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, and a frequency division value input port;
- and
- a random control signal generator, including a control port configured to receive a clock signal;
- 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, a frequency division value being input at the frequency division value input port, the frequency division value having an integral part and a fractional part, the fractional part being an accumulated value of a plurality of fractional frequency division values,
- 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 the 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 the respective chirp signal, the spurious signal being generated in response to the respective chirp signal being subjected to instantaneous phase changes caused by variation of the frequency division value between an integer and a next integer;
- and
- wherein in response to the clock signal reaching a target moment, the random control signal generator is configured to send a random control signal to the frequency division value input port of the phase-locked loop circuit, causing the accumulated value of the plurality of fractional frequency division values to be converted into a random value, and a plurality of phase differences respectively corresponding to the plurality of chirp signals to 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 the respective chirp signal of the plurality of chirp signals, the spurious signal being generated in response to the respective chirp signal of the plurality of chirp signals being subjected to instantaneous phase changes caused by variation of a frequency division value between an integer and a next integer, the frequency division value including an integer part and a fractional part, the fractional part being an accumulated value of a plurality of fractional frequency division values;
- receiving the frequency division value;
- performing, by the phase-locked loop circuit, frequency division on the plurality of chirp signals at a frequency division ratio obtained based on the frequency division value;
- and
- randomizing the accumulated value, such that a plurality of phase differences respectively corresponding to the plurality of chirp signals form a non-arithmetic sequence, in response to receiving a random control signal at the phase-locked loop circuit at a target moment.
Dependencies are inferred from the claim text.