A phase correction device for analog quadrature signals

Abstract

The present invention discloses an analog orthogonal signal phase correction device, belonging to the technical field of semiconductor integrated circuits. The analog orthogonal signal phase correction device comprises a first single-sideband mixer (100), a second single-sideband mixer (200) and a regenerative frequency divider (300); the regenerative frequency divider (300) is used to generate an orthogonal two-frequency output; the first single-sideband mixer (100) and the second single-sideband mixer (200) are used to cooperate with the regenerative frequency divider (300) to calibrate the phase error. The analog orthogonal signal phase correction device has a simple structure and a wide correction range.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor integrated circuits, and in particular to a simulated quadrature signal phase correction device. Background Art

[0002] Orthogonal signals are essential in direct conversion transceivers, and they play an important role in image suppression and advanced modulation methods. Non-orthogonal I / Q signals will reduce the signal-to-noise ratio and deteriorate the performance of the entire transceiver system. Many technologies have been proposed to compensate for I / Q signal mismatch, some of which are considered from the system perspective and some from the circuit module perspective. Correction from a system perspective requires DSP assistance and some complex algorithms. Since one of the main sources of I / Q mismatch is the orthogonal phase mismatch of LO, it is very convenient and effective to directly perform orthogonal phase correction on the LO signal. There are two correction methods in the prior art: analog correction and digital correction.

[0003] Method 1: General analog calibration is to detect the phase difference of the orthogonal signal and then convert it into current to adjust the bias of the relevant circuit. The disadvantage of this technology is that the calibration range is limited and it cannot be corrected when the orthogonal phase deviation is large.

[0004] Method 2: Digital correction requires the use of DSP and algorithms. The disadvantage of this technology is that the algorithm is complex and the correction range is wider than analog correction, but it is still very limited. Summary of the invention

[0005] In view of the problems existing in analog correction and digital correction, the present invention proposes an analog orthogonal signal phase correction device, which does not require a complex digital algorithm but can achieve a very wide correction range.

[0006] The present invention provides an analog quadrature signal phase correction device, comprising a first single-sideband mixer, a second single-sideband mixer and a regenerative frequency divider;

[0007] The output frequency of the regenerative frequency divider is fed back to the first single-sideband mixer, mixed with the input frequency of the regenerative frequency divider by the first single-sideband mixer and then output;

[0008] The output frequency of the regenerative frequency divider is fed back to the second single-sideband mixer, mixed with the input frequency of the regenerative frequency divider by the second single-sideband mixer and then output;

[0009] One half of the output frequency of the first single-sideband mixer and the second single-sideband mixer is equal to the input frequency of the analog quadrature signal phase correction device;

[0010] The output frequency of the first single-sideband mixer and the output frequency of the second single-sideband mixer are two input frequencies of the regenerative frequency divider; the input frequency of the regenerative frequency divider is twice the output frequency of the regenerative frequency divider; the output frequency of the regenerative frequency divider is equal to the input frequency of the analog orthogonal signal phase correction device, and the output frequencies of the regenerative frequency divider are orthogonal.

[0011] Preferably, the first single sideband mixer and the second single sideband mixer have the same structure but different input phase sequences.

[0012] Preferably, the regenerative frequency divider is composed of a first mixer, a second mixer, a third mixer, a fourth mixer, a first load unit and a second load unit;

[0013] The first mixer forms a first branch;

[0014] The second mixer forms a second branch;

[0015] The first branch and the second branch are two branch paths of the I branch of the regenerative frequency divider;

[0016] The third mixer forms a third branch;

[0017] The fourth mixer forms a fourth branch;

[0018] The third branch and the fourth branch are two branch paths of the Q branch of the regenerative frequency divider;

[0019] The input end of the first mixer and the input end of the second mixer are the input ends of the regenerative frequency divider I branch;

[0020] The input end of the third mixer and the input end of the fourth mixer are the input end of the Q branch of the regenerative divider; the first mixer and the third mixer are connected in parallel, and the output ends of the first mixer and the third mixer are connected to one end of the first load unit;

[0021] The circuit I current of the regenerative frequency divider is output from the other end of the first load unit;

[0022] The second mixer and the fourth mixer are connected in parallel, and the output ends of the second mixer and the fourth mixer are connected to one end of the second load unit;

[0023] The Q-path current of the regenerative frequency divider is output from the other end of the second load unit.

[0024] Preferably, the first mixer, the second mixer, the third mixer and the fourth mixer are four double-balanced active mixers based on Gilbert cells.

[0025] Preferably, the I-channel output current of the regenerative frequency divider is fed back to the first mixer, and after being mixed with the I-channel input current of the regenerative frequency divider by the first mixer, the output current of the first mixer is output;

[0026] The Q-path output current of the regenerative frequency divider is phase-shifted by 180 degrees and then fed back to the second mixer, and mixed with the I-path input current of the regenerative frequency divider by the Q-path phase shift of the second mixer to output the output current of the second mixer;

[0027] The Q-path output current of the regenerative frequency divider is fed back to the third mixer, and after being mixed with the Q-path input current of the regenerative frequency divider by the third mixer, the output current of the third mixer is output;

[0028] The I-channel output current of the regenerative frequency divider is fed back to the fourth mixer, and after being mixed with the Q-channel input current of the regenerative frequency divider by the fourth mixer, the output current of the fourth mixer is output.

[0029] Preferably, the first load unit includes a first resistor, a second resistor, a first PMOS transistor and a second PMOS transistor; the second load unit includes a third resistor, a fourth resistor, a third PMOS transistor and a fourth PMOS transistor;

[0030] The first PMOS tube and the second PMOS tube are cross-coupled;

[0031] The third PMOS tube and the fourth PMOS tube are cross-coupled.

[0032] Preferably, the first PMOS transistor, the second PMOS transistor, the third PMOS transistor and the fourth PMOS transistor are used to extend a calibration range.

[0033] Preferably, the output frequency of the first single sideband mixer and the output frequency of the second single sideband mixer are orthogonal.

[0034] One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

[0035] The present invention mainly aims at the problems of complex digital correction algorithm and limited analog correction range, and proposes an analog orthogonal signal phase correction device. The device adopts analog method to perform phase correction, has the characteristics of simple circuit structure, and has a wide correction range, which can reach ±90°, and has better performance than digital correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0037] Figure 1 A schematic diagram of the structure of a simulated quadrature signal phase correction device provided by an embodiment of the present invention;

[0038] Figure 2 A schematic diagram of the structure of a regenerative frequency divider in an analog quadrature signal phase correction device provided by an embodiment of the present invention;

[0039] Figure 3 A circuit schematic diagram of a regenerative frequency divider in an analog quadrature signal phase correction device provided by an embodiment of the present invention;

[0040] Figure 4 A diagram of phase correction simulation results of a simulated orthogonal signal phase correction device provided by an embodiment of the present invention;

[0041] Figure 5 A circuit schematic diagram of a single sideband mixer in an analog quadrature signal phase correction device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] The embodiment of the present invention provides a simulated quadrature signal phase correction device, such as Figure 1 As shown, the analog quadrature signal phase correction device includes a first single sideband mixer 100, a second single sideband mixer 200 and a regenerative frequency divider 300;

[0044] The output frequency of the regenerative frequency divider 300 is fed back to the first single sideband mixer 100, and is mixed with the input frequency of the first single sideband mixer 100 and then outputted;

[0045] The output frequency of the regenerative frequency divider 300 is fed back to the second single sideband mixer 200, and the input frequency of the second single sideband mixer 200 is output after being mixed with the second single sideband mixer 200;

[0046] One half of the output frequency of the first single sideband mixer 100 and the second single sideband mixer 200 is equal to the input frequency of the analog quadrature signal phase correction device;

[0047] The output frequency of the first single-sideband mixer 100 and the output frequency of the second single-sideband mixer 200 are two input frequencies of the regenerative frequency divider 300; the input frequency of the regenerative frequency divider 300 is twice the output frequency of the regenerative frequency divider 300; the output frequency of the regenerative frequency divider 300 is equal to the input frequency of the analog orthogonal signal phase correction device, and the output frequencies of the regenerative frequency divider 300 are orthogonal.

[0048] For example, if the input frequency of the analog quadrature signal phase correction device is ω, the output frequencies of the first single-sideband mixer 100 and the second single-sideband mixer 200 are both 2ω; the input frequency of the regenerative frequency divider 300 is 2ω, and the output frequency is ω. Under appropriate phase and gain conditions, this relationship can be maintained. Therefore, the regenerative frequency divider 300 can provide an orthogonal output with the same input frequency.

[0049] Furthermore, if Figure 2 As shown, the regenerative frequency divider 300 in the present invention includes a first mixer 301, a second mixer 302, a third mixer 303, a fourth mixer 304, a first load unit 305 and a second load unit 306. The first mixer 301 forms a first branch path1; the second mixer 302 forms a second branch path2; the first branch path1 and the second branch path2 are two branches of the I branch of the regenerative frequency divider 300; the third mixer 303 forms a third branch path3; the fourth mixer 304 forms a fourth branch path4; the third branch path3 and the fourth branch path4 are two branches of the Q branch of the regenerative frequency divider 300.

[0050] The input end of the first mixer 301 and the input end of the second mixer 302 are the input ends of the I branch of the regenerative frequency divider 300; the input end of the third mixer 303 and the input end of the fourth mixer 304 are the input ends of the Q branch of the regenerative frequency divider 300; the first mixer 301 and the third mixer 303 are connected in parallel, and the output ends of the first mixer 301 and the third mixer 303 are connected to one end of the first load unit 305. The I current of the circuit of the regenerative frequency divider 300 is output from the other end of the first load unit 305; the second mixer 302 and the fourth mixer 304 are connected in parallel, and the output ends of the second mixer 302 and the fourth mixer 304 are connected to one end of the second load unit 306; the Q current of the circuit of the regenerative frequency divider 300 is output from the other end of the second load unit 306. The I-way output current of the regenerative frequency divider 300 is fed back to the first mixer 301, and after being mixed with the I-way input current of the regenerative frequency divider 300 by the first mixer 301, the output current I of the first mixer 301 is output. L1 The Q-channel output current of the regenerative divider 300 is phase-shifted by 180 degrees and then fed back to the second mixer 302. After mixing with the I-channel input current of the regenerative divider 300 by the second mixer 302, the output current I of the second mixer 302 is output. L2 The Q-path output current of the regenerative divider 300 is fed back to the third mixer 303, and the Q-path input current of the regenerative divider 300 is mixed by the third mixer 303 to output the output current I of the third mixer 303. L3 The I output current of the regenerative divider 300 is fed back to the fourth mixer 304, and the Q input current of the regenerative divider 300 is mixed by the fourth mixer 304 to output the output current I of the fourth mixer 304. L4 .

[0051] In this embodiment, if Figure 2 As shown, the I input of the regenerative frequency divider 300 is denoted as In_I, and the I output is denoted as Out_I; the Q input is denoted as In_Q, and the Q output is denoted as Out_Q. Figure 1 It can be seen that when the input frequency of the analog quadrature signal phase correction device is ω, the input frequency of the regenerative frequency divider 300 is 2ω, and the output frequency of the regenerative frequency divider 300 is ω. Therefore, the input current of the I path can be expressed as The output current can be expressed as Where V in is the input signal swing of the regenerative divider 300, V out is the output signal swing of the reproducible divider 300, Indicates the initial phase of the I-channel input signal. represents the initial phase of the I output signal; the input current of the Q path can be expressed as The output current can be expressed as Indicates the initial phase of the Q-path input signal, Indicates the initial phase of the Q-channel output signal.

[0052] The I-way output current of the regenerative frequency divider 300 is fed back to the first mixer 301, and after being mixed with the I-way input current of the regenerative frequency divider 300 by the first mixer 301, the output current I of the first single-sideband mixer 301 is output. L1 , so I L1 It can be expressed as:

[0053]

[0054] Using the sum-difference product, we get formula (2):

[0055]

[0056] Where A = V in V out / 2.

[0057] Similarly, the output current I of the third single-sideband mixer 303 can be obtained. L3 , as shown in formula (3):

[0058]

[0059] I L1 with I L3 After superposition, the output voltage passes through the load. Assuming that the load transfer function is H and only considering the first-order component, the relationship between the output voltage and the input current can be expressed as:

[0060]

[0061] By simplifying the sum-difference-product formula, we can get:

[0062]

[0063] We can further obtain formula (6):

[0064]

[0065] Where K is a constant obtained by simplifying (5) to (6), representing the overall circuit gain of the regenerative divider 300; β is the phase shift caused by H.

[0066] This is the relationship for the I branch. For the Q branch, the same relationship can be obtained:

[0067]

[0068] Comparing equation (6) and equation (7),

[0069]

[0070] It can be seen from equation (8) that the output I-path signal and the output Q-path signal are orthogonal to each other.

[0071] Since the output signal of the regenerative frequency divider 300 is half of the input signal of the regenerative frequency divider 300, the frequency needs to be compensated. As mentioned in the above description, the first single-sideband mixer 100, the second single-sideband mixer 200 and the regenerative frequency divider 300 can form a regenerative structure again, so that the output frequency of the regenerative frequency divider 300 is equal to 1 / 2 of the mixer output frequency, but equal to the input frequency. Through this structure, the phase correction function is realized, but the output frequency will not be changed. The simulation results of phase correction are shown in FIG. Figure 4 This structure can correct ±90° deviation.

[0072] Furthermore, if Figure 3 As shown, the first mixer (301), the second mixer (302), the third mixer (303) and the fourth mixer (304) are four double-balanced active mixers based on Gilbert cells. The first load unit 305 includes a first resistor R1, a second resistor R2, a first PMOS tube M1 and a second PMOS tube M2; the second load unit 306 includes a third resistor R3, a fourth resistor R4, a third PMOS tube M3 and a fourth PMOS tube M4; the first PMOS tube M1 and the second PMOS tube M2 are cross-coupled; the third PMOS tube M3 and the fourth PMOS tube M4 are cross-coupled; the cross-coupled first PMOS tube M1, the second PMOS tube M2, the third PMOS tube M3 and the fourth PMOS tube M4 can expand the calibration range.

[0073] Furthermore, if Figure 5 As shown, the first single sideband mixer 100 and the second single sideband mixer 200 have the same structure, but different input phase sequences. For example, when the output current of the first single sideband mixer 100 is (cosωt*cosωt-sinωt*sinωt), the output current of the second single sideband mixer 200 is (sinωt*cosωt+cosωt*sinωt). The output frequency of the first single sideband mixer 100 and the output frequency of the second single sideband mixer 200 are orthogonal.

[0074] The present invention mainly aims at the problem that the existing digital correction algorithm is complex and the analog correction range is limited, and proposes an analog orthogonal signal phase correction device. The present invention adopts an analog method to perform phase correction, which has the characteristics of simple circuit and wide correction range, which can reach ±90° correction range, and has better performance than digital correction.

[0075] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0076] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A simulated quadrature signal phase correction device, characterized in that: The analog quadrature signal phase correction device comprises a first single-sideband mixer (100), a second single-sideband mixer (200) and a regenerative frequency divider (300); The output frequency of the regenerative frequency divider (300) is fed back to the first single-sideband mixer (100), mixed with the input frequency of the first single-sideband mixer (100), and then output after being mixed by the first single-sideband mixer (100); The output frequency of the regenerative frequency divider (300) is fed back to the second single-sideband mixer (200), mixed with the input frequency of the second single-sideband mixer (200), and then output after being mixed by the second single-sideband mixer (200); One half of the output frequency of the first single-sideband mixer (100) and the second single-sideband mixer (200) is equal to the input frequency of the analog quadrature signal phase correction device; The output frequency of the first single-sideband mixer (100) and the output frequency of the second single-sideband mixer (200) are two input frequencies of the regenerative frequency divider (300); the input frequency of the regenerative frequency divider (300) is twice the output frequency of the regenerative frequency divider (300); the output frequency of the regenerative frequency divider (300) is equal to the input frequency of the analog orthogonal signal phase correction device, and the output frequency of the regenerative frequency divider (300) is orthogonal; The first single-sideband mixer (100) and the second single-sideband mixer (200) have the same structure but different input phase sequences; The regenerative frequency divider (300) comprises a first frequency mixer (301), a second frequency mixer (302), a third frequency mixer (303), a fourth frequency mixer (304), a first load unit (305) and a second load unit (306); The first mixer (301) forms a first branch (path1); The second mixer (302) forms a second branch (path2); The first branch (path1) and the second branch (path2) are two branch paths of the I branch of the regenerative frequency divider (300); The third mixer (303) forms a third branch (path3); The fourth mixer (304) forms a fourth branch (path4); The third branch (path3) and the fourth branch (path4) are two branch paths of the Q branch of the regenerative frequency divider (300); The input end of the first mixer (301) and the input end of the second mixer (302) are the input ends of the I branch of the regenerative frequency divider (300); The input end of the third mixer (303) and the input end of the fourth mixer (304) are the input ends of the Q branch of the regenerative frequency divider (300); The first mixer (301) and the third mixer (303) are connected in parallel, and the output ends of the first mixer (301) and the third mixer (303) are connected to one end of the first load unit (305); A circuit current of the regenerative frequency divider (300) is output from the other end of the first load unit (305); The second mixer (302) and the fourth mixer (304) are connected in parallel, and the output ends of the second mixer (302) and the fourth mixer (304) are connected to one end of the second load unit (306); The Q-path current of the regenerative frequency divider (300) is output from the other end of the second load unit (306); The I-channel output current of the regenerative frequency divider (300) is fed back to the first mixer (301), and after being mixed with the I-channel input current of the regenerative frequency divider (300) by the first mixer (301), the output current (I L1 ); The Q-channel output current of the regenerative frequency divider (300) is phase-shifted by 180 degrees and then fed back to the second mixer (302). After being mixed with the I-channel input current of the regenerative frequency divider (300), the output current (I L2 ); The Q-path output current of the regenerative frequency divider (300) is fed back to the third mixer (303), and after being mixed with the Q-path input current of the regenerative frequency divider (300) by the third mixer (303), the output current (I L3 ); The I-channel output current of the regenerative frequency divider (300) is fed back to the fourth mixer (304), and after being mixed with the Q-channel input current of the regenerative frequency divider (300) by the fourth mixer (304), the output current (I L4 ).

2. The analog quadrature signal phase correction device according to claim 1, characterized in that: The first mixer (301), the second mixer (302), the third mixer (303) and the fourth mixer (304) are four double-balanced active mixers based on Gilbert cells.

3. The analog quadrature signal phase correction device according to claim 1, characterized in that: The first load unit (305) comprises a first resistor (R1), a second resistor (R2), a first PMOS transistor (M1) and a second PMOS transistor (M2); the second load unit (306) comprises a third resistor (R3), a fourth resistor (R4), a third PMOS transistor (M3) and a fourth PMOS transistor (M4); The first PMOS tube (M1) and the second PMOS tube (M2) are cross-coupled; The third PMOS transistor (M3) and the fourth PMOS transistor (M4) are cross-coupled.

4. The analog quadrature signal phase correction device according to claim 3, characterized in that: The first PMOS tube (M1), the second PMOS tube (M2), the third PMOS tube (M3) and the fourth PMOS tube (M4) are used to expand a calibration range.

5. The analog quadrature signal phase correction device according to claim 1, characterized in that: The output frequency of the first single sideband mixer (100) is orthogonal to the output frequency of the second single sideband mixer (200).

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