Abstract: Methods and systems disclosed herein use acoustic energy to determine a gap between a wafer and an integrated circuit (IC) processing system and/or determine a thickness of a material layer of the wafer during IC processing implemented by the IC processing system. An exemplary method includes emitting acoustic energy through a substrate and a material layer disposed thereover. The substrate is positioned within an IC processing system. The method further includes receiving reflected acoustic energy from a surface of the substrate and a surface of the material layer disposed thereover and converting the reflected acoustic energy into electrical signals. The electrical signals indicate a thickness of the material layer.

Abstract: A sensor system may be used to measure characteristics of an object in a wellbore. The sensor system may include an ultrasonic transducer that generates an ultrasonic wave in a medium of the wellbore and detects a reflection signal of the ultrasonic wave off the object in the wellbore. The sensor system may also include a processing device and a memory device in which instructions are stored. The memory may include instructions that cause the processing device to receive the reflection signal from the ultrasonic transducer, and to truncate and preprocess the reflection signal to generate a truncated reflection signal. The instructions may also cause the processing device to apply time gain compensation to the truncated reflection signal and determine an echo wavelet from the time gain compensated signal representing an echo of the ultrasonic wave off of a wall of the wellbore.

Abstract: An audio signal processing method includes: controlling the volume of a digital audio signal according to a latest value of an adaptive gain value which is adjustable; detecting whether data carried by the digital audio signal satisfies a specific criterion and utilizing a pendulum counter to count a number of times the data carried by the digital audio signal satisfies the specific criterion; if the counter value of the pendulum counter reaches an upper bond, selectively decreasing the adaptive gain value according to a decrement to decrease the volume of the digital audio signal; and if the counter value of the pendulum counter reaches a lower bond, selectively increasing the adaptive gain value according to an increment to increase the volume of the digital audio signal, where the magnitude of the decrement and the magnitude of the increment are different from each other.

Abstract: An automatic gain controller and the controlling method thereof are disclosed. The automatic gain controller includes a first multiplexer for receiving an input signal and a gain and generating a first output, a second multiplexer for receiving a signal time constant and a gain time constant and generating a second output, a filter electrically connected to the first multiplexer and the second multiplexer for generating one of a signal-energy and an actual gain in response to the first output and the second output, a signal-energy processing device electrically connected to the filter, the first multiplexer and the second multiplexer for generating the gain and the gain time constant in response to the signal-energy, and a multiplier electrically connected to the filter for multiplying the actual gain by the input signal to generate an output signal.

Abstract: Apparatus and methods for performing automatic gain control in a radar system. One embodiment of the system includes an attenuator that controls gain of signals received from a radar receiver. A digital signal processor determines coarse gain correction based on digitized noise data for a plurality of channels, determines fine gain correction based on the residual error after the coarse gain, and determines frequency vs. gain curve correction based on the digitized noise data for a plurality of channels and a mathematical model of frequency gain across a noise spectrum for the radar system. The result of the processor is a gain control signal that is sent to the attenuator to perform hardware gain control and a channel specific scale factor for software gain control. In one embodiment, the processor generates the gain control signal during an inactive scan mode of the radar system.

Abstract: A container having a port for holding a liquid medium and a reactant that interact to produce a change in gas levels within the container. A removable stopper for insertion into the port creating an airtight seal. A tube extending through the stopper into the container having a distal end for being submerged in the liquid medium for receiving the liquid medium and monitoring a change in the level of the liquid medium within the container. A controller is provided extending through the stopper into the container for setting the liquid medium at a level within the tube, wherein the controller is operable to direct the liquid medium into the tube to a desired level so that a change in gas levels caused by the interaction of the reactant with the liquid medium can be monitored through a change in the level of the liquid medium within the tube.

Abstract: A device and method are provided for fully realizing the precision gained internally from a conventional digital signal processor by generating a feed forward automatic gain control (AGC) signal. The feed forward AGC bit is indicative of the output of the digital signal processor being multiplied by a gain factor when the output from the digital filter included in the digital signal processor is below a threshold value. When the feed forward AGC signal is received by an inphase and quadrature (I/Q)-to-(logR/.phi.) converter connected to the digital signal processor, a corresponding value is subtracted from the radius component of the signal calculated by the (I/Q)-to-(logR/.phi.) converter. Because conventional digital signal processors have 16 IO bits, the feed forward AGC signal allows an input signal with a dynamic range and precision exceeding 16 bits to be transferred from the digital signal processor without loosing performance.

Abstract: A transducer circuit which includes a Wheatstone bridge balanced by negative integral feedback. The bridge includes responsive elements formed on a thin resilent diaphragm. When subjected to a force, the diaphragm deflects and unbalances the bridge. The unbalanced bridge produces an output voltage which drives an integrator having an output voltage that is an integral of the bridge output voltage. The integrator output voltage is applied to the bridge as negative feedback to rebalance the bridge. The integrator includes a capacitor which introduces a time delay to assure that the feedback is always negative. The negative feedback provides stability for the circuit. The integrator output voltage drives indicating and/or auxiliary devices. The complete transducer circuit may be disposed within a sealed module having the diaphragm as a surface.

Abstract: A sensing apparatus for sensing at least two physical quantities is disclosed. The sensing apparatus includes a first transducer that provides a first output signal proportional to a first measured quantity represented and a second transducer that provides a second output signal proportional to a second measured quantity. An excitation regulator device is connected to the first transducer and the second transducer. The excitation regulator device provides an excitation signal to the second transducer so that the second transducer output signal is referenced to the first transducer output signal in order to obtain a resultant output signal which is a combination of the first and second output signals.

Abstract: A method for the detection and evaluation of faults existing on the walls of metal tubes having internal helical ribs includes for each fault signal received by an ultrasonic emitter-receiver ER, the length of the to-and-fro travel completed by the ultrasonic beam corresponding to the signal is determined and after the amplitude of the signal has been compared with a specific threshold, a correction is applied to one of the terms of the comparison, taking into account the length of travel completed by the signal.

Abstract: A method and apparatus are provided for gain control in a Doppler or other scan system which projects a plurality of scan lines at a given angle to determine velocity of movement of a predetermined medium at the angle. A training line is generated at the angle of the scan lines, the training line being utilized to determine portions of the scan line which are in a flow medium of interest, such as blood, and portions of the scan line which are in clutter. Information from the training line is then utilized to control the gain of the scan lines so that the gain is substantially maximized when scan lines are in the flow medium, while being reduced so as not to saturate the system in general, and A/D converters in particular, when in clutter. When an image line is utilized in the system, this line may also function as the training line.

Abstract: Time gain compensation is provided on an automatic basis by storing an amplification gain function for an amplifier operating on the received signals and automatically varying the function until the intensity versus time functions of the received signal is substantially flat.

Abstract: An improved ultrasound transceiver providing enhanced imaging by selective filtering of the received signal to provide a variable frequency, constant bandwidth filtering of the received echo signals. The transceiver provides a constant bandwidth filtering by upconverting the received signals to a higher incremented frequency, which is thereafter detected. The resulting signals are then displayed wherein the number of false multiple images is reduced, and the signal quality from the deeper tissue discontinuities is enhanced. The resulting signal is thereafter post-processed to provide enhanced information which is used to display structural features.

Abstract: An ultrasound transceiver providing enhanced imaging by selective filtering of the received signal to provide a variable frequency, constant bandwidth filtering of the received echo signals. The resulting signals are then detected to produce a signal, which when displayed, has a reduced number of false multiple images and enhanced signal quality from the deeper tissue discontinuities. Additionally, the received signal is detected in quadrature by reference to a simulated carrier pilot tone having a nonconstant frequency relationship to the transmitted signal. The resulting signal is post-processed to provide information which is used to display structural features, and in addition, the velocity profile of blood flow. The structure and velocity image information is superimposed to provide a composite signal wherein the static and dynamic characteristic of a patient is completely reported to the observer.

Abstract: An ultrasonic, echo-ranging instrument for measuring the level of liquid in an open channel or tank. The instrument includes a transducer disposed at a fixed position directly above the liquid surface, the nature of the gaseous environment therebetween determining the velocity of ultrasonic energy propagated therethrough. The transducer is excited to emit periodic pulses which are intercepted by the liquid surface and by a reference point a fixed distance from the transducer to produce both reference and liquid echo pulses that are returned to the transducer and detected thereby. The respective transit times of the reference echo and the liquid echo pulses are determined, and the ratio between these transit times is computed to provide an output representing the level of liquid independent of changes in the gaseous environment. To ensure accurate readings, the reference echo and liquid echo pulses from the transducer are fed to a single automatic gain control circuit whose operation is time shared.

Abstract: An ultrasonic non-destructive testing apparatus of the electronic scanning type comprising transmitter for producing exciting pulses in response to a predetermined timing pulse, a probe coupled to said transmitter, having a plurality of transducers for transmitting ultrasonic waves into a body to be tested and for receiving ultrasonic echo waves, signal processor coupled to said probe for processing said ultrasonic echo waves received by said probe to generate an echo wave signal, a memory coupled to said signal processor for storing reference data on an amplitude attenuation of an ultrasonic echo coming through each beam propagating path which is obtained by transmitting the ultrasonic waves into a calibration body at the time of a calibration, calculator coupled to said memory for calculating a predetermined correction value on the basis of said reference data stored in said memory, said predetermined correction value being at each crossing points on a two dimensional coordinate by applying a linear interpo

Abstract: The invention relates to an ultrasonic test instrument, in which a receiver amplifier is controlled in dependence upon time by means of a depth compensation signal or else the ultrasonic signal amplified independently of the depth is evaluated by means of a time-dependent variable threshold signal. The depth compensation signals and the time-dependent threshold signals are derived from the same digital signal values stored in a main memory. The test instrument comprises a microprocessor by means of which the digital signal values for each material requiring testing are automatically measured by the instrument itself in conjunction with whichever test probe is used provided a corresponding test block of this material is available.

Abstract: A time gain control (TGC) signal for a variable gain amplifier in an ultrasonic scanner is derived by determining the attenuation at many levels in the object under examination and then constructing the TGC signal based on the cumulative attenuation of an ultrasonic signal through the object. A zero crossing detector such as a Schmitt triggered monostable multivibrator receives a reflected ultrasonic wave signal and generates pulses which are counted during time intervals corresponding to a depth level in the object. By comparing the zero crossing density at one level to the zero crossing density at another level a measure of attenuation between the two levels is obtained.

Abstract: In an ultrasonic wave distance detection system, an ultrasonic wave pulse radiated into the selected area is reflected on an object. Said reflected ultrasonic wave pulse is partly received by an ultrasonic wave transducer. The received signal is supplied to a variable gain amplifier, noise components are removed from the amplified signal through a band pass filter, the noise removed signal is detected by an envelope detector, the detected signal is compared with a predetermined level by a comparator, and the output of the comparator is applied to a flip-flop circuit.As the gain of the variable gain amplifier is set to be a lower level only at the beginning of the ultrasonic wave pulse to minimize the amplification of unnecessary signals without reducing the detection efficiency, a signal can be surely obtained which has a pulse width corresponding to the distance between the system and the object and thus the distance can be detected or measured.

Abstract: An ultrasonic flow rate measuring system in which a pulse of ultrasonic energy is emitted by a transducer placed on a pipe conducting the fluid to be metered, the energy being propagated through the fluid and being picked up by a second transducer at a different pipe position. The received signal burst includes a first pulsatory swing whose amplitude differs from subsequent swings, the signal burst being applied to the input of an amplifier having automatic-gain control. A clamp circuit coupled to the amplifier input is rendered operative immediately after the first swing is yielded in the amplifier output, the clamp acting to ground the input whereby the operative control level and the resultant gain of the amplifier is determined solely by the first swing.

Abstract: A device for measuring the level of a variable signal delivered by a sensor. It comprises a series of attenuators, receiving the signal from the sensor, a squaring and integrating chain for converting the value of the signal delivered by the attenuators into its root-mean-square value, and a recorder. The attenuations are calibrated in dB. The device comprises an AGC circuit, receiving the output signal from the squaring and integrating chain, for switching the attenuators and controlling the recorder. The output signal from the attenuators is maintained constant.

Abstract: In a receiver for pulsed ultrasonic beams, it is sometimes desirable to translate the received signal to a lower carrier frequency by a heterodyne process. It is also often desirable to vary the receiving channels' gain during the period when signals are being received from a single transmitted pulse, to compensate for the attenuation of later-arriving signals from a greater distance. To get both the heterodyne and the time-gain control functions in a prior-art receiver of N channels requires 2 mixers in each channel, or 2N mixers. According to the invention, the heterodyne and the time-gain control signals are combined in one master mixer and fed to all the channel mixers. The only N+1 mixers are required.

Abstract: An ultrasound examination apparatus comprises a processing circuit for echo signals from a mosaic of ultrasonic transducers which are made of an electrostrictive material with a non-remanent polarization. These signals are applied to processing channels which comprise coupling means (10i) for coupling the electrodes of the transducers to a circuit (20) for generating a polarization voltage ramp whose waveform is the inverse of that of the attenuation curve of the ultrasonic signals in the structures examined. These coupling means, for example, an RC circuit (11i, 12i) or a transformer (13i) enable the polarization voltage to be applied to the electrodes while inhibiting the transmission to the part of the processing channels which is situated behind the coupling means.

Abstract: Time gain compensation is provided in an ultrasonic scanner by storing a digital code in memory representing the desired signal gain for intervals of time during the reflected wave. Gain compensation due to transducer parameter can be provided in digital form in a separate memory, and the outputs of the two memories are combined and applied to a digital to analog converter. The resulting analog control signal is preferably filtered and then applied as a control signal to a gain control amplifier.

Abstract: For use in an ultrasonic pulse-echo apparatus including an ultrasonic wave transducer for transmitting an ultrasonic wave into an object to be examined and for producing a first image signal corresponding to echo pulses reflected from the interior of the object, an improved signal processing means for compensating for brightness varying effects caused by varying the object and for providing a second image signal corresponding to the first image signal, and an X-Y type display device for displaying the image of the object from the second image signal. Compensation for the brightness varying effect is secured by a gain controlled amplifier of which the gain is controlled by a control signal corresponding to the cumulative second image signal of the preceding frame.

Abstract: A function generator provides a voltage vs. time curve which is also applied to the oscilloscope and is adjusted by the operator to conform to the peak amplitudes of the displayed electrical pulses. During subsequent testing, this voltage function is applied to a control signal generator which, in accordance with a predetermined relationship, modifies the voltage function into a control signal which is applied to the receiver. The control signal varies the receiver gain with time to attenuate and equalize the displayed pulses to a preselected amplitude.The equalized pulses corresponding to the equal sized reflectors are dependent upon only the size of the reflector and are independent of the depth of the discontinuities within the test blocks. As a result of the adjustment to the receiver gain by the control signal, the magnitudes of all displayed echo pulses from workpieces subsequently tested by the system will be dependent only upon the sizes of the corresponding discontinuities in the workpieces.

Abstract: An ultrasonic diagnostic apparatus is provided comprising a clock pulse generator, and electro-acoustic transducer which responds to the clock pulse from the clock pulse generator to produce an ultrasonic wave, a receiving circuit for receiving the electrical signal from the electro-acoustic transducer, a variable gain amplifier for amplifying the output signal from the receiving circuit, a display device for displaying information corresponding to the signal from the amplifier, and a gain control circuit for controlling the gain of the variable gain amplifier.

Abstract: An echoscope for examination of objects with the aid of an ultrasound beam, comprising at least one electro-acoustic element for transmitting and receiving ultrasonic pulses during a transmission-reception period divided into n consecutive time intervals. The ultrasonic pulses are sent to the objects to be examined and are reflected therefrom. The echo signals supplied by the receiving element are amplified by an amplifier with time-dependent gain control. The gain control is brought about by a control voltage generator which supplies a control voltage to said amplifier for determining its signal gain as a function of time. Adjusting means for the control voltage generator are provided to make it possible to change the magnitude of the control voltage in the time intervals as a function of time. The apparatus also comprises a device for visually displaying the echo signals received during each transmission-reception period.