A quadrature local oscillator signal generator, local oscillator link and radio frequency transceiver

Abstract

This article discloses an orthogonal local oscillator signal generator, a local oscillator link and a radio frequency transceiver. The orthogonal local oscillator signal generator of an embodiment of the present invention includes: a multiphase filter including two-stage cascade units and a frequency multiplier with an orthogonal coupling function; wherein the first stage cascade unit of the multiphase filter converts the differential signal into a first orthogonal signal, and the second stage cascade unit performs bandwidth expansion on the obtained first orthogonal signal to obtain a second orthogonal signal; the frequency multiplier performs frequency multiplication amplification and phase shift of a preset angle on the obtained second orthogonal signal to obtain an orthogonal local oscillator signal of a preset frequency. The embodiment of the present invention performs signal conversion and bandwidth expansion on the differential signal respectively through a multiphase filter with a cascade structure, thereby improving the orthogonal performance of the generated orthogonal signal, and performs frequency multiplication amplification and phase shift of a preset angle on the obtained orthogonal signal through a frequency multiplier with an orthogonal coupling function, thereby improving the phase noise performance of the obtained local oscillator signal.

Description

Technical Field

[0001] The present invention relates to but is not limited to millimeter wave communication technology, and in particular to an orthogonal local oscillator signal generator, a local oscillator link and a radio frequency transceiver. Background Art

[0002] With the development of communication technology, people's demand for wireless transmission data rate is getting higher and higher, and bandwidth has become the main bottleneck. At present, most of the major commercial communication systems operate below 6GHz, and increasing the operating frequency is an effective way to overcome this bottleneck. In recent years, millimeter wave communication technology has developed rapidly, among which the 60 GHz frequency band is considered to be the most suitable frequency band for millimeter wave communication. The local oscillator link is the most difficult part to design in the millimeter wave RF transceiver, especially the orthogonal local oscillator signal generator in the local oscillator link.

[0003] In the related art, there are mainly three types of orthogonal local oscillator generators for realizing millimeter wave communication in the 60GHz frequency band: The first type: directly using an orthogonal voltage-controlled oscillator (QVCO) to generate a 60GHz four-phase orthogonal signal; this solution has a simple circuit, and the orthogonality of the in-phase (I) and quadrature (Q) signals is good, but the phase noise performance is poor. The second type: using a voltage-controlled oscillator (VCO) to generate a 60GHz differential signal, and then using a passive circuit to generate an orthogonal signal. This solution has the following problems: 1. The quality factor (Q value) of the capacitive tube at 60GHz is relatively low, and the phase noise performance of the VCO is poor; 2. The input and output impedances of passive devices are both around 50 ohms (ohm), which will introduce 8-10 decibels (dB) of loss in the local oscillator link. Considering the loss of about 6dB of the passive network local oscillator, there will be a total loss of more than 15dB. The third method is to use VCO to generate a low-frequency local oscillator first, and then use the quadrature injection locked frequency multiplier (QILO) to generate a 60GHz quadrature local oscillator signal; generally, a VCO is used to generate a 20GHz differential signal, and then a 60GHz quadrature local oscillator signal is generated through QILO. This scheme has better phase noise performance, but because the signal injected into the QILO is differential, the orthogonality of the output quadrature local oscillator signal is relatively poor, especially the amplitude mismatch.

[0004] In summary, designing and implementing a millimeter-wave orthogonal local oscillator signal generator with phase noise performance and orthogonality that meet the application requirements has become a problem that needs to be solved in local oscillator link design. Summary of the invention

[0005] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0006] The embodiments of the present invention provide an orthogonal local oscillator signal generator, a local oscillator link and a radio frequency transceiver, which can obtain an orthogonal local oscillator signal whose phase noise performance and orthogonality both meet millimeter wave judgment.

[0007] The embodiment of the present invention provides an orthogonal local oscillator signal generator, comprising: a multiphase filter including two-stage cascade units and a frequency multiplier with an orthogonal coupling function; wherein:

[0008] The multiphase filter is configured to: convert the differential signal into a first orthogonal signal through a first stage cascade unit; and perform bandwidth expansion on the first orthogonal signal obtained through a second stage cascade unit to obtain a second orthogonal signal;

[0009] The frequency multiplier is configured to: perform frequency multiplication amplification and phase shift of a preset angle on the obtained second orthogonal signal to obtain an orthogonal local oscillator signal of a preset frequency.

[0010] In an exemplary embodiment, there is a preset deviation between the operating frequencies of the first-stage cascade unit and the second-stage cascade unit.

[0011] In an exemplary embodiment, the first cascade unit comprises: four first filter modules connected in a ring; wherein,

[0012] The first filtering modules include a first resistor and a first capacitor connected in series, and each of the first filtering modules is configured to perform a phase shift of a preset phase difference on the differential signal to obtain the first orthogonal signal of a corresponding phase.

[0013] In an exemplary embodiment, the second cascade unit comprises: four second filter modules connected in a ring shape; wherein:

[0014] The second filtering module includes a second resistor and a second capacitor connected in series, and each of the second filtering modules is respectively configured to perform bandwidth expansion on the first orthogonal signal of one phase to obtain the second orthogonal signal corresponding to the first orthogonal signal of each phase.

[0015] In an exemplary embodiment, the first resistor includes:

[0016] Switched resistor array.

[0017] In an exemplary embodiment, the second resistor includes:

[0018] Switched resistor array.

[0019] In an exemplary embodiment, the frequency multiplier comprises: a quadrature injection locked frequency tripler.

[0020] In an exemplary embodiment, the quadrature injection locked frequency tripler comprises:

[0021] An in-phase I-path oscillator and an orthogonal Q-path oscillator with the same circuit structure, and a cross-coupling unit between the I-path oscillator and the Q-path oscillator.

[0022] In an exemplary embodiment, the oscillator includes: an injection tube, a coupling transformer, two adjustable capacitors and two cross-coupling tubes; wherein,

[0023] The gate of the injection tube is connected to the output end of the polyphase filter and is configured to generate third-order harmonics;

[0024] The coupling transformer comprises a primary coil and a secondary coil, wherein the primary coil is connected to the drain end of the injection tube and is configured to: couple the generated third-order harmonic into an oscillator;

[0025] The adjustable capacitor comprises a first connection port and a second connection port, the two adjustable capacitors are connected via the first connection port, one of the second connection ports of the two adjustable capacitors is connected to the secondary coil of the coupling transformer, and the other of the second connection ports of the two adjustable capacitors is connected to the drain end of the cross-coupling tube, and the two adjustable capacitors are configured to perform frequency tuning on the oscillator to achieve a tuning range of a preset width;

[0026] Between the two cross-coupled tubes, the gate end of the first cross-coupled tube is connected to the drain end of the second cross-coupled tube, and the drain end of the first cross-coupled tube is connected to the gate end of the second cross-coupled tube, which is configured to generate a negative resistance to ensure the oscillation of the oscillator.

[0027] In an exemplary embodiment, the cross-coupling tube comprises:

[0028] A coupling transistor consisting of four transistors connected end to end to form a loop.

[0029] On the other hand, an embodiment of the present invention further provides a local oscillator link, which includes the above-mentioned orthogonal local oscillator signal generator.

[0030] On the other hand, an embodiment of the present invention further provides a radio frequency transceiver, wherein the radio frequency transceiver includes the above-mentioned local oscillator link.

[0031] The orthogonal local oscillator signal generator of the embodiment of the present invention comprises: a multiphase filter including two stages of cascade units and a frequency multiplier with an orthogonal coupling function; wherein the first stage of the cascade unit of the multiphase filter converts the differential signal into a first orthogonal signal, and the second stage of the cascade unit performs bandwidth expansion on the obtained first orthogonal signal to obtain a second orthogonal signal; the frequency multiplier performs frequency multiplication amplification and phase shift of a preset angle on the obtained second orthogonal signal to obtain an orthogonal local oscillator signal of a preset frequency. The embodiment of the present invention performs signal conversion and bandwidth expansion on the differential signal respectively through a multiphase filter with a cascade structure, thereby improving the orthogonal performance of the generated orthogonal signal, and performs frequency multiplication amplification and phase shift of a preset angle on the obtained orthogonal signal through a frequency multiplier with an orthogonal coupling function, thereby improving the phase noise performance of the obtained local oscillator signal.

[0032] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0034] Figure 1 is a structural block diagram of an orthogonal local oscillator signal generator according to an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of an orthogonal local oscillator signal generator for an application example of the present invention;

[0036] Figure 3 A schematic diagram of an example polyphase filter according to the present invention;

[0037] Figure 4 A schematic diagram of an example switch resistor array for use in the present invention;

[0038] Figure 5 A schematic diagram of an oscillator for use with the present invention;

[0039] Figure 6 A schematic diagram of an example adjustable capacitor for application of the present invention;

[0040] Figure 7 This is a circuit diagram of a cross-coupled transistor according to an example of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0042] The steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. Also, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described can be performed in a sequence different from that shown here.

[0043] Figure 1 FIG. 4 is a structural block diagram of an orthogonal local oscillator signal generator according to an embodiment of the present invention. Figure 1 As shown, it includes: a multiphase filter including two-stage cascade units and a frequency multiplier with orthogonal coupling function; wherein,

[0044] The multiphase filter is configured to: convert the differential signal into a first orthogonal signal through a first stage cascade unit; and perform bandwidth expansion on the first orthogonal signal obtained through a second stage cascade unit to obtain a second orthogonal signal;

[0045] The frequency multiplier is configured to: perform frequency multiplication amplification and phase shift of a preset angle on the obtained second orthogonal signal to obtain an orthogonal local oscillator signal of a preset frequency.

[0046] It should be noted that the preset angle of the phase shift achieved by the frequency multiplier can be designed and implemented by those skilled in the art according to relevant principles, and the preset angle may include 90 degrees, and may also include other angles including 45 degrees.

[0047] In an exemplary embodiment, there is a preset deviation between the operating frequencies of the first-stage cascade unit and the second-stage cascade unit in the embodiment of the present invention.

[0048] In an exemplary embodiment, the first cascade unit of the embodiment of the present invention comprises: four first filter modules connected in a ring; wherein,

[0049] The first filtering modules include a first resistor and a first capacitor connected in series, and each of the first filtering modules is respectively configured to perform a phase shift of a preset phase difference on the differential signal to obtain a first orthogonal signal of a corresponding phase.

[0050] In an exemplary embodiment, the second cascade unit of the embodiment of the present invention comprises: four second filter modules connected in a ring; wherein,

[0051] The second filtering modules include a second resistor and a second capacitor connected in series, and each second filtering module is respectively configured to perform bandwidth expansion on a first orthogonal signal of one phase to obtain a second orthogonal signal corresponding to the first orthogonal signal of each phase.

[0052] In an exemplary embodiment, the first resistor of the embodiment of the present invention includes: a switch resistor array.

[0053] In an exemplary embodiment, the second resistor of the embodiment of the present invention includes: a switch resistor array.

[0054] In an exemplary embodiment, the frequency multiplier of the embodiment of the present invention includes: an integer multiple frequency multiplier.

[0055] It should be noted that the orthogonal coupling function of the frequency multiplier in the embodiment of the present invention can be added to the existing frequency multiplier by those skilled in the art according to relevant principles.

[0056] In an exemplary embodiment, the frequency multiplier comprises a quadrature injection locked frequency tripler.

[0057] In an exemplary embodiment, a quadrature injection locked frequency tripler comprises:

[0058] An in-phase I-path oscillator and an orthogonal Q-path oscillator with the same circuit structure, and a cross-coupling unit between the I-path oscillator and the Q-path oscillator.

[0059] In an exemplary embodiment, the oscillator includes: an injection tube, a coupling transformer, two adjustable capacitors and two cross-coupling tubes; wherein,

[0060] The grid of the injection tube is connected to the output of a polyphase filter, arranged to produce third-order harmonics;

[0061] The coupling transformer includes a primary coil and a secondary coil, the primary coil is connected to the drain end of the injection tube, and is configured to: couple the generated third-order harmonic into the oscillator;

[0062] The adjustable capacitor includes a first connection port and a second connection port, the two adjustable capacitors are connected through the first connection port, one of the second connection ports of the two adjustable capacitors is connected to the secondary coil of the coupling transformer, and the other second connection port of the two adjustable capacitors is connected to the drain end of the cross-coupling tube, and the two adjustable capacitors are configured to: perform frequency tuning on the oscillator to achieve a tuning range of a preset width;

[0063] Between the two cross-coupled tubes, the gate end of the first cross-coupled tube is connected to the drain end of the second cross-coupled tube, and the drain end of the first cross-coupled tube is connected to the gate end of the second cross-coupled tube, which is configured to generate a negative resistance to ensure the oscillation of the oscillator.

[0064] In an exemplary embodiment, a cross-coupling tube includes:

[0065] A coupling transistor consisting of four transistors connected end to end to form a loop.

[0066] The orthogonal local oscillator signal generator of the embodiment of the present invention includes: a multiphase filter including two-stage cascade units and a frequency multiplier with an orthogonal coupling function; wherein the first stage cascade unit of the multiphase filter converts the differential signal into a first orthogonal signal, and the second stage cascade unit performs bandwidth expansion on the obtained first orthogonal signal to obtain a second orthogonal signal; the frequency multiplier performs frequency multiplication amplification and phase shift of a preset angle on the obtained second orthogonal signal to obtain an orthogonal local oscillator signal of a preset frequency. The embodiment of the present invention performs signal conversion and bandwidth expansion on the differential signal respectively through a multiphase filter with a cascade structure, thereby improving the orthogonal performance of the generated orthogonal signal, and when the frequency multiplier with an orthogonal coupling function performs frequency multiplication amplification on the obtained orthogonal signal, a phase shift of a preset angle is achieved through the orthogonal coupling function, thereby improving the phase noise performance of the obtained local oscillator signal.

[0067] An embodiment of the present invention further provides a local oscillator link, which includes the above-mentioned orthogonal local oscillator signal generator.

[0068] The embodiment of the present invention further provides a radio frequency transceiver, the radio frequency transceiver comprising the above-mentioned local oscillator link. The following briefly describes the method of the embodiment of the present invention through application examples, which are only used to illustrate the present invention and are not used to limit the protection scope of the present invention.

[0069] Application Examples

[0070] This application example uses a quadrature local oscillator signal generator in the millimeter wave frequency band. Figure 2 Schematic diagram of an orthogonal local oscillator signal generator for an application example of the present invention, such as Figure 2 As shown, the orthogonal local oscillator signal generator includes a multiphase filter and a frequency multiplier with an orthogonal coupling function. The differential signal (20GHz) of the orthogonal local oscillator signal generator is input, and the local oscillator signal output by the orthogonal local oscillator signal generator is 60GHz; the multiphase filter converts the input differential signal into an orthogonal signal, and the orthogonal signal is injected into the frequency multiplier to generate an orthogonal 60GHz local oscillator signal. In an exemplary embodiment, the frequency multiplier of this application example includes: a triple frequency multiplier, a quadruple frequency multiplier, or a sextuple frequency multiplier; the frequency multiplier can be used to achieve a phase with a preset phase difference; for example, a phase with a phase difference of 90 degrees; taking the realization of 8 phases (each phase is 45 degrees apart) as an example, 8 phases can be generated by the phase shifter in the frequency multiplier, which is used to couple 4 oscillators (each oscillator generates 0 and 180 degrees), thereby obtaining 8 phases. Since the input signal of the frequency multiplier is an orthogonal signal, the orthogonal performance of the output signal is improved.

[0071] In an exemplary embodiment, the multiphase filter of this application example is composed of two stages of cascade units, and the differential signal is converted into a first orthogonal signal by the first stage of cascade units; the bandwidth of the first orthogonal signal obtained by the conversion is expanded by the second stage of cascade units to obtain a second orthogonal signal.

[0072] The second cascade unit of this application example is composed of four second filter modules connected in a ring manner; wherein each second filter module is composed of a second resistor and a second capacitor connected in series; each second filter module is respectively configured to perform a phase shift of a preset phase difference on the differential signal to obtain a first orthogonal signal. Figure 3 FIG. 1 is a schematic diagram of an example polyphase filter according to an application of the present invention, as shown in FIG. Figure 3 As shown, the first cascade unit is composed of four first filter modules, the first filter module is composed of a first resistor R1 and a first capacitor C1 connected in series, and two differential signals are respectively connected through the positive input terminal and the negative input terminal of the first cascade unit, and the four first filter modules connected in a ring are respectively phase-shifted with a preset phase difference; each first filter module outputs a first orthogonal signal of a phase. The second cascade unit includes: four second filter modules connected in a ring; wherein the second filter module is composed of a second resistor R2 and a second capacitor C2 connected in series, and each second filter module is respectively configured to perform bandwidth expansion on the first orthogonal signal of one phase, and obtain a second orthogonal signal corresponding to the first orthogonal information of each phase. A single-stage system can only achieve a relatively good orthogonal generation effect within a very narrow bandwidth range; the operating frequency of the two-stage cascade unit used in this application example has a preset deviation, and the deviation can be determined according to the bandwidth of the orthogonal signal to be formed, for example, the relative bandwidth is 60%, and the two-stage cascade forms a broadband orthogonal effect. Because the input signal is differential, the orthogonal signal generated by the cascade structure used in this application example will have a phase difference, which overcomes the problem of insufficient orthogonality of the single-stage system.

[0073] It should be noted that the first cascade unit and the second cascade unit are merely optional examples of this application example, and any circuit that can implement the first cascade unit and the second cascade unit can be applied to this application example.

[0074] The first stage cascade unit of this application example is a single-stage system of a multi-phase filter, and the operating frequency is determined by the first resistor R1 and the first capacitor C1; for example, it is determined by the calculation formula of operating frequency = 1 / (2*PI*R*C). In an exemplary embodiment, the first resistor and the second resistor can be implemented by a switch resistor array; Figure 4 Schematic diagram of an example switch resistor array for application of the present invention, such as Figure 4 As shown, the switch resistor array realizes resistance adjustment through switches SW0, SW1 and SW2, and the first cascade unit and the second cascade unit are realized by designing the switch resistor array, which can further expand the bandwidth of the orthogonal signal of the application example of the present invention.

[0075] Each stage of the cascade unit in this application example is composed of a low-pass network and a high-pass network. The output of the network always remains orthogonal in phase, and only outputs signals with the same amplitude at the frequency ω=1 / (RC); after obtaining the broadband signal through the cascade structure of the multi-phase filter, an orthogonal signal with the same amplitude is output at ω=1 / (RC). The product of RC will change with changes in temperature and process. This application example introduces a two-stage cascade unit. The two-stage cascade units can be set with the same capacitance and different resistance. The above-mentioned setting of the cascade unit can ensure the orthogonality of the phase of the orthogonal signal output within a relatively wide frequency range. In an exemplary embodiment, the orthogonality of the operating frequency point can be ensured by adjusting the resistance in the two-stage cascade unit.

[0076] The above-mentioned multiphase filter in this application example generally has a fixed gain loss of 6 decibels (dB). When operating near 20 GHz, the routing in the layout will also introduce a gain loss of 1-2 dB. Ultimately, the entire multiphase filter will introduce a gain loss of about 8 dB.

[0077] In an exemplary embodiment, the frequency multiplier of this application example includes: a quadrature injection locked frequency tripler. In an exemplary embodiment, the quadrature injection locked frequency tripler includes: an I-channel oscillator and a Q-channel oscillator with the same circuit structure, and a cross-coupling unit between the two oscillators.

[0078] In an exemplary embodiment, the oscillator of this application example includes: an injection tube, a coupling transformer, an adjustable capacitor and a cross-coupling tube; wherein,

[0079] The injection tube is connected to the multiphase filter to generate the third-order harmonic; the coupling transformer couples the third-order harmonic to the oscillator; the adjustable capacitor is used to realize the frequency tuning of the oscillator to achieve a preset width tuning range; the cross-coupling tube is used to generate a negative resistance to ensure the oscillation of the oscillator. This application example can tune the frequency of the oscillator by a preset percentage multiplied by the tuning range within a pre-defined limited tuning range, and the preset percentage can be about 30%;

[0080] Take the I-channel oscillator as an example. Figure 5 Schematic diagram of an oscillator for application example of the present invention, such as Figure 5As shown, Mi1a and Mi1b are injection tubes, and the output stage of the multiphase filter is connected to the gate of the injection tube; TI is a coupling transformer, and the coupling transformer includes a primary coil (Lipre) and a secondary coil (Lisec), and the coupling coefficient between the primary coil and the secondary coil is ki, and the primary coil is connected to the drain end of the injection tube; the adjustable capacitor Ci1 is connected to one end of the adjustable capacitor Ci2, and of the two connection ports where the adjustable capacitor Ci1 and the adjustable capacitor Ci2 are not connected, one end is connected to the secondary coil of the transformer, and one end is connected to the drain end of the cross-coupled tube; Mi2a and Mi2b are cross-coupled tubes, and the gate end of Mi2a is connected to the drain end of Mi2b, and the gate end of Mi2b is connected to the drain end of Mi2a. Figure 6 The figure is a schematic diagram of an adjustable capacitor according to an application example of the present invention. The adjustable capacitor can be adjusted by a switch (SW) shown in the figure. Figure 7 The circuit diagram of the cross-coupling tube of the present invention is shown as follows: Figure 7 As shown, the cross-coupled tube uses 4 transistors connected end to end to form a loop.

[0081] The cross-coupling unit in the quadrature injection locked frequency tripler in this application example can produce a 90-degree phase shift, which can ensure good phase noise performance.

[0082] The orthogonal local oscillator signal generator in this application example can be implemented based on complementary metal oxide semiconductor (CMOS) technology, which has the advantages of low power consumption, high integration and small chip area compared with other technologies.

[0083] The orthogonal local oscillator signal generator in this application example is implemented based on the above-mentioned multiphase filter, and is mainly composed of resistors and capacitors. When working at 20GHz, the areas of the resistors and capacitors are relatively small; the orthogonal input locked tripler works at 60GHz, and the inductance values ​​of the primary coil and the secondary coil of the coupling transformer in the orthogonal injection locked tripler are relatively small, so the layout area of ​​the coupling transformer is also relatively small; in addition, the orthogonal injection locked tripler used in this application example introduces a cross-coupled tube. The cross-coupled tube uses 4 transistors, which are connected end to end to form a loop design, realizing a 90-degree phase shift between adjacent nodes, which greatly saves the board area compared to other passive networks.

[0084] The orthogonal injection locked tripler in this application example uses top injection, which separates the injected frequency doubling part from the DC of the coupling transformer, so that the injection tube can be optimized independently, and the current of the coupling transformer can be flexibly controlled, which improves the locking range of the frequency multiplier compared to the frequency multiplier in the related technology. In addition, the use of the coupling transformer for top injection produces a phase platform (within a frequency range, the phase is around 0 degrees), further improving the locking range.

[0085] The quadrature injection locked frequency tripler in this application example uses quadrature injection, which improves the gain matching and increases the phase orthogonality of the output signal. The quadrature injection locked frequency tripler in this application example will oscillate freely and generate a free oscillation frequency. The free oscillation frequency is determined by the coupling transformer and the adjustable capacitor. In this application example, the adjustable capacitors of the I and Q channels can be made into a 6-bit array, and the free oscillation frequency can be adjusted by adjusting the adjustable capacitor. When the quadrature injection locked frequency tripler is actually working, the frequency of the injected orthogonal signal should be near the free oscillation frequency. When the frequency of the injected orthogonal signal is exactly the same as the free oscillation frequency, the orthogonality of the output local oscillator signal is better.

[0086] The phase noise performance of the output local oscillator signal of this application example mainly depends on the phase noise performance of the 20GHz differential signal injected into the multiphase filter and the noise performance of the frequency multiplier local oscillator signal after orthogonal injection locking. The phase noise performance of the input 20GHz differential signal mainly depends on the design of the previous oscillator (VCO), which is irrelevant to the design of this application example and will not be elaborated here. From the perspective of injection locking, the phase noise performance of the orthogonal oscillator in the related art is generally not good. The signal of the I path is coupled to the Q path, and the currents of the I path and the Q path are orthogonal. They are synthesized into the oscillator current I after injection locking. T , compared to the oscillation frequency ω of a single oscillator 0 , the oscillation frequency of the orthogonal oscillator is shifted to ω osc , the quality factor of the orthogonal oscillator decreases, so the phase noise of the orthogonal oscillator is much smaller than that of a single oscillator. In this application example, the orthogonal injection locked tripler is designed with a cross-coupling unit between the I and Q oscillators. A 90-degree phase shift is introduced through the cross-coupling unit. Although the currents of the I and Q paths are still orthogonal, the signal coupled from the Q path to the I path is in phase with the I path signal. Through the design of the cross-coupling unit, the quality factor of the oscillator will not decrease, and the phase noise performance of the orthogonal oscillator is equivalent to that of a single oscillator.

[0087] This application example provides a 60G orthogonal local oscillator signal generator, whose output local oscillator signal can cover 55-65GHz. In actual operation, first adjust the variable resistors R1 and R2 in the multiphase filter to ensure the orthogonality of the output signal of the multiphase filter; then adjust the capacitor array of the orthogonal injection locked tripler to ensure that its free oscillation frequency is equivalent to the injection frequency. Through the above adjustments, a local oscillator signal with good phase noise and orthogonality can be output.

[0088] “A person skilled in the art will appreciate that all or some of the steps, systems, and functional modules / units in the above disclosed methods may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transitory medium) and a communication medium (or a transient medium). As is known in the art, As is well known to those skilled in the art, the term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storing information such as computer readable instructions, data structures, program modules or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media typically contain computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. An orthogonal local oscillator signal generator, comprising: A multiphase filter comprising two stages of cascaded units and a frequency multiplier with orthogonal coupling function; wherein, The multiphase filter is configured to: convert the differential signal into a first orthogonal signal through a first stage cascade unit; and perform bandwidth expansion on the first orthogonal signal obtained through a second stage cascade unit to obtain a second orthogonal signal; The frequency multiplier is configured to: perform frequency multiplication amplification and phase shift of a preset angle on the obtained second orthogonal signal to obtain an orthogonal local oscillator signal of a preset frequency; The frequency multiplier comprises: a quadrature injection locked tripler; the quadrature injection locked tripler comprises: an in-phase I-way oscillator and an orthogonal Q-way oscillator with the same circuit structure, and a cross-coupling unit between the I-way oscillator and the Q-way oscillator; the oscillator comprises: an injection tube, a coupling transformer, two adjustable capacitors and two cross-coupling tubes; the gate of the injection tube is connected to the output end of the multi-phase filter and is configured to generate third-order harmonics; the coupling transformer comprises a primary coil and a secondary coil, the primary coil is connected to the drain end of the injection tube and is configured to couple the generated third-order harmonics into the oscillator; the adjustable capacitors The capacitor comprises a first connection port and a second connection port, the two adjustable capacitors are connected through the first connection port, one of the two adjustable capacitors, the second connection port is connected to the secondary coil of the coupling transformer, and the other of the two adjustable capacitors, the second connection port is connected to the drain end of the cross-coupling tube, and the two adjustable capacitors are configured to: perform frequency tuning on the oscillator to achieve a tuning range of preset width; between the two cross-coupling tubes, the gate end of the first cross-coupling tube is connected to the drain end of the second cross-coupling tube, and the drain end of the first cross-coupling tube is connected to the gate end of the second cross-coupling tube, and are configured to generate a negative resistance to ensure the oscillation of the oscillator.

2. The orthogonal local oscillator signal generator according to claim 1, characterized in that: There is a preset deviation between the operating frequencies of the first-stage cascade unit and the second-stage cascade unit.

3. The orthogonal local oscillator signal generator according to claim 1, characterized in that: The first stage cascade unit comprises: four first filtering modules connected in a ring shape; wherein, The first filtering modules include a first resistor and a first capacitor connected in series, and each of the first filtering modules is configured to perform a phase shift of a preset phase difference on the differential signal to obtain the first orthogonal signal of a corresponding phase.

4. The orthogonal local oscillator signal generator according to claim 3, characterized in that: The second stage cascade unit comprises: four second filtering modules connected in a ring shape; wherein, The second filtering module includes a second resistor and a second capacitor connected in series, and each of the second filtering modules is respectively configured to perform bandwidth expansion on the first orthogonal signal of one phase to obtain the second orthogonal signal corresponding to the first orthogonal signal of each phase.

5. The orthogonal local oscillator signal generator according to claim 3, characterized in that: The first resistor comprises: Switched resistor array.

6. The orthogonal local oscillator signal generator according to claim 4, characterized in that: The second resistor comprises: Switched resistor array.

7. The orthogonal local oscillator signal generator according to any one of claims 1 to 6, characterized in that: The cross-coupling tube comprises: A coupling transistor consisting of four transistors connected end to end to form a loop.

8. A local oscillator link, characterized in that: The local oscillator link comprises the orthogonal local oscillator signal generator as described in any one of claims 1 to 7.

9. A radio frequency transceiver, characterized in that: The radio frequency transceiver comprises the local oscillator link as claimed in claim 8.

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