CN112436810A

CN112436810A - Low noise amplifier, receiver and electronic equipment based on inverter

Info

Publication number: CN112436810A
Application number: CN202011436131.6A
Authority: CN
Inventors: 肖庭峰; 李科举
Original assignee: Fuman Microelectronics Group Co ltd
Current assignee: Fuman Microelectronics Group Co ltd
Priority date: 2020-12-10
Filing date: 2020-12-10
Publication date: 2021-03-02

Abstract

The invention provides a low noise amplifier, a receiver and an electronic device based on an inverter, wherein the low noise amplifier comprises: a first inverter, a second inverter and a third inverter; the input end of the first phase inverter is directly or indirectly connected with a signal receiving end, the output end of the first phase inverter is connected with the input end of the second phase inverter, the output end of the second phase inverter is connected with the input end of the third phase inverter, the output end of the second phase inverter and the output end of the third phase inverter are connected with a frequency mixer so as to output differential signals to the frequency mixer, and the first phase inverter, the second phase inverter and the third phase inverter are CMOS phase inverters.

Description

Low noise amplifier, receiver and electronic equipment based on inverter

Technical Field

The present invention relates to the field of signal processing, and in particular, to a low noise amplifier, a receiver, and an electronic device based on an inverter.

Background

To support the exponential increase of data rates in cellular systems operating in the band below 6GHz, techniques utilizing parallel receivers, such as carrier aggregation and Multiple-Input Multiple-Output (MIMO), have been introduced in electronic devices, such as mobile terminals. To save pin count and circuit board space, electronic devices, such as mobile terminals, typically employ single-ended input receivers. However, in order to enhance the rejection of common mode noise and interference, the radio frequency signal (i.e., RF signal) needs to be converted into a differential signal in the signal chain of the receiver as early as possible.

In the related art, an on-chip transformer (serving as a balun) is disposed in a mixer (or other circuit location) to which a back end of a Low-Noise Amplifier (LNA) is connected, so as to achieve excellent linearity and differential symmetry. It can be seen that, for the low noise amplifier, the input and output signals are not differential signals, which is not favorable for converting the signals into differential signals as soon as possible. At the same time, the means of placing an on-chip transformer (acting as a balun) to convert the signal to a differential signal also introduces bandwidth limitations.

In the related art, a CG-CS (common gate common source) topology is generally adopted in a low noise amplifier, and in order to realize low noise, a current signal at a CS (common source) output is much larger than a current at a CG (common gate) output, which may further cause signal imbalance and high even distortion.

Therefore, the low noise amplifier in the prior art cannot be converted to form a differential signal, the conversion mode of the transformer is biased to bring the limitation of bandwidth, and the low noise amplifier with the cascode structure is prone to generating the defects of signal imbalance, distortion and the like.

Disclosure of Invention

The invention provides a low noise amplifier, a receiver and electronic equipment based on an inverter, which are used for solving the problems that the low noise amplifier cannot be converted to form a differential signal, signal imbalance and distortion are easy to generate, and bandwidth limitation is caused by the use of an on-chip transformer.

According to a first aspect of the present invention, there is provided an inverter-based low noise amplifier comprising: the input end of the first phase inverter is directly or indirectly connected with a signal receiving end, the output end of the first phase inverter is connected with the input end of the second phase inverter, the output end of the second phase inverter is connected with the input end of the third phase inverter, the output end of the second phase inverter and the output end of the third phase inverter are connected with a frequency mixer so as to output differential signals to the frequency mixer, and the first phase inverter, the second phase inverter and the third phase inverter are CMOS phase inverters.

Optionally, the inverter-based low-noise amplifier further includes a differential-to-single-ended feedback module, an input side of the differential-to-single-ended feedback module is respectively connected to an output end of the second inverter and an output end of the third inverter, and an output end of the differential-to-single-ended feedback module is directly or indirectly connected to an input end of the first inverter;

the differential to single-ended feedback module is configured to: and converting the differential signal into a single-ended signal, and feeding the single-ended signal back to a position between the input end of the first inverter and the signal receiving end.

Optionally, the differential-to-single-ended feedback module includes: the first feedback NMOS tube and the second feedback NMOS tube;

the drain electrode of the first feedback NMOS tube is connected with a corresponding power end, the source electrode of the first feedback NMOS tube and the drain electrode of the second feedback NMOS tube are directly or indirectly connected with the input end of the first phase inverter, the source electrode of the second feedback NMOS tube is grounded, the grid electrode of the first feedback NMOS tube is connected with the output end of the third phase inverter through a first feedback capacitor, and the grid electrode of the second feedback NMOS tube is connected with the output end of the second phase inverter through a second feedback capacitor.

Optionally, an output end of the differential-to-single-ended feedback module is connected between the first inverter and the signal receiving end through a feedback resistor.

Optionally, the inverter-based low noise amplifier further includes a first auxiliary inverter and a second auxiliary inverter; the first auxiliary inverter and the second auxiliary inverter are both CMOS inverters;

the input end of the first auxiliary phase inverter is connected with the input end of the second phase inverter, the output end of the first auxiliary phase inverter is connected with the output end of the second phase inverter, the input end of the second auxiliary phase inverter is connected with the input end of the third phase inverter, and the output end of the second auxiliary phase inverter is connected with the output end of the third phase inverter;

the first auxiliary phase inverter and the second auxiliary phase inverter work in a weak inversion region, and the second phase inverter and the third phase inverter work in a strong inversion region.

Optionally, the first auxiliary inverter includes: two first auxiliary capacitors, a first auxiliary PMOS tube and a first auxiliary NMOS tube;

the first ends of the two first auxiliary capacitors are directly or indirectly connected with the input end of the second phase inverter, the second end of one first auxiliary capacitor is connected with the grid electrode of the first auxiliary PMOS tube, the second end of the other first auxiliary capacitor is connected with the grid electrode of the first auxiliary NMOS tube, the source electrode of the first auxiliary PMOS tube is connected with a corresponding power supply, the drain electrode of the first auxiliary PMOS tube and the drain electrode of the first auxiliary NMOS tube are both connected with the output end of the second phase inverter, and the source electrode of the first auxiliary NMOS tube is directly or indirectly grounded;

the second auxiliary inverter includes: two second auxiliary capacitors, a second auxiliary PMOS tube and a second auxiliary NMOS tube;

the first ends of the two second auxiliary capacitors are directly or indirectly connected with the input end of the third phase inverter, the second end of one second auxiliary capacitor is connected with the grid electrode of the second auxiliary PMOS tube, the second end of the other second auxiliary capacitor is connected with the grid electrode of the second auxiliary NMOS tube, the source electrode of the second auxiliary PMOS tube is connected with a corresponding power supply, the drain electrode of the second auxiliary PMOS tube and the drain electrode of the second auxiliary NMOS tube are both connected with the output end of the third phase inverter, and the source electrode of the first auxiliary NMOS tube is directly or indirectly grounded.

Optionally, the first inverter includes two first capacitors, a first PMOS transistor and a first NMOS transistor;

the first ends of the two first capacitors are directly or indirectly connected with the signal receiving end, the second end of one first capacitor is connected with the grid electrode of the first PMOS tube, the second end of the other first capacitor is connected with the grid electrode of the first NMOS tube, the source electrode of the first PMOS tube is connected with a first power supply, the drain electrode of the first PMOS tube and the drain electrode of the first NMOS tube are both connected with the input end of the second phase inverter, and the source electrode of the first NMOS tube is directly or indirectly grounded; and a first bias resistor is connected between the grid electrode and the drain electrode of the first PMOS tube.

Optionally, the second inverter includes two second capacitors, a second PMOS transistor and a second NMOS transistor;

the first ends of the two second capacitors are directly or indirectly connected with the output end of the first phase inverter, the second end of one second capacitor is connected with the grid electrode of the second PMOS tube, the second end of the other second capacitor is connected with the grid electrode of the second NMOS tube, the source electrode of the second PMOS tube is connected with a second power supply, the drain electrode of the second PMOS tube and the drain electrode of the second NMOS tube are both connected with the input end of the third phase inverter, and the source electrode of the second NMOS tube is directly or indirectly grounded; and a second bias resistor is connected between the grid electrode and the drain electrode of the second PMOS tube.

Optionally, the third inverter includes two third capacitors, a third PMOS transistor and a third NMOS transistor;

the first ends of the two third capacitors are directly or indirectly connected with the output end of the second phase inverter, the second end of one third capacitor is connected with the grid electrode of the third PMOS tube, the second end of the other third capacitor is connected with the grid electrode of the third NMOS tube, the source electrode of the third PMOS tube is connected with a third power supply, the drain electrode of the third PMOS tube and the drain electrode of the third NMOS tube are both connected to the input side of the frequency mixer, and the source electrode of the third NMOS tube is directly or indirectly grounded; and a third bias resistor is connected between the grid electrode and the drain electrode of the third PMOS tube.

According to a second aspect of the present invention there is provided a receiver comprising an inverter-based low noise amplifier of the first aspect and its alternatives.

Optionally, the receiver further includes a mixer connected to the output end of the second inverter and the output end of the third inverter.

According to a third aspect of the present invention there is provided an electronic device comprising an inverter-based low noise amplifier according to the first aspect and its alternatives.

In the low-noise amplifier, the receiver and the electronic equipment based on the phase inverters, provided by the invention, the three CMOS phase inverters are utilized to form a signal after two times of phase inversion and a signal after three times of phase inversion, and further, the output signals of the second phase inverter and the third phase inverter can form a differential signal in time, so that a radio-frequency signal is converted into the differential signal as early as possible in a signal receiving line, and the inhibition capability on common-mode noise and interference is enhanced.

Meanwhile, compared with a means of placing an on-chip transformer (used as a balun) to convert a signal into a differential signal, the means of utilizing the inverter to realize the differential signal in the signal amplifier can avoid using the on-chip transformer, thereby avoiding bandwidth limitation caused by the on-chip transformer and ensuring better bandwidth level.

In addition, based on the signal amplification effect of the CMOS inverter, the signal amplification is realized by the inverter, the signal amplification is avoided by adopting a CG-CS (common gate-common source) topological structure, further, the signal imbalance and high even distortion caused by the signal amplification are avoided, and therefore compared with the CG-CS (common gate-common source) topological structure in the prior art, the low-noise amplifier provided by the invention has better signal balance and lower distortion.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a first schematic diagram of a low noise amplifier according to an embodiment of the present invention;

FIG. 2 is a circuit diagram of a low noise amplifier that is not capable of outputting differential signals;

FIG. 3 is a second schematic diagram of the low noise amplifier according to an embodiment of the present invention;

FIG. 4 is a third schematic diagram of the low noise amplifier according to an embodiment of the present invention;

FIG. 5 is a fourth schematic diagram of the low noise amplifier according to an embodiment of the present invention;

FIG. 6 is a fifth schematic diagram of the low noise amplifier according to an embodiment of the present invention;

FIG. 7 is a sixth schematic diagram of the low noise amplifier according to an embodiment of the present invention;

FIG. 8 is a circuit diagram of a low noise amplifier according to an embodiment of the invention.

Description of reference numerals:

1-a first inverter;

2-a second inverter;

3-a third inverter;

4-differential to single-ended feedback module;

5-a first auxiliary inverter;

6-a second auxiliary inverter;

ma, Mb, Mc, Md-transistors;

m11-first PMOS tube; m12-first NMOS transistor; m21-second PMOS tube; m22-second NMOS tube; m31-third PMOS tube; m32-third PMOS tube; m41-first feedback NMOS transistor; m42-second feedback NMOS tube; m51-first auxiliary PMOS tube; m52-first auxiliary NMOS transistor; m61-second auxiliary PMOS tube; m62-second auxiliary NMOS tube;

c11, C12 — first capacitance; c21, C22-second capacitance; c31, C32-third capacitance; c41 — first feedback capacitance; c42 — second feedback capacitance; c51, C52 — first auxiliary capacitance; c61, C62-second auxiliary capacitance; cin — input capacitance; c20, C30, CF, CA-capacitance;

rb1 — first bias resistance; rb2 — second bias resistor; rb3 — third bias resistance; r11, R21, R22, R31, R32, R41, R42, R51, R52, R61, R62, RF-resistor; rf 0-feedback resistance;

l0 — input inductance.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein.

The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

The low noise amplifier according to the embodiment of the present invention may be applied to any circuit or device that performs low noise power amplification on a received signal, and the low noise amplifier may be a separate chip or a part of a chip.

Referring to fig. 1, an inverter-based low noise amplifier includes: the input end of the first inverter 1 is directly or indirectly connected with a signal receiving end (which can be understood as an Rfin + end), the output end of the first inverter 1 is connected with the input end of the second inverter 2, the output end of the second inverter 2 is connected with the input end of the third inverter 3, and the output ends of the second inverter 2 and the third inverter 3 are connected with a mixer (not shown) so as to output differential signals to the mixer.

The Low Noise Amplifier may be characterized as an LNA, specifically a Low-Noise Amplifier, and a front end of the Low Noise Amplifier may be directly or indirectly connected to an antenna, so as to obtain a signal received by the antenna. The devices and modules arranged between the low noise amplifier and the antenna may be, for example, at least one of (but not limited to): an input capacitor Cin, an input inductor L0, a radio frequency switch, a single-pole double-throw switch, and other devices or circuit modules for any functions of filtering, amplifying, noise reduction, etc.

The first inverter, the second inverter and the third inverter are specifically CMOS inverters.

The CMOS specifically refers to: a CMOS inverter, a cornplemetary MOS, can be understood as a structure consisting of a pair of complementary p-channel MOSFETs (i.e., PMOS transistors) and n-channel MOSFETs (i.e., NMOS transistors). Through the CMOS phase inverter, the inversion of signals can be realized, and the amplification of the signals can also be realized. Any existing or modified CMOS inverter in the art can be applied to the embodiments of the present invention, and the connection relationship of the above three inverters is formed without departing from the scope of the embodiments of the present invention.

In contrast to the above scheme, a low noise amplifier that cannot output a differential signal will be briefly described as follows:

referring to fig. 2, a transistor Ma (PMOS transistor) and a transistor Mb (NMOS transistor) may form a CMOS structure, wherein gates of the two transistors may be respectively connected to a signal receiving end (i.e., RFin end) through a capacitor, the RFin end is further connected to a first end of a capacitor Ca through an input resistor RF and an input capacitor CF, and a drain of the transistor Ma (PMOS transistor) and a source of the transistor Mb (NMOS transistor) are also connected to the first end of the capacitor Ca; the transistor Mc (NMOS transistor) and the transistor Md (NMOS transistor) may form a CS-FET (common source field effect transistor) structure, and further, the drain of the transistor Mc is used to output the amplified signal.

In which a complementary DS method with a CS configuration is employed. The transistor Mb (NMOS transistor) and the transistor Ma (PMOS transistor) operate as a main transistor and an auxiliary transistor, respectively, and are biased in strong inversion and weak inversion, respectively. Since the transconductance (gm) and the second order transconductance (gm2) have the same sign in Mb (NMOS transistor) and transistor Ma (PMOS transistor), the total transconductance increases, while the second order interaction (caused by second order distortion and feedback) decreases. Furthermore, since the third order transconductances (gm3) of the transistor Mb (NMOS transistor) and the transistor Ma (PMOS transistor) may have different signs due to different operating regions, the negative third order transconductances of the transistor Mb (NMOS transistor) are compensated by the positive third order transconductances of the transistor Mb (NMOS transistor). However, because the positive and negative characteristics of the third-order transconductance in each transistor (e.g., FET) are asymmetric, the remaining negative third-order transconductance in the output of the CMOS structure formed by the first stage will then be compensated by the CS-FET structure formed by the second stage, which is biased in weak inversion with the positive characteristics of the third-order transconductance, to expand the IMD3 (i.e., modulation Distortion 3, which may be understood as third-order Intermodulation Distortion) cancellation window. The resulting third order distortion of the low noise amplifier can be improved over a limited bias voltage range and, in addition, a size efficient switched transformer can be employed to achieve single-ended to differential conversion between the low noise amplifier (i.e., LNA) and the mixer (e.g., I/Q differential mixer).

To achieve low noise, the current signal at the CS (common source) output is much larger than the current at the CG (common gate) output, resulting in signal imbalance and high even distortion. Also CG (common gate) stage biasing requires either an on-chip current source, which reduces noise, or a large off-chip inductor.

Therefore, the embodiment of the invention adopts completely different circuit structures, and realizes signal amplification and single-end to differential conversion.

Furthermore, in the schemes shown in fig. 1 and fig. 3 to 8, three CMOS inverters are used to form a signal after two times of phase inversion and a signal after three times of phase inversion, and further, output signals of the second inverter and the third inverter can form a differential signal in time, so that a radio frequency signal is converted into the differential signal as early as possible in a signal receiving line, and the rejection capability of common mode noise and interference is enhanced.

In one embodiment, referring to fig. 3, the first inverter 1 includes two first capacitors (i.e., a first capacitor C11 and a first capacitor C12), a first PMOS transistor M11 and a first NMOS transistor M12.

The first ends of the two first capacitors (i.e., the first capacitor C11 and the first capacitor C12) are both directly or indirectly connected to the Rfin + end of the signal receiving terminal, the second end of one of the first capacitors C11 is connected to the gate of the first PMOS transistor M11, the second end of the other one of the first capacitors C12 is connected to the gate of the first NMOS transistor M12, the source of the first PMOS transistor M11 is connected to a first power supply, the drain of the first PMOS transistor M11 and the drain of the first NMOS transistor M12 are both connected to the input end of the second inverter 2, and the source of the first NMOS transistor M12 is directly or indirectly grounded.

In the scheme shown in the figure, a first bias resistor Rb1 is connected between the gate and the drain of the first PMOS transistor M11, and further, the first bias resistor Rb1 can be used for providing bias voltage, so that an external power supply is prevented from being biased, and power consumption caused by the external power supply is avoided. Similarly, the second bias resistor Rb2 in the second inverter 2 and the third bias resistor Rb3 in the third inverter 2 both function to effectively reduce power consumption.

In the scheme not shown in the figure, a means for providing a bias voltage by an external power source may also be adopted, for example, a voltage source may be connected, and then, for example, a current source may be connected, and at the same time, a corresponding resistor, an inductor, and a capacitor may be configured to match the current source and the voltage source, so as to provide a desired bias voltage.

Further, the gate of the first NMOS transistor M12 is also connected to the corresponding bias voltage vbi 1 through a resistor R11.

Similar to the first inverter 1, referring to fig. 3, the second inverter 2 includes two second capacitors (i.e., a second capacitor C21 and a second capacitor C22), a second PMOS transistor M21 and a second NMOS transistor M22.

First ends of the two second capacitors (i.e., the second capacitor C21 and the second capacitor C22) are both directly or indirectly connected to an output end of the first inverter 1, a second end of one second capacitor C21 is connected to a gate of the second PMOS transistor M21, a second end of the other second capacitor C22 is connected to a gate of the second NMOS transistor M22, a source of the second PMOS transistor M21 is connected to a second power supply, a drain of the second PMOS transistor M21 and a drain of the second NMOS transistor M22 are both connected to an input end of the third inverter 3, and a source of the second NMOS transistor M22 is directly or indirectly connected to ground; a second bias resistor Rb2 is connected between the grid and the drain of the second PMOS transistor M21.

Further, the drain of the second PMOS transistor M21 and the drain of the second NMOS transistor M22 are also connected to the first terminal of the capacitor C20, and the second terminal of the capacitor C20 is grounded via the resistor R22. The gate of the second NMOS transistor M22 is also connected to a corresponding bias voltage vbi 2 through a resistor R21.

Similar to the first inverter 1, referring to fig. 3, the third inverter 3 includes two third capacitors (i.e., a third capacitor C31 and a third capacitor C32), a third PMOS transistor M31 and a third NMOS transistor M32.

First ends of the two third capacitors (i.e., the third capacitor C31 and the third capacitor C32) are both directly or indirectly connected to an output end of the second inverter 2, a second end of one third capacitor C31 is connected to a gate of the third PMOS transistor M31, a second end of the other third capacitor C32 is connected to a gate of the third NMOS transistor M32, a source of the third PMOS transistor M31 is connected to a third power supply, a drain of the third PMOS transistor M31 and a drain of the third NMOS transistor M32 are both connected to an input side of the mixer, and a source of the third NMOS transistor M32 is directly or indirectly connected to ground; a third bias resistor Rb3 is connected between the gate and the drain of the third PMOS transistor M31.

Further, the drain of the third PMOS transistor M31 and the drain of the third NMOS transistor M32 are also connected to the first terminal of the capacitor C30, and the second terminal of the capacitor C30 is grounded via the resistor R32. The gate of the third NMOS transistor M32 also is connected to a corresponding bias voltage vbi 3 through a resistor R31.

In the above scheme, the multi-stage amplification (i.e., the amplification by the inverter that amplifies the signal) generates a differential output signal and directly drives the passive down-conversion mixer, and the above amplifier can be understood as a multi-stage amplifier.

CMOS inverters that perform the scaling function have higher frequencies but limited gain. Wherein the second inverter 2 and the third inverter 3 can drive the mixer without reducing the gain of the first inverter 1.

In addition, the second inverter 2 and the third inverter 3, and the devices therein, can be configured to have the same or similar parameters, thereby forming two inverters which are the same or similar.

In one embodiment, referring to fig. 4, the inverter-based low noise amplifier further includes a differential-to-single-ended feedback module 4, an input side of the differential-to-single-ended feedback module 4 is respectively connected to an output end of the second inverter 2 and an output end of the third inverter 3, so as to be capable of accessing differential signals (i.e., a signal at a Vout + end and a signal at a Vout-end), and an output end of the differential-to-single-ended feedback module 4 is directly or indirectly connected to an input end of the first inverter 1, so as to implement signal feedback;

the differential to single-ended feedback module 4 is configured to: and converting the differential signal into a single-ended signal, and feeding the single-ended signal back to between the input end of the first inverter 1 and the signal receiving end (i.e., the Rfin + end).

The differential-to-single-ended feedback module 4 may be any circuit module capable of converting a differential signal into a single-ended signal, and further, the differential-to-single-ended feedback module 4 may be an active differential-to-single-ended feedback module 4.

Based on the above differential to single-ended feedback module 4, a parallel feedback balun-LNA may be formed. Wherein balun is understood to be a balun transformation.

When the parallel feedback balun-LNA directly drives the passive mixer, the load causes a gain reduction. Even when coupling resistors are used between the LNA and the mixer. The multi-stage amplifier is more suitable for driving a lower resistive load and can also contribute to a reduction in power consumption. For example: the resistors R32 and R22 may be low-value load resistors (e.g., resistors less than or equal to 60 Ω), and their resistance values may be determined by coupling the series resistor and the input resistor of the mixer (e.g., passive mixer).

Specifically, referring to fig. 5, the differential-to-single-ended feedback module 4 includes: the feedback circuit comprises a first feedback NMOS transistor M41, a second feedback NMOS transistor M42, a first feedback capacitor C41 and a second feedback capacitor C42.

The drain of the first feedback NMOS transistor M41 is connected to a corresponding power source terminal, the source of the first feedback NMOS transistor M41 is connected to the drain of the second feedback NMOS transistor M42, the source of the first feedback NMOS transistor and the drain of the second feedback NMOS transistor are directly or indirectly connected to the input terminal of the first inverter, the source of the second feedback NMOS transistor M42 is grounded, the gate of the first feedback NMOS transistor M41 is connected to the output terminal of the third inverter 3 through the first feedback capacitor C41, and the gate of the second feedback NMOS transistor M42 is connected to the output terminal of the second inverter 2 through the second feedback capacitor C42.

The output terminal of the differential-to-single-ended feedback module 4 is connected between the first inverter 1 and the signal receiving terminal (i.e., Rfin + terminal) through a feedback resistor RF0, specifically, a first terminal of a feedback resistor RF0 may be connected between the source of the first feedback NMOS transistor and the drain of the second feedback NMOS transistor, a first terminal of an input capacitor Cin is connected to the signal receiving terminal (i.e., Rfin + terminal), a second terminal of the input capacitor Cin is connected to the first terminal of the input resistor R0, a second terminal of the input resistor R0 is connected to the input terminal of the first inverter 1, and a second terminal of a feedback resistor RF0 may be connected between the second terminal of the input capacitor Cin and the first terminal of the input resistor R0.

The differential-to-single-ended feedback block 4 can also be understood as a single-ended (D2S) differential buffer. A single-ended (D2S) differential buffer may drive the feedback resistor RF0 and provide wideband input matching.

The feedback resistor RF0 can be a large resistor, which acts as a degeneration for the transistor of the source follower (i.e. the second feedback NMOS transistor M42), while the nonlinearity generated by the first feedback NMOS transistor M41 is small, because the structure of the pair of transistors (i.e. the first feedback NMOS transistor M41-the second feedback NMOS transistor M42) acts as a current mirror, and the voltage-current nonlinearity of the first feedback NMOS transistor M41 is compensated by the current-voltage nonlinearity of the second feedback NMOS transistor M42, thereby ensuring the linearity of the feedback signal.

Furthermore, by limiting the impedance matching, the loop gain can be made small (e.g. just below 1) in the above parallel feedback low noise amplifier, so that the loop has no significant compression distortion.

Referring to fig. 5, in an exemplary embodiment, the gate of the first feedback NMOS transistor M41 may be connected to a power source terminal through a resistor R41, so as to be connected to a bias voltage, and the gate of the second feedback NMOS transistor M42 may be connected to the bias voltage VBin1 through a resistor R42. In other examples, other means for providing the bias may be used, not limited to the limitations of the figures.

The second inverter 2 and the Third inverter 3 can see a larger input signal and thus inject significant distortion into the loop, which may limit the OOB-IIP3 (i.e., Out-of-band Third-order intercept point) of the receiver, and for this reason, the embodiments shown in fig. 6 and 7 introduce an auxiliary inverter.

Referring to fig. 6, the inverter-based low noise amplifier further includes a first auxiliary inverter 5 and a second auxiliary inverter 6; the first auxiliary inverter 5 and the second auxiliary inverter 6 are both CMOS inverters.

For an understanding of the CMOS inverter, reference may be made to the related description above and will not be repeated here.

The input end of the first auxiliary inverter 5 is connected with the input end of the second inverter 2, and the output end of the first auxiliary inverter 5 is connected with the output end of the second inverter 2, namely: the first auxiliary inverter 5 is connected in parallel to two ends of the second inverter 2, an input end of the second auxiliary inverter 6 is connected to an input end of the third inverter 3, and an output end of the second auxiliary inverter 6 is connected to an output end of the third inverter 3, that is: the second auxiliary inverter 6 is connected in parallel to both ends of the third inverter 3.

The first auxiliary inverter 5 and the second auxiliary inverter 6 operate in a weak inversion region, and the second inverter 2 and the third inverter 3 operate in a strong inversion region.

It can be seen that the second inverter 2 can also be understood as a main inverter corresponding to the first auxiliary inverter 5, the third inverter 3 can also be understood as a main inverter corresponding to the second auxiliary inverter 6, and further, for the second inverter and the second inverter, a main inverter providing most of the gain and an auxiliary inverter for reducing distortion, which can be understood as MGTR (Multi-gate transistor) structure, can be respectively formed by the auxiliary inverters connected in parallel. In the main inverter (i.e., the second inverter 2 and the third inverter 3), the transistor operates in a strong inversion region, and in the auxiliary inverter (i.e., the first auxiliary inverter 5 and the second auxiliary inverter 6), the transistor operates in a weak inversion region. The distortion introduced by the second inverter 2 and the third inverter 3 can be significantly reduced due to the opposite signs of the nonlinear coefficients of the two parallel stages. In the case of the differential-to-single-ended feedback block 4, the input signal seen by the feedback path is the same as the second inverter 2 and the third inverter 3 and is very close to the same, so that the distortion is negligible.

Specifically, referring to fig. 7, the first auxiliary inverter 5 includes: two first auxiliary capacitors (i.e., the first auxiliary capacitor C51 and the first auxiliary capacitor C52), a first auxiliary PMOS transistor M51 and a first auxiliary NMOS transistor M52.

The first ends of the two first auxiliary capacitors C51 are both directly or indirectly connected to the output end of the first inverter 1, the second end of one first auxiliary capacitor C51 is connected to the gate of the first auxiliary PMOS transistor M51, the second end of the other first auxiliary capacitor C52 is connected to the gate of the first auxiliary NMOS transistor M52, the source of the first auxiliary PMOS transistor M51 is connected to a corresponding power supply, the drain of the first auxiliary PMOS transistor M51 and the drain of the first auxiliary NMOS transistor M52 are both connected to the output end of the second inverter 2, and the source of the first auxiliary NMOS transistor M52 is directly or indirectly connected to ground.

Specifically, referring to fig. 7, the second auxiliary inverter 6 includes: two second auxiliary capacitors (i.e., a second auxiliary capacitor C61 and a second auxiliary capacitor C62), a second auxiliary PMOS transistor M61 and a second auxiliary NMOS transistor M62.

First ends of the two second auxiliary capacitors (i.e., the second auxiliary capacitor C61 and the second auxiliary capacitor C62) are both directly or indirectly connected to an input end of the third inverter 3, a second end of one of the second auxiliary capacitors C61 is connected to a gate of the second auxiliary PMOS transistor M61, a second end of the other second auxiliary capacitor C62 is connected to a gate of the second auxiliary NMOS transistor M62, a source of the second auxiliary PMOS transistor M61 is connected to a corresponding power supply, a drain of the second auxiliary PMOS transistor M61 and a drain of the second auxiliary NMOS transistor M62 are both connected to an output end of the third inverter 3, and a source of the second auxiliary NMOS transistor M62 is directly or indirectly connected to ground.

In addition, the gate of the first auxiliary PMOS transistor M51 can be connected to the bias voltage VBpn via a resistor R51, the gate of the first auxiliary NMOS transistor M52 can be connected to the bias voltage VBan via a resistor R52, the gate of the second auxiliary PMOS transistor M61 can be connected to the bias voltage VBpn via a resistor R61, and the gate of the second auxiliary NMOS transistor M62 can be connected to the bias voltage VBan via a resistor R62. In other examples, the bias may be provided by other means.

Referring to fig. 8, in the low noise amplifier according to the above embodiments, the functions of the inverter, the active single-ended differential parallel feedback, and the differential output are combined, so that it can be understood as a low noise amplifier of single-ended input differential output based on the parallel feedback of the inverter, in which the LNA without inductance occupies a small area, and a large bandwidth can be designed, and further, the structure can show low noise and a small area as can be seen from the above description of the modules.

In particular, the low Noise amplifier, and the receiver using the same, provide good gain, NF (i.e., Noise Figure, which can be understood as a Noise Figure), and acceptable linearity with low power consumption. Due to the active feedback function of the embedded balun function, wide radio frequency bandwidth and small chip area can be realized.

Embodiments of the present invention also provide a receiver including an inverter-based low noise amplifier to which the above alternatives relate.

Further, the receiver further includes a mixer connected to the output end of the second inverter and the output end of the third inverter.

Embodiments of the present invention further provide an electronic device, which includes the inverter-based low noise amplifier according to the first aspect and the optional aspects thereof, and may specifically further include the above-mentioned mixer (i.e., the electronic device may include the above-mentioned receiver).

The electronic device may be any electronic device with a communication function, and for example, may be a mobile phone, a tablet computer, a smart wearable device, a network device, an in-vehicle device, and other communication-dedicated or non-communication-dedicated devices.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An inverter-based low noise amplifier, comprising: a first inverter, a second inverter and a third inverter; the input end of the first phase inverter is directly or indirectly connected with a signal receiving end, the output end of the first phase inverter is connected with the input end of the second phase inverter, the output end of the second phase inverter is connected with the input end of the third phase inverter, the output end of the second phase inverter and the output end of the third phase inverter are connected with a frequency mixer so as to output differential signals to the frequency mixer, and the first phase inverter, the second phase inverter and the third phase inverter are CMOS phase inverters.

2. The inverter-based low noise amplifier of claim 1, further comprising a differential-to-single-ended feedback module, wherein input sides of the differential-to-single-ended feedback module are respectively connected to an output terminal of the second inverter and an output terminal of the third inverter, and an output terminal of the differential-to-single-ended feedback module is directly or indirectly connected to an input terminal of the first inverter;

3. The inverter-based low noise amplifier of claim 2, wherein the differential to single-ended feedback module comprises: the NMOS feedback circuit comprises a first feedback NMOS tube, a second feedback NMOS tube, a first feedback capacitor and a second feedback capacitor;

the drain electrode of the first feedback NMOS tube is connected with a corresponding power supply end, the source electrode of the first feedback NMOS tube and the drain electrode of the second feedback NMOS tube are directly or indirectly connected with the input end of the first phase inverter, the source electrode of the second feedback NMOS tube is grounded, the grid electrode of the first feedback NMOS tube is connected with the output end of the third phase inverter through the first feedback capacitor, and the grid electrode of the second feedback NMOS tube is connected with the output end of the second phase inverter through the second feedback capacitor.

4. The inverter-based low noise amplifier of claim 2, wherein the output terminal of the differential-to-single-ended feedback module is connected between the first inverter and the signal receiving terminal through a feedback resistor.

5. The inverter-based low noise amplifier of any of claims 1 to 4, further comprising a first auxiliary inverter and a second auxiliary inverter;

the input end of the first auxiliary phase inverter is connected with the input end of the second phase inverter, the output end of the first auxiliary phase inverter is connected with the output end of the second phase inverter, the input end of the second auxiliary phase inverter is connected with the input end of the third phase inverter, and the output end of the second auxiliary phase inverter is connected with the output end of the third phase inverter; the first auxiliary inverter and the second auxiliary inverter are both CMOS inverters;

6. The inverter-based low noise amplifier of claim 5, wherein the first auxiliary inverter comprises: two first auxiliary capacitors, a first auxiliary PMOS tube and a first auxiliary NMOS tube;

the first ends of the two second auxiliary capacitors are directly or indirectly connected with the input end of the third phase inverter, the second end of one second auxiliary capacitor is connected with the grid electrode of the second auxiliary PMOS tube, the second end of the other second auxiliary capacitor is connected with the grid electrode of the second auxiliary NMOS tube, the source electrode of the second auxiliary PMOS tube is connected with a corresponding power supply, the drain electrode of the second auxiliary PMOS tube and the drain electrode of the second auxiliary NMOS tube are both connected with the output end of the third phase inverter, and the source electrode of the second auxiliary NMOS tube is directly or indirectly grounded.

7. The inverter-based low noise amplifier of any of claims 1 to 4, wherein the first inverter comprises two first capacitors, a first PMOS transistor and a first NMOS transistor;

the first ends of the two first capacitors are directly or indirectly connected with the signal receiving end, the second end of one first capacitor is connected with the grid electrode of the first PMOS tube, the second end of the other first capacitor is connected with the grid electrode of the first NMOS tube, the source electrode of the first PMOS tube is connected with a first power supply, the drain electrode of the first PMOS tube and the drain electrode of the first NMOS tube are both connected with the input end of the second phase inverter, and the source electrode of the first NMOS tube is directly or indirectly grounded; a first bias resistor is connected between the grid electrode and the drain electrode of the first PMOS tube;

the second phase inverter comprises two second capacitors, a second PMOS tube and a second NMOS tube;

the first ends of the two second capacitors are directly or indirectly connected with the output end of the first phase inverter, the second end of one second capacitor is connected with the grid electrode of the second PMOS tube, the second end of the other second capacitor is connected with the grid electrode of the second NMOS tube, the source electrode of the second PMOS tube is connected with a second power supply, the drain electrode of the second PMOS tube and the drain electrode of the second NMOS tube are both connected with the input end of the third phase inverter, and the source electrode of the second NMOS tube is directly or indirectly grounded; a second bias resistor is connected between the grid electrode and the drain electrode of the second PMOS tube;

the third phase inverter comprises two third capacitors, a third PMOS tube and a third NMOS tube;

8. A receiver comprising an inverter-based low noise amplifier according to any of claims 1 to 7.

9. The receiver of claim 8, further comprising a mixer coupled to the second inverter output and the third inverter output.

10. An electronic device comprising the inverter-based low noise amplifier of any of claims 1 to 9.