An object detection system for autonomous vehicle, comprising a radar unit and at least one ultra-low phase noise frequency synthesizer, is provided. The radar unit configured for detecting the presence and characteristics of one or more objects in various directions. The radar unit may include a transmitter for transmitting at least one radio signal; and a receiver for receiving the at least one radio signal returned from the one or more objects. The ultra-low phase noise frequency synthesizer may utilize Clocking device, Sampling Reference PLL, at least one fixed frequency divider, DDS and main PLL to reduce phase noise from the returned radio signal. This proposed system overcomes deficiencies of current generation state of the art Radar Systems by providing much lower level of phase noise which would result in improved performance of the radar system in terms of target detection, characterization etc. Further, a method for autonomous vehicle is also disclosed.

A signal generator. A voltage controlled oscillator generates a signal that is fed to a comb generator, e.g., a nonlinear transmission line. A tone, from among a comb of tones at the output of the comb generator, is selected by a bandpass filter, its frequency is divided, e.g., by a direct digital synthesizer, and the result is compared, e.g., by a phase and frequency detector that receives a reference signal at its other input. The output of the phase and frequency detector is fed back, e.g., through a lowpass filter, to the voltage controlled oscillator.

The disclosed embodiments relate to a system that controls a phase-locked loop (PLL), eliminating harmonic locking issues during subsampling operation and achieving better noise performance. During operation, the system performs a procedure to measure a first duty cycle that indicates a relationship between a reference signal, which has a frequency F.sub.REF, and a voltage-controlled oscillator (VCO) output signal, which has a frequency F.sub.VCO and is generated by a VCO. The system also performs the procedure to measure a second duty cycle that indicates a relationship between a second reference signal (with a frequency of c*F.sub.REF) and the VCO-output signal. Next, the system determines a frequency and phase relationship between the reference signal and the VCO-output signal based on the first and second duty cycles. Finally, the system uses the frequency and phase relationship to adjust the VCO so that the VCO-output signal, which is used as an output of the PLL, is frequency and phase aligned with the reference signal.

The disclosed embodiments relate to a system that controls a phase-locked loop (PLL), eliminating harmonic locking issues during subsampling operation and achieving better noise performance. During operation, the system performs a procedure to measure a first duty cycle that indicates a relationship between a reference signal, which has a frequency F.sub.REF, and a voltage-controlled oscillator (VCO) output signal, which has a frequency F.sub.VCO and is generated by a VCO. The system also performs the procedure to measure a second duty cycle that indicates a relationship between a second reference signal (with a frequency of c*F.sub.REF) and the VCO-output signal. Next, the system determines a frequency and phase relationship between the reference signal and the VCO-output signal based on the first and second duty cycles. Finally, the system uses the frequency and phase relationship to adjust the VCO so that the VCO-output signal, which is used as an output of the PLL, is frequency and phase aligned with the reference signal.

Techniques for generating signals with arbitrary noise shaping are discussed. One example apparatus configured to be employed within a transmitter can comprise a noise shaper configured to: receive an input signal x.sub.q; and apply noise shaping to the input signal x.sub.q to generate a noise shaped output signal y.sub.q, wherein an in-band noise of the noise shaped output signal y.sub.q is below an in-band noise threshold of a spectral mask associated with the noise shaper, wherein an out-of-band noise of the noise shaped output signal y.sub.q is below an out-of-band noise threshold of the spectral mask, and wherein a noise of the output signal y.sub.q in each of a plurality of bandpass regions is below an associated noise threshold for that bandpass region of the spectral mask.

Techniques for generating signals with arbitrary noise shaping are discussed. One example apparatus configured to be employed within a transmitter can comprise a noise shaper configured to: receive an input signal x.sub.q; and apply noise shaping to the input signal x.sub.q to generate a noise shaped output signal y.sub.q, wherein an in-band noise of the noise shaped output signal y.sub.q is below an in-band noise threshold of a spectral mask associated with the noise shaper, wherein an out-of-band noise of the noise shaped output signal y.sub.q is below an out-of-band noise threshold of the spectral mask, and wherein a noise of the output signal y.sub.q in each of a plurality of bandpass regions is below an associated noise threshold for that bandpass region of the spectral mask.

Provided are apparatus including a signal processing circuit. The signal processing circuit may be configured to process an input signal having an input bandwidth spanning a range of input radio frequencies, and may include a local oscillator to produce a local oscillator signal. In one embodiment, the signal processing circuit can include a staring mode of operation. In one embodiment, the signal processing circuit can include a selective mode of operation. In one embodiment, the signal processing circuit can include a staring mode of operation and a selective mode of operation.

Provided are apparatus including a signal processing circuit. The signal processing circuit may be configured to process an input signal having an input bandwidth spanning a range of input radio frequencies, and may include a local oscillator to produce a local oscillator signal. In one embodiment, the signal processing circuit can include a staring mode of operation. In one embodiment, the signal processing circuit can include a selective mode of operation. In one embodiment, the signal processing circuit can include a staring mode of operation and a selective mode of operation.

An object detection system for autonomous vehicle, comprising a radar unit and at least one ultra-low phase noise frequency synthesizer, is provided. The radar unit configured for detecting the presence and characteristics of one or more objects in various directions. The radar unit may include a transmitter for transmitting at least one radio signal; and a receiver for receiving the at least one radio signal returned from the one or more objects. The ultra-low phase noise frequency synthesizer may utilize Clocking device, Sampling Reference PLL, at least one fixed frequency divider, DDS and main PLL to reduce phase noise from the returned radio signal. This proposed system overcomes deficiencies of current generation state of the art Radar Systems by providing much lower level of phase noise which would result in improved performance of the radar system in terms of target detection, characterization etc. Further, a method for autonomous vehicle is also disclosed.

An object detection system for autonomous vehicle, comprising a radar unit and at least one ultra-low phase noise frequency synthesizer, is provided. The radar unit configured for detecting the presence and characteristics of one or more objects in various directions. The radar unit may include a transmitter for transmitting at least one radio signal; and a receiver for receiving the at least one radio signal returned from the one or more objects. The ultra-low phase noise frequency synthesizer may utilize Clocking device, Sampling Reference PLL, at least one fixed frequency divider, DDS and main PLL to reduce phase noise from the returned radio signal. This proposed system overcomes deficiencies of current generation state of the art Radar Systems by providing much lower level of phase noise which would result in improved performance of the radar system in terms of target detection, characterization etc. Further, a method for autonomous vehicle is also disclosed.