Texas Instruments Corporation

Sreekiran Samala

Karthik Subburaj

Raghu Ganesan

Karthik Ramasubramanian

Sriram Murali

Krishnanshu Dandu

Tom Altus

Krishnaswamy Nagaraj

Ajay Kumar

Indu Prathapan

Venkatesh Srinivasan

Vineet Mishra

Vijaya Bhaskar Rentala

Xiao Pu

Mahadevan Shankara Venkiteswaran

Shankar Narayanamoorthy

Anjan Prasad Eswaran

Daryl Barry

A radar transceiver includes a receiver. The receiver includes a low noise amplifier a mixer, a baseband filter, an integrator, and a phase shifter. The mixer includes an input coupled to an output of the low noise amplifier. The baseband filter includes an input coupled to an output of the mixer. The integrator includes an input coupled to an output of the baseband filter. The phase shifter includes a control input and an output. The control input is coupled to an output of the integrator.

Radar transceiver

In described examples, a frequency modulated continuous wave (FMCW) synthesizer includes a control engine, and a phase locked loop (PLL) including a frequency divider, a control voltage generator (CVG), and a voltage controlled oscillator (VCO). The frequency divider modifies a VCO output frequency based on a control input. The CVG generates a control voltage based on a frequency reference and the frequency divider output. The VCO outputs a FMCW output having the VCO output frequency in response to the control voltage. The control engine generates the control input so that the VCO output frequency: from a first time to a second time, is a first frequency; from the second time to a third time, changes at a first rate; from the third time to a fourth time, changes at a second rate different from the first rate; and from the fourth time to a fifth time, is a second frequency.

FMCW chirp bandwidth control

A noise-mitigated continuous-wave frequency-modulated radar includes, for example, a transmitter for generating a radar signal, a receiver for receiving a reflected radar signal and comprising a mixer for generating a baseband signal in response to the received radar signal and in response to a local oscillator (LO) signal, and a signal shifter coupled to at least one of the transmitter, LO input of the mixer in the receiver and the baseband signal generated by the mixer. The impact of amplitude noise or phase noise associated with interferers, namely, for example, strong reflections from nearby objects, and electromagnetic coupling from transmit antenna to receive antenna, on the detection of other surrounding objects is reduced by configuring the signal shifter in response to an interferer frequency and phase offset.

Noise mitigation in radar systems

A method of measuring phase noise (PN). A PLL frequency synthesizer is provided including a first phase frequency detector (PFD) receiving a reference frequency signal coupled to a first charge pump (CP) coupled to a VCO having an output fedback to the first PFD through a feedback divider that provides a divided frequency signal to the first PFD which outputs an error signal, and PN measurement circuitry including a replica CP coupled to an output of a second PFD or the first PFD. The error signal is received at the replica CP or the divided and reference frequency signal are received at the second PFD, wherein the replica CP outputs a scaled phase error current which is current-to-voltage converted and amplified to provide an amplified phase error voltage, and digitized to provide a digital phase error signal. The digital phase error signal is frequency analyzed to generate a PN measurement.

Dynamic measurement of frequency synthesizer noise spurs or phase noise

A method of frequency estimation. A clock output from a frequency synthesizer is received at an input of a ring encoder. The ring encoder generates outputs including a ring encoder output clock and an encoded output which represents LSBs of a clock cycle count of the clock output. A binary counter is run using the ring encoder output clock which provides an output count which represents MSBs of the clock cycle count. Using a reference clock, the encoded output is sampled to provide a sampled encoded output and the output count is sampled to provide a sampled output count. Error correcting is applied to the sampled encoded output to provide a corrected sampled encoded output. The corrected sampled encoded output and sampled output count are combined to provide a combined output which is used for estimating an instantaneous or average frequency of the clock output.

Frequency synthesizer output cycle counter including ring encoder

A testing device for FMCW radar includes an input for receiving a chirp signal generated by the radar. An IQ down-converter coupled to the input down-converts the chirp signal. A digitizer extracts digitized IQ signals from the down-converted chirp signal. A processor coupled to the digitizer determines at least one of frequency linearity and phase noise of the chirp signal.

Circuits and methods for determining chirp signal linearity and phase noise of a FMCW radar

Circuitry for providing an oscillating output signal. The circuitry comprises a transconductance circuit having a first input, a second input, and an output. The circuitry further comprises an oscillator circuit coupled to receive voltage from the output of the transconductance circuit, wherein the oscillating output signal is responsive to an output of the oscillator circuit. Also included are circuitry for providing a first voltage to the first input of the transconductance circuit and a frequency controlled circuit for providing a second voltage to the second input the transconductance circuit. The second voltage is response to a frequency of operation of the frequency controlled circuit, and the frequency of operation of the frequency controlled circuit is responsive to feedback from the output of the oscillator circuit.

Oscillator with frequency control loop

An inductive device is provided, which includes a substrate, a layer having a plurality of conductive metal traces and a metal shield layer. The conductive trace has an input port, a first portion, a second portion, a third portion and an output port. The metal shield layer is disposed between the substrate and the conductive trace. Each of the plurality of conductive metal traces has a respective length and a respective width. Each of the plurality of conductive metal traces are separated from one another. Each of the plurality of conductive metal traces are disposed perpendicularly with the first portion and the third portion. The metal shield layer provides spaced shield traces substantially perpendicular with the conductive metal traces.

IC rectangular inductor with perpendicular center and side shield traces

Oscillator circuits are disclosed herein. An embodiment of an oscillator circuit includes a first bias circuit and a second bias circuit. An oscillator first connection terminal is coupled to a node, wherein the node is coupled to the first bias circuit and the second bias circuit. An oscillator second connection terminal connected to the second bias circuit. An increase in the oscillation amplitude of the oscillator increases the current in the second bias circuit and causes a reduction in the bias current in the first bias circuit.

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Plano, TX, United States of America

Sreekiran Samala