Texas Instruments Corporation

Qualcomm Incorporated

University of Minnesota

Mohammad Elbadry

Robert Floyd Payne

Gerd Schuppener

Francesco Gatta

Marco Zanuso

Tsai-Pi Hung

Jingcheng Zhuang

Ramesh Harjani

Ravi Sridhara

Sachin Kalia

Satwik Patnaik

Yunliang Zhu

Bodhisatwa Sadhu

Martin D Sturm

A duty cycle correction circuit includes a charge pump and a controller. The charge pump includes a current source, a first output, and a second output. The charge pump routes current from the current source to the first output during a positive portion of a clock, and routes current from the current source to the second output during a negative portion of the clock. The controller compares charge accumulated from the first output to charge accumulated from the second output over a plurality of clock cycles to determine which of the positive portion of the clock and the negative portion of the clock is longer. The controller also generates a digital value that indicates an amount of adjustment to apply to a duty cycle of the clock based on which of the positive portion of the clock and the negative portion of the clock is longer.

Digital clock duty cycle correction

Digital clock-duty-cycle correction

Certain aspects of the present disclosure generally relate to techniques and circuits for phase correction, or at least adjustment, of multiple local-oscillator (LO) signals. For example, certain aspects provide an apparatus for phase adjustment. The apparatus generally includes a phase-locked loop (PLL), at least one frequency divider coupled to an output of the PLL, the at least one first frequency divider being external to the PLL, a phase adjustment circuit having an input coupled to an output of the frequency divider, and at least one mixer having an input coupled to at least one output of the phase adjustment circuit.

Local oscillator (LO) phase continuity

A phase discontinuity mitigation implementation within a phased lock loop (PLL) improves throughput of a radio access technology. The throughput is improved by maintaining a phase of the PLL while powering off some devices of the PLL, such as a local oscillator (LO) frequency divider. In one instance, when the PLL is powered down, one or more portions of a delta sigma modulator for the PLL are clocked with a reference clock for the PLL. This implementation maintains phase continuity when the first phase lock loop turns back on.

Phase continuity technique for frequency synthesis

A clock generator includes a duty cycle correction circuit. The duty cycle correction circuit includes a duty cycle detector. The duty cycle detector, includes a first programmable delay element and a controller. The first programmable delay element is configured to delay a clock signal. The controller is configured to vary an amount of delay applied to the clock signal by the first programmable delay element, and to apply a delayed version of the clock signal, provided by the first programmable delay element, to locate an edge of a different version of the clock signal and measure time during which the different version of the clock is high. The controller is also configured to generate a digital value that indicates an amount of adjustment to apply to a duty cycle of the clock signal based on measured time during which the different version of the clock is high.

A linear transform can be performed using a passive analog multi-stage charge re-use linear transform circuit. The passive analog multi-stage charge re-use linear transform circuit transforms an input analog circuit to generate a transformed analog output signal. The passive analog multi-stage charge re-use linear transform circuit may be included in a software defined radio (SDR), where the transformed analog output signal may be output to an analog-to-digital converter (ADC) of the SDR device so as to enable the ADC to perform wideband spectrum sensing. The passive analog multi-stage charge re-use linear transform circuit may also be included in a beamforming device so as to enable the device to perform spectral shifting and spatial shifting of signals. This passive analog multi-stage charge re-use linear transform circuit may promote reduced power consumption in comparison to other circuits while also supporting wideband applications at high sampling rates.

Pseudo true time delay for multi-antenna systems

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San Diego, CA, United States of America

Mohammad Elbadry