Orthogonal signal generation circuit and method

Abstract

The invention provides an orthogonal signal generation circuit and a generation method. The circuit comprises a Type-I PPF cascade multistage amplification circuit; the Type-I PPF is used for inputting a differential input signal and converting the differential input signal to obtain a first I-path differential signal and a first Q-path differential signal; the multi-stage amplification circuit is used for sequentially amplifying the first I-path differential signal and the first Q-path differential signal to obtain an I-path saturation output signal and a Q-path saturation output signal; the phase of the I-path saturation output signal and the phase of the Q-path saturation output signal are orthogonal; the amplitude of the I-path saturation output signal is equal to that of the Q-path saturation output signal; orthogonal signals with the phase difference constant to be 90 degrees are generated through the Type-I PPF, and the multi-stage amplifier is cascaded; the final-stage amplifier keeps full-swing output, so that the amplitude difference of the output orthogonal signal is in a frequency band, and a high-precision orthogonal signal with small amplitude and phase mismatch in the frequency band is generated.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to an orthogonal signal generating circuit and a generating method. Background Art

[0002] In RF transceivers using superheterodyne architecture, the image suppression capability of the orthogonal mixer can be used to eliminate the impact of image signals on transceiver performance. In the transmitter, the intermediate frequency input signal and the local oscillator input signal of the orthogonal mixer need to be decomposed into orthogonal signals, and the image signal can be eliminated after vector synthesis by the mixer, thus solving the image signal suppression problem.

[0003] A first-stage RC multiphase filter usually generates an orthogonal signal only when w*R*C=1. This structure not only has a narrow bandwidth, but also has a 3dB insertion loss at this frequency. There are two types of PPFs, called Type-Ⅰ and Type-Ⅱ. The phase difference of the IQ signal output by Type-Ⅰ PPF within the frequency band is constant and close to 90 degrees, and the amplitude difference varies with frequency. The amplitude difference of the IQ signal output by Type-Ⅱ PPF within the frequency band is constant and close to 0dB, and the phase difference varies with frequency, resulting in the inability of the generated orthogonal signal to simultaneously achieve high-precision orthogonal characteristics within a wide bandwidth. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an orthogonal signal generating circuit and method, which generates an orthogonal signal with a constant phase difference of 90 degrees through a Type-Ⅰ PPF, and then cascades a multi-stage amplifier; the final amplifier maintains a full-swing output, so that the amplitude difference of the output orthogonal signal can be within the frequency band, thereby generating a high-precision orthogonal signal with very small amplitude and phase mismatch within the frequency band.

[0005] In a first aspect, an embodiment of the present invention provides an orthogonal signal generating circuit, comprising: a Type-I PPF and a multi-stage amplifier circuit, wherein the Type-I PPF is cascaded to the multi-stage amplifier circuit;

[0006] The Type-Ⅰ PPF is used to input a differential input signal, convert the differential input signal, and obtain a first I-channel differential signal and a first Q-channel differential signal;

[0007] The multi-stage amplifier circuit is used to amplify the first I-path differential signal and the first Q-path differential signal in sequence to obtain an I-path saturated output signal and a Q-path saturated output signal;

[0008] The phase of the I-path saturated output signal is orthogonal to the phase of the Q-path saturated output signal; and the amplitude of the I-path saturated output signal is equal to the amplitude of the Q-path saturated output signal.

[0009] Furthermore, the Type-Ⅰ PPF includes a first-stage PPF and a second-stage PPF; the first-stage PPF and the second-stage PPF are cascaded;

[0010] The first-stage PPF includes a plurality of first RC filter circuits, and the second-stage PPF includes a plurality of second RC filter circuits.

[0011] Furthermore, the first-stage PPF is used to output a second I-channel differential signal and a second Q-channel differential signal;

[0012] The phase difference between the second I-path differential signal and the second Q-path differential signal is always 90 degrees, and the amplitudes of the second I-path differential signal and the second Q-path differential signal at the first frequency point are equal.

[0013] Furthermore, the first frequency point is calculated in the following manner:

[0014]

[0015] Wherein, R1 is the resistance value of the resistor RES1, C1 is the equivalent capacitance value of the capacitor CAP1, and f1 is the first frequency point.

[0016] Further, the second-stage PPF is used to output the first I-path differential signal and the first Q-path differential signal;

[0017] The phase difference between the first I-path differential signal and the first Q-path differential signal is always 90 degrees, and the amplitudes of the first I-path differential signal and the first Q-path differential signal at the second frequency point are equal.

[0018] Furthermore, the second frequency point is calculated in the following manner:

[0019]

[0020] Wherein, R2 is the resistance value of the resistor RES2, C2 is the equivalent capacitance value of the capacitor CAP2, and f2 is the second frequency point.

[0021] Further, in the first-stage PPF, the VCM node is grounded.

[0022] In a second aspect, an embodiment of the present invention provides an orthogonal signal generating method, which is applied to the orthogonal signal generating circuit as described above, wherein the orthogonal signal generating circuit comprises: a Type-I PPF and a multi-stage amplifier circuit, wherein the Type-I PPF cascades the multi-stage amplifier circuit; the method comprises:

[0023] The Type-Ⅰ PPF inputs a differential input signal, converts the differential input signal, and obtains a first I-channel differential signal and a first Q-channel differential signal;

[0024] The multi-stage amplifier circuit amplifies the first I-path differential signal and the first Q-path differential signal in sequence to obtain an I-path saturated output signal and a Q-path saturated output signal;

[0025] The phase of the I-path saturated output signal is orthogonal to the phase of the Q-path saturated output signal; and the amplitude of the I-path saturated output signal is equal to the amplitude of the Q-path saturated output signal.

[0026] In a third aspect, an embodiment of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program executable on the processor, and the processor implements the method described above when executing the computer program.

[0027] In a fourth aspect, an embodiment of the present invention provides a computer-readable medium having a non-volatile program code executable by a processor, wherein the program code enables the processor to execute the method as described above.

[0028] The embodiment of the present invention provides an orthogonal signal generating circuit and a generating method, the circuit includes: a Type-Ⅰ PPF and a multi-stage amplifier circuit, and a Type-Ⅰ PPF cascade multi-stage amplifier circuit; the Type-Ⅰ PPF is used to input a differential input signal, convert the differential input signal, and obtain a first I-path differential signal and a first Q-path differential signal; the multi-stage amplifier circuit is used to amplify the first I-path differential signal and the first Q-path differential signal in sequence to obtain an I-path saturated output signal and a Q-path saturated output signal; wherein the phase of the I-path saturated output signal is orthogonal to the phase of the Q-path saturated output signal; the amplitude of the I-path saturated output signal is equal to the amplitude of the Q-path saturated output signal; an orthogonal signal with a constant phase difference of 90 degrees is generated by the Type-Ⅰ PPF, and then a multi-stage amplifier is cascaded; the final amplifier maintains a full-swing output, so that the amplitude difference of the output orthogonal signal can be within the frequency band, thereby generating a high-precision orthogonal signal with a small amplitude and phase mismatch within the frequency band.

[0029] 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 are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the structure of an orthogonal signal generating circuit provided in Embodiment 1 of the present invention;

[0033] Figure 2 A schematic diagram of another orthogonal signal generating circuit structure provided in Embodiment 1 of the present invention;

[0034] Figure 3 A schematic diagram of the structure of a Type-I PPF provided in Embodiment 1 of the present invention;

[0035] Figure 4 A schematic diagram of an amplitude difference curve in different operating frequency bands provided in the first embodiment of the present invention;

[0036] Figure 5 A schematic diagram of another amplitude difference curve in different working frequency bands provided by the first embodiment of the present invention;

[0037] Figure 6 This is a flow chart of a method for generating orthogonal signals provided in Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0039] To facilitate understanding of this embodiment, the embodiment of the present invention is described in detail below.

[0040] Embodiment 1:

[0041] Figure 1 This is a schematic diagram of the structure of an orthogonal signal generating circuit provided in Embodiment 1 of the present invention.

[0042] Reference Figure 1 , including: Type-Ⅰ PPF and multi-stage amplifier circuit, Type-Ⅰ PPF cascade multi-stage amplifier circuit;

[0043] Type-Ⅰ PPF, used for inputting differential input signals, converting the differential input signals to obtain a first I-channel differential signal and a first Q-channel differential signal;

[0044] A multi-stage amplifier circuit, used for amplifying the first I-channel differential signal and the first Q-channel differential signal in sequence to obtain an I-channel saturated output signal and a Q-channel saturated output signal;

[0045] The phase of the I-channel saturated output signal is orthogonal to the phase of the Q-channel saturated output signal; the amplitude of the I-channel saturated output signal is equal to the amplitude of the Q-channel saturated output signal.

[0046] In this embodiment, a Type-I PPF is used to generate a quadrature signal with a constant phase difference of 90 degrees, and then a multi-stage amplifier is cascaded. The final amplifier maintains a full-swing output, which can make the amplitude difference of the output quadrature signal <0.05dB within the frequency band, thereby generating a high-precision quadrature signal with small amplitude and phase mismatch within the frequency band.

[0047] Further, see Figure 2 The entire circuit includes a Type-Ⅰ PPF (sub-circuit A), a first-stage amplifier circuit AMP1 (sub-circuit B) and a second-stage amplifier circuit AMP2.

[0048] The differential input signal is converted into a first I-channel differential signal and a first Q-channel differential signal by a Type-Ⅰ PPF. The first I-channel differential signal and the first Q-channel differential signal are respectively sent to the input ends of the two first-stage amplifier circuits AMP1; the output signal of the first-stage amplifier circuit AMP1 is sent to the input end of the second-stage amplifier AMP2, and finally an I-channel saturated output signal and a Q-channel saturated output signal are obtained.

[0049] Further, see Figure 3 , Type-Ⅰ PPF includes a first-stage PPF and a second-stage PPF; the first-stage PPF and the second-stage PPF are cascaded;

[0050] The first-stage PPF includes a plurality of first RC filter circuits, and the second-stage PPF includes a plurality of second RC filter circuits. The first RC filter circuit includes a resistor RES1 and a capacitor CAP1; in the first-stage PPF, the VCM node is grounded.

[0051] The second RC filter circuit includes a resistor (RES2) and a capacitor (CAP2), which widens the operating frequency band of the Type-I PPF.

[0052] In the first-stage PPF, OUT_IP1 and OUT_IN1 output the second I-path differential signal, and OUT_QP1 and OUT_QN1 output the second Q-path differential signal; in the second-stage PPF, OUT_IP and OUT_IN output the first I-path differential signal, and OUT_QP and OUT_QN output the first Q-path differential signal.

[0053] The first I-channel differential signal and the first Q-channel differential signal output by the Type-Ⅰ PPF are fed into two-stage cascade amplifiers AMP1 and AMP2 respectively. The two-stage cascade amplification is used to ensure that the output signal power of AMP2 is saturated output power. Therefore, the output signal of I-channel AMP2 and the output signal of Q-channel AMP2 are high-precision orthogonal signals with extremely small phase and amplitude mismatch within the working frequency band.

[0054] Further, the first stage PPF is used to output a second I-channel differential signal and a second Q-channel differential signal;

[0055] The phase difference between the second I-path differential signal and the second Q-path differential signal is always 90 degrees, and the amplitudes of the second I-path differential signal and the second Q-path differential signal at the first frequency point are equal.

[0056] Furthermore, the first frequency point is calculated in the following manner, referring to formula (1):

[0057]

[0058] Wherein, R1 is the resistance value of the resistor RES1, C1 is the equivalent capacitance value of the capacitor CAP1, and f1 is the first frequency point.

[0059] Further, the second stage PPF is used to output a first I-channel differential signal and a first Q-channel differential signal;

[0060] The phase difference between the first I-path differential signal and the first Q-path differential signal is always 90 degrees, and the amplitudes of the first I-path differential signal and the first Q-path differential signal at the second frequency point are equal.

[0061] Furthermore, the second frequency point is calculated in the following manner, referring to formula (2):

[0062]

[0063] Among them, R2 is the resistance value of resistor RES2, C2 is the equivalent capacitance value of capacitor CAP2, and f2 is the second frequency point. By adjusting the values ​​of R1, R2, C1 and C2, f1 and f2 are set to the two ends of the working frequency band respectively, so that the frequency response of the two-stage cascaded PPF presents broadband characteristics.

[0064] The output quadrature signal of the PPF designed in this application has a constant phase difference of 90° within the frequency band, but its amplitude difference is 0dB only at a fixed frequency point, and the amplitude mismatch is close to 0.1dB at other frequencies. Figure 4 As shown in the figure, frf1(G) is the operating frequency band; peak is the difference between the amplitude of the I-channel differential signal and the Q-channel differential signal.

[0065] Two amplifiers are cascaded at the output of the PPF to ensure that the output power of AMP2 is saturated output power, so that the signal power output of the IQ signal within the working frequency band is the same, and the output power mismatch is less than 0.01dB. The optimization results are shown in the attached figure. Figure 5 The output of AMP2 is a high-precision broadband orthogonal signal.

[0066] Compared with the prior art, the circuit structure of the present application produces a broadband high-precision orthogonal signal generation circuit. A constant-phase orthogonal signal is generated through a Type-I PPF; the working bandwidth is expanded through a cascaded PPF; and a constant-amplitude orthogonal signal is generated through a two-stage cascade amplifier.

[0067] Embodiment 2:

[0068] Figure 6 This is a flow chart of a method for generating orthogonal signals provided in Embodiment 2 of the present invention.

[0069] Reference Figure 6 , applied to the orthogonal signal generating circuit as described above, the orthogonal signal generating circuit comprises: a Type-Ⅰ PPF and a multi-stage amplifier circuit, a Type-Ⅰ PPF cascade multi-stage amplifier circuit; the method comprises the following steps:

[0070] Step S101, the Type-Ⅰ PPF inputs a differential input signal, converts the differential input signal, and obtains a first I-channel differential signal and a first Q-channel differential signal;

[0071] Step S102, the multi-stage amplifier circuit amplifies the first I-path differential signal and the first Q-path differential signal in sequence to obtain an I-path saturated output signal and a Q-path saturated output signal;

[0072] The phase of the I-channel saturated output signal is orthogonal to the phase of the Q-channel saturated output signal; the amplitude of the I-channel saturated output signal is equal to the amplitude of the Q-channel saturated output signal.

[0073] An embodiment of the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the orthogonal signal generating method provided in the above embodiment are implemented.

[0074] An embodiment of the present invention further provides a computer-readable medium having a non-volatile program code executable by a processor, wherein a computer program is stored on the computer-readable medium, and when the computer program is executed by the processor, the steps of the orthogonal signal generating method of the above embodiment are executed.

[0075] The computer program product provided in the embodiment of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the method described in the previous method embodiment. The specific implementation can be found in the method embodiment and will not be repeated here.

[0076] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0077] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0078] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0079] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0080] Furthermore, the terms “first”, “second”, and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0081] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A quadrature signal generating circuit, characterized in that: include: A Type-Ⅰ PPF and a multi-stage amplifier circuit, wherein the Type-Ⅰ PPF is cascaded to the multi-stage amplifier circuit; The Type-Ⅰ PPF is used to input a differential input signal, convert the differential input signal, and obtain a first I-channel differential signal and a first Q-channel differential signal; The multi-stage amplifier circuit is used to amplify the first I-path differential signal and the first Q-path differential signal in sequence to obtain an I-path saturated output signal and a Q-path saturated output signal; The phase of the I-path saturated output signal is orthogonal to the phase of the Q-path saturated output signal; and the amplitude of the I-path saturated output signal is equal to the amplitude of the Q-path saturated output signal.

2. The orthogonal signal generating circuit according to claim 1, characterized in that: The Type-Ⅰ PPF includes a first-stage PPF and a second-stage PPF; the first-stage PPF and the second-stage PPF are cascaded; The first-stage PPF includes a plurality of first RC filter circuits, and the second-stage PPF includes a plurality of second RC filter circuits.

3. The orthogonal signal generating circuit according to claim 2, characterized in that: The first-stage PPF is used to output a second I-channel differential signal and a second Q-channel differential signal; The phase difference between the second I-path differential signal and the second Q-path differential signal is always 90 degrees, and the amplitudes of the second I-path differential signal and the second Q-path differential signal at the first frequency point are equal.

4. The orthogonal signal generating circuit according to claim 3, characterized in that: The first frequency point is calculated by the following method: Wherein, R1 is the resistance value of the resistor RES1, C1 is the equivalent capacitance value of the capacitor CAP1, and f1 is the first frequency point.

5. The orthogonal signal generating circuit according to claim 2, characterized in that: The second-stage PPF is used to output the first I-path differential signal and the first Q-path differential signal; The phase difference between the first I-path differential signal and the first Q-path differential signal is always 90 degrees, and the amplitudes of the first I-path differential signal and the first Q-path differential signal at the second frequency point are equal.

6. The orthogonal signal generating circuit according to claim 5, characterized in that: The second frequency point is calculated by the following method: Wherein, R2 is the resistance value of the resistor RES2, C2 is the equivalent capacitance value of the capacitor CAP2, and f2 is the second frequency point.

7. The orthogonal signal generating circuit according to claim 2, characterized in that: In the first-stage PPF, the VCM node is grounded.

8. A method for generating an orthogonal signal, characterized in that: The orthogonal signal generating circuit applied to any one of claims 1 to 7, the orthogonal signal generating circuit comprising: a Type-I PPF and a multi-stage amplifier circuit, the Type-I PPF cascades the multi-stage amplifier circuit; the method comprises: The Type-Ⅰ PPF inputs a differential input signal, converts the differential input signal, and obtains a first I-channel differential signal and a first Q-channel differential signal; The multi-stage amplifier circuit amplifies the first I-path differential signal and the first Q-path differential signal in sequence to obtain an I-path saturated output signal and a Q-path saturated output signal; The phase of the I-path saturated output signal is orthogonal to the phase of the Q-path saturated output signal; and the amplitude of the I-path saturated output signal is equal to the amplitude of the Q-path saturated output signal.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, wherein: When the processor executes the computer program, the method according to claim 8 is implemented.

10. A computer readable medium having a non-volatile program code executable by a processor, characterized in that: The program code causes the processor to execute the method of claim 8.

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