CN112491364A - Millimeter wave CMOS quadrature mixer circuit - Google Patents
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Abstract
The invention discloses a millimeter wave CMOS (complementary metal oxide semiconductor) quadrature mixer circuit which comprises a transconductance input stage, a quadrature resonance stage, a switch mixing stage and an output load stage, wherein the transconductance input stage receives a radio-frequency voltage signal and performs amplification processing to convert the radio-frequency voltage signal into a current signal; the orthogonal resonance stage transmits the current signal to the I path and transmits the converted current signal to the Q path through transformer coupling; the switch mixing stage is controlled by a local oscillator signal, periodically commutates a current signal, converts the frequency from radio frequency to intermediate frequency, and finishes frequency down-conversion; and the commutating intermediate frequency current signal is converted into intermediate frequency voltage at the output load stage; the orthogonal resonance stage converts the current signal into two paths of signals with equal size and 90-degree phase difference, and the two paths of signals are respectively sent to the I path and the Q path, so that the orthogonality of the frequency mixer is realized. The circuit of the invention keeps lower power consumption, high conversion gain and low noise coefficient under high frequency, and obtains good orthogonality by designing the orthogonal resonance stage.
Description
Technical Field
The invention relates to the technical field of radio frequency integrated circuits, in particular to a millimeter wave CMOS quadrature mixer circuit.
Background
The millimeter wave phased array receiver has high carrier frequency, adopts a simple modulation scheme, can achieve high data rate, can improve space selectivity and spectral efficiency, is an ideal solution for broadband communication, and can be applied to the aspects of wireless high-definition video, wireless USB, butt joint, instant synchronization and the like.
As shown in fig. 1, a millimeter wave phased array receiver based on radio frequency path signal phase shift only needs one radio frequency path, has little hardware occupation space, and the structure avoids interference signals in an irrelevant direction, thereby generating a better signal-to-interference ratio and improving the performance of the receiver. However, the mixer part of such a receiver needs to shift the local oscillator signal into two orthogonal signals, and needs to implement two mixers, which inevitably needs an oscillator capable of providing the orthogonal local oscillator signal. Usually, extra power consumption of the oscillator is consumed, and the requirements of miniaturization and low power consumption of electronic equipment are not met.
The above problem can be solved if the mixer can provide quadrature characteristics. Note that the accuracy of the quadrature signal generation is also important because any mismatch in both the amplitude and phase of the quadrature signal will cause gain and phase imbalance in the I and Q outputs. Present wireless systems modulate different information in the I and Q signals, so the balance of amplitude and phase is critical. Conventionally, the quadrature generator in the quadrature mixer may be implemented by an RC-CR polyphase filter, which however has a larger insertion loss at high frequencies, and a polyphase filter based on CMOS technology is obviously not suitable for the design of the millimeter wave quadrature signal generator.
Disclosure of Invention
The present invention is directed to solve the above-mentioned problems, and an object of the present invention is to provide a millimeter wave CMOS quadrature mixer circuit, which maintains low power consumption, high conversion gain, and low noise figure at high frequency, and by designing a quadrature resonator stage, the I-path and Q-path outputs of the mixer are equal in size, the phase difference is 90 degrees, and good orthogonality is achieved.
The invention is realized by the following technical scheme:
a millimeter-wave CMOS quadrature mixer circuit, comprising: the input circuit comprises a transconductance input stage, a quadrature resonant stage, a switch mixing stage and an output load stage, wherein the switch mixing stage comprises an I-path mixer and a Q-path mixer;
the transconductance input stage receives a radio frequency voltage signal and performs amplification processing to convert the radio frequency voltage signal into a current signal;
the orthogonal resonance stage transmits the converted current signal to an I path and transmits the converted current signal to a Q path through transformer coupling;
the switch mixing stage is controlled by a local oscillator signal, periodically commutates the current signal, converts the frequency from radio frequency to intermediate frequency, and finishes frequency down-conversion; and the commutating intermediate frequency current signal is converted into an intermediate frequency voltage at the output load stage;
the orthogonal resonance stage converts the current signal into two paths of signals with equal size and 90-degree phase difference, and the two paths of signals are respectively sent to the I path and the Q path, so that the orthogonality of the frequency mixer is realized.
The working principle is as follows: based on the conventional method, the quadrature generator in the quadrature mixer can be realized by an RC-CR polyphase filter, however, the RC-CR polyphase filter has larger insertion loss at high frequency, and the polyphase filter based on CMOS technology is obviously not suitable for the design of the millimeter wave quadrature signal generator. The invention designs a millimeter wave CMOS quadrature mixer circuit, which comprises: the circuit comprises a transconductance input stage, a quadrature resonant stage, a switching mixing stage and an output load stage, wherein the quadrature resonant stage, the switching mixing stage and the output load stage of the circuit are of the same structure; according to the invention, through designing the orthogonal resonance stage, the I path output signal and the Q path output signal of the frequency mixer are equal in size, the phase difference is 90 degrees, and good orthogonality is realized; in addition, two mixer branches of the I path and the Q path share one group of radio frequency input ports, so that the realization of low power consumption is realized while the orthogonal frequency mixing is realized.
The circuit structure of the invention is reasonable, keeps lower power consumption, high conversion gain and low noise coefficient under high frequency, and ensures that the I path output and the Q path output of the frequency mixer have equal size and the phase difference is 90 degrees by designing the orthogonal resonance stage, thereby obtaining good orthogonality.
As a further preferred aspect, the spanThe conductive input stage comprises a first transistor M1A second transistor M2A third transistor M3A fourth transistor M4A first inductor L1A second inductor L2A third inductor L3A fourth inductor L4A first capacitor C1A second capacitor C2A first resistor R1A second resistor R2；
The first transistor M1Is connected with a first capacitor C1A first terminal of (C), a first capacitor C1Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF-First transistor M1Is connected with a first resistor R1A first terminal of (1), a first resistor R1Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF+First transistor M1Is connected with a third inductor L3First terminal of (1), third inductance L3Is connected to the third transistor M3A source electrode of (a);
the second transistor M2Is connected with a second capacitor C2A first terminal of a second capacitor C2Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF+Second transistor M2Is connected with a second resistor R2A first terminal of (1), a second resistor R2Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF-Second transistor M2Is connected with a fourth inductor L4First terminal of (1), fourth inductance L4A second terminal of the first transistor is connected with a source electrode of the fourth transistor;
the third transistor M3Is connected to a bias voltage VbA third transistor M3Is connected with a third inductor L3A second terminal of (1), a third transistor M3Is connected to the quadrature resonant stage (i.e. the fifth inductance L)5The first end of (a);
the fourth transistor M4Is connected to a bias voltage VbFourth transistor M4Is connected with a fourth inductor L4Second terminal of (1), fourth transistor M4Is connected to the quadrature resonant stage (i.e. the fifth inductance L)5Second end of (2)。
As a further preferable scheme, the quadrature resonance stage comprises an I-path quadrature resonance stage and a Q-path quadrature resonance stage, and the I-path quadrature resonance stage and the Q-path quadrature resonance stage are in alternating current coupling through a transformer; the I-path orthogonal resonant stage comprises a fifth inductor L5A third capacitor C3The Q-way quadrature resonant stage comprises a sixth inductor L6A fourth capacitor C4；
The fifth inductor L5Is connected to the transconductance input stage (i.e. the third transistor M)3Drain electrode of) the fifth inductor L5Is connected to the transconductance input stage (i.e. the fourth transistor M)4Drain electrode of) the fifth inductor L5The third end of the power supply is connected with a power supply voltage VDD(ii) a The fifth inductor L5And a third capacitor C3Parallel connection, a third capacitor C3Connecting the corresponding switching mixer stage (i.e. third capacitor C)3Is connected to the fifth transistor M5Source, sixth transistor M6Common to the sources);
sixth inductance L6Is connected with a fourth capacitor C4The first terminal of (1), the sixth inductance L6Is connected with a fourth capacitor C4Second terminal of (1), sixth inductance L6The third end of the power supply is connected with a power supply voltage VDD(ii) a Fourth capacitor C4Connecting the corresponding switching mixer stage (i.e. the fourth capacitor C)4Is connected to the ninth transistor M9Source, tenth transistor M10Common to the sources);
combined with a fifth inductor L5A sixth inductor L6Transformer coupling is achieved.
As a further preferable scheme, the coupling coefficient of the primary coil and the secondary coil of the transformer is k, and the value range of k is 0.2-0.3.
Preferably, the coupling coefficient between the primary coil and the secondary coil of the transformer is 0.23, and the self-inductance L of the primary coil and the secondary coil is L5＝L6＝210pH。
As a further preferred solution, the switching mixing stage comprises an I-switch mixer and a Q-switch mixerThe I-way switching mixer comprises a fifth transistor M5A sixth transistor M6The seventh transistor M7And an eighth transistor M8The Q-way switching mixer comprises a ninth transistor M9The tenth transistor M10Eleventh transistor M11The twelfth transistor M12；
The fifth transistor M5And the sixth transistor M6Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the third capacitor C3A first end of (a); seventh transistor M7And the eighth transistor M8Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the third capacitor C3A second end of (a); ninth transistor M9Source of and tenth transistor M10Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the fourth capacitor C4A first end of (a); eleventh transistor M11Source of and the twelfth transistor M12Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the fourth capacitor C4A second end of (a);
fifth transistor M5Grid connected local oscillator voltage signal VLO+Fifth transistor M5Is connected with a third resistor R3A first end of (a); sixth transistor M6Grid connected local oscillator voltage signal VLO-The sixth transistor M6Is connected with a fourth resistor R4A first end of (a); seventh transistor M7Grid connected local oscillator voltage signal VLO-(ii) a Seventh transistor M7Is connected with a third resistor R3A first end of (a); eighth transistor M8Grid connected local oscillator voltage signal VLO+The eighth transistor M8Is connected with a fourth resistor R4A first end of (a); ninth transistor M9Grid connected local oscillator voltage signal VLO+The ninth transistor M9Is connected with a fifth resistor R5A first end of (a); the tenth transistor M10Grid connected local oscillator voltage signal VLO-The tenth transistor M10Is connected with a sixth resistor R6A first end of (a); eleventh transistor M11Grid connected local oscillator voltage signalNumber VLO-An eleventh transistor M11Is connected with a fifth resistor R5A first end of (a); twelfth transistor M12Grid connected local oscillator voltage signal VLO+The twelfth transistor M12Is connected with a sixth resistor R6The first end of (a).
As a further preferable mode, the fifth transistor M5A sixth transistor M6The seventh transistor M7An eighth transistor M8The ninth transistor M9The tenth transistor M10Eleventh transistor M11The twelfth transistor M12Are designed by adopting 180nm CMOS process.
As a further preferred solution, the output load stage comprises an I-way output load stage and a Q-way output load stage, and the I-way output load stage comprises a third resistor R3A fourth resistor R4The Q-path output load stage comprises a fifth resistor R5A sixth resistor R6；
The third resistor R3Is connected with the intermediate frequency voltage signal VIF1+The second end is grounded; a fourth resistor R4Is connected with the intermediate frequency voltage signal VIF1-The second end is grounded; fifth resistor R5Is connected with the intermediate frequency voltage signal VIF2+The second end is grounded; a sixth resistor R6Is connected with the intermediate frequency voltage signal VIF2-And the second terminal is grounded.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. according to the invention, through designing the orthogonal resonance stage, the I path output signal and the Q path output signal of the frequency mixer are equal in size, the phase difference is 90 degrees, and good orthogonality is realized;
2. the two mixer branches of the I path and the Q path share one group of radio frequency input ports, so that the orthogonal frequency mixing is realized and the low power consumption is simultaneously utilized.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
fig. 1 is a schematic diagram of a millimeter wave phased array receiver based on radio frequency signal phase shift.
Fig. 2 is a circuit diagram of a millimeter wave CMOS quadrature mixer of the present invention.
Fig. 3 is a phase balance characteristic diagram of a millimeter wave CMOS quadrature mixer circuit of the present invention.
Fig. 4 is a conversion gain balance characteristic diagram of a millimeter wave CMOS quadrature mixer circuit of the present invention.
Fig. 5 is a noise figure diagram of a millimeter wave CMOS quadrature mixer circuit of the present invention.
Fig. 6 is a linearity diagram of a millimeter wave CMOS quadrature mixer circuit of the present invention.
FIG. 7 is a graph of the input reflection coefficient of a millimeter wave CMOS quadrature mixer circuit of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that: it is not necessary to employ these specific details to practice the present invention. In other instances, well-known structures, circuits, materials, or methods have not been described in detail so as not to obscure the present invention.
Throughout the specification, reference to "one embodiment," "an embodiment," "one example," or "an example" means: the particular features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the invention. Thus, the appearances of the phrases "one embodiment," "an embodiment," "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art will appreciate that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In the description of the present invention, it is to be understood that the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and therefore, are not to be construed as limiting the scope of the present invention.
Example 1
As shown in fig. 1 to 7, a millimeter wave CMOS quadrature mixer circuit of the present invention includes: the input circuit comprises a transconductance input stage, a quadrature resonant stage, a switch mixing stage and an output load stage, wherein the switch mixing stage comprises an I-path mixer and a Q-path mixer;
the transconductance input stage receives a radio frequency voltage signal and performs amplification processing to convert the radio frequency voltage signal into a current signal;
the orthogonal resonance stage transmits the converted current signal to an I path and transmits the converted current signal to a Q path through transformer coupling;
the switch mixing stage is controlled by a local oscillator signal, periodically commutates the current signal, converts the frequency from radio frequency to intermediate frequency, and finishes frequency down-conversion; and the commutating intermediate frequency current signal is converted into an intermediate frequency voltage at the output load stage;
the orthogonal resonance stage converts the current signal into two paths of signals with equal size and 90-degree phase difference, and the two paths of signals are respectively sent to the I path and the Q path, so that the orthogonality of the frequency mixer is realized.
The invention designs a millimeter wave CMOS quadrature mixer circuit, which comprises: the circuit comprises a transconductance input stage, a quadrature resonant stage, a switching mixing stage and an output load stage, wherein the quadrature resonant stage, the switching mixing stage and the output load stage of the circuit are of the same structure; according to the invention, through designing the orthogonal resonance stage, the I path output signal and the Q path output signal of the frequency mixer are equal in size, the phase difference is 90 degrees, and good orthogonality is realized; in addition, two mixer branches of the I path and the Q path share one group of radio frequency input ports, so that the realization of low power consumption is realized while the orthogonal frequency mixing is realized.
In this embodiment, the transconductance input stage includes a first transistor M1A second transistor M2A third transistor M3A fourth transistor M4A first inductor L1A second inductor L2A third inductor L3A fourth inductor L4A first capacitor C1A second capacitor C2A first resistor R1A second resistor R2；
The first transistor M1Is connected with a first capacitor C1A first terminal of (C), a first capacitor C1Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF-First transistor M1Is connected with a first resistor R1A first terminal of (1), a first resistor R1Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF+First transistor M1Is connected with a third inductor L3First terminal of (1), third inductance L3Is connected to the third transistor M3A source electrode of (a);
the second transistor M2Is connected with a second capacitor C2A first terminal of a second capacitor C2Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF+Second transistor M2Is connected with a second resistor R2A first terminal of (1), a second resistor R2Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF-Second transistor M2Is connected with a fourth inductor L4First terminal of (1), fourth inductance L4A second terminal of the first transistor is connected with a source electrode of the fourth transistor;
the third transistor M3Grid electrode ofIs connected with a bias voltage VbA third transistor M3Is connected with a third inductor L3A second terminal of (1), a third transistor M3Is connected to the fifth inductor L5A first end of (a);
the fourth transistor M4Is connected to a bias voltage VbFourth transistor M4Is connected with a fourth inductor L4Second terminal of (1), fourth transistor M4Is connected to the fifth inductor L5The second end of (a).
In this embodiment, the quadrature resonance stage includes an I-path quadrature resonance stage and a Q-path quadrature resonance stage, and the I-path quadrature resonance stage and the Q-path quadrature resonance stage are ac-coupled by a transformer; the I-path orthogonal resonant stage comprises a fifth inductor L5A third capacitor C3The Q-way quadrature resonant stage comprises a sixth inductor L6A fourth capacitor C4；
The fifth inductor L5Is connected to the third transistor M3Drain electrode of (1), fifth inductance L5Is connected to the fourth transistor M4Drain electrode of (1), fifth inductance L5The third end of the power supply is connected with a power supply voltage VDD(ii) a The fifth inductor L5And a third capacitor C3Parallel connection, a third capacitor C3Connecting a third capacitor C3Is connected to the fifth transistor M5Source, sixth transistor M6A common terminal of the source;
sixth inductance L6Is connected with a fourth capacitor C4The first terminal of (1), the sixth inductance L6Is connected with a fourth capacitor C4Second terminal of (1), sixth inductance L6The third end of the power supply is connected with a power supply voltage VDD(ii) a Fourth capacitor C4Is connected with a fourth capacitor C4Is connected to the ninth transistor M9Source, tenth transistor M10A common terminal of the source;
combined with a fifth inductor L5A sixth inductor L6Transformer coupling is achieved.
In the embodiment, the coupling coefficient of the primary coil and the secondary coil of the transformer is k, and the value range of k is 0.2-0.3.
In this embodiment, the coupling coefficient between the primary and secondary coils of the transformer is 0.23, and the primary and secondary coils have self-inductance L5＝L6＝210pH。
In this embodiment, the switching mixer stage includes an I-way switching mixer and a Q-way switching mixer, and the I-way switching mixer includes a fifth transistor M5A sixth transistor M6The seventh transistor M7And an eighth transistor M8The Q-way switching mixer comprises a ninth transistor M9The tenth transistor M10Eleventh transistor M11The twelfth transistor M12；
The fifth transistor M5And the sixth transistor M6Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the third capacitor C3A first end of (a); seventh transistor M7And the eighth transistor M8Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the third capacitor C3A second end of (a); ninth transistor M9Source of and tenth transistor M10Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the fourth capacitor C4A first end of (a); eleventh transistor M11Source of and the twelfth transistor M12Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the fourth capacitor C4A second end of (a);
fifth transistor M5Grid connected local oscillator voltage signal VLO+Fifth transistor M5Is connected with a third resistor R3A first end of (a); sixth transistor M6Grid connected local oscillator voltage signal VLO-The sixth transistor M6Is connected with a fourth resistor R4A first end of (a); seventh transistor M7Grid connected local oscillator voltage signal VLO-(ii) a Seventh transistor M7Is connected with a third resistor R3A first end of (a); eighth transistor M8Grid connected local oscillator voltage signal VLO+The eighth transistor M8Is connected with a fourth resistor R4A first end of (a); ninth transistor M9Grid connected local oscillator voltage signalVLO+The ninth transistor M9Is connected with a fifth resistor R5A first end of (a); the tenth transistor M10Grid connected local oscillator voltage signal VLO-The tenth transistor M10Is connected with a sixth resistor R6A first end of (a); eleventh transistor M11Grid connected local oscillator voltage signal VLO-An eleventh transistor M11Is connected with a fifth resistor R5A first end of (a); twelfth transistor M12Grid connected local oscillator voltage signal VLO+The twelfth transistor M12Is connected with a sixth resistor R6The first end of (a).
In this embodiment, the fifth transistor M5A sixth transistor M6The seventh transistor M7An eighth transistor M8The ninth transistor M9The tenth transistor M10Eleventh transistor M11The twelfth transistor M12Are designed by adopting 180nm CMOS process.
In this embodiment, the output load stage includes an I-path output load stage and a Q-path output load stage, and the I-path output load stage includes a third resistor R3A fourth resistor R4The Q-path output load stage comprises a fifth resistor R5A sixth resistor R6；
The third resistor R3Is connected with the intermediate frequency voltage signal VIF1+The second end is grounded; a fourth resistor R4Is connected with the intermediate frequency voltage signal VIF1-The second end is grounded; fifth resistor R5Is connected with the intermediate frequency voltage signal VIF2+The second end is grounded; a sixth resistor R6Is connected with the intermediate frequency voltage signal VIF2-And the second terminal is grounded.
When in implementation: the orthogonal resonance stage of the millimeter wave mixer utilizes a fifth inductor L5A sixth inductor L6The coupling structure of the transformer is realized, when the direction is proper, the coupling between the two inductance coils mutually enhances effective inductance, and the parasitic resistance of the inductance coils is not influenced by the coupling, which is equivalent to increase the effective quality of the inductanceThe value of the factor Q. The transformer is also essentially a higher order LC network with more degrees of freedom, more pole positions and therefore greater bandwidth. Specifically, the coupling coefficient between the primary and secondary windings of the transformer of this embodiment is 0.23, and the primary and secondary windings have self-inductance L5＝L6pH 210. The layout is as shown in fig. 2, and is realized by adopting thick metal close to the top layer, so that low ohmic loss obtains a higher Q value.
The orthogonal resonance level of the millimeter wave mixer enables the I path output signal and the Q path output signal of the mixer to be equal in size, the phase difference is 90 degrees, and good orthogonality is achieved. And the two mixer branches of the I path and the Q path share one group of radio frequency input ports, so that the power consumption is reduced while the orthogonal frequency mixing is realized.
The transconductance input stage of the millimeter wave mixer adopts a common gate + cascode structure, and the common gate transistor is a first transistor M1A second transistor M2Providing input impedance matching. In particular, the noise of the whole circuit is determined by the transconductance stage and can be expressed as:
gm1is a transistor M1Transconductance of (1). The parameter gamma represents the thermal noise figure. The input impedance of the circuit can be represented as:
note that in conventional common-gate structures, g needs to be satisfied even after capacitive cross-coupling is used, because of the impedance matching constraintsm1The noise figure can then be characterized as 1+ γ, given the requirement of 10 mS. After the device channel is shortened, the gamma value is large (its typical value is 2.5), so that the noise contribution of the common-gate tube becomes significant. Here the scheme introduces a resistor R1 (approximately 30 ohms) to increase the freedom of noise design, then at gm1The result of the latter two terms in equation (1) can be calculated to be 2.05, for equation (2) satisfied at 14.3mSCompared with the traditional structure, the noise reduction rate is reduced by nearly 0.5, and the noise advantage is obvious. The method has a remarkable effect especially under the condition of high gamma value of a device under the condition of a short channel. On the other hand, the cascode transistor is a third transistor M3A fourth transistor M4The output impedance and the input-output isolation can be improved, the interaction between the tuning output and the tuning input can be reduced, and the grid-drain parasitic capacitance C of the common-grid transistor can be reducedgdThe influence of (c). First inductance L1A second inductor L2Input parasitic capacitance for resonant absorption common-gate transistor, third inductance L3A fourth inductor L4And the output parasitic capacitance of the common-gate transistor and the input parasitic capacitance of the cascode transistor are used for resonance absorption, so that a pi-type resonance network is formed to obtain broadband interstage matching. Third inductance L3A fourth inductor L4Not only can the gain of the transconductance input stage at the central frequency be improved and the noise of the common-gate transistor be suppressed, but also the middle pole of the cascode stage can be adjusted and the lower f of the middle pole can be compensatedT.
The invention adopts 180nm CMOS process to design, uses Cadence spectrum software to simulate, uses Momentum of ADS to model and simulate the inductor, obtains EM model, introduces the inductor model into Cadence, and carries out post-layout simulation. The circuit works under the power supply voltage of 1.5V, and the power consumption of the circuit is 23.7 mW. The phase of the millimeter wave CMOS quadrature mixer circuit is shown in fig. 3, and it can be seen that, in the intermediate frequency range of 100MHz around the local oscillation frequency of 25GHz, the phase of the I path is 140 degrees, the phase of the Q path is 50 degrees, and the phase difference is approximately 90 degrees. The gain of the millimeter wave CMOS quadrature mixer circuit is shown in FIG. 4, and the gains of the I path and the Q path of the quadrature mixer circuit are observed in the 100MHz intermediate frequency near the local oscillation frequency of 25GHz, and the gains of the two paths are approximately equal and are 7.45 dB. Similarly, having simulated the noise performance of the millimeter wave quadrature mixer, FIG. 5 shows the variation of the noise figure of the proposed millimeter wave CMOS quadrature mixer circuit with respect to the intermediate frequency when the local oscillator frequency is fixed around 25GHz, the noise figure of the mixer is not higher than 9.51dB in the frequency range of 0-300 MHz. As shown in fig. 6, which is a simulation of the linearity of the millimeter wave CMOS quadrature mixer circuit, the two-tone test indicated that the IIP3 was 0.33 dBm. Fig. 7 shows an input reflection coefficient diagram of the millimeter wave CMOS quadrature mixer circuit, and it can be seen that the frequency range where the reflection coefficient of the rf port is lower than-10 dB is approximately 5Ghz, and a larger matching bandwidth is obtained.
Therefore, the circuit structure of the invention is reasonable, the low power consumption, the high conversion gain and the low noise coefficient are kept under the high frequency, the I path and the Q path of the frequency mixer are equal in output size through designing the orthogonal resonant stage, the phase difference is 90 degrees, and the good orthogonality is obtained.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (8)
1. A millimeter-wave CMOS quadrature mixer circuit, comprising: the input circuit comprises a transconductance input stage, a quadrature resonant stage, a switch mixing stage and an output load stage, wherein the switch mixing stage comprises an I-path mixer and a Q-path mixer;
the transconductance input stage receives a radio frequency voltage signal and performs amplification processing to convert the radio frequency voltage signal into a current signal;
the orthogonal resonance stage transmits the converted current signal to an I path and transmits the converted current signal to a Q path through transformer coupling;
the switch mixing stage is controlled by a local oscillator signal, periodically commutates the current signal, converts the frequency from radio frequency to intermediate frequency, and finishes frequency down-conversion; and the commutating intermediate frequency current signal is converted into an intermediate frequency voltage at the output load stage;
the orthogonal resonance stage converts the current signal into two paths of signals with equal size and 90-degree phase difference, and the two paths of signals are respectively sent to the I path and the Q path, so that the orthogonality of the frequency mixer is realized.
2. The millimeter-wave CMOS quadrature mixer circuit of claim 1, wherein the transconductance input stage comprises a first transistor M1A second transistor M2A third transistor M3A fourth transistor M4A first inductor L1A second inductor L2A third inductor L3A fourth inductor L4A first capacitor C1A second capacitor C2A first resistor R1A second resistor R2；
The first transistor M1Is connected with a first capacitor C1A first terminal of (C), a first capacitor C1Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF-First transistor M1Is connected with a first resistor R1A first terminal of (1), a first resistor R1Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF+First transistor M1Is connected with a third inductor L3First terminal of (1), third inductance L3Is connected to the third transistor M3A source electrode of (a);
the second transistor M2Is connected with a second capacitor C2A first terminal of a second capacitor C2Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF+Second transistor M2Is connected with a second resistor R2A first terminal of (1), a second resistor R2Second terminal of the second terminal is connected with a radio frequency input voltage signal VRF-Second transistor M2Is connected with a fourth inductor L4First terminal of (1), fourth inductance L4A second terminal of the first transistor is connected with a source electrode of the fourth transistor;
the third transistor M3Is connected to a bias voltage VbA third transistor M3Is connected with a third inductor L3A second terminal of (1), a third transistor M3Is connected to the quadrature resonant stage;
the fourth transistor M4Is connected to a bias voltage VbFourth transistor M4Is connected with a fourth inductor L4Second of (2)Terminal, fourth transistor M4Is connected to the quadrature resonant stage.
3. The millimeter wave CMOS quadrature mixer circuit of claim 1, wherein said quadrature resonator stages comprise an I-path quadrature resonator stage and a Q-path quadrature resonator stage, and said I-path quadrature resonator stage and said Q-path quadrature resonator stage are AC-coupled via a transformer; the I-path orthogonal resonant stage comprises a fifth inductor L5A third capacitor C3The Q-way quadrature resonant stage comprises a sixth inductor L6A fourth capacitor C4；
The fifth inductor L5Is connected to the transconductance input stage and a fifth inductor L5Is connected to the transconductance input stage, a fifth inductor L5The third end of the power supply is connected with a power supply voltage VDD(ii) a The fifth inductor L5And a third capacitor C3Parallel connection, a third capacitor C3Connecting the corresponding switching mixing stages;
sixth inductance L6Is connected with a fourth capacitor C4The first terminal of (1), the sixth inductance L6Is connected with a fourth capacitor C4Second terminal of (1), sixth inductance L6The third end of the power supply is connected with a power supply voltage VDD(ii) a Fourth capacitor C4Connecting the corresponding switching mixing stages;
combined with a fifth inductor L5A sixth inductor L6Transformer coupling is achieved.
4. The millimeter wave CMOS quadrature mixer circuit of claim 3, wherein the coupling coefficient of the primary and secondary coils of the transformer is k, and the value range of k is 0.2-0.3.
5. The millimeter wave CMOS quadrature mixer circuit of claim 4, wherein the coupling coefficient between the primary and secondary windings of the transformer is 0.23, and the primary and secondary windings have a self-inductance L5＝L6＝210pH。
6. According to the rightThe millimeter-wave CMOS quadrature mixer circuit of claim 3, wherein the switching mixing stage comprises an I-way switching mixer and a Q-way switching mixer, the I-way switching mixer comprising a fifth transistor M5A sixth transistor M6The seventh transistor M7And an eighth transistor M8The Q-way switching mixer comprises a ninth transistor M9The tenth transistor M10Eleventh transistor M11The twelfth transistor M12；
The fifth transistor M5And the sixth transistor M6Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the third capacitor C3A first end of (a); seventh transistor M7And the eighth transistor M8Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the third capacitor C3A second end of (a); ninth transistor M9Source of and tenth transistor M10Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the fourth capacitor C4A first end of (a); eleventh transistor M11Source of and the twelfth transistor M12Is connected with the source electrode of the first capacitor and the common end of the first capacitor is connected with the fourth capacitor C4A second end of (a);
fifth transistor M5Grid connected local oscillator voltage signal VLO+Fifth transistor M5Is connected with a third resistor R3A first end of (a); sixth transistor M6Grid connected local oscillator voltage signal VLO-The sixth transistor M6Is connected with a fourth resistor R4A first end of (a); seventh transistor M7Grid connected local oscillator voltage signal VLO-(ii) a Seventh transistor M7Is connected with a third resistor R3A first end of (a); eighth transistor M8Grid connected local oscillator voltage signal VLO+The eighth transistor M8Is connected with a fourth resistor R4A first end of (a); ninth transistor M9Grid connected local oscillator voltage signal VLO+The ninth transistor M9Is connected with a fifth resistor R5A first end of (a); the tenth transistor M10Grid connected local oscillator voltage signal VLO-Tenth, tenthTransistor M10Is connected with a sixth resistor R6A first end of (a); eleventh transistor M11Grid connected local oscillator voltage signal VLO-An eleventh transistor M11Is connected with a fifth resistor R5A first end of (a); twelfth transistor M12Grid connected local oscillator voltage signal VLO+The twelfth transistor M12Is connected with a sixth resistor R6The first end of (a).
7. The millimeter-wave CMOS quadrature mixer circuit of claim 6, wherein the fifth transistor M5A sixth transistor M6The seventh transistor M7An eighth transistor M8The ninth transistor M9The tenth transistor M10Eleventh transistor M11The twelfth transistor M12Are designed by adopting 180nm CMOS process.
8. The millimeter-wave CMOS quadrature mixer circuit of claim 1, wherein said output load stage comprises an I-way output load stage and a Q-way output load stage, said I-way output load stage comprising a third resistor R3A fourth resistor R4The Q-path output load stage comprises a fifth resistor R5A sixth resistor R6；
The third resistor R3Is connected with the intermediate frequency voltage signal VIF1+The second end is grounded; a fourth resistor R4Is connected with the intermediate frequency voltage signal VIF1-The second end is grounded; fifth resistor R5Is connected with the intermediate frequency voltage signal VIF2+The second end is grounded; a sixth resistor R6Is connected with the intermediate frequency voltage signal VIF2-And the second terminal is grounded.
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