Phase-locked loop, radar system and method for randomizing initial phases of fmcw signals
AssigneeCalterah Semiconductor Technology (Shanghai) Co., Ltd.
InventorsJianwei YANG, Wenting ZHOU
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Abstract
Embodiments of the present disclosure disclose a phase-locked loop, a radar system and a method for randomizing initial phases of FMCW signals. The phase-locked loop includes a phase-locked loop circuit and a random control signal generator. In response to a clock signal indicating a respective target moment of one or more target moments, the random control signal generator inputs a random control signal to the phase-locked loop circuit, so that the accumulated value of the plurality of fractional frequency division values is converted into a random value, and that a plurality of phase differences respectively corresponding to the plurality of chirp signals form a non-arithmetic sequence.
Claims20
A phase-locked loop, comprising:
- a phase-locked loop circuit, having a first input port, a second input port, a third input port, and a fourth input port;
- and
- a random control signal generator, including a control port;
- wherein the phase-locked loop circuit is configured to generate a plurality of frequency-modulated continuous chirp signals;
- wherein, in response to a reference signal being input at the first input port, a feedback signal being input at the second input port, an integral frequency division value being input at the third input port, and a plurality of fractional frequency division values being input at the fourth input port,
- the phase-locked loop circuit is configured to generate a respective chirp signal of the plurality of frequency-modulated continuous chirp signals based on the reference signal and the feedback signal, and to perform frequency division on the respective chirp signal at a frequency division ratio obtained based on an accumulated value of the plurality of fractional frequency division values and on the integral frequency division value, to generate another feedback signal that is fed back to the second input port;
- and
- wherein there is a phase difference between a phase of a spurious signal and an initial phase of a main signal in each respective chirp signal of the plurality of chirp signals;
- and
- wherein in response to a clock signal being input at the control port and indicating a respective target moment of one or more target moments, the random control signal generator inputs a random control signal to the fourth input port of the phase-locked loop circuit, so that the accumulated value of the plurality of fractional frequency division values is converted into a random value, and that a plurality of phase differences respectively corresponding to the plurality of chirp signals form a non-arithmetic sequence.
A method for randomizing an initial phase of a frequency-modulated continuous wave (FMCW) signal, applicable to a phase-locked loop including a phase-locked loop circuit, the method comprises:
- receiving a reference signal and a feedback signal at the phase-locked loop circuit;
- generating, by the phase-locked loop circuit, a respective chirp signal of a plurality of frequency-modulated continuous chirp signals, wherein there is a phase difference between a phase of a spurious signal and an initial phase of a main signal in each respective chirp signal of the plurality of chirp signals;
- receiving an integral frequency division value and a plurality of fractional frequency division values to the phase-locked loop circuit;
- performing, by the phase-locked loop circuit, frequency division on the plurality of chirp signals at a frequency division ratio obtained based on an accumulated value of the plurality of fractional frequency division values and on the integral frequency division value, to generate another feedback signal;
- and
- receiving a random control signal at the phase-locked loop circuit at each target moment of one or more target moments, to randomize the accumulated value, such that a plurality of phase differences respectively corresponding to the plurality of chirp signals form a non-arithmetic sequence.
Dependencies are inferred from the claim text.