Local oscillator leakage adjustment circuit and digital transmitter, analog transmitter based thereon

Abstract

The application discloses a local oscillator leakage adjusting circuit, a digital transmitter and an analog transmitter based on the same. The local oscillator leakage adjusting circuit comprises a digital pre-modulator, a digital power amplifier and a second modulation coding. The digital pre-modulator is used for power amplifying or reducing a local oscillator signal according to a first modulation coding to obtain a first modulation local oscillator signal, wherein the first modulation coding is used for controlling the gain of the digital pre-modulator. The digital power amplifier is used for power amplifying the first modulation local oscillator signal according to a second modulation coding to obtain an output signal, wherein the second modulation coding is used for controlling the gain of the digital power amplifier. The first modulation coding and the second modulation coding are used for controlling the total gain of the output signal relative to the local oscillator signal to be always a preset gain value. The application controls the local oscillator leakage through digital devices, does not depend on device parameter adjustment, can realize wideband and good robustness, and can realize extremely low local oscillator leakage.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of signal transmitters, and particularly relates to a local oscillator leakage adjusting circuit and a digital transmitter and an analog transmitter based on the same. BACKGROUND

[0002] With the continuous growth of data rates of modern wireless communication systems, transmitters are required to have high linearity, support high-order modulation, wideband modulation and the like. In addition, the operating frequency of the transmitter is increased from sub-6 GHz to the millimeter wave band to increase the available spectrum resources and bandwidth. However, the local oscillator leakage of the transmitter increases with the increase of the frequency, which restricts the increase of the data rate of the transmitter.

[0003] Ideally, the amplitude of the radio frequency output signal RF of the transmitter should change linearly with the baseband signal coding, and the output phase remains unchanged. However, due to the existence of the transistor parasitic capacitance C par , a part of the signal will leak from the input port to the output port through the transistor parasitic capacitance Figure 1 . The local oscillator leakage signal LO leak is generally different in phase from the amplified signal sig output by the amplifier; therefore, after the vector composition of the amplified signal and the local oscillator leakage signal, the radio frequency output signal will be distorted, and the linear relationship with the baseband signal coding will no longer exist; the dynamic range of the radio frequency output signal will also decrease with the increase of the local oscillator leakage, so that it is difficult to realize high-order modulation.

[0004] A current method for canceling the local oscillator leakage is to introduce a compensation signal LO comp equal in amplitude and opposite in phase to the local oscillator leakage signal Figure 1 to cancel the local oscillator leakage. The phase-inverted compensation signal is directly connected to the output terminal through an additional parallel capacitor Cp , and the local oscillator leakage is suppressed by phase inversion. When LO leak and LO comp the amplitudes are equal and the phases are opposite, the local oscillator leakage can be completely canceled.

[0005] However, this method of canceling the local oscillator leakage depends on the device parameter adjustment, and it is difficult to realize wideband; and the cancellation effect of the local oscillator leakage depends on the parameters of the compensation capacitor and the parasitic capacitor; and both of these two devices are analog devices, which are greatly affected by the environment (such as temperature), processing deviation and the like, and have poor robustness. SUMMARY

[0006] The embodiment of the present application provides a local oscillator leakage adjusting circuit and a digital transmitter and an analog transmitter based on the same, which can solve the problems of difficulty in realizing wideband and poor robustness according to the current local oscillator leakage cancellation method.

[0007] In a first aspect, the embodiment of the present application provides a local oscillator leakage adjusting circuit, comprising:

[0008] A digital pre-modulator is configured to perform power amplification or reduction on the local oscillator signal according to a first modulation code to obtain a first-modulated local oscillator signal, wherein the first modulation code is used to control the gain of the digital pre-modulator.

[0009] A digital power amplifier is configured to perform power amplification on the first-modulated local oscillator signal according to a second modulation code to obtain an output signal, wherein the second modulation code is used to control the gain of the digital power amplifier, and the first modulation code and the second modulation code are used to control the total gain of the output signal relative to the local oscillator signal to be always a preset gain value.

[0010] In a second aspect, the embodiment of the present application provides a digital transmitter based on the local oscillator leakage adjusting circuit, comprising:

[0011] A first local oscillator leakage adjusting circuit comprises a first digital pre-modulator and a first digital power amplifier, the first digital pre-modulator is configured to perform power amplification or reduction on a first quadrature component of the local oscillator signal according to a first modulation code to obtain a first quadrature component of a first-modulated local oscillator signal, and the first digital power amplifier is configured to perform power amplification on the first quadrature component of the first-modulated local oscillator signal according to a second modulation code to obtain a first quadrature component of an output signal.

[0012] A second local oscillator leakage adjusting circuit comprises a second digital pre-modulator and a second digital power amplifier, the second digital pre-modulator is configured to perform power amplification or reduction on a second quadrature component of the local oscillator signal according to the first modulation code to obtain a second quadrature component of the first-modulated local oscillator signal, and the second digital power amplifier is configured to perform power amplification on the second quadrature component of the first-modulated local oscillator signal according to the second modulation code to obtain a second quadrature component of the output signal.

[0013] The first modulation code is used to control the gain of the first digital pre-modulator and the second digital pre-modulator, the second modulation code is used to control the gain of the first digital power amplifier and the second digital power amplifier, and the first modulation code and the second modulation code are used to control the total gain of the output signal relative to the local oscillator signal to be always a preset gain value.

[0014] The signal synthesizer is used for signal synthesis processing of the first quadrature component of the output signal and the second quadrature component of the output signal to obtain the radio frequency output signal.

[0015] In a third aspect, an analog transmitter based on a local oscillator leakage adjusting circuit is provided in the embodiments of the present application, and the analog transmitter comprises:

[0016] The digital-to-analog converter is used for digital-to-analog conversion of the baseband signal coding to obtain the baseband signal.

[0017] The filter is used for filtering the baseband signal to obtain the intermediate frequency signal.

[0018] The digital pre-modulator is used for power amplification or reduction of the local oscillator signal according to the first modulation coding to obtain the first modulation local oscillator signal.

[0019] The mixer is used for mixing the first modulation local oscillator signal and the intermediate frequency signal to obtain the mixing output signal.

[0020] The digital power amplifier is used for power amplification of the mixing output signal according to the second modulation coding to obtain the output signal.

[0021] The power amplifier is used for amplifying the output signal to obtain the radio frequency output signal.

[0022] Compared with the prior art, the embodiments of the present application have the beneficial effects that: the first modulation coding and the second modulation coding are used to keep the total gain of the output signal relative to the local oscillator signal at a preset gain value, so that the linearity of the output signal can be maintained and the influence of the local oscillator leakage can be reduced; the digital pre-modulator and the digital power amplifier are used to modulate the local oscillator leakage, and the modulation is not dependent on circuit parameter adjustment, so that the modulation is not sensitive to factors such as frequency, process and temperature, the problem of poor robustness caused by analog devices can be avoided, and wideband local oscillator leakage suppression can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of a local oscillator leakage self-suppression technology;

[0024] Figure 2 It is a schematic diagram of a transmitter based on a local oscillator leakage self-suppression technology;

[0025] Figure 3 It is a schematic diagram of a local oscillator leakage adjusting circuit provided in the embodiments of the present application;

[0026] Figure 4 It is a schematic diagram of the relationship among the baseband signal coding, the first modulation coding and the second modulation coding provided in the embodiments of the present application;

[0027] Figure 5 A schematic diagram of a local oscillator leakage signal provided by an embodiment of the present invention;

[0028] Figure 6 The present invention is a structural diagram of a digital transmitter based on a local oscillator leakage adjustment circuit provided by Strength;

[0029] Figure 7 A schematic structural diagram of an analog transmitter based on a local oscillator leakage adjustment circuit provided in an embodiment of the present invention;

[0030] Figure 8 A schematic diagram showing a comparison of radio frequency output signals provided by an embodiment of the present invention;

[0031] Figure 9 A schematic diagram of a change in a local oscillator leakage signal when the secondary modulation code is 0 provided in an embodiment of the present invention;

[0032] Figure 10 A constellation diagram of two-level coding provided by an embodiment of the present invention;

[0033] Figure 11 This is a high-order modulation test diagram of the transmitter provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0035] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0036] It will also be understood that the term "and / or" used in the present description and appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0037] As used in the description of the application and the appended claims, the term "if' can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting." Similarly, the phrase "if determined" or "if detected [the described condition or event]" can be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [the described condition or event]" or "in response to detecting [the described condition or event]," as appropriate.

[0038] In addition, the description in the specification of the application and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0039] In the description of the application, the reference "one embodiment" or "some embodiments" means that the specific features, structures or characteristics described in connection with the embodiment are included in one or more embodiments of the application. Therefore, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in additional some embodiments" and the like appearing in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "include", "contain", "have" and their variants mean "include but not limited to", unless otherwise specifically emphasized.

[0040] Figure 2 The structure of a transmitter based on the local oscillator leakage self-suppression technology is shown.

[0041] Referring to Figure 2 , the current differential structure transmitter cancels the local oscillator leakage of the forward signal and the reverse signal by introducing two capacitors. When the local oscillator leakage self-suppression technology is not used, referring to Figure 2 , the phase of the radio frequency output signal has a large amplitude modulation-amplitude modulation distortion and amplitude modulation-phase modulation distortion. At the same time, when the local oscillator leakage is large, the dynamic range of the transmitter is limited.

[0042] After using the local oscillator leakage self-suppression technology, referring to Figure 2 , the linearity and dynamic range of the transmitter can be effectively improved to support larger bandwidth and higher order modulation signals.

[0043] However, this local oscillator leakage cancellation method depends on device tuning, and it is difficult to implement wideband; and the cancellation effect of the local oscillator leakage depends on the parameters of the compensation capacitor and the parasitic capacitor; and both of these two devices are analog devices, which are greatly affected by environmental factors (such as temperature), processing deviation and other factors, and have poor robustness.

[0044] In view of this, the present invention controls the total gain of the output signal relative to the local oscillator signal through primary modulation coding and secondary modulation coding to maintain a preset gain value, thereby maintaining the linearity of the output signal and reducing the impact of local oscillator leakage; modulating the local oscillator leakage through digital devices such as digital premodulators and digital power amplifiers does not rely on circuit parameter adjustment, is insensitive to factors such as frequency, process, and temperature, and can avoid the poor robustness problem caused by analog devices, thereby achieving broadband local oscillator leakage suppression.

[0045] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0046] Example 1

[0047] Figure 3 The figure shows a schematic diagram of the structure of a local oscillator leakage adjustment circuit provided by an embodiment of the present invention. As an example but not a limitation, the local oscillator leakage adjustment circuit may include a digital premodulator 1 and a digital power amplifier 2.

[0048] For example, see Figure 1 The first input terminal of the digital premodulator 1 can input the local oscillator signal LO (ie, carrier signal), and the second input terminal can input the first-level modulation code BB LO The output terminal can be connected to the first input terminal of the digital power amplifier 2. The second input terminal of the digital power amplifier 2 can input the secondary modulation code BB m .

[0049] For details, see Figure 4 , the digital premodulator 1 can be based on the first-level modulation code BB LO The local oscillator signal LOI is amplified or reduced to obtain a primary modulated local oscillator signal Mod.LO. The digital power amplifier 2 can amplify the primary modulated local oscillator signal according to the secondary modulation coding to obtain an output signal RFout.

[0050] Optionally, the digital power amplifier 2 can simultaneously implement functions such as digital-to-analog conversion, up-mixing, and power amplification.

[0051] For example, the primary modulation coding can be used to control the gain of the digital premodulator 1, and the secondary modulation coding can be used to control the gain of the digital power amplifier 2. Under the joint control of the primary modulation coding and the secondary modulation coding, the total gain of the output signal compared to the local oscillator signal is always a preset gain value.

[0052] Exemplarily, the total gain may be equal to the product of the gain P1 of the digital premodulator 1 and the gain P2 of the digital power amplifier, and the values ​​of P1 and P2 may be equal to the values ​​of the primary modulation code and the secondary modulation code, respectively.

[0053] In some embodiments, when the amplitude of the LO signal is 0, both the first modulation code and the second modulation code are 0; at this time, the digital pre-modulator 1 is turned off, so that the first modulated LO signal is minimized, and the LO leakage generated by the digital power amplifier 2 is greatly reduced.

[0054] In one possible implementation, the first modulation code can be positively correlated with the size of the LO signal, and the second modulation code can be negatively correlated with the size of the LO signal. When the LO signal decreases, the first modulated LO signal also greatly decreases with the decrease of the LO signal, generating a first modulated LO signal with a size that can be scaled. Compared with the first modulated LO signal with a constant gain, referring to Figure 5 , when the LO signal decreases, the LO leakage in the circuit also scales with the size of the first modulated LO signal, reducing the impact of the LO leakage.

[0055] In one example, if the LO leakage adjustment circuit is applied in a 2x8-bit transmitter, the baseband signal code BB, the first modulation code BB LO , and the second modulation code BB m work together; the product of the first modulation code and the second modulation code can be equal to the product of the baseband signal code BB and 2 N1 , that is, .

[0056] For example, the baseband signal code can include a plurality of value intervals, when the value of the baseband signal code is in the nth value interval, the value of the first modulation code can be 2 n ; n is a non-negative integer less than or equal to N1.

[0057] For example, when n is greater than 0, the nth value interval of the baseband signal code can be [2 n+3 , 2 n+4 -1]; the 0th value interval of the baseband signal code can be [1, 2 4 -1].

[0058] For another example, the 0th value interval of the baseband signal code is [1, 2 3 -1], the 1st value interval is [8, 2 5 -1], and from the 2nd value interval, the nth value interval is [2 n+3 , 2 n+4 -1].

[0059] It should be understood that the specific range of the value interval of the baseband signal code is not limited in the present application, as long as the total number of the value interval of the baseband signal code is equal to N1.

[0060] N1 is the number of bits of the digital pre-modulator.

[0061] For example, when the number of bits of the digital pre-modulator 1 is 2 3 , the values of the primary modulation code, the secondary modulation code and the value interval of the baseband signal code can refer to Table 1 below.

[0062] Table 1

[0063]

[0064] In another example, if the local oscillator leakage adjustment circuit is applied in a 2x11-bit transmitter, the baseband signal code BB, the primary modulation code BB LO , the secondary modulation code BB m work together, but the primary modulation code and the secondary modulation code are independent of each other; the values of the two are related to the interval in which the value of the baseband signal code is located.

[0065] Similarly, the baseband signal code can include multiple value intervals.

[0066] It should be understood that the present application does not limit the specific range of the value interval of the baseband signal code, as long as the total number of the value intervals of the baseband signal code is equal to N1, which is the number of bits of the digital pre-modulator.

[0067] For example, when the value of the baseband signal code is located in the nth value interval of the baseband signal, the value of the primary modulation code can be 2 n , and the value of the secondary modulation code can be 2 N1-n . Although the two satisfy the quantity relationship that the product is equal to 2 N1 , they are actually independent of each other.

[0068] For example, when the number of bits of the digital pre-modulator 1 is 2 3 , the values of the primary modulation code, the secondary modulation code and the value interval of the baseband signal code can refer to Table 2 below.

[0069] Table 2

[0070]

[0071] In another possible implementation, the primary modulation code can be negatively related to the size of the local oscillator signal, and the secondary modulation code is positively related to the size of the local oscillator signal.

[0072] The application can keep the linearity of the output signal and reduce the influence of the local oscillator leakage by keeping the total gain of the output signal relative to the local oscillator signal at a preset gain value through the first modulation coding and the second modulation coding, and can avoid the poor robustness problem caused by analog devices by modulating the local oscillator leakage through the digital pre-modulator and the digital power amplifier, which are not sensitive to factors such as frequency, process and temperature, and can realize wideband local oscillator leakage suppression and high-order modulation. Further, the two different setting modes of the first modulation coding and the second modulation coding enable the local oscillator leakage adjusting circuit provided by the application to be applied in a bit reconfigurable transmitter, thereby expanding the application range.

[0073] Embodiment 2

[0074] Based on the embodiment 1, Figure 6 The application is shown as a structure diagram of a digital transmitter based on a local oscillator leakage adjusting circuit. As an example but not limitation, the digital transmitter can include a first local oscillator leakage adjusting circuit 61, a second local oscillator leakage adjusting circuit 62 and a signal combiner 63.

[0075] For example, Figure 6 The first local oscillator leakage adjusting circuit 61 can include a first digital pre-modulator 611 and a first digital power amplifier 612, and the second local oscillator leakage adjusting circuit 62 can include a second digital pre-modulator 621 and a second digital power amplifier 622. The first input end of the first digital pre-modulator 611 can input the first quadrature component of the local oscillator signal, the second input end can input the first modulation coding, and the output end can be connected with the first input end of the first digital power amplifier 612. The second input end of the first digital power amplifier can input the second modulation coding, and the output end can be connected with the first input end of the signal combiner 63.

[0076] Similarly, the first input end of the second digital pre-modulator 621 can input the second quadrature component of the local oscillator signal, the second input end can input the first modulation coding, and the output end can be connected with the first input end of the second digital power amplifier 622. The second input end of the second digital power amplifier 622 can input the second modulation coding, and the output end can be connected with the second input end of the signal combiner 63.

[0077] Specifically, the first digital pre-modulator 611 is used for performing power amplification or reduction on the first quadrature component LOI of the local oscillator signal according to the first modulation coding BB LO The first digital power amplifier 612 is used for performing power amplification on the first quadrature component Mod.LOI of the first modulation signal according to the second modulation coding BB m The first digital power amplifier 612 is used for performing power amplification on the first quadrature component Mod.LOI of the first modulation signal according to the second modulation coding BBI The second digital pre-modulator 621 is configured to perform first modulation coding on the local oscillator signal to obtain a first modulation signal. LO The second quadrature component of the local oscillator signal LOQ is amplified or shrunk to obtain a second quadrature component Mod.LOQ of the first modulation signal. The second digital power amplifier 622 is configured to amplify the second quadrature component Mod.LOQ of the first modulation signal according to second modulation coding to obtain a second quadrature component RF Q The signal synthesizer 63 is configured to perform signal synthesis processing on the first quadrature component RF I , the second quadrature component RF Q to obtain a radio frequency output signal.

[0078] The application can keep the linearity of the output signal and reduce the influence of the local oscillator leakage by keeping the total gain of the output signal relative to the local oscillator signal at a preset gain value, and can avoid the problem of poor robustness caused by analog devices by modulating the local oscillator leakage by digital devices such as digital pre-modulators and digital power amplifiers, and is not sensitive to factors such as frequency, process and temperature, and can realize wideband local oscillator leakage suppression and high-order modulation, and can realize extremely low local oscillator leakage.

[0079] Embodiment 3

[0080] Based on the embodiment 1, Figure 7 The application provides a structure of an analog transmitter based on a local oscillator leakage adjustment circuit. As an example but not limitation, the analog transmitter can include a digital-to-analog converter 71, a filter 72, a mixer 73, a digital pre-modulator 74, a digital power amplifier 75 and a power amplifier 76.

[0081] For example, the input end of the digital-to-analog converter 71 can input a baseband signal code, the output end can be connected with the input end of the filter 72, and the output end of the filter 72 can be connected with the first input end of the mixer 73. The first input end of the digital pre-modulator 74 inputs a local oscillator signal, the second input end inputs first modulation coding, and the output end is connected with the second input end of the mixer 73. The output end of the mixer 73 can be connected with the first input end of the digital power amplifier 75. The second input end of the digital power amplifier 75 can input second modulation coding, and the output end is connected with the input end of the power amplifier 76.

[0082] Specifically, the digital-to-analog converter 71 can be used for digital-to-analog conversion of the baseband signal coding to obtain a baseband signal, and the filter 72 filters the baseband signal to obtain an intermediate frequency signal. The digital pre-modulator 74 performs power amplification or reduction on the local oscillator signal according to the first modulation coding to obtain the first modulation local oscillator signal. The mixer 73 mixes the intermediate frequency signal and the first modulation local oscillator signal to obtain a mixed output signal. The digital power amplifier 75 performs power amplification on the mixed output signal according to the second modulation coding to obtain an output signal. The power amplifier 76 performs power amplification on the output signal again to obtain a radio frequency output signal.

[0083] In order to better illustrate the beneficial effects of the present application, the following simulation experiments are carried out:

[0084] Figure 8 A comparison diagram of a radio frequency output signal provided by an embodiment of the present application is shown.

[0085] Exemplarily, Figure 8 (a) is a signal generated by a current local oscillator leakage self-suppression technology-based transmitter, Figure 8 (b) is a signal generated by a digital transmitter provided in Embodiment 2 of the present application. The red color is a radio frequency output signal, the black color is a local oscillator signal, and the purple color is a local oscillator leakage signal.

[0086] Referring to Figure 8 It can be seen that the phase Δ∅ and amplitude ΔA of the local oscillator leakage signal in the conventional technology increase with the increase of the local oscillator signal, thereby causing the non-linearity of the radio frequency output signal to increase and distortion to occur. In the present application, since the total gain of the radio frequency output signal compared with the local oscillator signal is unchanged, the amplitude and phase of the local oscillator leakage signal are kept within a stable range. Especially when the local oscillator signal is small or the local oscillator signal is 0, the gain of the first modulation local oscillator signal generated in the present application is reduced, or the digital pre-modulator is directly turned off, which can greatly reduce the amplitude and phase deviation of the local oscillator leakage signal.

[0087] Figure 9 A variation diagram of the local oscillator leakage signal when the second modulation coding is 0 is shown.

[0088] Exemplarily, the second modulation coding is set to 0, and the size of the local oscillator leakage signal is measured at a frequency of 28 GHz to obtain the curve in (c). Figure 9

[0089] Referring to Figure 9 ​Compared with the size of the local oscillator leakage signal when the first modulation coding is 8 (equivalent to the pre-modulator not working), the size of the local oscillator leakage signal is reduced by 18 dB when the first modulation coding is 1. When the first modulation coding is 0, the size of the local oscillator leakage signal is reduced by 48 dB. It can be seen that the application can greatly reduce the amplitude and phase deviation of the local oscillator leakage signal when the local oscillator signal is small, especially when the local oscillator signal is 0.

[0090] Figure 10 A two-level coding constellation provided by an embodiment of the application is shown.

[0091] For example, when the transmitter works in a 2x8 bit mode, the first modulation coding and the second modulation coding in the local oscillator leakage adjustment circuit should strictly comply with the corresponding relationship shown in Table 1, and the two-level coding is associated with each other. When the transmitter works in a 2x11 bit mode, the two-level coding can be independently selected to generate a constellation shown in Figure 10 The constellation provides more selectable coding points. Therefore, the local oscillator leakage adjustment circuit provided by the application can improve the bit of the transmitter.

[0092] Figure 11 A high-order modulation test diagram of a millimeter wave digital transmitter provided by an embodiment of the application is shown.

[0093] For example, referring to Figure 11 It can be seen that the transmitter provided by the application can perform modulation under the condition of 4096QAM and 1024QAM, and the modulation order of the application is higher than that of the current millimeter wave transmitter performing modulation under the condition of 256QAM.

[0094] Therefore, the application can keep the linearity of the output signal and reduce the influence of the local oscillator leakage by keeping the total gain of the output signal relative to the local oscillator signal at a preset gain value through the first modulation coding and the second modulation coding. The local oscillator leakage is modulated by the digital pre-modulator and the digital power amplifier, which are digital devices, and is not dependent on circuit parameter adjustment, and is not sensitive to factors such as frequency, process and temperature, thereby avoiding the poor robustness problem caused by analog devices, realizing wideband local oscillator leakage suppression and high-order modulation, and achieving extremely low local oscillator leakage.

[0095] In the description of the application, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0096] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0097] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art can understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0098] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art to which the present invention belongs, any modifications made without departing from the concept of the present invention should be deemed to fall within the scope of protection of the present invention.

Claims

1. A local oscillator leakage adjustment circuit, characterized in that: include: A digital premodulator, the digital premodulator being configured to amplify or reduce the power of a local oscillator signal according to a primary modulation code to obtain a primary modulated local oscillator signal, wherein the primary modulation code is used to control the gain of the digital premodulator; a digital power amplifier configured to amplify the primary modulated local oscillator signal according to secondary modulation coding to obtain an output signal, wherein the secondary modulation coding is configured to control the gain of the digital power amplifier, and the primary modulation coding and the secondary modulation coding are configured to control the total gain of the output signal relative to the local oscillator signal to always be a preset gain value; The primary modulation code is positively correlated with the magnitude of the local oscillator signal, and the secondary modulation code is negatively correlated with the magnitude of the local oscillator signal; Among them, the first-level modulation code BB LO With the secondary modulation code BB m The product of the baseband signal code BB and 2 N1 The product of N1 is the number of bits of the digital premodulator, the baseband signal coding includes multiple value intervals, if the value of the baseband signal coding is in the nth value interval, the value of the first-level modulation coding is 2 n , the value of the secondary modulation code is BB×2 N1-n , n is a non-negative integer less than or equal to N1; Alternatively, the product of the primary modulation code and the secondary modulation code is equal to 2 N1 If the baseband signal code value is in the nth value interval, the first level modulation code value is 2 n , the value of the secondary modulation code is 2 N1-n .

2. The local oscillator leakage adjustment circuit according to claim 1, characterized in that: When the amplitude of the local oscillator signal is 0, both the primary modulation code and the secondary modulation code are 0.

3. A digital transmitter based on a local oscillator leakage adjustment circuit, characterized in that: include: a first local oscillator leakage adjustment circuit, the first local oscillator leakage adjustment circuit comprising a first digital premodulator and a first digital power amplifier, the first digital premodulator being configured to amplify or reduce the power of a first quadrature component of a local oscillator signal according to primary modulation coding to obtain a first quadrature component of a primary modulated local oscillator signal, and the first digital power amplifier being configured to amplify the power of the first quadrature component of the primary modulated local oscillator signal according to secondary modulation coding to obtain a first quadrature component of an output signal; a second local oscillator leakage adjustment circuit, the second local oscillator leakage adjustment circuit comprising a second digital premodulator and a second digital power amplifier, the second digital premodulator being configured to amplify or reduce the power of a second quadrature component of the local oscillator signal according to the primary modulation coding to obtain a second quadrature component of the primary modulated local oscillator signal, and the second digital power amplifier being configured to amplify the power of the second quadrature component of the primary modulated local oscillator signal according to the secondary modulation coding to obtain a second quadrature component of the output signal; The primary modulation code is used to control the gain of the first digital premodulator and the second digital premodulator, the secondary modulation code is used to control the gain of the first digital power amplifier and the second digital power amplifier, and the primary modulation code and the secondary modulation code are used to control the total gain of the output signal relative to the local oscillator signal to always be a preset gain value; a signal synthesizer, the signal synthesizer being configured to perform signal synthesis processing on the first orthogonal component of the output signal and the second orthogonal component of the output signal to obtain a radio frequency output signal; The primary modulation code is positively correlated with the magnitude of the local oscillator signal, and the secondary modulation code is negatively correlated with the magnitude of the local oscillator signal; Among them, the first-level modulation code BB LO With the secondary modulation code BB m The product of the baseband signal code BB and 2 N1 The product of N1 is the number of bits of the digital premodulator, the baseband signal coding includes multiple value intervals, if the value of the baseband signal coding is in the nth value interval, the value of the first-level modulation coding is 2 n , the value of the secondary modulation code is BB×2 N1-n , n is a non-negative integer less than or equal to N1; Alternatively, the product of the primary modulation code and the secondary modulation code is equal to 2 N1 If the baseband signal code value is in the nth value interval, the first level modulation code value is 2 n , the value of the secondary modulation code is 2 N1-n .

4. An analog transmitter based on a local oscillator leakage adjustment circuit, characterized in that: include: A digital-to-analog converter, the digital-to-analog converter is used to perform digital-to-analog conversion on the encoded baseband signal to obtain a baseband signal; A filter, configured to filter the baseband signal to obtain an intermediate frequency signal; A digital premodulator, the digital premodulator is used to amplify or reduce the power of the local oscillator signal according to the primary modulation code to obtain a primary modulated local oscillator signal; A mixer, configured to mix the first-stage modulated local oscillator signal with the intermediate frequency signal to obtain a mixed output signal; a digital power amplifier, configured to amplify the mixed output signal according to secondary modulation coding to obtain an output signal; a power amplifier, configured to amplify the output signal to obtain a radio frequency output signal; The primary modulation code and the secondary modulation code are used to control the total gain of the output signal relative to the local oscillator signal to always be a preset gain value; The primary modulation code is positively correlated with the magnitude of the local oscillator signal, and the secondary modulation code is negatively correlated with the magnitude of the local oscillator signal; Among them, the first-level modulation code BB LO With the secondary modulation code BB m The product of the baseband signal code BB and 2 N1 The product of N1 is the number of bits of the digital premodulator, the baseband signal modulation code includes multiple value intervals, if the value of the baseband signal code is in the nth value interval, the value of the first-level modulation code is 2 n , the value of the secondary modulation code is BB×2 N1-n , n is a non-negative integer less than or equal to N1; Alternatively, the product of the primary modulation code and the secondary modulation code is equal to 2 N1 If the baseband signal code value is in the nth value interval, the first level modulation code value is 2 n , the value of the secondary modulation code is 2 N1-n .

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