Abstract: A microcontroller-based system for measuring the impedance of a device under test (DUT), responsive to a square wave stimulus, includes parallel stimulus signal paths, selectable by a switch, that can correspond to different stimulus frequency ranges. At least one of the paths includes an off-chip PLL and integer divider circuit to modify the frequency of the stimulus. A discrete Fourier transform executed by a processor is used to determine the impedance of the DUT at the stimulus frequency. Multiple frequencies can be analyzed at the same time by using a summation circuit and/or by analyzing odd harmonics of the stimulus frequency.

Abstract: A microcontroller-based system for measuring the impedance of a device under test (DUT) (35) responsive to a square wave stimulus. A clock generator circuit (26) in the microcontroller (20) generates a clock signal at a base clock frequency. A first timer (25) divides down the base clock frequency by a first frequency divisor integer to set the stimulus frequency of a square wave generated by a general purpose input/output (GPIO) function (24), and a second timer (28) divides down the base clock frequency by a second frequency divisor integer to set the sampling frequency of an analog-to-digital converter (ADC) (30). A discrete Fourier transform executed by a processor (22) is used to determine the impedance of the DUT at the stimulus frequency. The first and second integers are selected so that aliased harmonics fall in different DFT bins from the fundamental tone.

Abstract: A system includes a controller to provide at least one control output to an automated system in response to a control command received at a control input of the controller. The control output controls the operation of the automated system based on the control command. A signature analyzer generates the control command to the controller and receives an impedance signature related to a property of a material or object encountered by the automated system. The signature analyzer compares the impedance signature to at least one comparison signature to determine the property of the material or object. The signature analyzer adjusts the control command to the controller to control the operation of the automated system based on the determined property.

Abstract: A microcontroller-based system for measuring the impedance of a device under test (DUT), responsive to a square wave stimulus, includes parallel stimulus signal paths, selectable by a switch, that can correspond to different stimulus frequency ranges. At least one of the paths includes an off-chip PLL and integer divider circuit to modify the frequency of the stimulus. A discrete Fourier transform executed by a processor is used to determine the impedance of the DUT at the stimulus frequency. Multiple frequencies can be analyzed at the same time by using a summation circuit and/or by analyzing odd harmonics of the stimulus frequency.

Abstract: One example includes an ultrasonic ranging system. The system includes an ultrasonic transducer configured to transmit an ultrasonic signal and to receive reflected ultrasonic signal paths having been reflected from a plurality of target objects during a ranging operation. The system also includes a ranging processor configured to detect a location associated with the plurality of target objects based on monitoring phase information associated with the reflected ultrasonic signal paths.

Abstract: A phase rotator corrects the IQ imbalance in a wireless transceiver. The phase rotator is a part of a compensation system that detects and separates reception impairment images from transmission impairment images. The disclosed phase rotator introduces a phase shift between the transmission channel and the reception channel without perturbing the phase mismatch and the gain mismatch in the reception path. The phase rotator includes a first local oscillation (LO) circuit that generates a first LO signal at a first carrier frequency and a second LO circuit that generates a second LO signal at a second carrier frequency that deviates from the first carrier frequency for a phase rotation period. The phase rotation period is sufficiently long such that the frequency deviation can introduce a prescribed phase shift between the first LO signal and the second LO signal.

Abstract: A system includes a controller to provide at least one control output to an automated system in response to a control command received at a control input of the controller. The control output controls the operation of the automated system based on the control command. A signature analyzer generates the control command to the controller and receives an impedance signature related to a property of a material or object encountered by the automated system. The signature analyzer compares the impedance signature to at least one comparison signature to determine the property of the material or object. The signature analyzer adjusts the control command to the controller to control the operation of the automated system based on the determined property.

Abstract: A microcontroller-based system for identifying a paper type of a sample of paper from a measurement of its electrical impedance. An interdigital dielectric sensor (55) is deployed in the paper path of a printer (PTR), and the electrical impedance at the sensor, as affected by a sheet of paper (P) near the sensor, is measured over a plurality of frequencies of a stimulus signal. The stimulus signal may be sinusoidal or a square wave. The impedance characteristic, in magnitude or phase, or both, is compared against a plurality of reference impedance characteristics, each associated with a paper type, to identify the closest match and thus the type of paper of the sample sheet.

Abstract: A circuit for measuring an impedance of a device under test (DUT). The circuit includes: (i) circuitry for generating a stimulus wave at a stimulus frequency; (ii) an amplifier circuit coupled to the DUT to present a response signal from the DUT in response to the stimulus wave; (iii) switching circuitry for selectively coupling, between the stimulus wave and an input to the amplifier, either the DUT, a first calibration impedance, or a second calibration impedance. With the switching functionality, calibrations are performed so to provide a measure of impedance of the DUT in response to the plural calibrations.

Abstract: A microcontroller-based system for measuring the impedance of a device under test (DUT) (35) responsive to a square wave stimulus. A clock generator circuit (26) in the microcontroller (20) generates a clock signal at a base clock frequency. A first timer (25) divides down the base clock frequency by a first frequency divisor integer to set the stimulus frequency of a square wave generated by a general purpose input/output (GPIO) function (24), and a second timer (28) divides down the base clock frequency by a second frequency divisor integer to set the sampling frequency of an analog-to-digital converter (ADC) (30). A discrete Fourier transform executed by a processor (22) is used to determine the impedance of the DUT at the stimulus frequency. The first and second integers are selected so that aliased harmonics fall in different DFT bins from the fundamental tone.

Abstract: A phase rotator corrects the IQ imbalance in a wireless transceiver. The phase rotator is a part of a compensation system that detects and separates reception impairment images from transmission impairment images. The disclosed phase rotator introduces a phase shift between the transmission channel and the reception channel without perturbing the phase mismatch and the gain mismatch in the reception path. The phase rotator includes a first local oscillation (LO) circuit that generates a first LO signal at a first carrier frequency and a second LO circuit that generates a second LO signal at a second carrier frequency that deviates from the first carrier frequency for a phase rotation period. The phase rotation period is sufficiently long such that the frequency deviation can introduce a prescribed phase shift between the first LO signal and the second LO signal.

Abstract: A phase rotator corrects the IQ imbalance in a wireless transceiver. The phase rotator is a part of a compensation system that detects and separates reception impairment images from transmission impairment images. The disclosed phase rotator introduces a phase shift between the transmission channel and the reception channel without perturbing the phase mismatch and the gain mismatch in the reception path. The phase rotator includes a first local oscillation (LO) circuit that generates a first LO signal at a first carrier frequency and a second LO circuit that generates a second LO signal at a second carrier frequency that deviates from the first carrier frequency for a phase rotation period. The phase rotation period is sufficiently long such that the frequency deviation can introduce a prescribed phase shift between the first LO signal and the second LO signal.

Abstract: A phase rotator corrects the IQ imbalance in a wireless transceiver. The phase rotator is a part of a compensation system that detects and separates reception impairment images from transmission impairment images. The disclosed phase rotator introduces a phase shift between the transmission channel and the reception channel without perturbing the phase mismatch and the gain mismatch in the reception path. The phase rotator includes a first local oscillation (LO) circuit that generates a first LO signal at a first carrier frequency and a second LO circuit that generates a second LO signal at a second carrier frequency that deviates from the first carrier frequency for a phase rotation period. The phase rotation period is sufficiently long such that the frequency deviation can introduce a prescribed phase shift between the first LO signal and the second LO signal.

Abstract: A wireless receiver providing multiple services (FIG. 3) is disclosed. The wireless receiver includes an oscillator circuit (304, FIG. 4) arranged to produce a reference frequency (308). A first receiver (302) receives a first signal (300) having a first carrier frequency in response to the reference frequency. A second receiver (322) receives a second signal (320) having a second carrier frequency different from the first carrier frequency in response to the reference frequency.

Abstract: A matching network having a pi configuration between an antenna and another component in an RF circuit may be tuned by a process including computing the admittance of the antenna using measured reflection coefficients from three settings of the matching network, and identifying capacitance values for tuning the matching network. Capacitance values for an antenna side shunt and a circuit side shunt are found by computing target susceptance value for the shunts and comparing to a list of available susceptance values. The capacitance values corresponding to the available susceptances closest to the target susceptances are used to tune the antenna side shunt.

Abstract: A matching network having a pi configuration between an antenna and another component in an RF circuit may be tuned by a process including computing the admittance of the antenna using measured reflection coefficients from three settings of the matching network, and identifying capacitance values for tuning the matching network. Capacitance values for an antenna side shunt and a circuit side shunt are found by computing target susceptance value for the shunts and comparing to a list of available susceptance values. The capacitance values corresponding to the available susceptances closest to the target susceptances are used to tune the antenna side shunt.

Abstract: With high speed, high resolution time-interleaved (TI) analog-to-digital converters (ADCs), bandwidth mismatches between the various ADC branches can pose a significant problem. Previously, though, no adequate solution has been found. Here, a method and apparatus are provided that can calculate and compensate for bandwidth mismatches in a TI ADC, enabling a high speed, high resolution TI ADC to be produced.

Abstract: With high speed, high resolution time-interleaved (TI) analog-to-digital converters (ADCs), bandwidth mismatches between the various ADC branches can pose a significant problem. Previously, though, no adequate solution has been found. Here, a method and apparatus are provided that can calculate and compensate for bandwidth mismatches in a TI ADC, enabling a high speed, high resolution TI ADC to be produced.

Abstract: A wireless receiver providing multiple services (FIG. 3) is disclosed. The wireless receiver includes an oscillator circuit (304, FIG. 4) arranged to produce a reference frequency (308). A first receiver (302) receives a first signal (300) having a first carrier frequency in response to the reference frequency. A second receiver (322) receives a second signal (320) having a second carrier frequency different from the first carrier frequency in response to the reference frequency.