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 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 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 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.