Low noise amplifier and radio frequency receiving module

Abstract

The application provides a low noise amplifier and a radio frequency receiving module, wherein the low noise amplifier comprises a signal input end, an input matching circuit, an amplification circuit, an output matching circuit and a signal output end which are electrically connected in sequence; the input matching circuit comprises a first capacitor, a transformer and a first negative feedback inductor; the transformer comprises a primary coil inductor, a secondary coil inductor and a coupling coefficient formed by coupling of the primary coil inductor and the secondary coil inductor. The low noise amplifier in the application can improve the input matching effect of a wide band, so as to avoid the mismatching phenomenon of the low noise amplifier caused by changes of environmental temperature, frequency, signal source and load and other factors.

Description

[Technical Field]

[0001] This invention relates to the field of signal processing technology, and in particular to a low-noise amplifier and a radio frequency receiving module. [Background Technology]

[0002] With the massive growth in the number of wireless communication users and network data services, people have increasingly higher demands for the transmission rate and data throughput of wireless communication networks.

[0003] The 802.11 protocol suite is a standard developed by the Institute of Electrotechnical Engineers (IEEE) for wireless local area networks. 802.11ax (i.e. Wi-Fi 6) is the latest revision of this standard. Compared with the previous generation 802.11ac protocol, the 802.11ax protocol solves the problem of multi-user concurrent performance and has further improved the speed. It also supports the 2.4GHz and 5GHz frequency bands.

[0004] To meet the above technical requirements, the receiver's RF front-end must also meet the requirements for broadband operation. As the first amplification module in the receiver's RF front-end, the low-noise amplifier (LNA) needs to amplify the tiny signals received by the antenna. Its noise figure directly affects the sensitivity of the entire receiver and has a significant impact on the receiver's performance.

[0005] Traditional low-noise amplifiers often employ a structure of multiple narrowband low-noise amplifiers connected in parallel and switched by a switch. However, the insertion loss of the switch increases with the frequency, leading to a deterioration in the noise figure of the low-noise amplifier. At the same time, the structure of multiple narrowband low-noise amplifiers connected in parallel also significantly increases the circuit area and power consumption, making the low-noise amplifier susceptible to mismatch due to changes in ambient temperature, frequency, signal source, and load. [Summary of the Invention]

[0006] The purpose of this invention is to provide a new low-noise amplifier to solve the problem that existing low-noise amplifiers are prone to mismatch due to changes in ambient temperature, frequency, signal source, and load.

[0007] In a first aspect, the present invention provides a low-noise amplifier, which includes a signal input terminal, an input matching circuit, an amplification circuit, an output matching circuit, and a signal output terminal connected in sequence.

[0008] The input matching circuit is used to achieve impedance matching between the signal input terminal and the low-noise amplifier; the input matching circuit includes a first capacitor, a transformer, and a first negative feedback inductor;

[0009] The first terminal of the first capacitor is connected to the signal input terminal;

[0010] The transformer includes a primary coil inductor, a secondary coil inductor coupled to the primary coil inductor, and a coupling coefficient for the coupling between the primary coil inductor and the secondary coil inductor; a first terminal of the primary coil inductor is connected to a second terminal of the first capacitor, the second terminal of the primary coil inductor is grounded, a first terminal of the secondary coil inductor is connected to the input terminal of the amplifier circuit, and the second terminal of the secondary coil inductor is connected to a first power supply bias voltage; a first terminal of the first negative feedback inductor is connected to the amplifier circuit, and a second terminal of the first negative feedback inductor is grounded.

[0011] The amplifier circuit is used to amplify the signal output by the input matching circuit and then output it.

[0012] The output matching circuit is connected between the output terminal of the amplifier circuit and the signal output terminal to achieve impedance matching between the low-noise amplifier and the signal output terminal.

[0013] More preferably, the input matching circuit further includes a leakage inductance connected in series between the second terminal of the first capacitor and the first terminal of the primary coil inductance.

[0014] More preferably, the amplifier circuit includes a first-stage amplifier circuit, a second-stage amplifier circuit, and an inter-stage matching circuit connecting the first-stage amplifier circuit and the second-stage amplifier circuit; the inter-stage matching circuit is used to achieve impedance matching between the first-stage amplifier circuit and the second-stage amplifier circuit.

[0015] The first end of the secondary coil inductor and the first end of the first negative feedback inductor are respectively connected to the first stage amplifier circuit, and the output matching circuit is connected to the second stage amplifier circuit.

[0016] More preferably, the first-stage amplifier circuit includes a first MOS transistor and a second MOS transistor, forming a common-source, common-gate structure;

[0017] The gate of the first MOS transistor is connected to the first end of the secondary coil inductor as the input terminal of the amplifier circuit, and the source of the first MOS transistor is connected to the first end of the first negative feedback inductor.

[0018] The source of the second MOS transistor is connected to the drain of the first MOS transistor, the gate of the second MOS transistor is connected to the second power supply bias voltage, and the drain of the second MOS transistor is connected to the first power supply voltage.

[0019] The interstage matching circuit is connected to the drain of the second MOS transistor.

[0020] More preferably, the interstage matching circuit includes a first drain inductor, an interstage coupling capacitor, and a second negative feedback inductor.

[0021] The drain of the second MOS transistor is connected to the first power supply voltage via the first drain inductor in series.

[0022] The first terminal of the interstage coupling capacitor is connected to the drain of the second MOS transistor;

[0023] The first end of the second negative feedback inductor and the second end of the interstage coupling capacitor are respectively connected to the second stage amplifier circuit, and the second end of the second negative feedback inductor is grounded.

[0024] More preferably, the second-stage amplifier circuit includes a third MOS transistor and a fourth MOS transistor, forming a common-source, common-gate structure;

[0025] The gate of the third MOS transistor is connected to the second terminal of the interstage coupling capacitor, and the source of the third MOS transistor is connected to the first terminal of the second negative feedback inductor.

[0026] The source of the fourth MOS transistor is connected to the drain of the third MOS transistor, the gate of the fourth MOS transistor is connected to the third power supply bias voltage, and the drain of the fourth MOS transistor is connected to the second power supply voltage.

[0027] The output matching circuit is connected to the drain of the fourth MOS transistor.

[0028] More preferably, the output matching circuit includes a second drain inductor, a second capacitor, a third capacitor, and a fourth capacitor;

[0029] The drain of the fourth MOS transistor is connected to the second power supply voltage via the second drain inductor in series.

[0030] The first terminal of the second capacitor is connected to the drain of the fourth MOS transistor, and the second terminal of the second capacitor is connected to the signal output terminal.

[0031] The first terminal of the third capacitor is connected to the first terminal of the second capacitor, and the second terminal of the third capacitor is grounded.

[0032] The first terminal of the fourth capacitor is connected to the second terminal of the second capacitor, and the second terminal of the fourth capacitor is grounded.

[0033] More preferably, the output matching circuit further includes a resistor connected in series between the second drain inductor and the second power supply voltage.

[0034] Secondly, the present invention provides a radio frequency receiving module, the radio frequency receiving module including the low noise amplifier as described above.

[0035] Compared with existing technologies, the low-noise amplifier of the present invention, through the design of the primary coil inductance, secondary coil inductance, and coupling coefficient formed by the primary coil inductance and secondary coil inductance of the transformer, combined with the first capacitor, is equivalent to providing a high-order matching network. Compared with the matching network of a single-stage inductor and capacitor, it has higher degrees of freedom, provides more poles, and thus has a higher bandwidth, improves the wideband input matching effect, and avoids the mismatch phenomenon caused by changes in environmental temperature, frequency, signal source, and load. [Attached Image Description]

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0037] Figure 1 A circuit block diagram of a low-noise amplifier provided in an embodiment of the present invention;

[0038] Figure 2 A circuit block diagram of a low-noise amplifier provided in an embodiment of the present invention;

[0039] Figure 3 The figure shows the S-parameter simulation results of a low-noise amplifier provided in this embodiment of the invention.

[0040] Figure 4 The image shows the simulation results of the noise figure of a low-noise amplifier provided in an embodiment of the present invention.

[0041] Among them, 100 is a low-noise amplifier; 1 is an input matching circuit; 11 is a transformer; 2 is an amplifier circuit; 21 is the first amplifier stage circuit; 22 is the interstage matching circuit; 23 is the second amplifier stage circuit; and 3 is the output matching circuit.

Detailed Implementation Methods

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] This invention provides a low-noise amplifier 100, combined with... Figure 1 and Figure 2 As shown, it includes a signal input terminal IN, an input matching circuit 1, an amplifier circuit 2, an output matching circuit 3, and a signal output terminal OUT, which are connected in sequence.

[0044] The input matching circuit 1 is used to achieve impedance matching between the signal input terminal IN and the low-noise amplifier 100, and to transmit the radio frequency signal to the amplifier circuit 2. The amplifier circuit 2 is used to amplify the signal output from the input matching circuit 1 and output it. The output matching circuit 3 is used to achieve impedance matching between the low-noise amplifier 100 and the signal output terminal OUT. The output matching circuit 3 is connected between the output terminal OUT of the amplifier circuit 2.

[0045] Specifically, the input matching circuit 1 includes a first capacitor C1, a transformer 11, and a first negative feedback inductor L. S1 .

[0046] The first terminal of the first capacitor C1 is connected to the signal input terminal IN.

[0047] Transformer 11 includes a primary coil inductance L2, a secondary coil inductance L3 coupled to the primary coil inductance L2, and a coupling coefficient k1 for the coupling between the primary coil inductance L2 and the secondary coil inductance L3; the first end of the primary coil inductance L2 is connected to the second end of the first capacitor C1, the second end of the primary coil inductance L2 is grounded, the first end of the secondary coil inductance L3 is connected to the input terminal of the amplifier circuit 2, and the second end of the secondary coil inductance L3 is connected to the first power supply bias voltage V. G1 First negative feedback inductor L S1 The first terminal is connected to amplifier circuit 2, and the first negative feedback inductor L S1 The first end is grounded.

[0048] In this embodiment, the input matching circuit 1 further includes a leakage inductance L connected in series between the second terminal of the first capacitor C1 and the first terminal of the primary coil inductance L2. g .

[0049] Specifically, the amplifier circuit 2 includes a first-stage amplifier circuit 21, a second-stage amplifier circuit 23, and an inter-stage matching circuit 22 connecting the first-stage amplifier circuit 21 and the second-stage amplifier circuit 23; the inter-stage matching circuit 22 is used to achieve impedance matching between the first-stage amplifier circuit 21 and the second-stage amplifier circuit 23.

[0050] Among them, the first terminal of the secondary coil inductor L3 and the first negative feedback inductor L S1 The first end is connected to the first stage amplifier circuit 21, and the output matching circuit 3 is connected to the second stage amplifier circuit 23.

[0051] In this embodiment, the first-stage amplifier circuit 21 includes a first MOS transistor M1 and a second MOS transistor M2, forming a common-source, same-gate structure.

[0052] The gate of the first MOS transistor M1 is connected to the first terminal of the secondary coil inductor L3 as the input terminal of the amplifier circuit 2. The source of the first MOS transistor M1 is connected to the first negative feedback inductor L3. S1 The first end is connected.

[0053] The source of the second MOS transistor M2 is connected to the drain of the first MOS transistor M1, and the gate of the second MOS transistor M2 is connected to the second power supply bias voltage V. G2 The drain of the second MOS transistor M2 is connected to the first power supply voltage V. D1 .

[0054] The interstage matching circuit 22 is connected to the drain of the second MOS transistor M2.

[0055] In this embodiment, the interstage matching circuit 22 includes a first drain inductor L. d1 Interstage coupling capacitor C2 and second negative feedback inductor L S2 .

[0056] The drain of the second MOS transistor M2 is connected in series with the first drain inductor L. d1 Then connected to the first power supply voltage V D1 That is, the first drain inductance L d1 The first terminal is connected to the drain of the second MOS transistor M2, and the first drain inductance L d1 The second terminal is connected to the first power supply voltage V. D1 .

[0057] The first terminal of the interstage coupling capacitor C2 is connected to the drain of the second MOS transistor M2.

[0058] Second negative feedback inductor L S2 The first terminal and the second terminal of the interstage coupling capacitor C2 are respectively connected to the second amplifier stage circuit 23, and the second negative feedback inductor L S2 The second end is grounded.

[0059] In this embodiment, the second-stage amplifier circuit 23 includes a third MOS transistor M3 and a fourth MOS transistor M4, forming a common-source, same-gate structure.

[0060] The gate of the third MOS transistor M3 is connected to the second terminal of the interstage coupling capacitor C2, and the source of the third MOS transistor M3 is connected to the second negative feedback inductor L. S2 The first end is connected.

[0061] The source of the fourth MOS transistor M4 is connected to the drain of the third MOS transistor M3, and the gate of the fourth MOS transistor M4 is connected to the third power supply bias voltage V. G3 The drain of the fourth MOS transistor M4 is connected to the second power supply voltage V. D2 .

[0062] The output matching circuit 3 is connected to the drain of the fourth MOS transistor M4; that is, the drain of the fourth MOS transistor M4 also serves as the output terminal of the amplifier circuit 2.

[0063] Specifically, the output matching circuit 3 includes a second drain inductor L. d2 The second capacitor C4, the third capacitor C3, and the fourth capacitor C5.

[0064] The drain of the fourth MOS transistor M4 is connected in series with the second drain inductor L. d2 Then connected to the second power supply voltage V D2 That is, the second drain inductance L d2 The first terminal is connected to the drain of the fourth MOS transistor M4, and the second drain inductance L d2 The second terminal is connected to the second power supply voltage V. D2 .

[0065] The first terminal of the second capacitor C4 is connected to the drain of the fourth MOS transistor M4, and the second terminal of the second capacitor C4 is connected to the signal output terminal OUT.

[0066] The first terminal of the third capacitor C3 is connected to the first terminal of the second capacitor C4, and the second terminal of the third capacitor C3 is grounded.

[0067] The first terminal of the fourth capacitor C5 is connected to the second terminal of the second capacitor C4, and the second terminal of the fourth capacitor C5 is grounded.

[0068] In this embodiment, the output matching circuit 3 further includes a second drain inductor L connected in series. d2 With the second power supply voltage V D2 The resistor R1 between the first terminal of resistor R1 and the second drain inductance L; d2 The second terminal of resistor R1 is connected to the second power supply voltage V. D2 .

[0069] In this embodiment, the “connection” between the two devices should be understood as “electrical connection” or “electrical link”.

[0070] Compared with the prior art, the low-noise amplifier 100 of the present invention, through the design of the primary coil inductance L2, the secondary coil inductance L3 of the transformer 11 (on-chip transformer) and the coupling coefficient k1 between the primary coil inductance L2 and the secondary coil inductance L3, combined with the first capacitor C1 and the quality factor, is equivalent to providing a high-order matching network. Compared with the matching network of a single-stage inductor and capacitor (LC matching network), it has better degrees of freedom, provides more poles, and therefore has better bandwidth, improves the wideband input matching effect, and avoids the mismatch phenomenon caused by changes in ambient temperature, frequency, signal source and load. At the same time, the low-noise amplifier 100 can also achieve good matching in the 5-7GHz frequency band.

[0071] In the optimization design process of transformer 11, it is difficult to adjust a single parameter of transformer 11 without affecting other parameters. Therefore, the optimization design process of transformer 11 is relatively complex and often requires multiple iterations. To simplify the design steps and reduce the number of iterations, a leakage inductance L is inserted at its input terminal. g To assist in the design, a leakage inductance L is added to the first terminal of the primary coil inductance L2. g This leakage inductance L g This allows for the adjustment of the inductance of the primary coil L2 and the coupling coefficient k1 of the transformer 11 without affecting the inductance of the secondary coil L3, thereby simplifying the optimization design and iteration process of the transformer 11.

[0072] The first-stage amplifier circuit 21 and the second amplifier circuit 2 both adopt a common-source common-gate (CRM) structure, which can effectively reduce the impact of the Miller effect of the first MOS transistor M1 to the fourth MOS transistor M4 and the limited output impedance on the performance of the low-noise amplifier 100, and provide good reverse isolation performance, reduce the leakage of local oscillation signals, and make the low-noise amplifier 100 a unidirectional optimized amplifier structure, which can greatly simplify the design process and avoid its poor stability problem.

[0073] The first-stage amplifier circuit 21 and the second amplifier circuit 2 introduce a first negative feedback inductor L at the source of their common source transistors, respectively. S1 Second negative feedback inductor L S2 This allows for adjustment of the first negative feedback inductor L. S1 Second negative feedback inductor L S2 The specific parameters of the low-noise amplifier 100 are optimized to improve its noise figure, small-signal gain, input matching circuit 1, interstage matching circuit 22, and stability.

[0074] The second-stage amplifier circuit 23 can smooth out the small-signal gain curve by introducing a resistor R1 at the drain of the common gate transistor, thereby improving the in-band gain flatness.

[0075] The output matching circuit 3 uses a pi-type matching network, which enables broadband output matching and extends the bandwidth of the low-noise amplifier 100.

[0076] Figure 3 The figure shows the simulation results of the S-parameters (scattering parameters) of the low-noise amplifier 100 provided in this embodiment. In the figure, S12 is the reverse transmission coefficient, which is isolation; S21 is the forward transmission coefficient, which is gain; S11 is the input reflection coefficient, which is input return loss; and S22 is the output reflection coefficient, which is output return loss. Figure 4 This is a simulation result of the noise figure of the low-noise amplifier 100 provided in this embodiment, where NF represents the noise figure; thus Figure 3 and Figure 4 It can be concluded that the low-noise amplifier 100 has good matching in the 5-7GHz frequency band, and both the input and output return losses are greater than 10dB, providing high gain, with the highest gain reaching 19.41dB. The gain curve changes very smoothly in the frequency band, with a gain flatness of 1.1dB. In addition, it provides a low noise figure, which is only between 1.43-1.67dB, all less than 2dB.

[0077] In addition, the present invention also provides an embodiment of a radio frequency receiving module, which includes the low noise amplifier 100 in the above embodiment.

[0078] Since the radio frequency receiving module in this embodiment includes the low noise amplifier 100 in the above embodiment, it can also achieve the technical effect achieved by the low noise amplifier 100 in the above embodiment, which will not be elaborated here.

[0079] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A low-noise amplifier, comprising a signal input terminal, an input matching circuit, an amplification circuit, an output matching circuit, and a signal output terminal connected in sequence; the input matching circuit is used to achieve impedance matching between the signal input terminal and the low-noise amplifier; characterized in that, The input matching circuit includes a first capacitor, a transformer, and a first negative feedback inductor; The first terminal of the first capacitor is connected to the signal input terminal; The transformer includes a primary coil inductor, a secondary coil inductor coupled to the primary coil inductor, and a coupling coefficient for the coupling between the primary coil inductor and the secondary coil inductor; a first terminal of the primary coil inductor is connected to a second terminal of the first capacitor, the second terminal of the primary coil inductor is grounded, a first terminal of the secondary coil inductor is connected to the input terminal of the amplifier circuit, and the second terminal of the secondary coil inductor is connected to a first power supply bias voltage; a first terminal of the first negative feedback inductor is connected to the amplifier circuit, and a second terminal of the first negative feedback inductor is grounded. The amplifier circuit is used to amplify the signal output by the input matching circuit and then output it. The output matching circuit is connected between the output terminal of the amplifier circuit and the signal output terminal to achieve impedance matching between the low-noise amplifier and the signal output terminal. The output matching circuit includes a second drain inductor, a second capacitor, a third capacitor, a fourth capacitor, and a resistor connected in series between the second terminal of the second drain inductor and the second power supply voltage.

2. The low-noise amplifier as described in claim 1, characterized in that, The input matching circuit also includes a leakage inductance connected in series between the second terminal of the first capacitor and the first terminal of the primary coil inductance.

3. The low-noise amplifier as described in claim 1, characterized in that, The amplifier circuit includes a first-stage amplifier circuit, a second-stage amplifier circuit, and an inter-stage matching circuit connecting the first-stage amplifier circuit and the second-stage amplifier circuit; the inter-stage matching circuit is used to achieve impedance matching between the first-stage amplifier circuit and the second-stage amplifier circuit. The first end of the secondary coil inductor and the first end of the first negative feedback inductor are respectively connected to the first stage amplifier circuit, and the output matching circuit is connected to the second stage amplifier circuit.

4. The low-noise amplifier as described in claim 3, characterized in that, The first-stage amplifier circuit includes a first MOS transistor and a second MOS transistor, forming a common-source, common-gate structure; The gate of the first MOS transistor is connected to the first end of the secondary coil inductor as the input terminal of the amplifier circuit, and the source of the first MOS transistor is connected to the first end of the first negative feedback inductor. The source of the second MOS transistor is connected to the drain of the first MOS transistor, the gate of the second MOS transistor is connected to the second power supply bias voltage, and the drain of the second MOS transistor is connected to the first power supply voltage. The interstage matching circuit is connected to the drain of the second MOS transistor.

5. The low-noise amplifier as described in claim 4, characterized in that, The interstage matching circuit includes a first drain inductor, an interstage coupling capacitor, and a second negative feedback inductor. The drain of the second MOS transistor is connected to the first power supply voltage via the first drain inductor in series. The first terminal of the interstage coupling capacitor is connected to the drain of the second MOS transistor; The first end of the second negative feedback inductor and the second end of the interstage coupling capacitor are respectively connected to the second stage amplifier circuit, and the second end of the second negative feedback inductor is grounded.

6. The low-noise amplifier as described in claim 5, characterized in that, The second-stage amplifier circuit includes a third MOS transistor and a fourth MOS transistor, forming a common-source, common-gate structure; The gate of the third MOS transistor is connected to the second terminal of the interstage coupling capacitor, and the source of the third MOS transistor is connected to the first terminal of the second negative feedback inductor. The source of the fourth MOS transistor is connected to the drain of the third MOS transistor, the gate of the fourth MOS transistor is connected to the third power supply bias voltage, and the drain of the fourth MOS transistor is connected to the second power supply voltage. The output matching circuit is connected to the drain of the fourth MOS transistor.

7. The low-noise amplifier as described in claim 6, characterized in that, The drain of the fourth MOS transistor is connected to the second power supply voltage via the second drain inductor in series. The first terminal of the second capacitor is connected to the drain of the fourth MOS transistor, and the second terminal of the second capacitor is connected to the signal output terminal. The first terminal of the third capacitor is connected to the first terminal of the second capacitor, and the second terminal of the third capacitor is grounded. The first terminal of the fourth capacitor is connected to the second terminal of the second capacitor, and the second terminal of the fourth capacitor is grounded.

8. A radio frequency receiving module, characterized in that, The radio frequency receiving module includes a low-noise amplifier as described in any one of claims 1 to 7.

Images