Abstract: Apparatuses, systems and methods associated with an instrument for testing of an audio device are described herein. In embodiments, a module to be coupled to an analyzer may be described. The module may include an antenna, communication circuitry coupled to the antenna, and processor circuitry coupled to the communication circuitry. The processor circuitry may be to receive an indication of a configuration for the module, configure the module in accordance with the configuration, cause the communication circuitry to establish a wireless connection between the module and a device under test (DUT), and cause the communication circuitry to perform a test procedure for the DUT via the wireless connection. Other embodiments may be described and/or claimed.

Abstract: Apparatuses, systems and methods associated isolation to avoid interference from wireless signals in a circuit assembly are disclosed herein. In embodiments, a wireless signal isolation assembly may include an outer shield enclosure, the outer shield enclosure to enclose circuitry of a circuit board that is to be isolated from interference, wherein the outer shield enclosure is to attenuate wireless signals. The wireless signal isolation assembly may further include a first inner shield enclosure located within the outer shield enclosure, the first inner shield enclosure to enclose first circuitry, wherein the first inner shield enclosure is to attenuate wireless signals. The wireless signal isolation assembly may further include a second inner shield enclosure located within the outer shield enclosure, the second inner shield enclosure to enclose second circuitry, wherein the second inner shield enclosure is to attenuate wireless signals. Other embodiments may be described and/or claimed.

Abstract: A method and apparatus for measuring channel characteristics of a multi-channel system. In accordance with the method and the apparatus, a first chirp is applied as an input to one channel of a multi-channel system at a first time, and a second chirp is applied as an input to another channel of the multi-channel system at a second time, the second time being separated from the first time by a predetermined first time interval. An output signal is acquired from a selected one of the channels. At least one crosstalk component is separated from non-crosstalk components in the output signal to characterize the selected channel based on non-crosstalk components. Preferably, the chirp is an exponential chirp that enables harmonic distortion components to be distinguished and measured in one channel in the presence of crosstalk from one or more other channels.

Abstract: An amplitude-compensated digital-to-analog converter circuit and method of compensation. A unipolar digital-to-analog converter is provided, having a reference connection and a pair of differential, unipolar signal outputs. A sensing circuit senses the common mode component of the differential outputs and produces a common mode signal. A reference source produces a first reference signal, and a differential control amplifier compares the common mode signal to the first reference signal and applies a second reference signal applied to the reference connection of the digital-to-analog converter, thereby stabilizing the reference current for the digital-to-analog converter. The circuit includes a single signal output reference to ground and a multiple-pole low-pass filter.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal. The multitone test signals a unique combination which is extracted at the output for identifying the source, or location, of the test signals.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A master-slave processor human interface system. An electronic device, a slave processor for controlling the electronic device and performing certain computational functions, a master processor for controlling the slave processor, an input device and an output device associated with the master processor, and an information storage device are provided. Individual slave processor programs are selected, retrieved from the information storage device, and loaded into the slave processor for implementing corresponding functions of the slave processor and electronic device, while a single master processor program which adapts itself to the selected slave processor program accepts input data and operational selections and displays output information according to a predetermined spatial arrangement for each such function, thereby providing the human interface.

Abstract: A method and apparatus for testing a digital signal processing system for the occurrence of bit errors. A mathematically-predictable test signal is applied to the input of a digital signal processing system The test signal components are removed from the output signal of the system by filtering, curve fitting or other techniques, leaving a resultant signal. The peak amplitude of the resultant signal is measured as an indication of the occurrence of errors. A time integrated measure of the resultant signal is made as an indication of the amount of noise and distortion artifacts. The peak amplitude is compared to a reference or the time integrated measure to identify errors. A histogram of the resultant signal amplitude may also be produced.

Abstract: A tunable bandpass filter system and filtering method wherein the bandwidth of a tunable bandpass filter is adjusted as a function of the fundamental frequency of an input signal. Either a constant bandwidth or a constant quality factor tunable bandpass filter may be used. The center frequency of the tunable bandpass filter is adjusted in direct proportion to the product of the fundamental frequency and the number of a selected harmonic thereof. In the case of a constant bandwidth filter the bandwidth is adjusted in direct proportion to the quotient of the fundamental frequency divided by a selected filter quality factor. In the case of a constant quality factor filter, the bandwidth is indirectly controlled by adjusting the center frequency while adjusting the quality factor in inverse proportion to the harmonic number. The output amplitude of the filter is measured to determine the amount of distortion in the input signal. The fundamental frequency may be determined by measuring the input signal.

Abstract: A hybrid form digital filter. A digital filter is provided wherein the zeros of its transfer function are provided by a direct form digital filter portion and the poles of the transfer function are provided by a normal form digital filter portion. The hybrid filter provides truncation noise and stability characteristics like those of a normal form digital filter, but its filter coefficients may be calculated more rapidly than those for a normal form digital filter having the same transfer function, thereby enabling the coefficients to be calculated in real time for tuning the filter. While the preferred embodiment is a second order hybrid digital filter, the same principles are applicable to higher order digital filters as well.

Abstract: A method and circuit for reducing the effect of variations in resistances within a multiplying digital-to-analog converter. A first resistor is connected at one end to the feedback resistor of the MDAC, the other end providing a compensated circuit input. A second resistor is connected from the MDAC input to the feedback resistor. The MDAC output to which the feedback resistor is internally connected is connected to the MDAC reference connection, the other output providing a compensated circuit output. The first and second resistors are chosen such that the product of their resistances is equal to the product of the feedback resistance times the MDAC input resistance.