidth of the distortion position is improved by 17 times, so that the sound quality of the piezoelectric speaker is better; and in addition, the rigidity and quality distribution of the diaphragm are improved, thus the output of the acoustic pressure of the speaker at the medium frequency range is obviously increased.

The design of a diaphragm for a rotary loudspeaker driver that all but eliminates phase cancellation and therefore eliminates the necessity of a box to acoustically isolate the front sound from the back. The key element of the design of the diaphragm is to use a cross section of at least three equal sides. This allows for the long sides of the diaphragm to create essentially positive pressure only as it rotates and creates a very rigid structure. Further by sizing the cross section to the width of the highest frequency to be produced you allow for a nearly perfect 360 degree radiation at all frequencies.

The invention discloses an adjacent harmonic and inter-harmonic separation and measurement method under an IEC (international electrotechnical commission) framework. The method includes the following steps: firstly, performing discrete sampling on a power grid signal; secondly, performing ten-cycle Hanning window addition DFT / FFT (discrete Fourier transform / fast Fourier transform) spectral transformation on a sampling value according to IEC standards so as to obtain a spectrum; thirdly, multiplying the spectrum by rotary phase factors to obtain a new spectrum; fourthly, solving a vector sum of neighboring spectral lines of the new spectrum so as to offset sidelobe interference of rest components on the new spectrum, and solving corresponding frequency, a frequency deviation value and amplitude phase via a spectral line phase cancellation interpolation method; fifthly, rejecting spectrum leakage values of a fundamental component and the rest components at spectral line attention positions on a frequency domain; sixthly, solving a harmonic spectrum value to obtain parameters of h subharmonics, and solving parameters of inter-harmonics adjacent to the h subharmonics. By the method, the problem that the parameters of the two adjacent harmonics and inter-harmonics cannot be measured accurately during limited data asynchronous sampling is solved.

Conduit spacers useful in preparing duct banks with reduced electromagnetic fields (EMF) are disclosed. The conduit spacers are designed to maximize phase cancellation of EMF from a closely-spaced series of electric power cables placed in conduits supported underground by the conduit spacers. The spacers are also designed to minimize the EMF above ground by reducing the distance needed to bury the cables for a given EMF above ground. In one embodiment, the spacers place conduits adjacent one another for maximum cancellation of a single three-phase cable installation. In another embodiment, the spacers place conduits adjacent one another for maximum cancellation for a dual three-phase cable installation, including cross-phase cancellation, e.g., A-B-C and C-B-A.

A universal noise controller is constructed of two windings on a magnetic core with a potentiometer connected across the windings. The input is connected in parallel to the windings and the potentiometer and the output is taken from a node in the center of the windings and a wiper arm of the potentiometer. This arrangement allows a phase change of 360 degrees by overlaying another signal thus providing phase cancellation from positive 180 degrees to negative 180 degrees thereby providing suitable noise cancellation based on the position of the wiper arm.

Tinnitus is defined as sound(s) heard by an individual when no external sound it present and often takes the form of a hissing, ringing, chirping or clicking sound which may be either intermittent or constant. According to the American Tinnitus Association, tinnitus affects tens of millions of Americans and many suffer so severely from tinnitus they are not able to function normally on a daily basis. Unfortunately the exact cause or causes of tinnitus are not understood by the medical community and thus many tinnitus sufferers are told by their doctors to “learn to live with if”.In accordance with novel aspects of Applicant's monofrequency tinnitus patient treatment apparatus and process, phase cancellation effects are achieved by utilizing an externally generated sound which is subjectively selected by the monofrequency tinnitus patient to match in both tone and loudness his or her tinnitus sound. This subjectively selected externally generated sound wave which matches in tone and loudness the patient's tinnitus sound, is either (i) sequentially phase shifted through a plurality of phase shift sequence steps totaling at least 180 degrees or (ii) alternatively is directly phase shifted in essentially a single step motion into a 180 degree, out-of-phase reciprocal, canceling relationship with the patient determined tinnitus tone. The sequential steps of the phase shifted tone or the directly phase shifted tone are applied to the tinnitus patient to effect cancellation or diminishment of the patient's tinnitus.

The invention discloses a distributed optical fiber sensing system, which comprises a narrow linewidth laser, a modulator, an optical isolator, an erbium-doped optical fiber amplifier, a circulator, an optical fiber grating, a sensing optical fiber, an optical detector, a microwave amplifier, a high pass filter, a power distributor, a first filter module, a first microwave detection module, a first low-frequency amplifier, a second filter module, a second microwave detection module, a second low-frequency amplifier, a data acquisition card and a computer. Distributed optical fiber vibration or sound signal measurement is realized, dynamic large-phase signal measurement is effectively realized, a phase cancellation and fading problem can be eliminated, a high-speed data acquisition device with a GS / s sampling rate is not needed, the cost is reduced, the response time is not influenced, the strength and the frequency shift changes of Brillouin scattering light can be measured respectively on the premise of eliminating instability of a laser source and line loss, and temperature changes and the strain are further obtained.

The invention discloses a self-adaptation four-port cancellation network structure and a self-adaptation cancellation method. The structure comprises an amplitude-phase cancellation network and a self-adaptation adjusting structure, wherein the amplitude-phase cancellation network comprises a coupler, an adjustable gain amplifier, an analog phase shifter, a power amplifier, a matched load and a attenuator, the aim that the transmitting chain is coupled with part of energy is achieved, amplitude phase adjustment is performed on a coupling signal, then, the amplitude of a received link coupler and the amplitude of a received same-frequency interference signal are approximately equal, the phase of the received link coupler and the phase of the received same-frequency interference signal are approximately opposite, finally, the amplitude of the received same-frequency interference signal is restrained to be on a lower level, and therefore the received channel carrier-to-noise ratio is improved. The self-adaptation adjusting structure comprises a coupler, a detector, a comparator matched load and a gain adjustable amplifier, the amplitude of the received same-frequency interference signal set on a parallel comparator public reference end is restrained to be the target level detection voltage, and a loop self-adaptation adjusting structure can automatically adjust the adjustable gain amplifier and the analog phase shifter in the amplitude phase cancellation network.

The design of a diaphragm for a rotary loudspeaker driver that eliminates phase cancellation and therefore eliminates the necessity of a box to acoustically isolate the front sound from the back. The key element of the design of the diaphragm is to use a cross section of at least three equal sides. This allows for the long sides of the diaphragm to create essentially positive pressure only as it rotates and creates a very rigid structure. Further by sizing the cross section to the width of the highest frequency to be produced you allow for a nearly perfect 360 degree radiation at all frequencies.

The invention discloses a phase-cancellation-based target detection method for clutter suppression of an agile coherent radar. The method comprises: carrying out sampling and pulse compression on a radar echo pulse signal to obtain a pulse pressure echo; carrying out clutter suppression on the pulse pressure echo by using a phase cancellation technique and carrying out phase correction on the echoby phase compensation; and then carrying out non-uniform Fourier transform and mean-like constant false alarm detection to realize coherent accumulation of the echo signal and moving target detection. Therefore, a problem that the clutter suppression can not be realized effectively because the Doppler frequency range of the clutter cannot be accurately estimated and no deep clutter depression canbe formed in the actual main clutter region while the echo data not sufficient in the prior art is solved. According to the invention, a deep clutter recession part can be formed in an actual main clutter region without massive echo data, so that clutters are suppressed effectively.

Conduit spacers useful in preparing duct banks with reduced electromagnetic fields (EMF) are disclosed. The conduit spacers are designed to maximize phase cancellation of EMF from a closely-spaced series of electric power cables placed in conduits supported underground by the conduit spacers. The spacers are also designed to minimize the EMF above ground by reducing the distance needed to bury the cables for a given EMF above ground. In one embodiment, the spacers place conduits adjacent one another for maximum cancellation of a single three-phase cable installation. In another embodiment, the spacers place conduits adjacent one another for maximum cancellation for a dual three-phase cable installation, including cross-phase cancellation, e.g., A-B-C and C-B-A.

A method for realizing RF switching circuit of high-degree insulation and low insertion loss comprises a phase offset channel arranged in parallel connection with regular switch device. The phase offset channel is composed of a closed switch device and a 180 degree phase delayer. The 180 degree phase delayer can be a half-wavelength RF transmission line or a 180 degree phase shifter. Due to the phase delaying and impedance converting functions of the half-wavelength RF transmission line, two insulation peak values, namely phase offset and parallel resonance can be generated within the working band frequency, thus enhancing the degree of insulation and ensuring larger working band. The 180 degree phase shifter may realize phase offset with a very wide frequency band to further broaden the working bandwidth. The method can be used in RF switch integrated circuit or regular circuit.

The invention refers to a broadband reflective phase cancelling network interface device. The network interface device includes a signal splitter which conducts CATV signals through an active branch circuit, the active branch circuit including an active signal conditioner which modifies characteristics of active branch signals conducted through the active branch circuit, a sensor connected to sense normal, inoperative and abnormally operative conditions, the sensor removing a control signal indicative of inoperative and abnormal operating conditions, a selectable switch connected to the active branch circuit, the selectable switch communicating the CATV signals between the CATV network and the subscriber devices when in an activated position, and the selectable switch passing the signals to a signal reduction path when in a deactivated position, the selectable switch assuming the deactivated position in response to the de-assertion of the control signal, and a phase cancellation circuit connected to the signal reduction path.

A novel ribbon microphone incorporates rounded-edge magnet motor assembly, a backwave chamber, and a phantom-powered JFET circuit. In one embodiment of the invention, one or more novel rounded-edge magnets may be placed close to a ribbon of the ribbon microphone, wherein the one or more novel rounded-edge magnets reduce or minimize reflected sound wave interferences with the vibration of the ribbon during an operation of the ribbon microphone. Furthermore, in one embodiment of the invention, a novel backwave chamber operatively connected to a backside of the ribbon can minimize acoustic pressure, anomalies in frequency responses, and undesirable phase cancellation and doubling effects. Moreover, in one embodiment of the invention, a novel phantom-powered JFET preamplifier gain circuit can minimize undesirable sound distortions and reduce the cost of producing a conventional preamplifier gain circuit.

A transceiver antenna has a transmit antenna coil defining a substantially closed transmit coil geometry circumscribing a transmit coil inner area. The transmit antenna coil is configured to conduct a current to generate a magnetic field. One or more receive antenna coils each define a closed receive coil geometry with a number of coil turns. The receive antenna coils are positioned to define one or more inner areas located within the transmit antenna coil inner area and one or more outer areas located outside of the transmit antenna coil. The inner areas and the outer areas of the receive antenna coil(s) are configured so that a first voltage induced by the transmit magnetic field into the outer areas of the receive antenna coils is attenuated by a second voltage induced by the transmit magnetic field into the inner areas of the receive antenna due to phase cancellation.

The invention discloses an environment-friendly sound insulation wall for communities. The wall includes a mortise, a sound insulation main body, a tenon and an active noise reduction system; the leftside of the mortise is provided with the sound insulation main body; the sound insulation main body is fixedly connected to the mortise; the left side of the sound insulation main body is provided with the tenon; the tenon is fixedly connected to the sound insulation main body; the internal of the tenon is provided with the active noise reduction system; the active noise reduction system is embedded in the tenon; the surface of the active noise reduction system is provided with a concave-convex noise attenuation board; and the concave-convex acoustical panel is tightly attached to the activenoise reduction system. The active noise reduction system is arranged at the internal, an acoustic wave generator can emit sound waves with an opposite phase and identical frequency and amplitude withregard to noise, so that phase cancellation can be realized, and noise can be radically eliminated; and the soundproof board is provided with the mortise and the tenon, and the mortise and the tenonare connected to each other through an embedded manner, so that the problem of infirm contact of joints can be well solved.

The invention relates to a method for improving low interception and interference resistance of a radar, which comprises the steps of constructing a frequency agile transmitted signal, performing pulse compression processing on a received echo signal, performing frequency agile signal phase cancellation processing, and performing frequency agile signal detection fusion processing. According to the method, every two adjacent target echoes after pulse compression are conjugated and multiplied, so that a phase interference term coupled with the number of transmitted pulses, the pulse transmitting time, the target distance and the speed in an echo signal is changed into a constant phase term, coherent processing and target detection can be further realized, and the adaptability of the algorithm is improved. Meanwhile, the method can realize coherent processing of echo matrixes of two frequency agile models, can realize fusion detection of detection results, and improves the anti-interference performance and adaptability of a signal processing algorithm. The method is suitable for low, medium and high repetition frequency modes, and has good expansibility.

A saddle of a multi-stringed instrument includes a highly efficient means of coupling to sensors, vibrations from plucked musical instruments strings. The saddle includes a downwardly extending body portion for mechanically conveying string vibrations to transducers by way of cavities beneath a string saddle that define a vertically compliant area of sensitivity. The vertically compliant area beneath each respective string is mechanically responsive to vertical string motion. These areas couple the strings to transducers mounted within said cavities, and are selectively sensitive to vertical string vibrations from the top of the saddle, beneath the string. The uni-directional sensitivity does not respond to vibratory information from beneath the saddle and is only sensitive from its top or positive Z axis direction. This eliminates the introduction of micro-phonic noise from the body of the instrument in the amplified signal. Isolating the vertical component of the string vibration further maximizes fidelity, clarity of sound and responsiveness. The cavities housing the transducers are arranged in alternating phase relationships to avoid phase cancellation effects between the adjacent transducers. A string saddle kit for a multi-stringed instrument includes multiple string saddle segments each providing a highly efficient means of coupling to sensors, vibrations from plucked musical instruments strings.