Near-earth orbit satellite internet millimeter wave oscillator based on single-phase multi-winding transformer

Abstract

The invention relates to a near-earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer, which belongs to the field of near-earth orbit satellite communication design and comprises three resonance circuits with the same structure and a negative resistance active circuit. Each resonant circuit comprises a switch capacitor, a blocking capacitor, a resonant capacitor, a grounding resistor, a tuning resistor, a resonant inductor and a switch coupling inductor, and each negative resistance active circuit comprises a cross coupling pair MOS tube and a current source. The resonant inductor and all the switch coupling inductors are of a single-phase multi-winding transformer structure, only one voltage-controlled oscillation unit works under different working frequency bands, and tuning of the VCO bandwidth is achieved in a combined mode of switching on and switching off of the switch capacitors and switching on and switching off of the switch coupling inductors. Under the condition that the layout area and the design complexity of a chip are ensured, all frequency bands currently distributed by the working millimeter waves of the voltage-controlled oscillator are enabled to realize a wide frequency tuning range.

Description

Technical Field

[0001] The invention belongs to the field of satellite communication design and relates to a low-Earth orbit satellite Internet millimeter wave oscillator based on a single-phase multi-winding transformer. Background Art

[0002] 5G mobile communications provide broadband, massive connections and low-latency services to people with three major application scenarios: enhanced mobile broadband, large-connection Internet of Things, and low-latency and high-reliability communications, which effectively promotes social and economic development. At present, 5G network coverage is still centered on base stations, and there are still a large number of communication blind spots in areas such as deserts, uninhabited areas, and oceans that are not covered by base stations. At the same time, the communication objects of 5G are concentrated in a limited space range within 10km above the land surface, and it is impossible to realize the communication vision of seamless coverage of "air, space, sea and land". The overall vision of 6G is a further expansion and upgrade of the 5G vision, which is characterized by full coverage, full spectrum and full application. Although the 6G vision has not yet been fully clarified, its basic goals can be seen. Based on 5G, it is not possible to truly achieve "global full domain" and "interconnection of all things". Therefore, the medium and low orbit satellite network, namely the Internet of Space (IoS), will be an important part of 6G, integrated with the ground B5G system to realize the ubiquitous connection of the integrated communication network of air, space, land and sea.

[0003] Broadband transmission technology is the foundation of supporting communication networks. To realize an integrated high-speed communication network covering air, land, and sea, broadband transmission technology will be the core. The terahertz band is limited by the characteristics of semiconductor processes, and has problems such as insufficient output power, poor noise coefficient indicators, high cost, and complex processing technology. Compared with the terahertz band, the millimeter wave band has been fully developed in the 5G era, the device capabilities have been greatly improved, and the industrial chain is complete and rich. Therefore, for 6G, the millimeter wave band will be the first choice for inter-satellite links, user links covered by satellites downward, and feeder links from satellites to ground stations. For example, SpaceX's Starlink mainly uses the Ka and Q bands, and the O3B medium-orbit satellite network uses the Ku and Ka bands.

[0004] At the 2019 World Radiocommunication Conference, the frequency bands for millimeter waves were unified as 24.25GHz to 27.5GHz, 37GHz to 43.5GHz, and 66GHz to 71GHz. These frequency bands have wide bandwidths and high frequencies, and it is very challenging to design and implement a voltage-controlled oscillator with low phase noise, low power consumption, and a wide tuning range. At present, most voltage-controlled oscillator designs operate at 24.25GHz to 27.5GHz, a few voltage-controlled oscillators are designed to operate at 66GHz to 71GHz, and very few voltage-controlled oscillators are designed to operate at 24.25GHz to 27.5GHz and 37GHz to 43.5GHz at the same time. No voltage-controlled oscillator has been found to be able to operate in three frequency bands. For wireless communications, different frequency bands correspond to different transmission bandwidths, which determine different applicable scenarios. Higher frequencies often have larger bandwidth space, which means greater data throughput and higher rates. Therefore, in order to meet the requirements of 6G full coverage, full spectrum and full application, it is of great significance to study how to achieve full-band wide-band tuning range while ensuring the performance and layout area of ​​the voltage-controlled oscillator. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a low-Earth orbit satellite Internet millimeter wave oscillator based on a single-phase multi-winding transformer. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] The present invention provides a low-Earth orbit satellite Internet millimeter wave oscillator based on a single-phase multi-winding transformer, comprising:

[0007] Three resonant circuits and negative resistance active circuits with the same structure, namely, a first resonant circuit, a second resonant circuit, a third resonant circuit, a first negative resistance active circuit, a second negative resistance active circuit and a third negative resistance active circuit;

[0008] The resonant circuits all include: a switching capacitor, a DC blocking capacitor, a resonant capacitor, a grounding resistor, a tuning resistor, a resonant inductor, a switch coupling inductor, and a switch MOS tube. In the first resonant circuit, the DC blocking capacitor C1, the grounding resistor R1, the switching capacitor Var1, the tuning resistor R3, the switching capacitor Var2, the grounding resistor R2, and the DC blocking capacitor C2 are sequentially connected in series, the other ends of the DC blocking capacitors C1 and C2 are respectively connected to the two ends of the resonant inductor L1, the other ends of the grounding resistors R1 and R2 are both grounded, the other end of the tuning resistor R3 is connected to the input control voltage Vctrl1, the resonant capacitors C3 and C4 are connected in series, and the other ends of the resonant capacitors C3 and C4 are respectively connected to the two ends of the resonant inductor L1. In the second resonant circuit, the DC blocking capacitor C5, the grounding resistor R4, the switching capacitor Var3, the tuning resistor R6, the switching capacitor Var4, the grounding resistor R5, and the DC blocking capacitor C6 are connected in series in sequence, the other ends of the DC blocking capacitors C5 and C6 are respectively connected to the two ends of the resonant inductor L2, the other ends of the grounding resistors R4 and R5 are both grounded, the other end of the tuning resistor R6 is connected to the input control voltage Vctrl2, the resonant capacitors C7 and C8 are connected in series, and the other ends of the resonant capacitors C7 and C8 are respectively connected to the two ends of the resonant inductor L2. In the third resonant circuit, the DC blocking capacitor C9, the grounding resistor R7, the switch capacitor Var5, the tuning resistor R9, the switch capacitor Var6, the grounding resistor R8, and the DC blocking capacitor C10 are connected in series in sequence, the other ends of the DC blocking capacitors C9 and C10 are connected to the two ends of the resonant inductor L3 respectively, the other ends of the grounding resistors R7 and R8 are both grounded, the other end of the tuning resistor R9 is connected to the input control voltage Vctrl3, the resonant capacitors C11 and C12 are connected in series, the other ends of the resonant capacitors C11 and C12 are connected to the two ends of the resonant inductor L3 respectively. The two ends of the switch coupling inductor L4 are respectively connected to the drain and source of the switch MOS tube M7, the base of the switch MOS tube M7 is connected to the control voltage Vctrl4, the drain of the switch MOS tube M7 is connected to the grounding resistor R10, the source of the switch MOS tube M7 is connected to the grounding resistor R11, and the other ends of the grounding resistors R10 and R11 are both grounded.

[0009] The negative resistance active circuits all include: a cross-coupled MOS transistor and a current source. In the first negative resistance active circuit, the drain of the cross-coupled MOS transistor M1 and the drain of the cross-coupled MOS transistor M2 are respectively connected to the two ends of the resonant inductor L1, the gate of the cross-coupled MOS transistor M1 is connected to the drain of the cross-coupled MOS transistor M2, the drain of the cross-coupled MOS transistor M1 is connected to the gate of the cross-coupled MOS transistor M2, the source of the cross-coupled MOS transistor M1 is connected to the source of the cross-coupled MOS transistor M2, and is connected in series with the input end of the current source I1, and the output end of the current source I1 is grounded. In the second negative resistance active circuit, the drain of the cross-coupling pair MOS transistor M3 and the drain of the cross-coupling pair MOS transistor M4 are respectively connected to the two ends of the resonant inductor L2, the gate of the cross-coupling pair MOS transistor M3 is connected to the drain of the cross-coupling pair MOS transistor M4, the drain of the cross-coupling pair MOS transistor M3 is connected to the gate of the cross-coupling pair MOS transistor M4, the source of the cross-coupling pair MOS transistor M3 is connected to the source of the cross-coupling pair MOS transistor M4, and is connected in series with the input end of the current source I2, and the output end of the current source I2 is grounded. In the third negative resistance active circuit, the drain of the cross-coupling pair MOS transistor M5 and the drain of the cross-coupling pair MOS transistor M6 are respectively connected to the two ends of the resonant inductor L3, the gate of the cross-coupling pair MOS transistor M5 is connected to the drain of the cross-coupling pair MOS transistor M6, the drain of the cross-coupling pair MOS transistor M5 is connected to the gate of the cross-coupling pair MOS transistor M5, the source of the cross-coupling pair MOS transistor M5 is connected to the source of the cross-coupling pair MOS transistor M6 and is connected in series with the input end of the current source I3, and the output end of the current source I3 is grounded.

[0010] Further, the first voltage-controlled oscillator unit includes a first resonant circuit, a switch coupling inductor L4, a switch MOS tube M7, a grounding resistor R10, a grounding resistor R11, and a first negative resistance active circuit. The second voltage-controlled oscillator unit includes a second resonant circuit, a switch coupling inductor L4, a switch MOS tube M7, a grounding resistor R10, a grounding resistor R11, and a second negative resistance active circuit. The third voltage-controlled oscillator unit includes a third resonant circuit, a switch coupling inductor L4, a switch MOS tube M7, a grounding resistor R10, a grounding resistor R11, and a third negative resistance active circuit.

[0011] Furthermore, the voltage controlled oscillator controls the voltage difference across the varactor to fine-tune the bandwidth of the voltage controlled oscillator. By changing the voltage difference across the varactor to change the capacitance value, and then changing the resonant frequency, the output frequency can be continuously adjusted.

[0012] Furthermore, the voltage-controlled oscillator controls the switching coupling inductor to turn on and off to roughly adjust the bandwidth of the voltage-controlled oscillator. By adjusting the magnitude of the control voltage Vctrl4, the switching MOS tube M7 is controlled to turn on and off, thereby controlling whether the switching coupling inductor L4 is connected to the transformer, and by changing the coupling coefficient of the transformer, the resonant inductance value of the LC loop in the resonant circuit is changed, thereby changing the frequency of the oscillation signal, thereby achieving the purpose of expanding the bandwidth.

[0013] Furthermore, the resonant inductors L1, L2, L3 and the switch coupled inductor L4 in the resonant circuit form a single-phase multi-winding transformer structure, wherein the switch coupled inductor L4 is the input winding, and the resonant inductors L1, L2, L3 are the output windings.

[0014] Furthermore, the switch coupling inductor L4 is arranged in the innermost circle, the resonant inductor L1 is arranged in the outermost circle, and the resonant inductor L3 and the resonant inductor L2 are arranged in sequence between the switch coupling inductor L4 and the resonant inductor L1.

[0015] Furthermore, when the voltage-controlled oscillator is working, only one voltage-controlled oscillation unit works normally at a time. When the first voltage-controlled oscillation unit is working, the tail current source I1 in the first negative resistance active circuit is turned on, and the tail current source I2 in the second negative resistance active circuit and the tail current source I3 in the third negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a signal in the high frequency band. When the second voltage-controlled oscillation unit is working, the tail current source I2 in the second negative resistance active circuit is turned on, and the tail current source I1 in the first negative resistance active circuit and the tail current source I3 in the third negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a signal in the medium frequency band. When the third voltage-controlled oscillation unit is working, the tail current source I3 in the third negative resistance active circuit is turned on, and the tail current source I1 in the first negative resistance active circuit and the tail current source I2 in the second negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a signal in the low frequency band.

[0016] Furthermore, the frequency range of the high-band signal output by the first oscillation unit is 67.5 GHz to 72.5 GHz, the frequency range of the mid-band signal output by the second oscillation unit is 38.5 GHz to 45 GHz, and the frequency range of the low-band signal output by the third oscillation unit is 26.75 GHz to 29 GHz.

[0017] Furthermore, taking various influencing factors into comprehensive consideration, after the voltage-controlled oscillator is finally processed into a physical object, the output frequency range will be reduced by 1.5 GHz as a whole. The output frequency range of the voltage-controlled oscillator after the reduction can completely and accurately cover all frequency bands currently allocated to millimeter waves.

[0018] The beneficial effects of the present invention are:

[0019] The schematic diagram of the millimeter wave oscillator for low earth orbit satellite internet based on a single-phase multi-winding transformer described in the present invention is as follows: Figure 1 As shown. The resonant inductor and all the switch-coupled inductors of the present invention adopt a single-phase multi-winding transformer structure. Only one voltage-controlled oscillator unit works in different operating frequency bands. The VCO bandwidth is tuned by combining the switching capacitor on and off and the switching-coupled inductor on and off. While ensuring the chip layout area and design complexity, the voltage-controlled oscillator works in all the frequency bands currently allocated for millimeter waves, achieving a wide frequency tuning range. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of a low-Earth orbit satellite Internet millimeter wave oscillator based on a single-phase multi-winding transformer according to the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the transformer in the voltage-controlled oscillator of the present invention. DETAILED DESCRIPTION

[0022] In order to further understand the present invention, the technical solutions in the present invention will be described below in conjunction with the accompanying drawings and specific embodiments. These descriptions are only to further explain the features and advantages of the present invention, but the protection scope of the present invention is not limited thereto.

[0023] The present invention provides a low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer, such as Figure 1 As shown, this may include:

[0024] Three resonant circuits and negative resistance active circuits with the same structure, namely, a first resonant circuit, a second resonant circuit, a third resonant circuit, a first negative resistance active circuit, a second negative resistance active circuit and a third negative resistance active circuit.

[0025] The resonant circuits all include: a switching capacitor, a DC blocking capacitor, a resonant capacitor, a grounding resistor, a tuning resistor, a resonant inductor, a switch coupling inductor, and a switch MOS tube. In the first resonant circuit, the DC blocking capacitor C1, the grounding resistor R1, the switching capacitor Var1, the tuning resistor R3, the switching capacitor Var2, the grounding resistor R2, and the DC blocking capacitor C2 are sequentially connected in series, the other ends of the DC blocking capacitors C1 and C2 are respectively connected to the two ends of the resonant inductor L1, the other ends of the grounding resistors R1 and R2 are both grounded, the other end of the tuning resistor R3 is connected to the input control voltage Vctrl1, the resonant capacitors C3 and C4 are connected in series, and the other ends of the resonant capacitors C3 and C4 are respectively connected to the two ends of the resonant inductor L1. In the second resonant circuit, the DC blocking capacitor C5, the grounding resistor R4, the switching capacitor Var3, the tuning resistor R6, the switching capacitor Var4, the grounding resistor R5, and the DC blocking capacitor C6 are connected in series in sequence, the other ends of the DC blocking capacitors C5 and C6 are respectively connected to the two ends of the resonant inductor L2, the other ends of the grounding resistors R4 and R5 are both grounded, the other end of the tuning resistor R6 is connected to the input control voltage Vctrl2, the resonant capacitors C7 and C8 are connected in series, and the other ends of the resonant capacitors C7 and C8 are respectively connected to the two ends of the resonant inductor L2. In the third resonant circuit, the DC blocking capacitor C9, the grounding resistor R7, the switch capacitor Var5, the tuning resistor R9, the switch capacitor Var6, the grounding resistor R8, and the DC blocking capacitor C10 are connected in series in sequence, the other ends of the DC blocking capacitors C9 and C10 are connected to the two ends of the resonant inductor L3 respectively, the other ends of the grounding resistors R7 and R8 are both grounded, the other end of the tuning resistor R9 is connected to the input control voltage Vctrl3, the resonant capacitors C11 and C12 are connected in series, the other ends of the resonant capacitors C11 and C12 are connected to the two ends of the resonant inductor L3 respectively. The two ends of the switch coupling inductor L4 are respectively connected to the drain and source of the switch MOS tube M7, the base of the switch MOS tube M7 is connected to the control voltage Vctrl4, the drain of the switch MOS tube M7 is connected to the grounding resistor R10, the source of the switch MOS tube M7 is connected to the grounding resistor R11, and the other ends of the grounding resistors R10 and R11 are both grounded.

[0026] The negative resistance active circuits all include: a cross-coupled MOS transistor and a current source. In the first negative resistance active circuit, the drain of the cross-coupled MOS transistor M1 and the drain of the cross-coupled MOS transistor M2 are respectively connected to the two ends of the resonant inductor L1, the gate of the cross-coupled MOS transistor M1 is connected to the drain of the cross-coupled MOS transistor M2, the drain of the cross-coupled MOS transistor M1 is connected to the gate of the cross-coupled MOS transistor M2, the source of the cross-coupled MOS transistor M1 is connected to the source of the cross-coupled MOS transistor M2, and is connected in series with the input end of the current source I1, and the output end of the current source I1 is grounded. In the second negative resistance active circuit, the drain of the cross-coupling pair MOS transistor M3 and the drain of the cross-coupling pair MOS transistor M4 are respectively connected to the two ends of the resonant inductor L2, the gate of the cross-coupling pair MOS transistor M3 is connected to the drain of the cross-coupling pair MOS transistor M4, the drain of the cross-coupling pair MOS transistor M3 is connected to the gate of the cross-coupling pair MOS transistor M4, the source of the cross-coupling pair MOS transistor M3 is connected to the source of the cross-coupling pair MOS transistor M4, and is connected in series with the input end of the current source I2, and the output end of the current source I2 is grounded. In the third negative resistance active circuit, the drain of the cross-coupling pair MOS transistor M5 and the drain of the cross-coupling pair MOS transistor M6 are respectively connected to the two ends of the resonant inductor L3, the gate of the cross-coupling pair MOS transistor M5 is connected to the drain of the cross-coupling pair MOS transistor M6, the drain of the cross-coupling pair MOS transistor M5 is connected to the gate of the cross-coupling pair MOS transistor M5, the source of the cross-coupling pair MOS transistor M5 is connected to the source of the cross-coupling pair MOS transistor M6 and is connected in series with the input end of the current source I3, and the output end of the current source I3 is grounded.

[0027] In the embodiment of the present invention, a transformer structure is adopted, and the inductor parts of the three resonant circuits are designed as transformers. By overlapping large areas with small areas, the chip area occupied by the inductor is reduced. Figure 2 As shown, the resonant inductors L1, L2, L3 and the switch coupled inductor L4 in the resonant circuit form a single-phase multi-winding transformer structure, wherein the switch coupled inductor L4 is the input winding, and the resonant inductors L1, L2, L3 are the output windings. The switch coupled inductor L4 is arranged in the innermost circle, the resonant inductor L1 is arranged in the outermost circle, and the resonant inductor L3 and the resonant inductor L2 are arranged in sequence between the switch coupled inductor L4 and the resonant inductor L1.

[0028] In the embodiment of the present invention, Figure 2 As shown, the switch coupling inductor L4 is an octagonal inductor, and the resonant inductors L1, L2, and L3 are octagonal inductors with center taps, thereby improving the inductor symmetry and reducing the layout area.

[0029] In the embodiment of the present invention, the coupling between the resonant inductors L1 and L2 is relatively weak, and the coupling between the resonant inductors L2 and L3 is relatively weak.

[0030] In the embodiment of the present invention, the transformer is composed of multiple groups of inductors, so different metal layers are used to prevent metal overlap. The resonant inductors L1, L2, and L3 use the thickest layer of metal in this design process, and their parasitic resistance and other related parameters are relatively small, the loss is small, and the Q value is high. The switch coupling inductor L4 uses a metal layer adjacent to the resonant inductors L1, L2, and L3.

[0031] In the embodiment of the present invention, the resonant inductor L1, the switched coupling inductor L4, the resonant capacitor C3, the resonant capacitor C4, the blocking capacitor C1, the blocking capacitor C2, the grounding resistor R1, the grounding resistor R2, the tuning resistor R3, the switch capacitor Var1 and the switch capacitor Var2 constitute the resonant cavity of the first voltage-controlled oscillator unit. The resonant inductor L2, the switched coupling inductor L4, the resonant capacitor C7, the resonant capacitor C8, the blocking capacitor C5, the blocking capacitor C6, the grounding resistor R4, the grounding resistor R5, the tuning resistor R6, the switch capacitor Var3 and the switch capacitor Var4 constitute the resonant cavity of the second voltage-controlled oscillator unit. The resonant inductor L3, the switched coupling inductor L4, the resonant capacitor C11, the resonant capacitor C12, the blocking capacitor C9, the blocking capacitor C10, the grounding resistor R7, the grounding resistor R8, the tuning resistor R9, the switch capacitor Var5 and the switch capacitor Var6 constitute the resonant cavity of the third voltage-controlled oscillator unit.

[0032] In an embodiment of the present invention, the negative resistance active circuit adopts an NMOS row cross-coupling structure and uses an NMOS transistor as a negative resistance unit of a voltage-controlled oscillator. Compared with other structures, while achieving the same transconductance, the layout is smaller, the parasitic capacitance is smaller, and it is more conducive to achieving a wide bandwidth.

[0033] In the embodiment of the present invention, the cross coupling in the negative resistance active circuit provides negative resistance to the MOS transistor to compensate for the loss of the resonant cavity, so that the circuit generates an oscillation signal.

[0034] In the embodiment of the present invention, the resistors R1, R2, R3, R5, R6, R7, R8, and R9 all have the function of preventing signal and current leakage. The resistors R10 and R11 prevent the RF signal from leaking to the ground on the one hand, and provide a 0V potential for the drain and source of the MOS tube M7 on the other hand.

[0035] In the embodiment of the present invention, the bandwidth of the voltage-controlled oscillator is tuned by combining the switching capacitor on and off and the switching coupling inductor on and off. On the one hand, the voltage-controlled oscillator controls the switching coupling inductor on and off to roughly adjust the bandwidth of the voltage-controlled oscillator. By adjusting the size of the control voltage Vctrl4, the switching on and off of the MOS tube M7 is controlled, thereby controlling whether the switching coupling inductor L4 is connected to the transformer. When the MOS tube M7 is turned on, it is approximately considered that the switching coupling inductor L4 is connected to the transformer. When the MOS tube is turned off, it is approximately considered that the switching coupling inductor L4 is not connected to the transformer. In this way, the coupling coefficient of the transformer is changed, and then the resonant inductance value of the LC loop in the resonant circuit is changed, thereby changing the frequency of the oscillation signal, so as to achieve the purpose of expanding the bandwidth. On the other hand, the voltage-controlled oscillator controls the switching capacitor on and off to fine-tune the bandwidth of the voltage-controlled oscillator. Since one end of the varactor is a potential of 0V, the potential of the other end is determined by the tuning voltage Vctrl1 / Vctrl2 / Vctrl3. Therefore, by changing the voltage difference across the varactor in the resonant circuit, that is, changing the voltage values ​​of Vctrl1, Vctrl2 and Vctrl3, the capacitance value is changed, and then the resonant frequency is changed, thereby achieving continuous adjustable output frequency.

[0036] In the embodiment of the present invention, the three-band output is realized by three coupled resonant circuits. The center frequency of the voltage-controlled oscillator in different working frequency bands, the total inductance L, the total capacitance C, the coupling coefficient k1 of the inductance in the first resonant circuit and the second resonant circuit, the coupling coefficient k2 of the inductance in the second resonant circuit and the third resonant circuit, and the coupling coefficient k3 of the inductance in the first resonant circuit and the third resonant circuit will change. By reasonably selecting the above parameters, the voltage-controlled oscillator can be made to oscillate in different frequency bands. When the first voltage-controlled oscillator is working, the value range of the resonant inductance L1 is 68.96pH~74.07pH, the total resonant capacitance is 4.819fF, the resonant inductance C3 and C4 are both 2.44fF, and the value range of the switch capacitance Var1 and Var2 is 0~0.37fF. When the second voltage-controlled oscillator unit is working, the value range of the resonant inductor L2 is 11.11pH~12.98pH, the total resonant capacitance is 12.5fF, the resonant inductors C7 and C8 are both 6.25fF, and the value range of the switch capacitors Var1 and Var2 is 0~2.29fF. When the third voltage-controlled oscillator unit is working, the value range of the resonant inductor L3 is 172.4pH~186.9pH, the total resonant capacitance is 174.705fF, the resonant capacitors C11 and C12 are both 87.35fF, and the value range of the switch capacitors Var1 and Var2 is 0~15.3fF.

[0037] In an embodiment of the present invention, when the voltage-controlled oscillator is working, only one voltage-controlled oscillator unit works normally at a time. When the first voltage-controlled oscillator unit is working, the tail current source I2 in the second negative resistance active circuit and the tail current source I3 in the third negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a high-frequency signal, and the frequency range of the signal is 67.5GHz to 72.5GHz. When the second voltage-controlled oscillator unit is working, the tail current source I2 in the second negative resistance active circuit is turned on, and the tail current source I1 in the first negative resistance active circuit and the tail current source I3 in the third negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a mid-frequency signal, and the frequency range of the signal is 38.5GHz to 45GHz. When the third voltage-controlled oscillator unit is working, the tail current source I3 in the third negative resistance active circuit is turned on, and the tail current source I1 in the first negative resistance active circuit and the tail current source I2 in the second negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a low-frequency signal, and the frequency range of the signal is 26.75GHz to 29GHz.

[0038] It should be noted that in the description of the present invention, it should be understood that the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A low-Earth orbit satellite Internet millimeter wave oscillator based on a single-phase multi-winding transformer, characterized in that: It comprises three resonant circuits and negative resistance active circuits with the same structure, namely a first resonant circuit, a second resonant circuit, a third resonant circuit, a first negative resistance active circuit, a second negative resistance active circuit and a third negative resistance active circuit. The resonant circuits all include: a switching capacitor, a DC blocking capacitor, a resonant capacitor, a grounding resistor, a tuning resistor, a resonant inductor, a switch coupling inductor, and a switch MOS tube. In the first resonant circuit, the DC blocking capacitor C1, the grounding resistor R1, the switching capacitor Var1, the tuning resistor R3, the switching capacitor Var2, the grounding resistor R2, and the DC blocking capacitor C2 are sequentially connected in series, the other ends of the DC blocking capacitors C1 and C2 are respectively connected to the two ends of the resonant inductor L1, the other ends of the grounding resistors R1 and R2 are both grounded, the other end of the tuning resistor R3 is connected to the input control voltage Vctrl1, the resonant capacitors C3 and C4 are connected in series, and the other ends of the resonant capacitors C3 and C4 are respectively connected to the two ends of the resonant inductor L1. In the second resonant circuit, the DC blocking capacitor C5, the grounding resistor R4, the switching capacitor Var3, the tuning resistor R6, the switching capacitor Var4, the grounding resistor R5, and the DC blocking capacitor C6 are connected in series in sequence, the other ends of the DC blocking capacitors C5 and C6 are respectively connected to the two ends of the resonant inductor L2, the other ends of the grounding resistors R4 and R5 are both grounded, the other end of the tuning resistor R6 is connected to the input control voltage Vctrl2, the resonant capacitors C7 and C8 are connected in series, and the other ends of the resonant capacitors C7 and C8 are respectively connected to the two ends of the resonant inductor L2. In the third resonant circuit, the DC blocking capacitor C9, the grounding resistor R7, the switch capacitor Var5, the tuning resistor R9, the switch capacitor Var6, the grounding resistor R8, and the DC blocking capacitor C10 are connected in series in sequence, the other ends of the DC blocking capacitors C9 and C10 are connected to the two ends of the resonant inductor L3 respectively, the other ends of the grounding resistors R7 and R8 are both grounded, the other end of the tuning resistor R9 is connected to the input control voltage Vctrl3, the resonant capacitors C11 and C12 are connected in series, the other ends of the resonant capacitors C11 and C12 are connected to the two ends of the resonant inductor L3 respectively. The two ends of the switch coupling inductor L4 are respectively connected to the drain and source of the switch MOS tube M7, the base of the switch MOS tube M7 is connected to the control voltage Vctrl4, the drain of the switch MOS tube M7 is connected to the grounding resistor R10, the source of the switch MOS tube M7 is connected to the grounding resistor R11, and the other ends of the grounding resistors R10 and R11 are both grounded. The negative resistance active circuits all include: a cross-coupled MOS transistor and a current source. In the first negative resistance active circuit, the drain of the cross-coupled MOS transistor M1 and the drain of the cross-coupled MOS transistor M2 are respectively connected to the two ends of the resonant inductor L1, the gate of the cross-coupled MOS transistor M1 is connected to the drain of the cross-coupled MOS transistor M2, the drain of the cross-coupled MOS transistor M1 is connected to the gate of the cross-coupled MOS transistor M2, the source of the cross-coupled MOS transistor M1 is connected to the source of the cross-coupled MOS transistor M2, and is connected in series with the input end of the current source I1, and the output end of the current source I1 is grounded. In the second negative resistance active circuit, the drain of the cross-coupling pair MOS transistor M3 and the drain of the cross-coupling pair MOS transistor M4 are respectively connected to the two ends of the resonant inductor L2, the gate of the cross-coupling pair MOS transistor M3 is connected to the drain of the cross-coupling pair MOS transistor M4, the drain of the cross-coupling pair MOS transistor M3 is connected to the gate of the cross-coupling pair MOS transistor M4, the source of the cross-coupling pair MOS transistor M3 is connected to the source of the cross-coupling pair MOS transistor M4, and is connected in series with the input end of the current source I2, and the output end of the current source I2 is grounded. In the third negative resistance active circuit, the drain of the cross-coupling pair MOS transistor M5 and the drain of the cross-coupling pair MOS transistor M6 are respectively connected to the two ends of the resonant inductor L3, the gate of the cross-coupling pair MOS transistor M5 is connected to the drain of the cross-coupling pair MOS transistor M6, the drain of the cross-coupling pair MOS transistor M5 is connected to the gate of the cross-coupling pair MOS transistor M5, the source of the cross-coupling pair MOS transistor M5 is connected to the source of the cross-coupling pair MOS transistor M6 and is connected in series with the input end of the current source I3, and the output end of the current source I3 is grounded.

2. The low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer according to claim 1, characterized in that: The first voltage-controlled oscillation unit includes a first resonant circuit, a switch coupling inductor L4, a switch MOS tube M7, a grounding resistor R10, a grounding resistor R11 and a first negative resistance active circuit; the second voltage-controlled oscillation unit includes a second resonant circuit, a switch coupling inductor L4, a switch MOS tube M7, a grounding resistor R10, a grounding resistor R11 and a second negative resistance active circuit; the third voltage-controlled oscillation unit includes a third resonant circuit, a switch coupling inductor L4, a switch MOS tube M7, a grounding resistor R10, a grounding resistor R11 and a third negative resistance active circuit.

3. The low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer according to claim 1, characterized in that: The voltage controlled oscillator controls the voltage difference across the varactor to fine tune the bandwidth of the voltage controlled oscillator. By changing the voltage difference across the varactor to change the capacitance value, the resonant frequency is changed, and the output frequency is continuously adjustable.

4. The low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer according to claim 1, characterized in that: The voltage controlled oscillator controls the switch coupling inductor to turn on and off to roughly adjust the bandwidth of the voltage controlled oscillator. By adjusting the size of the control voltage Vctrl4, the switch MOS tube M7 is controlled to turn on and off, thereby controlling whether the switch coupling inductor L4 is connected to the transformer, and by changing the coupling coefficient of the transformer, the resonant inductance value of the LC loop in the resonant circuit is changed, thereby changing the frequency of the oscillation signal, thereby achieving the purpose of expanding the bandwidth.

5. The low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer according to claim 1, characterized in that: The resonant inductors L1, L2, L3 and the switch coupling inductor L4 in the resonant circuit form a single-phase multi-winding transformer structure, wherein the switch coupling inductor L4 is the input winding and the resonant inductors L1, L2, L3 are the output windings.

6. The low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer according to claim 5, characterized in that: The switch coupling inductor L4 is arranged in the innermost circle, the resonant inductor L1 is arranged in the outermost circle, and the resonant inductor L3 and the resonant inductor L2 are arranged in sequence between the switch coupling inductor L4 and the resonant inductor L1.

7. The low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer according to claim 2, characterized in that: When the voltage-controlled oscillator is working, only one voltage-controlled oscillation unit works normally at a time. When the first voltage-controlled oscillation unit is working, the tail current source I1 in the first negative resistance active circuit is turned on, and the tail current source I2 in the second negative resistance active circuit and the tail current source I3 in the third negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a signal in the high frequency band. When the second voltage-controlled oscillation unit is working, the tail current source I2 in the second negative resistance active circuit is turned on, and the tail current source I1 in the first negative resistance active circuit and the tail current source I3 in the third negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a signal in the medium frequency band. When the third voltage-controlled oscillation unit is working, the tail current source I3 in the third negative resistance active circuit is turned on, and the tail current source I1 in the first negative resistance active circuit and the tail current source I2 in the second negative resistance active circuit are turned off, and the voltage-controlled oscillator outputs a signal in the low frequency band.

8. The low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer according to claim 7, characterized in that: The frequency range of the high-band signal output by the first oscillation unit is 67.5 GHz to 72.5 GHz, the frequency range of the mid-band signal output by the second oscillation unit is 38.5 GHz to 45 GHz, and the frequency range of the low-band signal output by the third oscillation unit is 26.75 GHz to 29 GHz.

9. The low earth orbit satellite internet millimeter wave oscillator based on a single-phase multi-winding transformer according to claim 8, characterized in that: Taking various influencing factors into consideration, after the voltage-controlled oscillator is finally processed into a physical object, the output frequency range will be reduced by 1.5 GHz as a whole. The output frequency range of the voltage-controlled oscillator after the reduction can completely and accurately cover all currently allocated millimeter-wave frequency bands.

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