Broadband injection locking frequency-quad divider based on three-point injection

Abstract

The invention discloses a broadband injection locking frequency-quad divider based on three-point injection, relates to the technical field of radio frequency integrated circuits, and is used for solving the technical problems that the actual locking bandwidth range is insufficient and the working frequency is reduced in the prior art. The invention discloses a broadband injection-locked frequency-quad divider based on three-point injection. The broadband injection-locked frequency-quad divider comprises a first ring oscillation unit and a second ring oscillation unit, wherein the n first ring vibration units are connected in series to form a chain type structure; the second ring oscillation unit is configured with a direct injection unit, a tail current injection unit and a cross-coupled inverter injection unit; the differential output end of the first ring vibration unit is connected with the differential input end of the second ring vibration unit; a first signal is injected into a direct injection unit, a tail current injection unit and / or a cross-coupled inverter injection unit; the second ring vibration unit receives a second signal from the first ring vibration unit, and the second signal is converted into a four-frequency-division signal through the second ring vibration unit.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency integrated circuits, and more particularly to a broadband injection-locked four-frequency divider based on three-point injection. Background Art

[0002] Frequency dividers are key modules in RF and millimeter-wave communication systems, used to divide high-frequency signals into lower frequencies for subsequent signal processing. In systems such as phase-locked loops (PLLs), frequency synthesizers, and wireless transceivers, the performance of the frequency divider directly impacts the system's frequency stability, phase noise, and power consumption. Injection-locked frequency dividers, with their low power consumption, low phase noise, and high operating frequency, are a preferred solution for high-frequency applications.

[0003] Existing injection-locked frequency dividers based on LC resonant cavities offer high-frequency operation and low phase noise, but their locking range is limited by the resonant cavity's Q factor, resulting in a narrow bandwidth. Furthermore, the on-chip integrated inductor occupies a large chip area, making it difficult to meet miniaturization requirements. In contrast, frequency dividers based on ring oscillators, thanks to their inductor-free design, excel in compactness and wide locking range. However, their inherent multi-stage inverter cascade structure significantly increases power consumption, particularly in high-frequency millimeter-wave scenarios. Currently, mainstream ring oscillator injection-locked frequency dividers employ single-point or dual-node injection schemes, such as direct gate injection or tail current injection, utilizing a single or two injection nodes to couple external signals to extend the locking range. However, these schemes still suffer from the following drawbacks: Single-point injection has limited synchronization efficiency, making it difficult to fully excite the oscillator's harmonic response, resulting in an insufficient actual locking bandwidth. Furthermore, while dual-node injection can enhance injection strength, its bandwidth expansion effect is limited. Further bandwidth improvement often requires increasing the injector size, resulting in a decrease in operating frequency. Summary of the Invention

[0004] The present invention aims to provide a broadband injection-locked four-way frequency divider based on three-point injection. This approach addresses the technical issues of existing ring oscillator injection-locked frequency dividers, which employ single-point or dual-node injection schemes, resulting in insufficient locking bandwidth and a reduction in operating frequency due to the increased size of the injector. In view of this, the present invention achieves this goal through the following solution.

[0005] The present invention provides a broadband injection-locked four-frequency divider based on three-point injection, comprising: The first ring oscillator unit, n The first ring oscillating units are connected in series to form a chain structure; a second ring oscillator unit, configured with a direct injection unit, a tail current injection unit, and a cross-coupled inverter injection unit; a differential output end of the first ring oscillator unit is connected to a differential input end of the second ring oscillator unit; The first signal is injected into the direct injection unit, the tail current injection unit and / or the cross-coupled inverter injection unit; the second ring oscillator unit receives the second signal from the first ring oscillator unit, and the second signal is converted into a third signal by the second ring oscillator unit, and the third signal is a four-frequency signal; in, n An odd number greater than or equal to 3.

[0006] Compared with the prior art, in the broadband injection-locked four-way divider based on three-point injection of the present invention, multiple first ring oscillator units are connected in series to form a chain structure, and the first ring oscillator unit is interconnected with the second ring oscillator unit through the differential output end; the second ring oscillator unit is configured with a direct injection unit, a tail current injection unit and a cross-coupled inverter injection unit; the first signal can be injected into the direct injection unit, the tail current injection unit and / or the cross-coupled inverter injection unit, and at the same time, the second ring oscillator unit receives the second signal from the first ring oscillator unit, and the second signal is converted into a four-way third signal through the second ring oscillator unit, thereby dividing the high-frequency second signal into a lower-frequency third signal. In the above technical solution, the first signal is injected through three methods: a direct injection unit, a tail current injection unit, and a cross-coupled inverter injection unit, thereby improving the injection strength and expanding the locking bandwidth. The signal injection method of the cross-coupled inverter injection unit can directly utilize the cross-coupled inverter structure in the negative resistance unit to achieve injection, which can further increase the total injected current. Compared with the existing dual-node injection, the present invention does not increase the injector size, and therefore does not cause the operating frequency to decrease, and can simultaneously meet the requirements of ultra-wideband and high frequency. The above technical solution of the present invention solves the technical problems of the single-point or dual-node injection method used in the existing ring oscillator injection-locked divider, which leads to insufficient actual locking bandwidth range, and the operating frequency decrease due to the need to increase the injector size.

[0007] Furthermore, in the broadband injection-locked four-way divider based on three-point injection of the present invention, the first output end of the direct injection unit is connected to the first output end of the cross-coupled inverter injection unit, and the second output end of the direct injection unit is connected to the second output end of the cross-coupled inverter injection unit; the common source node of the cross-coupled inverter injection unit is connected to the tail current injection unit.

[0008] Furthermore, in the broadband injection-locked four-way frequency divider based on three-point injection of the present invention, the direct injection unit includes a first NMOS transistor, a first capacitor and a first resistor; The first end of the first capacitor is connected to the first injection signal, and the first end of the second resistor is connected to the bias voltage; The gate terminal of the first NMOS transistor is connected to the second terminal of the first capacitor and the first terminal of the first resistor, the drain terminal of the first NMOS transistor is connected to the first output terminal of the direct injection unit, and the source terminal of the first NMOS transistor is connected to the second output terminal of the direct injection unit.

[0009] Furthermore, in the broadband injection-locked four-way frequency divider based on three-point injection of the present invention, the tail current injection unit includes a fourteenth NMOS transistor, a second capacitor and a second resistor; A first end of the second capacitor is connected to the first injection signal, and a second end of the second resistor is connected to the bias voltage; The gate terminal of the fourteenth NMOS transistor is connected to the second end of the second capacitor and the first end of the second resistor, the drain terminal of the fourteenth NMOS transistor is connected to the common source node, and the source terminal of the fourteenth NMOS transistor is connected to the power ground.

[0010] Furthermore, in the broadband injection-locked four-frequency divider based on three-point injection of the present invention, the cross-coupled inverter injection unit includes a fourth PMOS transistor, a fifth PMOS transistor, a sixth NMOS transistor, a seventh NMOS transistor, an eighth PMOS transistor, a ninth PMOS transistor, a tenth NMOS transistor and an eleventh NMOS transistor; The gate terminal of the fourth PMOS transistor is connected to the gate terminal of the seventh NMOS transistor, the source terminal of the fourth PMOS transistor is connected to the power supply terminal, and the drain terminal of the fourth PMOS transistor is connected to the source terminal of the fifth PMOS transistor; the gate terminal of the fifth PMOS transistor is connected to the second injection signal, and the drain terminal of the fifth PMOS transistor is connected to the drain terminal of the sixth NMOS transistor; the gate terminal of the sixth NMOS transistor is connected to the third injection signal, the source terminal of the sixth NMOS transistor is connected to the drain terminal of the seventh NMOS transistor, and the source terminal of the seventh NMOS transistor is connected to the The source terminal of the eleventh NMOS transistor is connected; the gate terminal of the eighth PMOS transistor is connected to the gate terminal of the eleventh NMOS transistor, the source terminal of the eighth PMOS transistor is connected to the power supply terminal, and the drain terminal of the eighth PMOS transistor is connected to the source terminal of the ninth PMOS transistor; the gate terminal of the ninth PMOS transistor is connected to the third injection signal, and the drain terminal of the ninth PMOS transistor is connected to the drain terminal of the tenth NMOS transistor; the gate terminal of the tenth NMOS transistor is connected to the third injection signal, and the source terminal of the tenth NMOS transistor is connected to the drain terminal of the eleventh NMOS transistor.

[0011] Furthermore, in the broadband injection-locked four-frequency divider based on three-point injection of the present invention, the second ring oscillator unit further includes a second PMOS transistor, a third NMOS transistor, a twelfth PMOS transistor, and a thirteenth NMOS transistor; The gate terminal of the second PMOS transistor is connected to the gate terminal of the third NMOS transistor, the drain terminal of the second PMOS transistor is connected to the drain terminal of the third NMOS transistor, and the source terminal of the second PMOS transistor is connected to the source terminal of the twelfth PMOS transistor; the source terminal of the third NMOS transistor is connected to the source terminal of the thirteenth NMOS transistor; the gate terminal of the twelfth PMOS transistor is connected to the gate terminal of the thirteenth NMOS transistor, and the drain terminal of the twelfth PMOS transistor is connected to the drain terminal of the thirteenth NMOS transistor.

[0012] Furthermore, in the broadband injection-locked four-frequency divider based on three-point injection of the present invention, the first ring oscillator unit includes a fifteenth PMOS transistor, a sixteenth NMOS transistor, a seventeenth PMOS transistor, an eighteenth NMOS transistor, a nineteenth PMOS transistor, a twentieth NMOS transistor, a twenty-first PMOS transistor, and a twenty-second NMOS transistor; The gate terminal of the fifteenth PMOS transistor is connected to the gate terminal of the sixteenth NMOS transistor, the source terminal of the fifteenth PMOS transistor is connected to the source terminal of the seventeenth PMOS transistor, the source terminal of the nineteenth PMOS transistor and the source terminal of the twenty-first PMOS transistor, and the connection point is connected to the power supply terminal, the drain terminal of the fifteenth PMOS transistor is connected to the drain terminal of the sixteenth NMOS transistor, the drain terminal of the seventeenth PMOS transistor, the drain terminal of the eighteenth NMOS transistor, the gate terminal of the nineteenth PMOS transistor and the gate terminal of the 20th NMOS transistor; the source terminal of the sixteenth NMOS transistor is connected to the source terminal of the eighteenth NMOS transistor, the source terminal of the twentieth NMOS transistor and the source terminal of the twenty-second NMOS transistor, and the connection point is connected to the power ground terminal; the gate terminal of the seventeenth PMOS transistor is connected to the gate terminal of the eighteenth NMOS transistor, the drain terminal of the nineteenth PMOS transistor, the drain terminal of the twentieth NMOS transistor, the drain terminal of the twenty-first PMOS transistor and the drain terminal of the twenty-second NMOS transistor; the gate terminal of the twenty-first PMOS transistor is connected to the gate terminal of the twenty-second NMOS transistor.

[0013] Furthermore, in the broadband injection-locked four-frequency divider based on three-point injection of the present invention, the first ring oscillator unit is provided with a first input end, a second input end, a first output end and a second output end; Among them, after the gate terminal of the fifteenth PMOS transistor is connected to the gate terminal of the sixteenth NMOS transistor, the connection point is used as the first input terminal of the first ring oscillation unit; after the gate terminal of the twenty-first PMOS transistor is connected to the gate terminal of the twenty-second NMOS transistor, the connection point is used as the second input terminal of the first ring oscillation unit; after the gate terminal of the seventeenth PMOS transistor is connected to the gate terminal of the eighteenth NMOS transistor, the drain terminal of the nineteenth PMOS transistor, the drain terminal of the twentieth NMOS transistor, the drain terminal of the twenty-first PMOS transistor and the drain terminal of the twenty-second NMOS transistor, the connection point is used as the first output terminal of the first ring oscillation unit; after the drain terminal of the fifteenth PMOS transistor is connected to the drain terminal of the sixteenth NMOS transistor, the drain terminal of the seventeenth PMOS transistor, the drain terminal of the eighteenth NMOS transistor, the gate terminal of the nineteenth PMOS transistor and the gate terminal of the 20th NMOS transistor, the connection point is used as the second output terminal of the first ring oscillation unit.

[0014] Furthermore, in the broadband injection-locked four-frequency divider based on three-point injection of the present invention, the second ring oscillator unit is provided with a first input end, a second input end, a first output end and a second output end; Wherein: after the gate terminal of the second PMOS transistor is connected to the gate terminal of the third NMOS transistor, the connection serves as the first input terminal of the second ring oscillation unit; after the gate terminal of the twelfth PMOS transistor is connected to the gate terminal of the thirteenth NMOS transistor, the connection serves as the second input terminal of the second ring oscillation unit; after the drain terminal of the first NMOS transistor is connected to the drain terminal of the ninth PMOS transistor, the drain terminal of the tenth PMOS transistor, the drain terminal of the twelfth PMOS transistor and the drain terminal of the thirteenth NMOS transistor, the connection serves as the first output terminal of the second ring oscillation unit; after the source terminal of the first NMOS transistor is connected to the drain terminal of the second PMOS transistor, the drain terminal of the third NMOS transistor, the drain terminal of the fifth PMOS transistor, the drain terminal of the sixth NMOS transistor, the gate terminal of the eighth PMOS transistor and the gate terminal of the eleventh NMOS transistor, the connection serves as the second output terminal of the second ring oscillation unit.

[0015] Furthermore, in the broadband injection-locked four-frequency divider based on three-point injection of the present invention, the first ring oscillator unit includes a first-stage first ring oscillator unit, a second-stage first ring oscillator unit and a third-stage first ring oscillator unit; The first output end of the first-level first ring oscillator unit is connected to the first input end of the second-level first ring oscillator unit, and the second output end of the first-level first ring oscillator unit is connected to the second input end of the second-level first ring oscillator unit; the first output end of the second-level first ring oscillator unit is connected to the first input end of the third-level first ring oscillator unit, and the second output end of the second-level first ring oscillator unit is connected to the second input end of the third-level first ring oscillator unit; the first output end of the third-level first ring oscillator unit is connected to the first input end of the second ring oscillator unit, and the second output end of the third-level first ring oscillator unit is connected to the second input end of the second ring oscillator unit; the first output end of the second ring oscillator unit is connected to the second input end of the first-level first ring oscillator unit, and the second output end of the second ring oscillator unit is connected to the first input end of the first-level first ring oscillator unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 Schematic diagram of the structure of a broadband injection-locked four-way frequency divider based on three-point injection according to the present invention; Figure 2 Schematic diagram of the structure of the first ring oscillator unit in the present invention; Figure 3 Schematic diagram of the structure of the second ring oscillator unit in the present invention; Figure 4 Schematic diagram of simulation results of the locking range in simulation 1 of the present invention.

[0017] Reference numerals: Figures 1 to 3In the embodiment, M1 is a first NMOS transistor; M2 is a second PMOS transistor; M3 is a third NMOS transistor; M4 is a fourth PMOS transistor; M5 is a fifth PMOS transistor; M6 is a sixth NMOS transistor; M7 is a seventh NMOS transistor; M8 is an eighth PMOS transistor; M9 is a ninth PMOS transistor; M10 is a tenth NMOS transistor; M11 is an eleventh NMOS transistor; M12 is a twelfth PMOS transistor; M13 is a thirteenth NMOS transistor; M14 is a fourteenth NMOS transistor; M15 is a fifteenth PMOS transistor; M16 is a sixteenth NMOS transistor; M17 is a tenth Seventh PMOS transistor; M18, eighteenth NMOS transistor; M19, nineteenth PMOS transistor; M20, twentieth NMOS transistor; M21, twenty-first PMOS transistor; M22, twenty-second NMOS transistor; INJ_S, first injection signal; INJ_N, second injection signal; INJ_P, third injection signal; CLK_P, first input terminal / first output terminal; CLK_N, second input terminal / second output terminal; VBIAS1, first bias voltage; VBIAS2, second bias voltage; VDD, power supply voltage; C1, first capacitor; C2, second capacitor; R1, first resistor; R2, second resistor. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. "Several" means one or more, unless otherwise specifically defined.

[0021] Existing injection-locked frequency dividers based on LC resonant cavities offer high-frequency operation and low phase noise, but their locking range is limited by the resonant cavity's Q factor, resulting in a narrow bandwidth. Furthermore, the on-chip integrated inductor occupies a large chip area, making it difficult to meet miniaturization requirements. In contrast, frequency dividers based on ring oscillators, thanks to their inductor-free design, excel in compactness and wide locking range. However, their inherent multi-stage inverter cascade structure significantly increases power consumption, particularly in high-frequency millimeter-wave scenarios. Currently, mainstream ring oscillator injection-locked frequency dividers employ single-point or dual-node injection schemes, such as direct gate injection or tail current injection, utilizing a single or two injection nodes to couple external signals to extend the locking range. However, these schemes still suffer from the following drawbacks: Single-point injection has limited synchronization efficiency, making it difficult to fully excite the oscillator's harmonic response, resulting in an insufficient actual locking bandwidth. Furthermore, while dual-node injection can enhance injection strength, its bandwidth expansion effect is limited. Further bandwidth improvement often requires increasing the injector size, resulting in a decrease in operating frequency.

[0022] See also Figures 1 to 4 In order to solve the above technical problems, the present invention provides a broadband injection-locked four-way frequency divider based on three-point injection, comprising a first ring oscillator unit and a second ring oscillator unit; wherein: n The first ring oscillator units are connected in series to form a chain structure; the second ring oscillator unit is configured with a direct injection unit, a tail current injection unit and a cross-coupled inverter injection unit; the differential output end of the first ring oscillator unit is connected to the differential input end of the second ring oscillator unit; the first signal is injected into the direct injection unit, the tail current injection unit and / or the cross-coupled inverter injection unit; the second ring oscillator unit receives the second signal from the first ring oscillator unit, and the second signal is converted into a third signal by the second ring oscillator unit, and the third signal is a four-frequency signal; wherein, n An odd number greater than or equal to 3.

[0023] When adopting the above technical solution, in the broadband injection-locked four-way divider based on three-point injection of the present invention, multiple first ring oscillator units are connected in series to form a chain structure, and the first ring oscillator unit is interconnected with the second ring oscillator unit through the differential output end; the second ring oscillator unit is configured with a direct injection unit, a tail current injection unit and a cross-coupled inverter injection unit; the first signal can be injected into the direct injection unit, the tail current injection unit and / or the cross-coupled inverter injection unit, and at the same time, the second ring oscillator unit receives the second signal from the first ring oscillator unit, and the second signal is converted into a four-way third signal through the second ring oscillator unit, thereby dividing the high-frequency second signal into a lower-frequency third signal. In the above technical solution, the first signal is injected through three methods: a direct injection unit, a tail current injection unit, and a cross-coupled inverter injection unit, thereby improving the injection strength and expanding the locking bandwidth. The signal injection method of the cross-coupled inverter injection unit can directly utilize the cross-coupled inverter structure in the negative resistance unit to achieve injection, which can further increase the total injected current. Compared with the existing dual-node injection, the present invention does not increase the injector size, and therefore does not cause the operating frequency to decrease, and can simultaneously meet the requirements of ultra-wideband and high frequency. The above technical solution of the present invention solves the technical problems of the single-point or dual-node injection method used in the existing ring oscillator injection-locked divider, which leads to insufficient actual locking bandwidth range, and the operating frequency decrease due to the need to increase the injector size.

[0024] As a possible implementation, in the broadband injection-locked four-way divider based on three-point injection of the present invention, the first output of the direct injection unit is connected to the first output of the cross-coupled inverter injection unit, and the second output of the direct injection unit is connected to the second output of the cross-coupled inverter injection unit. The common source node of the cross-coupled inverter injection unit is connected to the tail current injection unit. Using this technical solution, the present invention achieves deep synergy of the three-point injection structure through specific circuit connections, further optimizing high-frequency performance and energy efficiency while maintaining ultra-wideband locking capability. In other implementations of the present invention, each stage of the ring oscillator unit (the first and second ring oscillator units) is directly interconnected with the differential input of the next stage of the ring oscillator unit via differential outputs, and the final stage of the ring oscillator unit (the second ring oscillator unit) ultimately outputs a four-way frequency signal. Conventional ring oscillator units are composed of cross-coupled CMOS inverters, forming a closed-loop positive feedback oscillation circuit. By introducing three injection methods—direct injection, tail current injection, and cross-coupled inverter injection—into the broadband injection-locked four-way divider, the present invention can simultaneously meet ultra-wideband and high-frequency requirements.

[0025] See also Figure 3As a possible embodiment, in the broadband injection-locked four-way divider based on three-point injection of the present invention, the direct injection unit includes a first NMOS transistor M1, a first capacitor, and a first resistor. The first end of the first capacitor is connected to the first injection signal INJ_S, and the first end of the first resistor is connected to the first bias voltage VBIAS1. The gate of the first NMOS transistor M1 is connected to the second end of the first capacitor and the second end of the first resistor. The drain of the first NMOS transistor M1 is connected to the first output of the direct injection unit, and the source of the first NMOS transistor M1 is connected to the second output of the direct injection unit. When using this technical solution, the first capacitor is connected in series in the injection signal path to block the DC component and only allow the high-frequency injection signal (the first signal) to pass through, avoiding DC bias conflicts that affect the oscillator operating point and ensuring the intrinsic frequency stability of the ring oscillator unit. The first resistor biases the gate to a fixed voltage Vbias and forms a high-pass network with the capacitor, which can ensure the lossless passage of signals in the target frequency band (such as millimeter waves) while suppressing low-frequency noise. The first NMOS transistor M1 can adopt a minimum channel length (such as L=28nm under a 28nm process), and the drain and source are directly connected to the differential output terminal to avoid introducing additional parasitic capacitance; in other embodiments of the present invention, the direct injection method is implemented by a direct injection module. For example, the direct injection module is implemented by the first NMOS transistor M1; specifically: the drain of the first NMOS transistor M1 is connected to the first output terminal, and the source is connected to the second output terminal, forming a common-source amplifier structure; the gate receives the single-ended injection signal INJ_S through the first DC blocking capacitor, that is, through the first capacitor C1, and is connected to the DC bias voltage through the first bias resistor, that is, through the first resistor R1, that is, connected to the first bias voltage VBIAS1, to form a direct modulation path for the high-frequency signal; at the same time, an RC filtering network is added to the direct injection path to optimize the noise performance.

[0026] See also Figure 3As a possible implementation, in the broadband injection-locked four-way divider based on three-point injection of the present invention, the tail current injection unit includes a fourteenth NMOS transistor M14, a second capacitor C2, and a second resistor R2; a first end of the second capacitor C2 is connected to the first injection signal INJ_S, and a first end of the second resistor R2 is connected to the second bias voltage VBIAS2; a gate end of the fourteenth NMOS transistor M14 is connected to the second end of the second capacitor C2 and the second end of the second resistor, a drain end of the fourteenth NMOS transistor M14 is connected to the common source node, and a source end of the fourteenth NMOS transistor M14 is connected to the power ground. When adopting this technical solution, the core of the tail current injection unit or tail current injection module is the fourteenth NMOS transistor M14. Specifically: the source of the transistor (i.e., the fourteenth NMOS transistor M14) is directly grounded, the four transistors connected to the drain form a common source node, and the gate receives the injection signal INJ_S through the second DC blocking capacitor, i.e., through the second capacitor C2, and is connected to the second bias voltage VBIAS2 through the second bias resistor, i.e., connected to the second bias voltage VBIAS2 through the second resistor R2; this structure changes the AC impedance of the common source node by modulating the transconductance value gm of the fourteenth NMOS transistor M14, and utilizes the nonlinear characteristics of the transistor to expand the low-frequency band locking range.

[0027] See also Figure 3As a possible implementation, in the broadband injection-locked four-way frequency divider based on three-point injection of the present invention, the cross-coupled inverter injection unit includes a fourth PMOS transistor M4, a fifth PMOS transistor M5, a sixth NMOS transistor M6, a seventh NMOS transistor M7, an eighth PMOS transistor M8, a ninth PMOS transistor M9, a tenth NMOS transistor M10, and an eleventh NMOS transistor M11; a gate terminal of the fourth PMOS transistor M4 is connected to a gate terminal of the seventh NMOS transistor M7, a source terminal of the fourth PMOS transistor M4 is connected to a power supply terminal, and a drain terminal of the fourth PMOS transistor M4 is connected to a source terminal of the fifth PMOS transistor M5; a gate terminal of the fifth PMOS transistor M5 is connected to a second injection signal INJ_N, a drain terminal of the fifth PMOS transistor M5 is connected to a drain terminal of the sixth NMOS transistor M6; a gate terminal of the sixth NMOS transistor M6 is connected to a second injection signal INJ_N, and a drain terminal of the fifth PMOS transistor M5 is connected to a drain terminal of the sixth NMOS transistor M6; a gate terminal of the sixth NMOS transistor M6 is connected to a second injection signal INJ_N. The gate terminal is connected to the third injection signal INJ_P, the source terminal of the sixth NMOS transistor M6 is connected to the drain terminal of the seventh NMOS transistor M7, and the source terminal of the seventh NMOS transistor M7 is connected to the source terminal of the eleventh NMOS transistor M11; the gate terminal of the eighth PMOS transistor M8 is connected to the gate terminal of the eleventh NMOS transistor M11, the source terminal of the eighth PMOS transistor M8 is connected to the power supply terminal, and the drain terminal of the eighth PMOS transistor M8 is connected to the source terminal of the ninth PMOS transistor M9; the gate terminal of the ninth PMOS transistor M9 is connected to the third injection signal INJ_P, and the drain terminal of the ninth PMOS transistor M9 is connected to the drain terminal of the tenth NMOS transistor M10; the gate terminal of the tenth NMOS transistor M10 is connected to the third injection signal INJ_P, and the source terminal of the tenth NMOS transistor M10 is connected to the drain terminal of the eleventh NMOS transistor M11. When adopting this technical solution, the cross-coupled inverter is realized by a cross-coupled structure of two differential input stages. The gates and drains of the two are cross-interconnected to form a positive feedback loop, and the output ends generate complementary four-frequency signals respectively; furthermore, the injection signal of the cross-coupled inverter is a pair of differential injection signals with equal amplitudes and opposite phases, which directly drive the gates of the transistors to realize mid-frequency band signal injection; at the same time, the transistor at the top receives the direct injection signal through its gate, and cooperates with the injection signal of the middle cross-coupling pair to directly drive the phase locking of the oscillator.

[0028] See also Figure 3As a possible implementation, in the broadband injection-locked four-way frequency divider based on three-point injection of the present invention, the second ring oscillator unit further includes a second PMOS transistor M2, a third NMOS transistor M3, a twelfth PMOS transistor M12, and a thirteenth NMOS transistor M13; the drain terminal of the second PMOS transistor M2 is connected to the source terminal of the first NMOS transistor M1, the gate terminal of the second PMOS transistor M2 is connected to the gate terminal of the third NMOS transistor M3, the source terminal of the second PMOS transistor M2 is connected to the source terminal of the fourth PMOS transistor M4 and the source terminal of the tenth NMOS transistor M13. The source terminal of the second PMOS transistor M12 is connected; the drain terminal of the third NMOS transistor M3 is connected to the source terminal of the first NMOS transistor M1; the source terminal of the third NMOS transistor M3 is connected to the source terminal of the seventh NMOS transistor M7; the drain terminal of the twelfth PMOS transistor M12 is connected to the drain terminal of the thirteenth NMOS transistor M13; the gate terminal of the twelfth PMOS transistor M12 is connected to the gate terminal of the thirteenth NMOS transistor M13; and the source terminal of the thirteenth NMOS transistor M13 is connected to the drain terminal of the fourteenth NMOS transistor M14. With this technical solution, the second ring oscillator unit achieves a wider locking range and a higher operating frequency based on the existing injection-locked frequency divider by combining direct injection, tail injection, and cross-coupled inverter injection, significantly improving the overall performance of the circuit.

[0029] See also Figure 2As a possible embodiment, in the broadband injection-locked four-frequency divider based on three-point injection of the present invention, the first ring oscillation unit includes a fifteenth PMOS transistor M15, a sixteenth NMOS transistor M16, a seventeenth PMOS transistor M17, an eighteenth NMOS transistor M18, a nineteenth PMOS transistor M19, a twentieth NMOS transistor M20, a twenty-first PMOS transistor M21, and a twenty-second NMOS transistor M22; the gate terminal of the fifteenth PMOS transistor M15 is connected to the gate terminal of the sixteenth NMOS transistor M16, the source terminal of the fifteenth PMOS transistor M15 is connected to the source terminal of the seventeenth PMOS transistor M17, the source terminal of the nineteenth PMOS transistor M19, and the source terminal of the twenty-first PMOS transistor M21, and the connection point is connected to the power supply terminal, and the drain terminal of the fifteenth PMOS transistor M15 is connected to the drain terminal of the sixteenth NMOS transistor M16. The gate terminal of the seventeenth PMOS transistor M17 is connected to the gate terminal of the eighteenth NMOS transistor M18, the drain terminal of the eighteenth NMOS transistor M18, the gate terminal of the nineteenth PMOS transistor M19 and the gate terminal of the twentieth NMOS transistor M20; the source terminal of the sixteenth NMOS transistor M16 is connected to the source terminal of the eighteenth NMOS transistor M18, the source terminal of the twentieth NMOS transistor M20 and the source terminal of the twenty-second NMOS transistor M22, and the connection point is connected to the power ground; the gate terminal of the seventeenth PMOS transistor M17 is connected to the gate terminal of the eighteenth NMOS transistor M18, the drain terminal of the nineteenth PMOS transistor M19, the drain terminal of the twentieth NMOS transistor M20, the drain terminal of the twenty-first PMOS transistor M21 and the drain terminal of the twenty-second NMOS transistor M22; the gate terminal of the twenty-first PMOS transistor M21 is connected to the gate terminal of the twenty-second NMOS transistor M22. When adopting this technical solution, multiple first ring oscillator units are composed of cross-coupled CMOS inverters to form a closed-loop positive feedback oscillation circuit. The oscillation frequency is jointly determined by the transistor transconductance and the node parasitic capacitance. There is no external signal injection port inside the unit.

[0030] See also Figure 2As a possible embodiment, in the broadband injection-locked four-way divider based on three-point injection of the present invention, the first ring oscillation unit is provided with a first input terminal, a second input terminal, a first output terminal, and a second output terminal; wherein, the gate terminal of the fifteenth PMOS transistor M15 is connected to the gate terminal of the sixteenth NMOS transistor M16, and the connection point serves as the first input terminal of the first ring oscillation unit; the gate terminal of the twenty-first PMOS transistor M21 is connected to the gate terminal of the twenty-second NMOS transistor M22, and the connection point serves as the second input terminal of the first ring oscillation unit; the gate terminal of the seventeenth PMOS transistor M17 is connected to the gate terminal of the eighteenth NMOS transistor M18, After the drain terminal of the nineteenth PMOS transistor M19, the drain terminal of the twentieth NMOS transistor M20, the drain terminal of the twenty-first PMOS transistor M21, and the drain terminal of the twenty-second NMOS transistor M22 are connected, the connection point serves as the first output terminal of the first ring oscillator unit; after the drain terminal of the fifteenth PMOS transistor M15, the drain terminal of the sixteenth NMOS transistor M16, the drain terminal of the seventeenth PMOS transistor M17, the drain terminal of the eighteenth NMOS transistor M18, the gate terminal of the nineteenth PMOS transistor M19, and the gate terminal of the twentieth NMOS transistor M20 are connected, the connection point serves as the second output terminal of the first ring oscillator unit. When this technical solution is adopted, the first ring oscillator unit and the second ring oscillator unit can be connected through the first input terminal, the second input terminal, the first output terminal, and the second output terminal of the multiple first ring oscillator units to form the broadband injection-locked four-way divider based on three-point injection of the present invention.

[0031] See also Figure 3As a possible embodiment, in the broadband injection-locked four-way frequency divider based on three-point injection of the present invention, the second ring oscillation unit is provided with a first input terminal, a second input terminal, a first output terminal, and a second output terminal; wherein: after the gate terminal of the second PMOS transistor M2 is connected to the gate terminal of the third NMOS transistor M3, the connection serves as the first input terminal of the second ring oscillation unit; after the gate terminal of the twelfth PMOS transistor M12 is connected to the gate terminal of the thirteenth NMOS transistor M13, the connection serves as the second input terminal of the second ring oscillation unit; the drain terminal of the first NMOS transistor M1 is connected to the gate terminal of the ninth PMOS transistor M2. After the drain terminal of M9, the drain terminal of the tenth PMOS transistor M10, the drain terminal of the twelfth PMOS transistor M12, and the drain terminal of the thirteenth NMOS transistor M13 are connected, the connection serves as the first output terminal of the second ring oscillator unit; after the source terminal of the first NMOS transistor M1 is connected with the drain terminal of the second PMOS transistor M2, the drain terminal of the third NMOS transistor M3, the drain terminal of the fifth PMOS transistor M5, the drain terminal of the sixth NMOS transistor M6, the gate terminal of the eighth PMOS transistor M8, and the gate terminal of the eleventh NMOS transistor M11, the connection serves as the second output terminal of the second ring oscillator unit. When this technical solution is adopted, the second ring oscillator unit can be connected to the first ring oscillator unit via its first input terminal, second input terminal, first output terminal, and second output terminal to form the broadband injection-locked four-way divider based on three-point injection of the present invention.

[0032] As a possible embodiment, in the broadband injection-locked four-way divider based on three-point injection of the present invention, the first ring oscillator unit includes a first-stage first ring oscillator unit, a second-stage first ring oscillator unit, and a third-stage first ring oscillator unit; the first output end of the first-stage first ring oscillator unit is connected to the first input end of the second-stage first ring oscillator unit, and the second output end of the first-stage first ring oscillator unit is connected to the second input end of the second-stage first ring oscillator unit; the first output end of the second-stage first ring oscillator unit is connected to the first input end of the third-stage first ring oscillator unit, and the second output end of the second-stage first ring oscillator unit is connected to the second input end of the third-stage first ring oscillator unit; the first output end of the third-stage first ring oscillator unit is connected to the first input end of the second ring oscillator unit, and the second output end of the third-stage first ring oscillator unit is connected to the second input end of the second ring oscillator unit; the first output end of the second ring oscillator unit is connected to the second input end of the first-stage first ring oscillator unit, and the second output end of the second ring oscillator unit is connected to the first input end of the first-stage first ring oscillator unit. When adopting this technical solution, the frequency lock range of the divider is expanded by increasing the injection intensity without introducing the influence of parasitic capacitance.

[0033] Furthermore, a simulation experiment was conducted on the broadband injection-locked four-way frequency divider based on three-point injection of the present invention. The simulation experiment results are shown in FIG. Figure 4.

[0034] Specifically, the components used in the simulation experiment were fabricated using a SMIC 40nm RF CMOS process. A complete four-divider circuit was constructed using the Cadence IC617 simulation platform under a Linux system environment. The simulation was performed using the Spectre RF simulation tool, with a power supply voltage (VDD) of 1.2V, an operating temperature of 27°C, a first bias voltage (VBIAS1) of 0.75V, and a second bias voltage (VBIAS2) of 0.65V.

[0035] Simulation 1: Under standard working conditions, the Spectre RF simulation tool is used to set an output port at the differential output end of the broadband injection-locked four-way divider of the present invention and perform a frequency range scanning simulation. The results are as follows: Figure 4 As shown, Figure 4 This figure shows the locking range in Simulation 1. The horizontal axis represents the input signal frequency in GHz, and the vertical axis represents the input power in dBm. The simulation results show that when the input power is 0 dBm, the locking range is 2.12-29.20 GHz.

[0036] Simulation 2: To verify the functionality of the circuit units corresponding to the three-point injection, a special injection efficiency comparison simulation was designed. While maintaining the total injection power constant, the locking ranges for a single injection path and for combined three-point injection were simulated. The results showed that the locking range for direct injection alone was 82.8%, for tail injection it was 64.5%, and for cross-coupled inverter injection it was ±50.2%. However, the locking range for combined three-point injection expanded to 172.5%, demonstrating the significant advantages of multi-path coordinated injection.

[0037] Simulation 3: A transient simulation was performed to analyze the startup characteristics. The input signal was applied at 5ns. The results showed that the circuit achieved initial lock within 15ns and reached full stability within 35ns.

[0038] Simulation results demonstrate that the broadband injection-locked four-way divider based on three-point injection, proposed in this paper, achieves an ultra-wide locking range and excellent phase noise performance while maintaining low power consumption and low voltage. These excellent performance indicators fully demonstrate the technical advantages of the three-point injection architecture and provide a high-performance frequency conversion solution for millimeter-wave communication systems.

[0039] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0040] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A broadband injection-locked four-way frequency divider based on three-point injection, characterized in that: include: The first ring oscillator unit, n The first ring oscillating units are connected in series to form a chain structure; a second ring oscillator unit, configured with a direct injection unit, a tail current injection unit, and a cross-coupled inverter injection unit; a differential output end of the first ring oscillator unit is connected to a differential input end of the second ring oscillator unit; The first signal is injected into the direct injection unit, the tail current injection unit and / or the cross-coupled inverter injection unit; the second ring oscillator unit receives the second signal from the first ring oscillator unit, and the second signal is converted into a third signal by the second ring oscillator unit, and the third signal is a four-frequency signal; in, n An odd number greater than or equal to 3.

2. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 1, characterized in that: The first output end of the direct injection unit is connected to the first output end of the cross-coupled inverter injection unit, and the second output end of the direct injection unit is connected to the second output end of the cross-coupled inverter injection unit; the common source node of the cross-coupled inverter injection unit is connected to the tail current injection unit.

3. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 1 or 2, characterized in that: The direct injection unit includes a first NMOS transistor, a first capacitor and a first resistor; The first end of the first capacitor is connected to the first injection signal, and the second end of the first resistor is connected to the bias voltage; The gate terminal of the first NMOS transistor is connected to the second terminal of the first capacitor and the first terminal of the first resistor, the drain terminal of the first NMOS transistor is connected to the first output terminal of the direct injection unit, and the source terminal of the first NMOS transistor is connected to the second output terminal of the direct injection unit.

4. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 3, characterized in that: The tail current injection unit includes a fourteenth NMOS transistor, a second capacitor and a second resistor; A first end of the second capacitor is connected to the first injection signal, and a second end of the second resistor is connected to the bias voltage; The gate terminal of the fourteenth NMOS transistor is connected to the second end of the second capacitor and the first end of the second resistor, the drain terminal of the fourteenth NMOS transistor is connected to the common source node, and the source terminal of the fourteenth NMOS transistor is connected to the power ground.

5. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 4, characterized in that: The cross-coupled inverter injection unit includes a fourth PMOS transistor, a fifth PMOS transistor, a sixth NMOS transistor, a seventh NMOS transistor, an eighth PMOS transistor, a ninth PMOS transistor, a tenth NMOS transistor and an eleventh NMOS transistor; The gate terminal of the fourth PMOS transistor is connected to the gate terminal of the seventh NMOS transistor, the source terminal of the fourth PMOS transistor is connected to the power supply terminal, and the drain terminal of the fourth PMOS transistor is connected to the source terminal of the fifth PMOS transistor; the gate terminal of the fifth PMOS transistor is connected to the second injection signal, and the drain terminal of the fifth PMOS transistor is connected to the drain terminal of the sixth NMOS transistor; the gate terminal of the sixth NMOS transistor is connected to the third injection signal, the source terminal of the sixth NMOS transistor is connected to the drain terminal of the seventh NMOS transistor, and the source terminal of the seventh NMOS transistor is connected to the The source terminal of the eleventh NMOS transistor is connected; the gate terminal of the eighth PMOS transistor is connected to the gate terminal of the eleventh NMOS transistor, the source terminal of the eighth PMOS transistor is connected to the power supply terminal, and the drain terminal of the eighth PMOS transistor is connected to the source terminal of the ninth PMOS transistor; the gate terminal of the ninth PMOS transistor is connected to the third injection signal, and the drain terminal of the ninth PMOS transistor is connected to the drain terminal of the tenth NMOS transistor; the gate terminal of the tenth NMOS transistor is connected to the third injection signal, and the source terminal of the tenth NMOS transistor is connected to the drain terminal of the eleventh NMOS transistor.

6. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 5, characterized in that: The second ring oscillator unit further includes a second PMOS transistor, a third NMOS transistor, a twelfth PMOS transistor, and a thirteenth NMOS transistor; The gate terminal of the second PMOS transistor is connected to the gate terminal of the third NMOS transistor, the drain terminal of the second PMOS transistor is connected to the drain terminal of the third NMOS transistor, and the source terminal of the second PMOS transistor is connected to the source terminal of the twelfth PMOS transistor; the source terminal of the third NMOS transistor is connected to the source terminal of the thirteenth NMOS transistor; the gate terminal of the twelfth PMOS transistor is connected to the gate terminal of the thirteenth NMOS transistor, and the drain terminal of the twelfth PMOS transistor is connected to the drain terminal of the thirteenth NMOS transistor.

7. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 6, characterized in that: The first ring oscillation unit includes a fifteenth PMOS transistor, a sixteenth NMOS transistor, a seventeenth PMOS transistor, an eighteenth NMOS transistor, a nineteenth PMOS transistor, a twentieth NMOS transistor, a twenty-first PMOS transistor and a twenty-second NMOS transistor; The gate terminal of the fifteenth PMOS transistor is connected to the gate terminal of the sixteenth NMOS transistor, the source terminal of the fifteenth PMOS transistor is connected to the source terminal of the seventeenth PMOS transistor, the source terminal of the nineteenth PMOS transistor, and the source terminal of the twenty-first PMOS transistor, and the connection point is connected to the power supply terminal, the drain terminal of the fifteenth PMOS transistor is connected to the drain terminal of the sixteenth NMOS transistor, the drain terminal of the seventeenth PMOS transistor, the drain terminal of the eighteenth NMOS transistor, the gate terminal of the nineteenth PMOS transistor, and the gate terminal of the 20th NMOS transistor; the source terminal of the sixteenth NMOS transistor is connected to the source terminal of the eighteenth NMOS transistor, the source terminal of the 20th NMOS transistor, and the source terminal of the twenty-second NMOS transistor, and the connection point is connected to the power ground terminal; The gate terminal of the seventeenth PMOS transistor is connected to the gate terminal of the eighteenth NMOS transistor, the drain terminal of the nineteenth PMOS transistor, the drain terminal of the twentieth NMOS transistor, the drain terminal of the twenty-first PMOS transistor and the drain terminal of the twenty-second NMOS transistor; the gate terminal of the twenty-first PMOS transistor is connected to the gate terminal of the twenty-second NMOS transistor.

8. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 7, characterized in that: The first ring oscillator unit is provided with a first input end, a second input end, a first output end and a second output end; Among them, after the gate terminal of the fifteenth PMOS transistor is connected to the gate terminal of the sixteenth NMOS transistor, the connection point is used as the first input terminal of the first ring oscillation unit; after the gate terminal of the twenty-first PMOS transistor is connected to the gate terminal of the twenty-second NMOS transistor, the connection point is used as the second input terminal of the first ring oscillation unit; after the gate terminal of the seventeenth PMOS transistor is connected to the gate terminal of the eighteenth NMOS transistor, the drain terminal of the nineteenth PMOS transistor, the drain terminal of the twentieth NMOS transistor, the drain terminal of the twenty-first PMOS transistor and the drain terminal of the twenty-second NMOS transistor, the connection point is used as the first output terminal of the first ring oscillation unit; after the drain terminal of the fifteenth PMOS transistor is connected to the drain terminal of the sixteenth NMOS transistor, the drain terminal of the seventeenth PMOS transistor, the drain terminal of the eighteenth NMOS transistor, the gate terminal of the nineteenth PMOS transistor and the gate terminal of the 20th NMOS transistor, the connection point is used as the second output terminal of the first ring oscillation unit.

9. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 8, characterized in that: The second ring oscillator unit is provided with a first input end, a second input end, a first output end and a second output end; Wherein: after the gate terminal of the second PMOS transistor is connected to the gate terminal of the third NMOS transistor, the connection serves as the first input terminal of the second ring oscillation unit; after the gate terminal of the twelfth PMOS transistor is connected to the gate terminal of the thirteenth NMOS transistor, the connection serves as the second input terminal of the second ring oscillation unit; after the drain terminal of the first NMOS transistor is connected to the drain terminal of the ninth PMOS transistor, the drain terminal of the tenth PMOS transistor, the drain terminal of the twelfth PMOS transistor and the drain terminal of the thirteenth NMOS transistor, the connection serves as the first output terminal of the second ring oscillation unit; after the source terminal of the first NMOS transistor is connected to the drain terminal of the second PMOS transistor, the drain terminal of the third NMOS transistor, the drain terminal of the fifth PMOS transistor, the drain terminal of the sixth NMOS transistor, the gate terminal of the eighth PMOS transistor and the gate terminal of the eleventh NMOS transistor, the connection serves as the second output terminal of the second ring oscillation unit.

10. The broadband injection-locked four-way frequency divider based on three-point injection according to claim 9, characterized in that: The first ring oscillator unit includes a first-stage first ring oscillator unit, a second-stage first ring oscillator unit, and a third-stage first ring oscillator unit; The first output end of the first-stage first ring oscillator unit is connected to the first input end of the second-stage first ring oscillator unit, and the second output end of the first-stage first ring oscillator unit is connected to the second input end of the second-stage first ring oscillator unit; The first output end of the second-stage first ring oscillator unit is connected to the first input end of the third-stage first ring oscillator unit, and the second output end of the second-stage first ring oscillator unit is connected to the second input end of the third-stage first ring oscillator unit; the first output end of the third-stage first ring oscillator unit is connected to the first input end of the second ring oscillator unit, and the second output end of the third-stage first ring oscillator unit is connected to the second input end of the second ring oscillator unit; the first output end of the second ring oscillator unit is connected to the second input end of the first-stage first ring oscillator unit, and the second output end of the second ring oscillator unit is connected to the first input end of the first-stage first ring oscillator unit.

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