Frequency locking method, phase-locked loop circuit and transceiver

Abstract

The invention discloses a frequency locking method, a phase-locked loop circuit and a transceiver. If the current frequency of the transceiver is located in the first frequency interval and the target frequency of the transceiver is located in the second frequency interval, switching the voltage-controlled oscillator of the transceiver to a second voltage-controlled oscillator, and outputting the target frequency through the second voltage-controlled oscillator, wherein the second frequency interval is the frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator. Therefore, due to the fact that the second frequency interval is the common frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, when the current frequency of the transceiver and the target frequency of the transceiver are in different frequency intervals, switching of the voltage-controlled oscillators can be achieved through the common frequency interval. Therefore, the switching of the voltage-controlled oscillator is realized through the transceiver, and compared with the related technology, the switching of the voltage-controlled oscillator by using an external switching circuit is avoided, so that the frequency locking time efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of phase-locked loop circuits, and in particular to a frequency locking method, a phase-locked loop circuit, and a transceiver. Background Art

[0002] A PLL (phase-locked loop) circuit achieves an interlocked state by switching the VCO (voltage-controlled oscillator) within the PLL circuit, effectively locking the frequency within the PLL circuit. Related art techniques employ an external switching circuit to switch the VCO within the PLL circuit. However, this external switching circuit can slow down the frequency lockup time required to lock the frequency within the PLL circuit. Therefore, improving frequency lockup time is a key concern for those skilled in the art. Summary of the Invention

[0003] Based on the above problems, the present application provides a frequency locking method, a phase-locked loop circuit, and a transceiver to improve the frequency locking time efficiency. The embodiments of the present application disclose the following technical solutions:

[0004] In a first aspect, the present application discloses a frequency locking method, which is applied to a transceiver, wherein the transceiver includes a first voltage-controlled oscillator and a second voltage-controlled oscillator. The frequency locking method includes:

[0005] If the current frequency of the transceiver is within a first frequency interval and the target frequency of the transceiver is within a second frequency interval, switching the voltage-controlled oscillator of the transceiver to the second voltage-controlled oscillator, and outputting the target frequency through the second voltage-controlled oscillator, wherein the first frequency interval is a frequency interval of the first voltage-controlled oscillator, the second frequency interval is a frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, the frequency of the first frequency interval is less than the frequency of the second frequency interval, and the time required for the second voltage-controlled oscillator to output the target frequency is less than the time required for the first voltage-controlled oscillator to output the target frequency;

[0006] If the current frequency of the transceiver is within the third frequency range and the target frequency of the transceiver is within the second frequency range, the voltage-controlled oscillator of the transceiver is switched to the first voltage-controlled oscillator, and the target frequency is output through the first voltage-controlled oscillator, wherein the third frequency range is the frequency range of the second voltage-controlled oscillator, the frequency of the second frequency range is less than the frequency of the third frequency range, and the time required for the second voltage-controlled oscillator to output the target frequency is greater than the time required for the first voltage-controlled oscillator to output the target frequency.

[0007] Optionally, switching the voltage-controlled oscillator of the transceiver to the second voltage-controlled oscillator, and outputting the target frequency through the second voltage-controlled oscillator, includes: switching the first voltage-controlled oscillator to the second voltage-controlled oscillator, and adjusting a control voltage input to the second voltage-controlled oscillator so that the output frequency of the second voltage-controlled oscillator is the target frequency;

[0008] Switching the voltage-controlled oscillator of the transceiver to the first voltage-controlled oscillator, and outputting the target frequency through the first voltage-controlled oscillator, includes: switching the second voltage-controlled oscillator to the first voltage-controlled oscillator, and adjusting a control voltage input to the first voltage-controlled oscillator so that the output frequency of the first voltage-controlled oscillator is the target frequency;

[0009] The control voltage corresponding to the target frequency output by the first voltage-controlled oscillator is greater than the control voltage corresponding to the target frequency output by the second voltage-controlled oscillator.

[0010] Optionally, the frequency locking method further includes:

[0011] If the current frequency of the transceiver is within the second frequency range and the target frequency of the transceiver is within the second frequency range, the voltage controlled oscillator currently used by the transceiver is maintained unchanged.

[0012] Optionally, the frequency locking method further includes:

[0013] If the target frequency of the transceiver is within a first frequency range, the voltage controlled oscillator of the transceiver is switched to the first voltage controlled oscillator.

[0014] Optionally, the frequency locking method further includes:

[0015] If the target frequency of the transceiver is within a third frequency range, the voltage controlled oscillator of the transceiver is switched to the second voltage controlled oscillator.

[0016] Optionally, the control voltage range of the first voltage-controlled oscillator corresponding to the first frequency interval is the same as the control voltage range of the second voltage-controlled oscillator corresponding to the second frequency interval.

[0017] Optionally, the control voltage range of the first voltage-controlled oscillator corresponding to the second frequency interval is the same as the control voltage range of the second voltage-controlled oscillator corresponding to the third frequency interval.

[0018] Optionally, the bandwidth of the first frequency interval is equal to the bandwidth of the third frequency interval.

[0019] In a second aspect, an embodiment of the present application provides a phase-locked loop circuit, the phase-locked loop circuit including a voltage-controlled oscillator module and a loop filter, the voltage-controlled oscillator module including a first voltage-controlled oscillator and a second voltage-controlled oscillator, a first frequency interval being a frequency interval of the first voltage-controlled oscillator, a second frequency interval being a frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, and a frequency of the first frequency interval being less than a frequency of the second frequency interval; a third frequency interval being a frequency interval of the second voltage-controlled oscillator, and a frequency of the second frequency interval being less than a frequency of the third frequency interval; the loop filter being configured to provide a control voltage for the first voltage-controlled oscillator and the second voltage-controlled oscillator;

[0020] When the current frequency of the phase-locked loop circuit is within a first frequency range and the target frequency of the phase-locked loop circuit is within a second frequency range, the voltage-controlled oscillator of the phase-locked loop circuit is switched to the second voltage-controlled oscillator, and the target frequency is output through the second voltage-controlled oscillator, wherein a time required for the second voltage-controlled oscillator to output the target frequency is less than a time required for the first voltage-controlled oscillator to output the target frequency;

[0021] When the current frequency of the phase-locked loop circuit is within the third frequency range and the target frequency of the phase-locked loop circuit is within the second frequency range, the voltage-controlled oscillator of the phase-locked loop circuit is switched to the first voltage-controlled oscillator, and the target frequency is output through the first voltage-controlled oscillator, wherein the time required for the second voltage-controlled oscillator to output the target frequency is greater than the time required for the first voltage-controlled oscillator to output the target frequency.

[0022] In a third aspect, an embodiment of the present application provides a transceiver, comprising a phase-locked loop circuit as provided in the second aspect, a computer-readable storage medium and a processor connected to each other, wherein the computer-readable storage medium is used to store a computer program, and when the computer program is executed by the processor, it is used to implement the frequency locking method provided in the first aspect.

[0023] Compared with the existing technology, this application has the following beneficial effects:

[0024] In the present application, it is first determined that if the current frequency of the transceiver is within the first frequency range and the target frequency of the transceiver is within the second frequency range, the voltage-controlled oscillator of the transceiver is switched to the second voltage-controlled oscillator, and the target frequency is output through the second voltage-controlled oscillator; or it is determined that if the current frequency of the transceiver is within the third frequency range and the target frequency of the transceiver is within the second frequency range, the voltage-controlled oscillator of the transceiver is switched to the first voltage-controlled oscillator, and the target frequency is output through the first voltage-controlled oscillator.

[0025] It should be noted that the first frequency interval in the present application is the frequency interval of the first voltage-controlled oscillator, the second frequency interval is the frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, and the third frequency interval is the frequency interval of the second voltage-controlled oscillator, and the frequency of the second frequency interval is less than the frequency of the third frequency interval. It can be seen that since the second frequency interval in the present application is the common frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, when the current frequency of the transceiver and the target frequency of the transceiver are in different frequency intervals, the voltage-controlled oscillator can be switched through the common frequency interval, and the present application uses the transceiver itself to switch the voltage-controlled oscillator. Compared with the related art, it avoids the use of an external switching circuit to switch the voltage-controlled oscillator, thereby improving the frequency locking time efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 A flow chart of a frequency locking method provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of frequency intervals for a frequency locking method provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of a control voltage range of a frequency locking method provided in an embodiment of the present application;

[0030] Figure 4 A frequency locking schematic diagram of a frequency locking method provided in an embodiment of the present application;

[0031] Figure 5 A schematic diagram of a phase-locked loop circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.

[0033] As previously described, a PLL circuit (phase-locked loop) achieves an interlocked state by switching the VCO (voltage-controlled oscillator) within the PLL circuit, effectively locking the frequency within the PLL circuit. Related art techniques employ an external switching circuit to switch the VCO within the PLL circuit. However, this external switching circuit can slow down the frequency lockup time required to lock the frequency within the PLL circuit. Therefore, improving frequency lockup time is a key concern for those skilled in the art.

[0034] As is understandable, frequency adjustment is achieved in a PLL circuit by adjusting the VCO control voltage, thereby locking the frequency within the phase-locked loop circuit. However, when locking the frequency within the phase-locked loop circuit, the dielectric absorption effect of some capacitors in the external switching circuit can slow down the frequency locking process and lead to a poor locking effect. Therefore, improving the frequency locking time is a key issue for those skilled in the art.

[0035] Therefore, the inventors proposed the technical solution of the present application. In the present application, it is first determined that if the current frequency of the transceiver is within the first frequency interval and the target frequency of the transceiver is within the second frequency interval, the voltage-controlled oscillator of the transceiver is switched to the second voltage-controlled oscillator, and the target frequency is output through the second voltage-controlled oscillator, and the time required for the second voltage-controlled oscillator to output the target frequency is less than the time required for the first voltage-controlled oscillator to output the target frequency; or it is determined that if the current frequency of the transceiver is within the third frequency interval and the target frequency of the transceiver is within the second frequency interval, the voltage-controlled oscillator of the transceiver is switched to the first voltage-controlled oscillator, and the target frequency is output through the first voltage-controlled oscillator, and the time required for the second voltage-controlled oscillator to output the target frequency is greater than the time required for the first voltage-controlled oscillator to output the target frequency.

[0036] It should be noted that the first frequency interval in the present application is the frequency interval of the first voltage-controlled oscillator, the second frequency interval is the frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, and the third frequency interval is the frequency interval of the second voltage-controlled oscillator. The frequency of the first frequency interval is less than the frequency of the second frequency interval, and the frequency of the second frequency interval is less than the frequency of the third frequency interval. It can be seen that since the second frequency interval in the present application is the common frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, when the target frequency is in the common frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, a voltage-controlled oscillator with a short locking time can be selected as the voltage-controlled oscillator that needs to be switched, thereby realizing the switching of the voltage-controlled oscillator through the common frequency interval and shortening the locking time. In addition, the present application realizes the switching of the voltage-controlled oscillator through the transceiver itself. Compared with the related art, it avoids the use of an external switching circuit to realize the switching of the voltage-controlled oscillator, thereby improving the switching time of the voltage-controlled oscillator and also improving the frequency locking time, thereby realizing the rapid interlocking of the phase-locked loop circuit.

[0037] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0038] The following describes a frequency locking method provided by the present application through an embodiment. Figure 1 , which is a flow chart of a frequency locking method provided by an embodiment of the present application, such as Figure 1 As shown, the method includes:

[0039] S101: If the current frequency of the transceiver is within the first frequency range and the target frequency of the transceiver is within the second frequency range, switch the voltage controlled oscillator of the transceiver to a second voltage controlled oscillator, and output the target frequency through the second voltage controlled oscillator.

[0040] First, it should be noted that the frequency locking method in this application is applied to a transceiver, which includes a first voltage-controlled oscillator and a second voltage-controlled oscillator, wherein the transceiver can know the current frequency and the voltage-controlled oscillator currently in use. In this step, the first frequency interval is the frequency interval of the first voltage-controlled oscillator, the second frequency interval is the frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, the frequency of the first frequency interval is less than the frequency of the second frequency interval, and the time required for the second voltage-controlled oscillator to output the target frequency is less than the time required for the first voltage-controlled oscillator to output the target frequency.

[0041] The current frequency is the current operating frequency of the transceiver, and the target frequency is the next operating frequency of the transceiver, that is, the frequency to be locked by the phase-locked loop next time. This application achieves frequency locking in the phase-locked loop circuit by making the current frequency close to the target frequency.

[0042] Specifically, in this step, if it is determined that the current frequency of the transceiver is within the first frequency range, it can be determined that the current voltage-controlled oscillator of the transceiver is the first voltage-controlled oscillator, and if the target frequency of the transceiver is within the second frequency range, since the time required for the second voltage-controlled oscillator to output the target frequency is less than the time required for the first voltage-controlled oscillator to output the target frequency, it can be determined that the transceiver needs to switch to the second voltage-controlled oscillator to output the target frequency through the second voltage-controlled oscillator to achieve frequency locking in the phase-locked loop circuit, thereby achieving rapid locking to the target frequency.

[0043] S102: If the current frequency of the transceiver is in the third frequency range and the target frequency of the transceiver is in the second frequency range, switch the voltage controlled oscillator of the transceiver to the first voltage controlled oscillator, and output the target frequency through the first voltage controlled oscillator.

[0044] In this step, the third frequency interval is the frequency interval of the second voltage-controlled oscillator, the frequency of the second frequency interval is lower than the frequency of the third frequency interval, and the time required for the second voltage-controlled oscillator to output the target frequency is longer than the time required for the first voltage-controlled oscillator to output the target frequency. It is understood that the frequency interval of the first voltage-controlled oscillator includes the first frequency interval and the second frequency interval, and the frequency interval of the second voltage-controlled oscillator includes the second frequency interval and the third frequency interval, wherein the frequency range of the second frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator is the same, but the control voltage range of the first voltage-controlled oscillator in the second frequency interval is different from the control voltage range of the second voltage-controlled oscillator in the second frequency interval.

[0045] Specifically, in this step, if it is determined that the current frequency of the transceiver is within the third frequency range, it can be determined that the current voltage-controlled oscillator of the transceiver is the second voltage-controlled oscillator, and if the target frequency of the transceiver is within the second frequency range, since the time required for the second voltage-controlled oscillator to output the target frequency is greater than the time required for the first voltage-controlled oscillator to output the target frequency, it can be determined that the transceiver needs to switch to the first voltage-controlled oscillator to output the target frequency through the first voltage-controlled oscillator to achieve frequency locking in the phase-locked loop circuit, thereby achieving rapid locking to the target frequency.

[0046] It can be understood that since the second frequency range in the present application is a common frequency range of the first voltage-controlled oscillator and the second voltage-controlled oscillator, when the current frequency of the transceiver and the target frequency of the transceiver are in different frequency ranges, the voltage-controlled oscillator can be switched through the common frequency range, and the frequency adjustment and locking can be achieved through the switching of the voltage-controlled oscillator. Moreover, since the second frequency range is a common frequency range of the first voltage-controlled oscillator and the second voltage-controlled oscillator, when adjusting the frequency, a voltage-controlled oscillator with a shorter locking time can be selected to output the target frequency, thereby further improving the frequency locking time efficiency.

[0047] See also Figure 2 , Figure 2 A frequency range diagram of a frequency locking method provided in an embodiment of the present application. Figure 2 In the embodiment, the first frequency range of the first voltage-controlled oscillator is f1 to f2L, the second frequency range of the first voltage-controlled oscillator is f2L to f3, the second frequency range of the second voltage-controlled oscillator is f2 to f3H, and the third frequency range of the second voltage-controlled oscillator is f3H to f4. For example, the first frequency range of the first voltage-controlled oscillator may be 100 MHz to 200 MHz; the second frequency range of the first voltage-controlled oscillator may be 200 MHz to 300 MHz; the second frequency range of the second voltage-controlled oscillator may also be 200 MHz to 300 MHz; and the third frequency range of the second voltage-controlled oscillator may be 300 MHz to 400 MHz.

[0048] It should be noted that in this application, the first frequency interval includes the first frequency point (i.e., f1), the second frequency interval includes the second frequency point (i.e., f2, f2L) and the third frequency point (i.e., f3, f3H), and the third frequency interval includes the fourth frequency point (i.e., f4), where the first frequency point is smaller than the second frequency point, the second frequency point is smaller than the third frequency point, and the third frequency point is smaller than the fourth frequency point.

[0049] It can be understood that if the current frequency is the first frequency point f1 and the target frequency is the third frequency point f3H, the first voltage-controlled oscillator can be switched to the second voltage-controlled oscillator, and the first frequency point f1 can be further adjusted to the third frequency point f3H; or if the current frequency is the fourth frequency point f4 and the target frequency is the second frequency point f2L, the second voltage-controlled oscillator can be switched to the first voltage-controlled oscillator, and the fourth frequency point f4 can be further adjusted to the second frequency point f2L, so as to achieve frequency adjustment between different voltage-controlled oscillators.

[0050] Furthermore, when the current frequency of the transceiver is within the first frequency range and the target frequency of the transceiver is within the second frequency range, the first voltage-controlled oscillator can be switched to the second voltage-controlled oscillator, and the control voltage input to the second voltage-controlled oscillator can be adjusted so that the output frequency of the second voltage-controlled oscillator is the target frequency.

[0051] Alternatively, when the current frequency of the transceiver is within the third frequency interval and the target frequency of the transceiver is within the second frequency interval, the second voltage-controlled oscillator can be switched to the first voltage-controlled oscillator, and the control voltage input to the first voltage-controlled oscillator is adjusted so that the output frequency of the first voltage-controlled oscillator is the target frequency, wherein the control voltage corresponding to the target frequency output by the first voltage-controlled oscillator is greater than the control voltage corresponding to the target frequency output by the second voltage-controlled oscillator. In this way, in the present application, the output frequency can be adjusted by adjusting the control voltage of the voltage-controlled oscillator, and in the present application, the switching of the voltage-controlled oscillator can be achieved through the second frequency interval, and the corresponding control voltage adjustment is also small, that is, the time required to output the target frequency is short, thereby improving the frequency adjustment time efficiency.

[0052] It should be further noted that in the present application, the control voltage range of the first voltage-controlled oscillator corresponding to the first frequency interval is the same as the control voltage range of the second voltage-controlled oscillator corresponding to the second frequency interval, the control voltage range of the first voltage-controlled oscillator corresponding to the second frequency interval is the same as the control voltage range of the second voltage-controlled oscillator corresponding to the third frequency interval, and the bandwidth of the first frequency interval is equal to the bandwidth of the third frequency interval. In this way, the charge and discharge time can be shortened by reducing the adjustment change of the control voltage, thereby improving the frequency locking time.

[0053] See also Figure 3 , Figure 3 A schematic diagram of the control voltage range of a frequency locking method provided in an embodiment of the present application. Figure 3 In the example, the voltage corresponding to the frequency point f1 in the first frequency interval of the first voltage-controlled oscillator is V1, the voltage corresponding to the frequency point f3 in the second frequency interval of the first voltage-controlled oscillator is V3, the voltage corresponding to the frequency point f2 in the second frequency interval of the second voltage-controlled oscillator is V2, and the voltage corresponding to the frequency point f4 in the third frequency interval of the second voltage-controlled oscillator is V4. The voltage corresponding to the frequency point f2L in the first frequency interval of the first voltage-controlled oscillator and the voltage corresponding to the frequency point f2L in the second frequency interval of the first voltage-controlled oscillator are both V2L, and the voltage corresponding to the frequency point f3H in the second frequency interval of the second voltage-controlled oscillator and the voltage corresponding to the frequency point f3H in the third frequency interval of the second voltage-controlled oscillator are both V3H. For example: V1 is 1V; V2L is 2.5V; V3 is 4V; V2 is 1V, V3H is 2.5V, and V4 is 4V.

[0054] It can be understood that if the current frequency is the first frequency point f1 and the target frequency is the third frequency point f3H, the first voltage-controlled oscillator can be switched to the second voltage-controlled oscillator, and V1 can be further adjusted to V3H. For example, 1V can be adjusted to 2.5V to achieve frequency adjustment from the first frequency point f1 to the third frequency point f3H. If the voltage-controlled oscillator is not switched and the first voltage-controlled oscillator is continued to be used to output the target frequency, V1 needs to be adjusted to V3, for example, 1V is adjusted to 4V. At this time, the voltage change is 3V.

[0055] Alternatively, if the current frequency is the fourth frequency point f4 and the target frequency is the second frequency point f2L, the second voltage-controlled oscillator can be switched to the first voltage-controlled oscillator, and V4 can be further adjusted to V2L. For example, 4V can be adjusted to 2.5V to achieve the adjustment from the fourth frequency point f4 to the second frequency point f2L. If the voltage-controlled oscillator is not switched and the second voltage-controlled oscillator is continued to be used to output the target frequency, V4 needs to be adjusted to V2, for example, 4V is adjusted to 1V. At this time, the voltage change is 3V.

[0056] Through the method of this embodiment, the voltage change when the first voltage-controlled oscillator switches to the second voltage-controlled oscillator, and the voltage change when the second voltage-controlled oscillator switches to the first voltage-controlled oscillator are both 1.5 V. In this way, when implementing the switching of the voltage-controlled oscillators, the present application not only reduces the change in the control voltage, but also improves the frequency locking time.

[0057] In a feasible implementation, the present application can determine whether the current frequency of the transceiver is within the second frequency range and whether the target frequency of the transceiver is within the second frequency range. If the current frequency of the transceiver is within the second frequency range and the target frequency of the transceiver is within the second frequency range, then it is determined that the current voltage-controlled oscillator of the transceiver is the first voltage-controlled oscillator or the second voltage-controlled oscillator. At this time, the voltage-controlled oscillator currently used by the transceiver can be maintained unchanged, and there is no need to switch the voltage-controlled oscillator, which simplifies the locking process.

[0058] In addition, the present application can also determine whether the target frequency of the transceiver is within the first frequency interval. If the target frequency of the transceiver is within the first frequency interval, the voltage-controlled oscillator of the transceiver can be switched to the first voltage-controlled oscillator. Specifically, if the current frequency of the transceiver is within the first frequency interval or the second frequency interval, and the voltage-controlled oscillator currently used by the transceiver is the first voltage-controlled oscillator, then no switching is required, and the first voltage-controlled oscillator continues to be used to output the target frequency. If the current frequency of the transceiver is within the second frequency interval or the third frequency interval, and the voltage-controlled oscillator currently used by the transceiver is the second voltage-controlled oscillator, then the voltage-controlled oscillator of the transceiver needs to be switched to the first voltage-controlled oscillator.

[0059] Furthermore, the present application can also determine whether the target frequency of the transceiver is within the third frequency range and whether the current frequency of the transceiver is not within the third frequency range. If the target frequency of the transceiver is within the third frequency range and the current frequency of the transceiver is not within the third frequency range, the voltage-controlled oscillator of the transceiver can be switched to the second voltage-controlled oscillator.

[0060] Specifically, if the current frequency of the transceiver is within the second frequency interval or the third frequency interval, and the voltage-controlled oscillator currently used by the transceiver is the second voltage-controlled oscillator, no switching is required, and the second voltage-controlled oscillator continues to be used to output the target frequency. If the current frequency of the transceiver is within the first frequency interval or the second frequency interval, and the voltage-controlled oscillator currently used by the transceiver is the first voltage-controlled oscillator, the voltage-controlled oscillator of the transceiver needs to be switched to the second voltage-controlled oscillator.

[0061] Next, combine Figure 4 For further explanation of the frequency locking process in this application, see Figure 4 , Figure 4 A frequency locking diagram of a frequency locking method provided in an embodiment of the present application, Figure 4 In the embodiment, there are three situations in which frequencies need to be locked. The three frequency locking situations are described below. Figure 4 In the figure, [F1, F2) represents the first frequency interval, [F2, F3) represents the second frequency interval, [F3, F4] represents the third frequency interval, the first VCO represents the first voltage-controlled oscillator, and the second VCO represents the second voltage-controlled oscillator.

[0062] The first frequency locking situation: In this application, the frequency range of the current frequency f0 is first determined, that is, whether the current frequency f0 is in the first frequency range [F1, F2). If the current frequency f0 is in the first frequency range [F1, F2), it can be determined whether the target frequency fn is in the first frequency range [F1, F2). If the target frequency fn is in the first frequency range [F1, F2), it is still in the first VCO, that is, there is no need to switch the VCO, and continue to obtain the next target frequency fn2 for judgment.

[0063] If the target frequency fn is not within the first frequency interval [F1, F2), it can be determined whether the target frequency fn is within the second frequency interval [F2, F3) or the third frequency interval [F3, F4]. If the target frequency fn is within the second frequency interval [F2, F3) or the third frequency interval [F3, F4], the first VCO is switched to the second VCO, and the current frequency f0 is adjusted so that the second VCO outputs the target frequency fn. If the target frequency fn is not within the second frequency interval [F2, F3) or the third frequency interval [F3, F4], the determination is terminated.

[0064] The second frequency locking situation: In this application, when the current frequency f0 is not in the first frequency interval [F1, F2), it can be determined whether the current frequency f0 is in the second frequency interval [F2, F3). If the current frequency f0 is in the second frequency interval [F2, F3), then it is determined whether the target frequency fn is in the second frequency interval [F2, F3). If the target frequency fn is in the second frequency interval [F2, F3), the current VCO is kept enabled and the next target frequency fn2 is obtained for judgment.

[0065] If the target frequency fn is not within the second frequency interval [F2, F3), it can be determined whether the target frequency fn is within the first frequency interval [F1, F2) or the third frequency interval [F3, F4]. If the target frequency fn is within the first frequency interval [F1, F2), if the current VCO is the second VCO, the second VCO is switched to the first VCO. If the current VCO is the first VCO, the first VCO is kept enabled, the current frequency f0 is adjusted, and the target frequency fn is output; or if the target frequency fn is within the third frequency interval [F3, F4], if the current VCO is the first VCO, the first VCO is switched to the second VCO. If the current VCO is the second VCO, the second VCO is kept enabled, the current frequency f0 is adjusted, the target frequency fn is output, and the next target frequency fn2 is obtained for determination; and if the target frequency fn is not within the first frequency interval [F1, F2) or the third frequency interval [F3, F4], the determination is terminated.

[0066] The third frequency locking situation: In this application, when the current frequency f0 is not within the first frequency interval [F1, F2) and the second frequency interval [F2, F3), it can be determined whether the current frequency f0 is within the third frequency interval [F3, F4]. If the current frequency f0 is within the third frequency interval [F3, F4], then determine whether the target frequency fn is within the third frequency interval [F3, F4]. If the target frequency fn is within the third frequency interval [F3, F4], make it still in the second VCO, and continue to obtain the next target frequency fn2 for judgment.

[0067] If the target frequency fn is not within the third frequency interval [F3, F4], it can be determined whether the target frequency fn is within the first frequency interval [F1, F2) or the second frequency interval [F2, F3). If the target frequency fn is within the first frequency interval [F1, F2) or the second frequency interval [F2, F3), the second VCO is switched to the first VCO, and the current frequency f0 is adjusted so that the first VCO can output the target frequency fn; and if the target frequency fn is not within the first frequency interval [F1, F2) or the second frequency interval [F2, F3), the determination is terminated.

[0068] It should be further clarified that the voltage-controlled oscillator in this application is a frequency oscillation unit that is voltage-regulated. That is, each frequency range of the voltage-controlled oscillator corresponds to a voltage range, and the voltage range is determined by the voltage-controlled oscillator. The operating voltage of the first voltage-controlled oscillator in the first frequency range [F1, F2) is 1V-2.5V, the operating voltage of the first voltage-controlled oscillator in the second frequency range [F2, F3) is 2.5V-4V, the operating voltage of the second voltage-controlled oscillator in the second frequency range [F2, F3) is 1V-2.5V, and the operating voltage of the second voltage-controlled oscillator in the third frequency range [F3, F4] is 2.5V-4V.

[0069] At this time, when switching from the first voltage-controlled oscillator to the second voltage-controlled oscillator, the voltage needs to be adjusted from 1V to 2.5V to adjust the current frequency f0 in the first frequency range [F1, F2) to the second frequency range [F2, F3), with a ΔV voltage difference of 1.5V. Alternatively, when switching from the second voltage-controlled oscillator to the first voltage-controlled oscillator, the voltage needs to be adjusted from 4V to 2.5V to adjust the current frequency f0 in the third frequency range [F3, F4] to the second frequency range [F2, F3), with a ΔV voltage difference of 1.5V. In this way, by setting the same frequency range, both the frequency adjustment and switching between different voltage-controlled oscillators can be achieved quickly, while also reducing the voltage variation and achieving fast interlocking of the phase-locked loop circuit.

[0070] Further, as shown in Table 1, Table 1 is a VCO enable table of a frequency locking method provided in an embodiment of the present application. Table 1 shows the enable state of the VCO (voltage controlled oscillator) when the target frequency locking circuit is used. When the current frequency needs to be adjusted from A (first frequency interval) to B1 (second frequency interval under the first VCO) or B2 (second frequency interval under the second VCO), the second VCO is powered on and the second VCO is enabled; when the current frequency needs to be adjusted from C (third frequency interval) to B1 or B2, the first VCO is powered on and the first VCO is enabled; when the current frequency needs to be adjusted from B1 or B2 to B2 or B1, the voltage controlled oscillator remains enabled; and when the current frequency needs to be adjusted from A or B1 or B2 or C to A, the first VCO is powered on and the first VCO is enabled, and when the current frequency needs to be adjusted from A or B1 or B2 or C to C, the second VCO is powered on and the second VCO is enabled. In this way, since the same frequency range exists between different voltage-controlled oscillators, frequency adjustment between frequency crossover ranges can be achieved, and frequencies can be switched and locked between the same frequency ranges, thereby minimizing the voltage change of the voltage-controlled oscillator.

[0071] Table 1

[0072]

[0073] Furthermore, as shown in Table 2, Table 2 is a locking circuit time table of a frequency locking method provided in an embodiment of the present application. Table 2 shows the circuit locking time when the circuit is interlocked by switching the voltage-controlled oscillator using this solution, taking a product with an operating frequency band of 340MHz-470MHz and BW=120MHz as an example. In this example, ft1 (350MHz) in the first frequency interval under the first VCO is adjusted to ft2 (396.65MHz) in the second frequency interval under the second VCO, and the locking time is only 3.40ms; ft3 (470MHz) in the third frequency interval under the second VCO is adjusted to ft4 (350MHz) in the second frequency interval under the second VCO, and the locking time is only 2.85ms; ft2 (396.65MHz) in the second frequency interval under the second VCO is adjusted to ft5 (350MHz) in the first frequency interval under the first VCO, and the locking time is only 3.75ms. It should be noted that, during the above frequency adjustment process, the voltage change of the voltage controlled oscillator did not exceed 1.5V.

[0074] In this way, compared with the related art, the present application can achieve frequency locking within the same frequency range of different voltage-controlled oscillators, minimize the voltage change of the voltage-controlled oscillator, and achieve fast locking. In addition, the voltage-controlled oscillator can be used as a receiving PLL configuration or as a transmitting PLL configuration within the same frequency range. The receiving and transmitting PLLs can be used crosswise, and the control flexibility is high. In addition, the present application streamlines an external fast-lock switch and peripheral circuit, and there is no need to set a preset voltage, which simplifies the circuit design, reduces the design cost, and saves space on the circuit board.

[0075] Table 2

[0076] Adjust status Lock time (ms) Adjust ft1 to ft2 3.40 Adjust ft3 to ft4 2.85 Adjust ft2 to ft5 3.75

[0077] In this way, the present application realizes frequency locking through the shared frequency range between the first voltage-controlled oscillator and the second voltage-controlled oscillator, and can realize switching between different voltage-controlled oscillators by controlling the voltage-controlled oscillator to be enabled through software logic. That is, compared with the related art, the present application improves the frequency locking time efficiency, improves the voltage-controlled oscillator switching time efficiency, reduces the voltage change, shortens the charging and discharging time, optimizes the circuit locking time, and thus realizes the rapid interlocking of the phase-locked loop circuit.

[0078] The following describes a phase-locked loop circuit provided by an embodiment of the present application. The frequency locking method described above can be applied to the phase-locked loop circuit. Figure 5 , which is a schematic diagram of a phase-locked loop circuit provided by an embodiment of the present application, such as Figure 5 shown.

[0079] The phase-locked loop circuit in the present application includes a voltage-controlled oscillator module and a loop filter, wherein the voltage-controlled oscillator module includes a first voltage-controlled oscillator and a second voltage-controlled oscillator, and the first voltage-controlled oscillator and the second voltage-controlled oscillator are the voltage-controlled oscillators described in the above-mentioned frequency locking method. The loop filter is used to provide control voltages for the first voltage-controlled oscillator and the second voltage-controlled oscillator, wherein the first frequency interval is the frequency interval of the first voltage-controlled oscillator, the second frequency interval is the frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, and the frequency of the first frequency interval is less than the frequency of the second frequency interval; and the third frequency interval is the frequency interval of the second voltage-controlled oscillator, and the frequency of the second frequency interval is less than the frequency of the third frequency interval.

[0080] Specifically, when the current frequency of the phase-locked loop circuit is within the first frequency range and the target frequency of the phase-locked loop circuit is within the second frequency range, the voltage-controlled oscillator of the phase-locked loop circuit can be switched to a second voltage-controlled oscillator to output the target frequency through the second voltage-controlled oscillator, wherein the time required for the second voltage-controlled oscillator to output the target frequency is less than the time required for the first voltage-controlled oscillator to output the target frequency.

[0081] And when the current frequency of the phase-locked loop circuit is within the third frequency range and the target frequency of the phase-locked loop circuit is within the second frequency range, the voltage-controlled oscillator of the phase-locked loop circuit can be switched to the first voltage-controlled oscillator to output the target frequency through the first voltage-controlled oscillator, wherein the time required for the second voltage-controlled oscillator to output the target frequency is greater than the time required for the first voltage-controlled oscillator to output the target frequency.

[0082] It should be noted that the voltage controlled oscillator enabling process, voltage controlled oscillator switching process, frequency locking process and voltage change process are all described in detail in the above frequency locking method and will not be repeated here.

[0083] Furthermore, the phase-locked loop circuit in the present application also includes a low-pass filter, a feedback filter, a reference clock, and a PLL chip, wherein the PLL chip includes an R counter, an N counter, and a phase detector charge pump. The reference clock is connected to the R counter, the R counter is connected to the phase detector charge pump, the phase detector charge pump is connected to the loop filter, the loop filter is connected to the voltage-controlled oscillator module, the voltage-controlled oscillator module is connected to the low-pass filter, the voltage-controlled oscillator module is also connected to the feedback filter, the feedback filter is connected to the N counter, and the N counter is in turn connected to the phase detector charge pump. It should be noted that the reference clock inputs the target frequency of the phase-locked loop circuit, so that the voltage-controlled oscillator is switched according to the voltage-controlled oscillator module itself, thereby achieving frequency locking, and then making the current frequency of the voltage-controlled oscillator module close to the target frequency. In this way, the interlocking capability of the voltage-controlled oscillator is utilized to achieve fast locking of the phase-locked loop circuit, thereby improving the circuit locking time efficiency.

[0084] The present application also provides a transceiver, which includes a phase-locked loop circuit, a computer-readable storage medium, and a processor connected to each other, wherein the computer-readable storage medium is used to store a computer program, and when the computer program is executed by the processor, the computer program is used to implement the above-mentioned frequency locking method.

[0085] It should be noted that the frequency locking method, phase-locked loop circuit, and transceiver provided by the present invention can be used in the field of phase-locked loop circuit technology. The above is only an example and does not limit the application field of the frequency locking method, phase-locked loop circuit, and transceiver provided by the present invention.

[0086] It should also be noted that the "first" and "second" (if any) in the names mentioned in the embodiments of this application are only used as name identifiers and do not represent the first or second in order.

[0087] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the circuits disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0088] The above is a detailed introduction to a frequency locking method, phase-locked loop circuit, and transceiver provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only intended to help understand the method and core concept of the present application. It should be noted that, for those skilled in the art, various improvements and modifications may be made to the present application without departing from the principles of the present application, and such improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A frequency locking method, characterized in that: Applied to a transceiver, the transceiver includes a first voltage-controlled oscillator and a second voltage-controlled oscillator, and the frequency locking method includes: If the current frequency of the transceiver is within a first frequency interval and the target frequency of the transceiver is within a second frequency interval, switching the voltage-controlled oscillator of the transceiver to the second voltage-controlled oscillator, and outputting the target frequency through the second voltage-controlled oscillator, wherein the first frequency interval is a frequency interval of the first voltage-controlled oscillator, the second frequency interval is a frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, the frequency of the first frequency interval is less than the frequency of the second frequency interval, and the time required for the second voltage-controlled oscillator to output the target frequency is less than the time required for the first voltage-controlled oscillator to output the target frequency; If the current frequency of the transceiver is within the third frequency range and the target frequency of the transceiver is within the second frequency range, the voltage-controlled oscillator of the transceiver is switched to the first voltage-controlled oscillator, and the target frequency is output through the first voltage-controlled oscillator, wherein the third frequency range is the frequency range of the second voltage-controlled oscillator, the frequency of the second frequency range is less than the frequency of the third frequency range, and the time required for the second voltage-controlled oscillator to output the target frequency is greater than the time required for the first voltage-controlled oscillator to output the target frequency.

2. The frequency locking method according to claim 1, wherein: Switching the voltage-controlled oscillator of the transceiver to the second voltage-controlled oscillator, and outputting the target frequency through the second voltage-controlled oscillator, includes: switching the first voltage-controlled oscillator to the second voltage-controlled oscillator, and adjusting a control voltage input to the second voltage-controlled oscillator so that the output frequency of the second voltage-controlled oscillator is the target frequency; Switching the voltage-controlled oscillator of the transceiver to the first voltage-controlled oscillator, and outputting the target frequency through the first voltage-controlled oscillator, includes: switching the second voltage-controlled oscillator to the first voltage-controlled oscillator, and adjusting a control voltage input to the first voltage-controlled oscillator so that the output frequency of the first voltage-controlled oscillator is the target frequency; The control voltage corresponding to the target frequency output by the first voltage-controlled oscillator is greater than the control voltage corresponding to the target frequency output by the second voltage-controlled oscillator.

3. The frequency locking method according to claim 1, wherein: The frequency locking method further includes: If the current frequency of the transceiver is within the second frequency range and the target frequency of the transceiver is within the second frequency range, the voltage controlled oscillator currently used by the transceiver is maintained unchanged.

4. The frequency locking method according to claim 1, wherein: The frequency locking method further includes: If the target frequency of the transceiver is within a first frequency range, the voltage controlled oscillator of the transceiver is switched to the first voltage controlled oscillator.

5. The frequency locking method according to claim 1, wherein: The frequency locking method further includes: If the target frequency of the transceiver is within a third frequency range, the voltage controlled oscillator of the transceiver is switched to the second voltage controlled oscillator.

6. The frequency locking method according to claim 1, wherein: A control voltage range of the first voltage-controlled oscillator corresponding to the first frequency interval is the same as a control voltage range of the second voltage-controlled oscillator corresponding to the second frequency interval.

7. The frequency locking method according to claim 6, characterized in that: The control voltage range of the first voltage-controlled oscillator corresponding to the second frequency interval is the same as the control voltage range of the second voltage-controlled oscillator corresponding to the third frequency interval.

8. The frequency locking method according to claim 7, characterized in that: The bandwidth of the first frequency interval is equal to the bandwidth of the third frequency interval.

9. A phase-locked loop circuit, characterized in that: The phase-locked loop circuit includes a voltage-controlled oscillator module and a loop filter. The voltage-controlled oscillator module includes a first voltage-controlled oscillator and a second voltage-controlled oscillator. The first frequency interval is the frequency interval of the first voltage-controlled oscillator, the second frequency interval is the frequency interval of the first voltage-controlled oscillator and the second voltage-controlled oscillator, and the frequency of the first frequency interval is lower than the frequency of the second frequency interval; the third frequency interval is the frequency interval of the second voltage-controlled oscillator, and the frequency of the second frequency interval is lower than the frequency of the third frequency interval; the loop filter is used to provide a control voltage for the first voltage-controlled oscillator and the second voltage-controlled oscillator; When the current frequency of the phase-locked loop circuit is within a first frequency range and the target frequency of the phase-locked loop circuit is within a second frequency range, the voltage-controlled oscillator of the phase-locked loop circuit is switched to the second voltage-controlled oscillator, and the target frequency is output through the second voltage-controlled oscillator, wherein a time required for the second voltage-controlled oscillator to output the target frequency is less than a time required for the first voltage-controlled oscillator to output the target frequency; When the current frequency of the phase-locked loop circuit is within the third frequency range and the target frequency of the phase-locked loop circuit is within the second frequency range, the voltage-controlled oscillator of the phase-locked loop circuit is switched to the first voltage-controlled oscillator, and the target frequency is output through the first voltage-controlled oscillator, wherein the time required for the second voltage-controlled oscillator to output the target frequency is greater than the time required for the first voltage-controlled oscillator to output the target frequency.

10. A transceiver, characterized in that: The method comprises the phase-locked loop circuit according to claim 9, a computer-readable storage medium and a processor connected to each other, wherein the computer-readable storage medium is used to store a computer program, and when the computer program is executed by the processor, it is used to implement the frequency locking method according to any one of claims 1 to 8.

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