CN112600555B - Method for generating frequency modulation continuous wave signal - Google Patents
Method for generating frequency modulation continuous wave signal Download PDFInfo
- Publication number
- CN112600555B CN112600555B CN202011223628.XA CN202011223628A CN112600555B CN 112600555 B CN112600555 B CN 112600555B CN 202011223628 A CN202011223628 A CN 202011223628A CN 112600555 B CN112600555 B CN 112600555B
- Authority
- CN
- China
- Prior art keywords
- frequency
- voltage
- controlled oscillator
- continuous wave
- array
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 25
- 238000003491 array Methods 0.000 claims abstract description 20
- 230000010355 oscillation Effects 0.000 claims abstract description 11
- 230000000737 periodic effect Effects 0.000 claims abstract description 11
- OIGNJSKKLXVSLS-VWUMJDOOSA-N prednisolone Chemical compound O=C1C=C[C@]2(C)[C@H]3[C@@H](O)C[C@](C)([C@@](CC4)(O)C(=O)CO)[C@@H]4[C@@H]3CCC2=C1 OIGNJSKKLXVSLS-VWUMJDOOSA-N 0.000 claims description 3
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 claims 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 239000000306 component Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
- H03L7/00—Automatic control of frequency or phase; Synchronisation
- H03L7/06—Automatic control of frequency or phase; Synchronisation using a reference signal applied to a frequency- or phase-locked loop
- H03L7/08—Details of the phase-locked loop
- H03L7/099—Details of the phase-locked loop concerning mainly the controlled oscillator of the loop
Landscapes
- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
Abstract
The invention is a method for producing frequency modulation continuous wave signal, it includes the frequency synthesizer, the frequency synthesizer includes the voltage controlled oscillator, has integral/decimal frequency divider, frequency discriminator, etc. of FMCW signal generator, the above-mentioned components form the frequency synthesizer of the closed loop; the method comprises the following steps: s1, controlling the output frequency of a voltage-controlled oscillator, and dividing the whole frequency tuning range into 2 N frequency arrays; wherein the overall frequency tuning range is from a minimum oscillation frequency F min to a maximum oscillation frequency F max; s2. The FMCW signal generator generates a corresponding periodic frequency step change value F step according to the instruction given by the system and combined with the frequency control phase of the voltage controlled oscillators of 2 N frequency arrays, and drives the voltage controlled oscillators to generate the frequency modulated continuous wave signal through the closed-loop frequency synthesizer. The beneficial effects of the invention are as follows: the phase noise performance of the voltage controlled oscillator and the entire FMCW generator can be improved.
Description
Technical Field
The application relates to the technical field of electronic equipment and electronic devices, in particular to a method for generating a frequency modulation continuous wave signal, which is applied to the field of radar communication.
Background
A frequency modulated continuous wave signal source is a core component of a frequency modulated continuous wave radar, and the noise level of the signal source has a direct impact on the performance of the radar communication system. A conventional frequency-modulated continuous wave signal generator uses the loop frequency locking characteristic of a frequency synthesizer and the principle of voltage-to-frequency conversion of a voltage-controlled oscillator to periodically change a frequency divider in the frequency synthesizer, and simultaneously, the frequency of the voltage-controlled oscillator is locked again every time the frequency divider is changed, so that a frequency-modulated continuous wave signal with a specific pattern is generated. The conventional method requires a higher voltage controlled oscillator gain to meet the frequency range requirement of the frequency modulated continuous wave, and thus limits the phase noise performance of the voltage controlled oscillator.
Disclosure of Invention
The invention aims at: a method for generating a frequency modulated continuous wave signal is provided which is capable of improving the phase noise performance of a voltage controlled oscillator and an entire FMCW generator.
The invention is realized by the following technical scheme: a method for generating frequency modulated continuous wave signals comprises a frequency synthesizer, wherein the frequency synthesizer comprises a voltage controlled oscillator, an integer/fractional frequency divider with an FMCW signal generator, a phase frequency detector, a charge pump circuit and a loop filter, and the five components form a closed loop frequency synthesizer; wherein the voltage controlled oscillator has N frequency control bits for discretely controlling the output frequency of the voltage controlled oscillator;
The method comprises the following steps:
S1, controlling the output frequency of a voltage-controlled oscillator, and dividing the whole frequency tuning range into 2 N frequency arrays; wherein the overall frequency tuning range is from a minimum oscillation frequency F min to a maximum oscillation frequency F max;
S2, an FMCW signal generator in the integer/fractional frequency divider generates a corresponding periodic frequency step change value F step according to instructions given by a system and combined with frequency control phases of voltage-controlled oscillators of 2 N frequency arrays, and drives the voltage-controlled oscillators to generate frequency-modulated continuous wave signals through a closed-loop frequency synthesizer.
Compared with the prior art, the invention has the beneficial effects that:
1. The frequency tuning range of the voltage-controlled oscillator is divided into a plurality of equivalent frequency arrays, and in the process of generating the frequency-modulated continuous wave signal, corresponding frequency array control values are automatically generated before the frequency division number of the frequency divider in the frequency synthesizer is changed each time, so that the voltage-controlled oscillator can work in the corresponding frequency array range, and the frequency locking speed of the whole frequency synthesizer can be accelerated.
2. The FMCW generator can be made to avoid the use of a high gain voltage controlled oscillator, thereby improving the phase noise performance of the voltage controlled oscillator and the overall FMCW generator.
3. The frequency locking time of the frequency synthesizer can be shortened, so that a rapidly changing frequency modulation continuous wave can be generated.
Drawings
FIG. 1 is a diagram of a frequency synthesizer architecture capable of generating a FM continuous wave signal;
FIG. 2 is a schematic diagram of a voltage controlled oscillator frequency array;
FIG. 3 is a schematic diagram of a sawtooth frequency modulated continuous wave;
Detailed Description
The invention is described in detail below with reference to the accompanying drawings:
As shown in fig. 1: a method for generating frequency modulated continuous wave signals comprises a frequency synthesizer, wherein the frequency synthesizer comprises a voltage controlled oscillator, an integer/fractional frequency divider with an FMCW signal generator, a phase frequency detector, a charge pump circuit and a loop filter, and the five components form a closed loop frequency synthesizer; wherein the voltage controlled oscillator has N frequency control bits for discretely controlling the output frequency of the voltage controlled oscillator;
The method comprises the following steps:
S1, controlling the output frequency of a voltage-controlled oscillator, and dividing the whole frequency tuning range into 2 N frequency arrays; wherein the overall frequency tuning range is from a minimum oscillation frequency F min to a maximum oscillation frequency F max;
S2, an FMCW signal generator in the integer/fractional frequency divider generates a corresponding periodic frequency step change value F step according to instructions given by a system and combined with frequency control phases of voltage-controlled oscillators of 2 N frequency arrays, and drives the voltage-controlled oscillators to generate frequency-modulated continuous wave signals through a closed-loop frequency synthesizer.
The phase frequency detector, charge pump and loop filter may be any conventional circuit configuration. The vco has N frequency control bits to discretely control the output frequency of the vco and divide the overall frequency tuning range (from the minimum oscillation frequency F min to the maximum oscillation frequency F max) into 2 N frequency arrays, as shown in fig. 2. Thus, the original vco frequency gain Kvco can be reduced from (F max-Fmin)/Vtune to F zl/Vtune, where V tune is the vco frequency control voltage range and F zl is the frequency tuning range within a frequency array.
The following description is made in connection with specific embodiments:
When the oscillation frequency of the VCO in the frequency synthesizer is F min to F max and there are N-bit frequency array control bits, a periodic saw-tooth-shaped fm continuous wave signal is generated, the period is T, the frequency ranges from F start to F end, and F min≤Fstart<Fend≤Fmax, the frequency step is F step, and m×f step＝Fend-Fstart is satisfied, and at this time, the frequency difference Δf=f step between adjacent frequency arrays in the VCO is the following steps, so the fm continuous wave generation process may be divided into the following steps:
The first step, the whole frequency synthesizer is locked at F start frequency point by the automatic frequency calibration function of the voltage controlled oscillator and the frequency division number generated by the frequency divider with FMCW signal generator, at this time the frequency array control number of the voltage controlled oscillator is A (1 is less than or equal to A <2 N); this time is denoted as time 0;
Step two, starting from the moment 0, automatically adding 1 to the frequency array control number of the voltage-controlled oscillator every time T/M time passes, and simultaneously updating the frequency division number in the frequency divider to enable the frequency synthesizer loop to generate corresponding frequencies, namely, i T/M times pass, wherein the frequency array control number of the voltage-controlled oscillator is A+i, and the corresponding output frequency is F start +i multiplied by delta F;
and thirdly, resetting the frequency array control number of the voltage-controlled oscillator and the frequency division number of the frequency divider to be a value at 0 moment after the T time passes, and returning to the first step to start circulation. As shown in fig. 3.
When Δf is greater than F step, where Δf is the frequency difference between adjacent frequency arrays in the vco;
Generating a periodic sawtooth-shaped frequency modulation continuous wave signal, wherein the period of the frequency modulation continuous wave signal is T, the frequency is from F start to F end, F min≤Fstart<Fend≤Fmax, the frequency step is F step, M is multiplied by F step＝Fend-Fstart;ΔF＝k*Fstep+Frd, k is a natural number, and F rd is a number smaller than F step;
scheme 1: the whole frequency synthesizer is locked at the frequency point F start through the automatic frequency calibration function of the voltage-controlled oscillator and the frequency division number generated by the frequency divider with the FMCW signal generator, and the control number of the frequency array of the voltage-controlled oscillator is A (1 is less than or equal to A <2 N); this time is denoted as time 0;
Scheme 2: step two, starting from the moment 0, automatically adding 1 to the control number of the frequency array of the voltage-controlled oscillator every time k T/M times pass, and simultaneously updating the frequency division number in the frequency divider to enable the frequency synthesizer loop to generate corresponding frequency, namely k times i T/M times pass, wherein the control number of the frequency array of the voltage-controlled oscillator is A+i, and the corresponding output frequency is F start+k×i×Fstep; when the desired frequency of the FMCW signal is between F start +i x ΔF and F start + (i+1) x ΔF, the voltage controlled oscillator is at the ith frequency array and the desired frequency point is generated by a closed loop frequency synthesizer from the frequency division value generated by the FMCW signal generator.
And 3, resetting the frequency array control number of the voltage-controlled oscillator and the frequency division number of the frequency divider to be a value at 0 moment after the T time passes, and returning to the first step to start the cycle.
When Δf is less than F step, where Δf is the frequency difference between adjacent frequency arrays in the vco;
Generating a periodic saw-tooth shaped frequency modulated continuous wave signal with a period of T, a frequency of F start to F end, a frequency step of F min≤Fstart<Fend≤Fmax, F step, M x F step＝Fend-Fstart;Fstep＝k*ΔF+Frd, k being a natural number, F rd being a number less than ΔF;
scheme 1: the whole frequency synthesizer is locked at the frequency point F start through the automatic frequency calibration function of the voltage-controlled oscillator and the frequency division number generated by the frequency divider with the FMCW signal generator, and the control number of the frequency array of the voltage-controlled oscillator is A (1 is less than or equal to A <2 N); this time is denoted as time 0;
Scheme 2: step two, starting from the moment 0, automatically adding k to the frequency array control number of the voltage-controlled oscillator every 1T/M time, simultaneously updating the frequency division number in the frequency divider, wherein F rd frequency is obtained by generating corresponding voltage-controlled oscillator control voltage by a frequency synthesizer loop, i.e. i T/M times are passed, at the moment, the frequency array control number of the voltage-controlled oscillator is A+kxi, and the corresponding output frequency is F start+k×i×Fstep; when the desired frequency of the FMCW signal is between F start +k x i x DeltaF and F start + (k x i+1) x DeltaF, the voltage controlled oscillator is in the k x i frequency array and the desired frequency point is generated by a closed loop frequency synthesizer depending on the frequency division value generated by the FMCW signal generator.
And 3, resetting the frequency array control number of the voltage-controlled oscillator and the frequency division number of the frequency divider to be a value at 0 moment after the T time passes, and returning to the first step to start the cycle.
The working principle is as follows:
The mechanism of the invention is mainly that the frequency array of the voltage controlled oscillator is applied to the generation mechanism of the frequency modulated continuous wave signal, namely, according to the magnitude relation between the frequency step change value F step of the frequency modulated continuous wave signal system and the frequency difference value delta F between adjacent frequency arrays in the voltage controlled oscillator, different frequency array control words (such as N-bit frequency control bits shown in the figure-1) are automatically generated through a certain algorithm in the process of generating linear frequency of the voltage controlled oscillator, so that the voltage controlled oscillator works under different frequency arrays, and meanwhile, the frequency division value generated by the FMCW signal generator is combined, so that the whole closed-loop frequency synthesizer is stabilized under the new voltage controlled oscillator frequency array. The invention can avoid the use of a high-gain voltage-controlled oscillator for the FMCW generator, thereby improving the phase noise performance of the voltage-controlled oscillator and the whole FMCW generator. The frequency-modulated continuous wave generating method can shorten the frequency locking time of the frequency synthesizer, so that the frequency-modulated continuous wave with rapid change can be generated.
While the invention has been illustrated and described with respect to specific embodiments and alternatives thereof, it will be appreciated that various changes and modifications can be made therein without departing from the spirit of the invention. It is, therefore, to be understood that the invention is not to be in any way limited except by the appended claims and their equivalents.
Claims (4)
1. A method of generating a frequency modulated continuous wave signal, comprising: the frequency synthesizer comprises a voltage-controlled oscillator, an integer/decimal frequency divider with an FMCW signal generator, a phase frequency detector, a charge pump circuit and a loop filter, wherein the five components form a closed loop frequency synthesizer; wherein the voltage controlled oscillator has N frequency control bits for discretely controlling the output frequency of the voltage controlled oscillator;
The method comprises the following steps:
S1, controlling the output frequency of a voltage-controlled oscillator, and dividing the whole frequency tuning range into 2 N frequency arrays; wherein the overall frequency tuning range is from a minimum oscillation frequency F min to a maximum oscillation frequency F max;
S2, an FMCW signal generator in the integer/fractional frequency divider generates a corresponding periodic frequency step F step according to an instruction given by a system and combined with frequency control phases of voltage-controlled oscillators of 2 N frequency arrays, and drives the voltage-controlled oscillators to generate frequency-modulated continuous wave signals through a closed-loop frequency synthesizer;
Wherein, in S2, F is a step according to the frequency of the frequency modulation continuous wave signal system step
The magnitude relation between the frequency difference delta F between adjacent frequency arrays in the voltage-controlled oscillator and the voltage-controlled oscillator automatically generates different frequency array control words through an algorithm in the process of generating linear frequency by the voltage-controlled oscillator, so that the voltage-controlled oscillator works under different frequency arrays, and meanwhile, the frequency division value generated by the FMCW signal generator is combined, so that the whole closed-loop frequency synthesizer is stabilized under a new voltage-controlled oscillator frequency array.
2. A method of generating a frequency modulated continuous wave signal as defined in claim 1, wherein:
S2, specifically, the flow of the periodic frequency modulation continuous wave signal is as follows:
when Δf=f step, where Δf is the frequency difference between adjacent frequency arrays in the voltage controlled oscillator;
When the signal is a sawtooth-shaped frequency modulation continuous wave signal, the period of the frequency modulation continuous wave signal which generates a periodic sawtooth shape is T, the frequency is from F start to F end, F min≤Fstart<Fend≤Fmax, the frequency step is F step, and M multiplied by F step=Fend-Fstart is satisfied;
Scheme 1: the whole frequency synthesizer is locked at the frequency point F start through the automatic frequency calibration function of the voltage-controlled oscillator and the frequency division number generated by the frequency divider with the FMCW signal generator, and the control number of the frequency array of the voltage-controlled oscillator is A (1 is less than or equal to A <2 N); this time is denoted as time 0;
Scheme 2: starting from the moment 0, automatically adding 1 to the control number of the frequency array of the voltage-controlled oscillator every time T/M time passes, and updating the frequency division number in the frequency divider to enable the frequency synthesizer loop to generate corresponding frequencies, namely, i T/M times pass, wherein the control number of the frequency array of the voltage-controlled oscillator is A+i, and the corresponding output frequency is F start+i×Fstep;
in the process 3, after the T time passes, the control number of the frequency array of the voltage controlled oscillator and the frequency division number of the frequency divider are reset to the value of 0 moment, and the process returns to the process 1 to start the cycle.
3. A method of generating a frequency modulated continuous wave signal as defined in claim 1, wherein:
When Δf is greater than F step, where Δf is the frequency difference between adjacent frequency arrays in the vco;
When the signal is a sawtooth-shaped frequency modulation continuous wave signal, a periodic frequency modulation continuous wave signal with a sawtooth shape is generated, the period is T, the frequency is from F start to F end, F min≤Fstart<Fend≤Fmax, the frequency step is F step, M multiplied by F step=Fend-Fstart;ΔF=k*Fstep+Frd is satisfied, k is a natural number, and F rd is a number smaller than F step;
Scheme 1: the whole frequency synthesizer is locked at the frequency point F start through the automatic frequency calibration function of the voltage-controlled oscillator and the frequency division number generated by the frequency divider with the FMCW signal generator, and the control number of the frequency array of the voltage-controlled oscillator is A (1 is less than or equal to A <2 N); this time is denoted as time 0;
Scheme 2: starting from the moment 0, the control number of the frequency array of the voltage-controlled oscillator automatically performs 1 adding operation every time k T/M times pass, and meanwhile, the frequency dividing number in the frequency divider is updated to enable the frequency synthesizer loop to generate corresponding frequency, namely k times i T/M times pass, at the moment, the control number of the frequency array of the voltage-controlled oscillator is A+i, and the corresponding output frequency is F start+ k×i×Fstep; when the expected frequency of the FMCW signal is between F start +i×ΔF and F start + (i+1) ×ΔF, the voltage-controlled oscillator is in the ith frequency array, and the required frequency point is generated by the closed-loop frequency synthesizer by means of the frequency division value generated by the FMCW signal generator;
in the process 3, after the T time passes, the control number of the frequency array of the voltage controlled oscillator and the frequency division number of the frequency divider are reset to the value of 0 moment, and the process returns to the process 1 to start the cycle.
4. A method of generating a frequency modulated continuous wave signal as defined in claim 1, wherein:
When Δf is less than F step, where Δf is the frequency difference between adjacent frequency arrays in the vco;
When the signal is a sawtooth-shaped frequency modulation continuous wave signal, a periodic frequency modulation continuous wave signal with a sawtooth shape is generated, the period is T, the frequency is from F start to F end, F min≤Fstart<Fend≤Fmax, the frequency step is F step, M multiplied by F step=Fend-Fstart;Fstep =k*ΔF +Frd is satisfied, k is a natural number, and F rd is a number smaller than DeltaF;
Scheme 1: the whole frequency synthesizer is locked at the frequency point F start through the automatic frequency calibration function of the voltage-controlled oscillator and the frequency division number generated by the frequency divider with the FMCW signal generator, and the control number of the frequency array of the voltage-controlled oscillator is A (1 is less than or equal to A <2 N); this time is denoted as time 0;
Scheme 2: from time 0, the frequency array control number of the voltage-controlled oscillator automatically performs k adding operation every time 1T/M time passes, meanwhile, the frequency division number in the frequency divider is updated, F rd frequency is obtained by generating corresponding voltage-controlled oscillator control voltage by the frequency synthesizer loop, i.e. i T/M times pass, at the moment, the frequency array control number of the voltage-controlled oscillator is A+k multiplied by i, and the corresponding output frequency is F start+k×i×Fstep; when the desired frequency of the FMCW signal is between F start +kIxDeltaF and F start + (kIx1) xDeltaF, the voltage controlled oscillator is in the kth xi frequency array and the desired frequency point is generated by the closed loop frequency synthesizer by means of the frequency division value generated by the FMCW signal generator;
in the process 3, after the T time passes, the control number of the frequency array of the voltage controlled oscillator and the frequency division number of the frequency divider are reset to the value of 0 moment, and the process returns to the process 1 to start the cycle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011223628.XA CN112600555B (en) | 2020-11-05 | 2020-11-05 | Method for generating frequency modulation continuous wave signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011223628.XA CN112600555B (en) | 2020-11-05 | 2020-11-05 | Method for generating frequency modulation continuous wave signal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112600555A CN112600555A (en) | 2021-04-02 |
| CN112600555B true CN112600555B (en) | 2024-05-17 |
Family
ID=75180595
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011223628.XA Active CN112600555B (en) | 2020-11-05 | 2020-11-05 | Method for generating frequency modulation continuous wave signal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112600555B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113933791B (en) * | 2021-09-06 | 2022-05-27 | 珠海正和微芯科技有限公司 | Crystal-oscillator-free FMCW radar transceiver device and frequency calibration method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001339300A (en) * | 2000-05-26 | 2001-12-07 | Matsushita Electric Ind Co Ltd | Pll frequency synthesizer |
| CN102868399A (en) * | 2012-10-11 | 2013-01-09 | 广州润芯信息技术有限公司 | Phase-locked loop frequency synthesizer and phase-locked loop loss lock detecting and adjusting method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100317679B1 (en) * | 2000-03-22 | 2001-12-24 | 조정남 | Self-calibration circuit and method for calibrating phase offset between output waveforms of ring oscillator |
| JP2005109619A (en) * | 2003-09-29 | 2005-04-21 | Fujitsu Ltd | Atomic oscillator |
-
2020
- 2020-11-05 CN CN202011223628.XA patent/CN112600555B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001339300A (en) * | 2000-05-26 | 2001-12-07 | Matsushita Electric Ind Co Ltd | Pll frequency synthesizer |
| CN102868399A (en) * | 2012-10-11 | 2013-01-09 | 广州润芯信息技术有限公司 | Phase-locked loop frequency synthesizer and phase-locked loop loss lock detecting and adjusting method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112600555A (en) | 2021-04-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7724097B2 (en) | Direct digital synthesizer for reference frequency generation | |
| US8242850B2 (en) | Direct digital synthesizer for reference frequency generation | |
| US7791415B2 (en) | Fractional-N synthesized chirp generator | |
| US9479185B2 (en) | Modified delta-sigma modulator for phase coherent frequency synthesis applications | |
| US6147561A (en) | Phase/frequency detector with time-delayed inputs in a charge pump based phase locked loop and a method for enhancing the phase locked loop gain | |
| US8699650B2 (en) | Fractional type phase-locked loop circuit with compensation of phase errors | |
| CN108988857B (en) | Broadband low-phase-noise frequency synthesizer and method based on photoelectric oscillator | |
| US9628066B1 (en) | Fast switching, low phase noise frequency synthesizer | |
| CN112600555B (en) | Method for generating frequency modulation continuous wave signal | |
| US7579916B1 (en) | Low noise frequency synthesizer | |
| US7786815B2 (en) | Apparatus and method for generation of noise signal | |
| US9077592B2 (en) | Low phase-noise indirect frequency synthesizer | |
| CN113114237B (en) | Loop system capable of realizing rapid frequency locking | |
| US8736325B1 (en) | Wide frequency range clock generation using a single oscillator | |
| US8502574B2 (en) | Device and method for generating a signal of parametrizable frequency | |
| WO2009056835A1 (en) | Precision oscillator | |
| RU2602991C1 (en) | High-speed frequency synthesiser | |
| KR101030499B1 (en) | A apparatus and method for synthesizing broadband frequency | |
| CN116938233B (en) | Clock center spread spectrum method and device of phase-locked loop | |
| RU2148881C1 (en) | Hydrogen frequency standard | |
| KR101655514B1 (en) | Spread spectrum clock generator and control module thereof | |
| US11018680B1 (en) | Phase lock loops (PLLS) and methods of initializing PLLS | |
| US7778377B2 (en) | Methods and apparatus for spread spectrum generation using a voltage controlled delay loop | |
| Rohde et al. | Digital frequency synthesizer using adaptive mode-coupled resonator mechanism for low phase noise and low jitter applications | |
| Ghasemzadeh et al. | Fast and accurate fractional frequency synthesizer in 0.18 μm technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |