Low-noise amplifiers and RF front-end modules

Abstract

This invention provides a low-noise amplifier and an RF front-end module. The low-noise amplifier includes a tunable input matching circuit, a power amplifier circuit, and an output matching circuit. The input terminal of the tunable input matching circuit is used to receive an RF signal. The tunable input matching circuit adjusts its capacitance value according to the different frequency bands of the received RF signals. The input terminal of the power amplifier circuit is connected to the output terminal of the tunable input matching circuit and is used to receive a first bias voltage. The ground terminal of the power amplifier circuit is grounded. The first input terminal of the output matching circuit is connected to the output terminal of the power amplifier circuit, the second input terminal of the output matching circuit is used to receive the operating voltage, and the output terminal of the output matching circuit is used to output an RF signal. The low-noise amplifier of this invention is compatible with RF signals of different frequency bands. When applied to an RF front-end module, it has high integration, low insertion loss, reduced cost, and a better noise figure.

Description

Technical Field

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

[0002] Low-noise amplifiers (LNAs) belong to the fields of microwave / radio frequency (RF) technology and wireless communication. As the first step in any wireless receiving system, they can amplify the signal received from the antenna with as little additional noise as possible. That is, they have two functions: low noise, which means that the noise they generate is extremely low, and signal amplification, which means that they amplify weak signals.

[0003] With the widespread adoption of 5G, the sub-6GHz frequency band, especially Frequency Range 1 (FR1), is becoming increasingly congested. According to the core technical specifications defining the radio frequency transmission and reception performance of user equipment (3GPP TS 38.101), 5G New Radio (NR) allocates multiple frequency bands within the FR1 band. Among them, N77 (3.3-4.2GHz) and N79 (4.4-5.0GHz) are mid-bands widely deployed by mainstream operators globally, carrying the core services of enhanced mobile broadband (eMBB).

[0004] However, the congestion of the Sub-6GHz band presents a severe interference challenge. Of particular concern is the second harmonic (approximately 10.3-11.7GHz) of the 5GHz (5.15-5.85GHz) wireless network (WiFi), which, although far from the N77, may have nonlinear products, out-of-band spurious emissions, and intermodulation components in its transmission link falling into the N77's receiving band, causing a degradation in receiver sensitivity. This type of harmonic interference places extremely high demands on the linearity and selectivity of the RF receiving front-end.

[0005] At the same time, 5G terminals will pursue multi-band and multi-mode compatibility. However, in related technologies, the solution of one filter and one LNA for one frequency band faces difficulties such as the expansion of printed circuit board (PCB) area, high overall bill of materials (BOM) cost, and accumulation of insertion loss.

[0006] The aforementioned LNAs are narrowband LNAs, and each LNA only supports a single frequency band. The Low-Noise Front-End Module (LFEM), which includes two single-frequency N77 LNAs, also only supports the N77 band and not the N79 band. The N77 band has a large bandwidth, which can lead to congestion due to high data transmission volumes. The N79 band is relatively less congested than the N77 band and can be used for traffic offloading. The RF front-end module (LNA-PA Module Integrated Filter, L-PAMiF), which includes two single-frequency N77 LNAs and two single-frequency N79 LNAs, needs to be designed with two N77 band LNAs and two N79 band LNAs to handle combined applications, following relevant design principles.

[0007] In summary, for LFEM modules, the single N77 band is clearly insufficient to meet the ever-increasing data transmission demands, and transmission efficiency is limited by the single N77 band. For L-PAMiF modules, adopting the principle of one filter and one LNA per band requires two N77 band filters, two N79 band filters, two N77 band LNAs, and two N79 band LNAs, totaling four filters and four LNAs. This results in a larger RF front-end module architecture area, the discrete solution cannot adapt to dynamic changes in band combinations, higher module costs, and greater insertion loss. Furthermore, each additional filter and switch introduces 1-2 dB of insertion loss, worsening the noise figure of the receiver link.

[0008] Therefore, a new low-noise amplifier and RF front-end module are needed to solve the above problems. Summary of the Invention

[0009] To address the shortcomings of the aforementioned related technologies, this invention proposes a novel low-noise amplifier and RF front-end module. This addresses the problems that, when low-noise amplifiers are applied to RF front-end modules, the resulting RF front-end module architecture becomes large, unable to adapt to dynamic changes in frequency band combinations, has high module costs, high insertion loss, and deteriorates the noise figure of the receiving link.

[0010] To address the aforementioned technical problems, in a first aspect, the present invention provides a low-noise amplifier, which includes a tunable input matching circuit, a power amplification circuit, and an output matching circuit. The input terminal of the tunable input matching circuit is used to receive radio frequency signals; the tunable input matching circuit is used to adjust its capacitance value according to the radio frequency signals in different frequency bands to generate or cancel harmonic suppression for radio frequency signals in different frequency bands. The input terminal of the power amplifier circuit is connected to the output terminal of the tunable input matching circuit and is used to connect to the first bias voltage. The first input terminal of the output matching circuit is connected to the output terminal of the power amplifier circuit, the second input terminal of the output matching circuit is used to connect to the operating voltage, and the output terminal of the output matching circuit is used to output radio frequency signals.

[0011] Preferably, the tunable input matching circuit includes a first inductor, a control switch, a first switched capacitor assembly, and a second switched capacitor assembly; The first end of the first inductor serves as the input terminal of the tunable input matching circuit, and the second end of the first inductor serves as the output terminal of the tunable input matching circuit. The first terminal of the control switch is connected to the first terminal of the first inductor, and the second terminal of the control switch is connected to the second terminal of the first inductor. The first terminal of the first switched capacitor assembly is connected to the first terminal of the control switch, and the second terminal of the first switched capacitor assembly is connected to the second terminal of the control switch; the first switched capacitor assembly is used to control the conduction or de-conduction of its capacitor according to the radio frequency signal in different frequency bands. The first terminal of the second switched capacitor assembly is connected to the first terminal of the first inductor, and the second terminal of the second switched capacitor assembly is grounded; the second switched capacitor assembly is used to control the conduction or de-conduction of its capacitor according to the radio frequency signal in different frequency bands.

[0012] Preferably, the control switch is a single-pole single-throw switch; or, the control switch includes a first resistor, a first field-effect transistor, and a second resistor. The first end of the first resistor is used to connect to the first control voltage; The gate of the first field-effect transistor is connected to the second terminal of the first resistor, the source of the first field-effect transistor serves as the first terminal of the control switch, and the drain of the first field-effect transistor serves as the second terminal of the control switch. The two ends of the second resistor are respectively connected to the source and the drain of the first field-effect transistor.

[0013] Preferably, the first switched capacitor assembly is a first variable capacitor; or, the first switched capacitor assembly includes a third resistor, a second field-effect transistor, a fourth resistor, and a first capacitor. The first end of the third resistor is used to connect to the second control voltage; The gate of the second field-effect transistor is connected to the second terminal of the third resistor, and the source of the second field-effect transistor serves as the first terminal of the first switched capacitor assembly. The two ends of the fourth resistor are respectively connected to the source and the drain of the second field-effect transistor; The first terminal of the first capacitor is connected to the drain of the second field-effect transistor, and the second terminal of the first capacitor serves as the second terminal of the first switched capacitor assembly. The second switched capacitor assembly is a second variable capacitor; or, the second switched capacitor assembly includes a second capacitor, a fifth resistor, a third field-effect transistor, and a sixth resistor; The first terminal of the second capacitor serves as the first terminal of the second switched capacitor assembly; The first end of the fifth resistor is used to connect to the third control voltage; The gate of the third field-effect transistor is connected to the second terminal of the fifth resistor, the drain of the third field-effect transistor is connected to the second terminal of the second capacitor, and the source of the third field-effect transistor serves as the second terminal of the second switched capacitor assembly. The two ends of the sixth resistor are respectively connected to the source and the drain of the third field-effect transistor.

[0014] Preferably, the output matching circuit includes a fourth field-effect transistor, a second inductor, a third inductor, a third capacitor, a third switched capacitor assembly, and a fourth switched capacitor assembly. The source of the fourth field-effect transistor serves as the first input terminal of the output matching circuit, and the gate of the fourth field-effect transistor is used to connect to the second bias voltage. The first terminal of the second inductor is connected to the drain of the fourth field-effect transistor; The first end of the third inductor is connected to the second end of the second inductor, and the second end of the third inductor serves as the second input end of the output matching circuit; the third inductor and the second inductor are coupled to each other. The first terminal of the third capacitor is connected to the second terminal of the second inductor, and the second terminal of the third capacitor serves as the output terminal of the output matching circuit. The first terminal of the third switched capacitor assembly is connected to the drain of the fourth field-effect transistor, and the second terminal of the third switched capacitor assembly is connected to the second terminal of the third capacitor; the third switched capacitor assembly is used to control the conduction or cutoff of its capacitor according to the radio frequency signal in different frequency bands. The first terminal of the fourth switched capacitor assembly is connected to the second terminal of the third inductor, and the second terminal of the fourth switched capacitor assembly is connected to the second terminal of the third capacitor; the fourth switched capacitor assembly is used to control the conduction or de-conduction of its capacitor according to the radio frequency signal in different frequency bands.

[0015] Preferably, the third switched capacitor assembly is a third variable capacitor; or, the third switched capacitor assembly includes a fourth capacitor, a seventh resistor, a fifth field-effect transistor, and an eighth resistor. The first terminal of the fourth capacitor serves as the first terminal of the third switched capacitor assembly. The first terminal of the seventh resistor is used to connect to the fourth control voltage; The gate of the fifth field-effect transistor is connected to the second terminal of the seventh resistor, the source of the fifth field-effect transistor is connected to the second terminal of the fourth capacitor, and the drain of the fifth field-effect transistor serves as the second terminal of the third switched capacitor assembly. The two ends of the eighth resistor are respectively connected to the source and the drain of the fifth field-effect transistor; The fourth switched capacitor assembly is a fourth variable capacitor; or, the fourth switched capacitor assembly includes a fifth capacitor, a ninth resistor, a sixth field-effect transistor, and a tenth resistor. The first terminal of the fifth capacitor serves as the first terminal of the fourth switched capacitor assembly. The first terminal of the ninth resistor is used to connect to the fifth control voltage; The gate of the sixth field-effect transistor is connected to the second terminal of the ninth resistor, the drain of the sixth field-effect transistor is connected to the second terminal of the fifth capacitor, and the source of the sixth field-effect transistor serves as the second terminal of the fourth switched capacitor assembly. The two ends of the tenth resistor are respectively connected to the source and the drain of the sixth field-effect transistor.

[0016] Preferably, the low-noise amplifier further includes an eleventh resistor and a twelfth resistor; The input terminal of the power amplifier circuit is connected in series with the eleventh resistor and then connected to the first bias voltage. The gate of the fourth field-effect transistor is connected in series with the twelfth resistor and then connected to the second bias voltage.

[0017] Preferably, the low-noise amplifier includes a sixth capacitor and a fourth inductor; The input terminal of the power amplifier circuit is connected in series with the sixth capacitor and the fourth inductor, and then connected to the output terminal of the tunable input matching circuit.

[0018] Preferably, the power amplifier circuit includes a seventh field-effect transistor; the gate of the seventh field-effect transistor serves as the input terminal of the power amplifier circuit, the drain of the seventh field-effect transistor serves as the output terminal of the power amplifier circuit, and the source of the seventh field-effect transistor is grounded; The low-noise amplifier also includes a fifth inductor; the source of the power amplifier circuit is grounded after being connected in series with the fifth inductor.

[0019] In a second aspect, the present invention provides a radio frequency front-end module comprising a low-noise amplifier as described above.

[0020] Compared with related technologies, the low-noise amplifier of this invention designs a tunable input matching circuit to adjust its capacitance value according to the different frequency bands of the incoming RF signals, thereby generating or canceling harmonic suppression for RF signals of different frequency bands. This allows it to be compatible with RF signals of different frequency bands, such as covering the N77 and N79 bands. When applied to an RF front-end module, by adjusting the capacitance value of the tunable input matching circuit, it can suppress harmonics of the 5G Wi-Fi band when operating in the N77 band, and not suppress the 5G Wi-Fi band when operating in the N79 band, thus ensuring low noise and interference-free operation in the N77 band, while achieving high gain performance in the N79 band. For the LFEM module, when the N77 band has a high transmission rate and high transmission density, it can switch to the idle N79 band for transmission to improve data transmission efficiency. For the L-PAMiF module, only two low-noise amplifiers are needed to achieve dynamic changes in the combination of the N77 and N79 bands, which realizes the function of the discrete solution, ensures data transmission efficiency, and saves two low-noise amplifiers, two filters, and additional switching area. This not only results in a smaller architecture area and improved module integration, but also reduces module cost, and has low insertion loss and better noise figure. Attached Figure Description

[0021] The present invention will now be described in detail with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and more readily understood through the detailed description following the accompanying drawings. In the drawings: Figure 1 The schematic diagram is of the low-noise amplifier provided in Embodiment 1 of the present invention; Figure 2 The circuit diagram of the tunable input matching circuit of the low-noise amplifier provided in Embodiment 1 of the present invention is shown, wherein the fourth inductor and the sixth capacitor are connected. Figure 3 A circuit diagram of the output matching circuit of the low-noise amplifier provided in Embodiment 1 of the present invention; Figure 4 The simulation results of the input return loss of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N77 frequency band are shown in the figure. Figure 5 This is a simulation result diagram of the reverse isolation of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N77 frequency band; Figure 6 The gain simulation result diagram of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N77 frequency band is shown. Figure 7 The simulation result of the output return loss of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N77 frequency band is shown in the figure. Figure 8 The noise figure simulation results of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N77 frequency band are shown in the figure. Figure 9 The simulation results of the input return loss of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N79 frequency band are shown in the figure. Figure 10 This is a simulation result diagram of the reverse isolation of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N79 frequency band; Figure 11 The gain simulation results of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N79 frequency band are shown in the figure. Figure 12 The output return loss simulation result diagram of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N79 frequency band; Figure 13 The noise figure simulation results of the tunable input matching circuit provided in Embodiment 1 of the present invention operating in the N79 frequency band are shown in the figure. Figure 14 This is an architecture diagram of the LFEM module provided in Embodiment 2 of the present invention; Figure 15 This is an architecture diagram of the L-PAMiF module provided in Embodiment 2 of the present invention. Detailed Implementation

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] 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 some embodiments of the present invention, and not all embodiments. 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.

[0025] Example 1 This invention provides a low-noise amplifier 100, combined with... Figures 1 to 3 As shown, it includes a tunable input matching circuit 1, a power amplifier circuit 2, and an output matching circuit 3. The input terminal of the tunable input matching circuit 1 is used to receive the radio frequency signal RFIN; the tunable input matching circuit 1 is used to adjust its capacitance value according to the different frequency band ranges of the received radio frequency signals, so as to generate or cancel harmonic suppression for the radio frequency signals of different frequency band ranges.

[0026] The tunable input matching circuit 1 includes a first inductor L1, a control switch 11, a first switched capacitor assembly 12, and a second switched capacitor assembly 13.

[0027] The first end of the first inductor L1 serves as the input terminal of the tunable input matching circuit 1, and the second end of the first inductor L1 serves as the output terminal of the tunable input matching circuit 1.

[0028] The first terminal of the control switch 11 is connected to the first terminal of the first inductor L1, and the second terminal of the control switch 11 is connected to the second terminal of the first inductor L1.

[0029] like Figure 1 As shown, one design of the control switch 11 is a single-pole single-throw switch S1, with the common terminal of the single-pole single-throw switch S1 serving as the first terminal of the control switch 11, and the normally open terminal of the single-pole single-throw switch S1 serving as the second terminal of the control switch 11.

[0030] like Figure 2 As shown, another design of the control switch 11 includes a first resistor R1, a first field-effect transistor M1, and a second resistor R2.

[0031] The first terminal of the first resistor R1 is used to connect the first control voltage V1.

[0032] The gate of the first field-effect transistor M1 is connected to the second terminal of the first resistor R1. The source of the first field-effect transistor M1 serves as the first terminal of the control switch 11, and the drain of the first field-effect transistor M1 serves as the second terminal of the control switch 11.

[0033] The two ends of the second resistor R2 are connected to the source and drain of the first field-effect transistor M1, respectively.

[0034] The first terminal of the first switched capacitor assembly 12 is connected to the first terminal of the control switch 11, and the second terminal of the first switched capacitor assembly 12 is connected to the second terminal of the control switch 11; the first switched capacitor assembly 12 is used to control the conduction or de-conduction of its capacitor according to the radio frequency signal in different frequency band ranges.

[0035] like Figure 1 As shown, one design of the first switched capacitor assembly 12 is a first variable capacitor Ci1, with the first end of the first variable capacitor Ci1 serving as the first end of the first switched capacitor assembly 12, and the second end of the first variable capacitor Ci1 serving as the second end of the first switched capacitor assembly 12.

[0036] like Figure 2 As shown, another design of the first switched capacitor assembly 12 includes a third resistor R3, a second field-effect transistor M2, a fourth resistor R4, and a first capacitor C1.

[0037] The first terminal of the third resistor R3 is used to connect the second control voltage V2.

[0038] The gate of the second field-effect transistor M2 is connected to the second terminal of the third resistor R3, and the source of the second field-effect transistor M2 serves as the first terminal of the first switched capacitor assembly 12.

[0039] The two ends of the fourth resistor R4 are connected to the source and drain of the second field-effect transistor M2, respectively.

[0040] The first terminal of the first capacitor C1 is connected to the drain of the second field-effect transistor M2, and the second terminal of the first capacitor C1 serves as the second terminal of the first switched capacitor assembly 12.

[0041] The first terminal of the second switched capacitor assembly 13 is connected to the first terminal of the first inductor L1, and the second terminal of the second switched capacitor assembly 13 is grounded; the second switched capacitor assembly 13 is used to control the conduction or cutoff of its capacitor according to the radio frequency signal in different frequency band ranges.

[0042] like Figure 1 As shown, one design of the second switched capacitor assembly 13 is a second variable capacitor Ci2, with the first end of the second variable capacitor Ci2 serving as the first end of the second switched capacitor assembly 13, and the second end of the second variable capacitor Ci2 serving as the second end of the second switched capacitor assembly 13.

[0043] like Figure 2 As shown, another design of the second switched capacitor assembly 13 includes a second capacitor C2, a fifth resistor R5, a third field-effect transistor M3, and a sixth resistor R6.

[0044] The first terminal of the second capacitor C2 serves as the first terminal of the second switched capacitor assembly 13.

[0045] The first terminal of the fifth resistor R5 is used to connect the third control voltage V3.

[0046] The gate of the third field-effect transistor M3 is connected to the second terminal of the fifth resistor R5, the drain of the third field-effect transistor M3 is connected to the second terminal of the second capacitor C2, and the source of the third field-effect transistor M3 serves as the second terminal of the second switched capacitor assembly 13.

[0047] The two ends of the sixth resistor R6 are connected to the source and drain of the third field-effect transistor M3, respectively.

[0048] The input terminal of the power amplifier circuit 2 is connected to the output terminal of the tunable input matching circuit 1 and is used to connect the first bias voltage Vbias1.

[0049] The power amplifier circuit 2 includes a seventh field-effect transistor M7; the gate of the seventh field-effect transistor M7 serves as the input terminal of the power amplifier circuit 2, the drain of the seventh field-effect transistor M7 serves as the output terminal of the power amplifier circuit 2, and the source of the seventh field-effect transistor M7 is grounded.

[0050] The first input terminal of the output matching circuit 3 is connected to the output terminal of the power amplifier circuit 2, the second input terminal of the output matching circuit 3 is used to connect the working voltage VDD, and the output terminal of the output matching circuit 3 is used to output the radio frequency signal RUOUT.

[0051] The output matching circuit 3 includes a fourth field-effect transistor M4, a second inductor L2, a third inductor L3, a third capacitor C3, a third switched capacitor assembly 31, and a fourth switched capacitor assembly 32.

[0052] The source of the fourth field-effect transistor M4 serves as the first input terminal of the output matching circuit 3, and the gate of the fourth field-effect transistor M4 is used to connect the second bias voltage Vbias2. The fourth field-effect transistor M4 and the seventh field-effect transistor M7 have a common source and common gate structure.

[0053] The first terminal of the second inductor L2 is connected to the drain of the fourth field-effect transistor M4.

[0054] The first end of the third inductor L3 is connected to the second end of the second inductor L2. The second end of the third inductor L3 serves as the second input of the output matching circuit 3. The third inductor L3 and the second inductor L2 are coupled to each other, and the coupling coefficient is k.

[0055] The first terminal of the third capacitor C3 is connected to the second terminal of the second inductor L2, and the second terminal of the third capacitor C3 serves as the output terminal of the output matching circuit 3.

[0056] The first terminal of the third switched capacitor assembly 31 is connected to the drain of the fourth field-effect transistor M4, and the second terminal of the third switched capacitor assembly 31 is connected to the second terminal of the third capacitor C3; the third switched capacitor assembly 31 is used to control the conduction or cutoff of its capacitor according to the radio frequency signal in different frequency band ranges.

[0057] like Figure 1 As shown, one design of the third switched capacitor assembly 31 is a third variable capacitor Co3, with the first end of the third variable capacitor Co3 serving as the first end of the third switched capacitor assembly 31 and the second end of the third variable capacitor Co3 serving as the second end of the third switched capacitor assembly 31.

[0058] like Figure 3 As shown, another design of the third switched capacitor assembly 31 includes a fourth capacitor C4, a seventh resistor R7, a fifth field-effect transistor M5, and an eighth resistor R8.

[0059] The first terminal of the fourth capacitor C4 serves as the first terminal of the third switched capacitor assembly 31.

[0060] The first terminal of the seventh resistor R7 is used to connect the fourth control voltage V4.

[0061] The gate of the fifth field-effect transistor M5 is connected to the second terminal of the seventh resistor R7, the source of the fifth field-effect transistor M5 is connected to the second terminal of the fourth capacitor C4, and the drain of the fifth field-effect transistor M5 serves as the second terminal of the third switched capacitor assembly 31.

[0062] The two ends of the eighth resistor R8 are connected to the source and drain of the fifth field-effect transistor M5, respectively.

[0063] The first terminal of the fourth switched capacitor assembly 32 is connected to the second terminal of the third inductor L3, and the second terminal of the fourth switched capacitor assembly 32 is connected to the second terminal of the third capacitor C3; the fourth switched capacitor assembly 32 is used to control the conduction or cutoff of its capacitor according to the radio frequency signal in different frequency band ranges.

[0064] like Figure 1 As shown, one design of the fourth switched capacitor assembly 32 is a fourth variable capacitor Co4, with the first end of the fourth switched capacitor assembly 32 serving as the first end of the fourth switched capacitor assembly 32 and the second end of the fourth switched capacitor assembly 32 serving as the second end of the fourth switched capacitor assembly 32.

[0065] like Figure 3 As shown, another design of the fourth switched capacitor assembly 32 includes a fifth capacitor C5, a ninth resistor R9, a sixth field-effect transistor M6, and a tenth resistor R10.

[0066] The first terminal of the fifth capacitor C5 serves as the first terminal of the fourth switched capacitor assembly 32.

[0067] The first terminal of the ninth resistor R9 is used to connect the fifth control voltage V5.

[0068] The gate of the sixth field-effect transistor M6 is connected to the second terminal of the ninth resistor R9, the drain of the sixth field-effect transistor M6 is connected to the second terminal of the fifth capacitor C5, and the source of the sixth field-effect transistor M6 serves as the second terminal of the fourth switched capacitor assembly 32.

[0069] The two ends of the tenth resistor R10 are connected to the source and drain of the sixth field-effect transistor M6, respectively.

[0070] In this embodiment, the low-noise amplifier 100 also includes an eleventh resistor R11 and a twelfth resistor R12.

[0071] The input terminal of power amplifier circuit 2 is connected in series with the eleventh resistor R11 and then connected to the first bias voltage Vbias1; the gate of the fourth field-effect transistor M4 is connected in series with the twelfth resistor R12 and then connected to the second bias voltage Vbias2.

[0072] The low-noise amplifier 100 includes a sixth capacitor C6 and a fourth inductor L4; the input terminal of the power amplifier circuit 2 is connected in series with the sixth capacitor C6 and the fourth inductor L4 and then connected to the output terminal of the tunable input matching circuit 1.

[0073] The low-noise amplifier 100 also includes a fifth inductor L5; the source of the power amplifier circuit 2 is grounded after being connected in series with the fifth inductor L5.

[0074] The low-noise amplifier 100 in this embodiment is applied to an RF front-end module, such as an LFEM module or an L-PAMiF module, and is compatible with RF signals from two different frequency bands, N77 and N79.

[0075] When the N77 band is operating, the first control voltage V1 is low, the first field-effect transistor M1 is off or not conducting, the second control voltage V2 and the third control voltage V3 are both high, the second field-effect transistor M2 and the third field-effect transistor M3 are both conducting, the first capacitor C1 is included in the main structure of the tunable input matching circuit 1 and takes effect, the first capacitor C1, the first inductor L1 and the second capacitor C2 form a low-pass filter network, which essentially makes the tunable input matching circuit 1 form a low-pass filter network. At this time, a suppression point is formed in the 5G WiFi band, and its gain S21 cutoff frequency is near the 5G WiFi band. It can be seen that the gain S21 has a notch point, thus forming a suppression of the 5G WiFi band signal, which to a certain extent eliminates the interference from the 5G WiFi band when the low noise amplifier 100 is operating in the N77 band.

[0076] When the N79 band is working, since the in-band signal of the N79 band is too close to the 5G Wi-Fi band, it is not necessary to suppress the 5G Wi-Fi band signal when the N79 band is working. At this time, the second control voltage V2 and the third control voltage V3 are both low level, the second field-effect transistor M2 and the third field-effect transistor M3 are both off or not conducting, the first capacitor C1 and the second capacitor C2 are not effective. Although there is parasitic capacitance, it does not need to be considered here. The first control voltage V1 is high level, the first field-effect transistor M1 is conducting, and the path formed here makes the first inductor L1 short-circuited. The first inductor L1 is not effective, and the accessed radio frequency signal is directly output to the fourth inductor L4 and subsequent circuits through the first field-effect transistor M1.

[0077] Therefore, by controlling the high or low levels of the first control voltage V1, the second control voltage V2, and the third control voltage V3, independent control of the N77 and N79 frequency bands can be achieved. That is, when the N77 frequency band is working, the suppression of the 5G Wi-Fi frequency band is enabled, and when the N79 frequency band is working, the suppression of the 5G Wi-Fi frequency band is not enabled. Moreover, the entire control process can be achieved in the tunable input matching circuit 1.

[0078] The working principle of output matching circuit 3 is as follows: When the working voltage VDD is applied and the N79 frequency band is working, the RF signal amplified by the seventh field-effect transistor M7 is output from the drain of the fourth field-effect transistor M4, then through the intermediate node between the second inductor L2 and the third inductor L3, and finally through the third capacitor C3 to the next stage circuit. At the same time, the fourth control voltage V4 is low, the fifth field-effect transistor M5 is turned off or not conducting, and the fourth capacitor C4 does not participate in output matching circuit 3. Although it has parasitic capacitance, it does not dominate, so it is not considered. When the fifth control voltage V5 is high, the sixth field-effect transistor M6 is turned on, and the fifth capacitor C5 is effective. This can ensure the gain of the N79 frequency band and good output return loss S22.

[0079] When the N77 band is operating, the fourth control voltage V4 is high, the fifth field-effect transistor M5 is turned on, and the fourth capacitor C4 is active. The output matching circuit 3 adds the fourth capacitor C4 to the third capacitor C3, making the output return loss S22 of the N77 band better than when only the third capacitor C3 is active. When the fifth control voltage V5 is low, the sixth field-effect transistor M6 is turned off or not turned on, the fifth capacitor C5 is not active, and does not participate in the output matching circuit 3. Although there is parasitic capacitance, it is not dominant, so it is not considered.

[0080] Therefore, by controlling the high and low levels of the fourth control voltage V4 and the fifth control voltage V5, the capacitors in the output matching circuit 3 can be switched on or off to select either the fourth capacitor C4 or the fifth capacitor C5 to participate in the output matching circuit 3. This allows for precise matching of the output return loss S22 in the N77 and N79 frequency bands, ensuring high-gain output in the N77 and N79 frequency bands and achieving good output return loss S22. Furthermore, the output matching circuit 3 in this embodiment has a simple structure, does not occupy the layout area of ​​the low-noise amplifier 100, and can also reduce the cost of the low-noise amplifier 100.

[0081] The simulation results of the input return loss when the tunable input matching circuit 1 in this embodiment operates in the N77 frequency band are as follows: Figure 4 As shown, the simulation results of the reverse isolation are as follows: Figure 5 As shown, the simulation results of the gain are as follows: Figure 6 As shown, the simulation results of the output return loss are as follows: Figure 7 As shown, the noise figure simulation results are as follows: Figure 8 As shown. The simulation results of the input return loss when the tunable input matching circuit 1 in this embodiment operates in the N79 frequency band are as follows. Figure 9 As shown, the simulation results of the reverse isolation are as follows: Figure 10 As shown, the simulation results of the gain are as follows: Figure 11 As shown, the simulation results of the output return loss are as follows: Figure 12 As shown, the simulation results for the noise figure are as follows: Figure 13 As shown.

[0082] Compared with related technologies, the low-noise amplifier 100 of this embodiment designs the tunable input matching circuit 1 to adjust its capacitance value according to the different frequency band ranges of the incoming radio frequency signals, so as to generate or cancel harmonic suppression for radio frequency signals of different frequency band ranges. This makes it compatible with radio frequency signals of different frequency band ranges, such as covering the N77 band and the N79 band. When it is applied to the radio frequency front-end module, by adjusting the capacitance value of the tunable input matching circuit 1, it can suppress the harmonics of the 5G Wi-Fi band when the N77 band is working, and not suppress the 5G Wi-Fi band when the N79 band is working, so as to ensure low noise and interference-free operation when the N77 band is working, and achieve good performance with high gain when the N79 band is working. For the LFEM module, when the N77 band has a high transmission rate and high transmission density, it can switch to the idle N79 band for transmission to improve data transmission efficiency. For the L-PAMiF module, only two low-noise amplifiers 100 are needed to achieve dynamic changes in the combination of the N77 and N79 bands, which realizes the function of the discrete solution, ensures data transmission efficiency, and saves two low-noise amplifiers 100, two filters, and additional switching area. This not only results in a smaller architecture area and improved module integration, but also reduces module cost, and has low insertion loss and better noise figure.

[0083] Example 2 This embodiment provides a radio frequency front-end module, which includes the low-noise amplifier in Embodiment 1.

[0084] When the RF front-end module is an LFEM module 200, such as Figure 14 As shown, it includes two low-noise amplification paths, a first post-stage circuit 202, and a first interface module 203; wherein, each low-noise amplification path includes a low-noise amplifier 100 of Embodiment 1 and a first filter 201 connected in series with the low-noise amplifier 100, and the first post-stage circuit 202 is connected to the first filter 201; the first interface module 203 includes a power supply pin VIO, a serial data pin SDATA, a serial clock pin SCLK, and an address selection pin USID.

[0085] When the RF front-end module is an L-PAMiF module 300, such as Figure 15As shown, it includes a power amplification path, two low-noise amplification paths, a second post-stage circuit 304, and two second interface modules 305. The power amplification path includes a power amplifier 301 and a second filter 302 connected in series with the power amplifier 301. Each low-noise amplification path includes a low-noise amplifier 100 as described in Embodiment 1 and a third filter 303 connected in series with the low-noise amplifier 100. The second post-stage circuit 304 is connected to the second filter 302 and the third filter 303 respectively. The second interface module 305 is basically the same as the first interface module 203, and will not be described in detail here.

[0086] Since the RF front-end module in this embodiment includes the low-noise amplifier 100 in Embodiment 1, it can also achieve the same technical effect as the low-noise amplifier 100 in Embodiment 1, which will not be elaborated here.

[0087] It should be noted that the various embodiments described above with reference to the accompanying drawings are merely illustrative of the present invention and not intended to limit its scope. Those skilled in the art should understand that any modifications or equivalent substitutions made to the present invention without departing from its spirit and scope should be included within the scope of the present invention. Furthermore, unless the context otherwise requires, words appearing in the singular include those in the plural, and vice versa. Additionally, unless specifically stated otherwise, all or part of any embodiment may be used in conjunction with all or part of any other embodiment.

Claims

1. A low-noise amplifier, characterized in that, The low-noise amplifier includes a tunable input matching circuit, a power amplifier circuit, and an output matching circuit. The input terminal of the tunable input matching circuit is used to receive radio frequency signals; the tunable input matching circuit is used to adjust its capacitance value according to the radio frequency signals in different frequency bands to generate or cancel harmonic suppression for radio frequency signals in different frequency bands. The input terminal of the power amplifier circuit is connected to the output terminal of the tunable input matching circuit and is used to connect to the first bias voltage. The first input terminal of the output matching circuit is connected to the output terminal of the power amplifier circuit, the second input terminal of the output matching circuit is used to connect to the operating voltage, and the output terminal of the output matching circuit is used to output radio frequency signals. The tunable input matching circuit includes a first inductor, a control switch, a first switched capacitor assembly, and a second switched capacitor assembly. The first end of the first inductor serves as the input terminal of the tunable input matching circuit, and the second end of the first inductor serves as the output terminal of the tunable input matching circuit. The first terminal of the control switch is connected to the first terminal of the first inductor, and the second terminal of the control switch is connected to the second terminal of the first inductor. The first terminal of the first switched capacitor assembly is connected to the first terminal of the control switch, and the second terminal of the first switched capacitor assembly is connected to the second terminal of the control switch; the first switched capacitor assembly is used to control the conduction or de-conduction of its capacitor according to the radio frequency signal in different frequency bands. The first terminal of the second switched capacitor assembly is connected to the first terminal of the first inductor, and the second terminal of the second switched capacitor assembly is grounded; the second switched capacitor assembly is used to control the conduction or de-conduction of its capacitor according to the radio frequency signal in different frequency bands.

2. The low-noise amplifier as described in claim 1, characterized in that, The control switch is a single-pole single-throw switch; or, the control switch includes a first resistor, a first field-effect transistor, and a second resistor. The first end of the first resistor is used to connect to the first control voltage; The gate of the first field-effect transistor is connected to the second terminal of the first resistor, the source of the first field-effect transistor serves as the first terminal of the control switch, and the drain of the first field-effect transistor serves as the second terminal of the control switch. The two ends of the second resistor are respectively connected to the source and the drain of the first field-effect transistor.

3. The low-noise amplifier as described in claim 1, characterized in that, The first switched capacitor assembly is a first variable capacitor; or, the first switched capacitor assembly includes a third resistor, a second field-effect transistor, a fourth resistor, and a first capacitor. The first end of the third resistor is used to connect to the second control voltage; The gate of the second field-effect transistor is connected to the second terminal of the third resistor, and the source of the second field-effect transistor serves as the first terminal of the first switched capacitor assembly. The two ends of the fourth resistor are respectively connected to the source and the drain of the second field-effect transistor; The first terminal of the first capacitor is connected to the drain of the second field-effect transistor, and the second terminal of the first capacitor serves as the second terminal of the first switched capacitor assembly. The second switched capacitor assembly is a second variable capacitor; or, the second switched capacitor assembly includes a second capacitor, a fifth resistor, a third field-effect transistor, and a sixth resistor; The first terminal of the second capacitor serves as the first terminal of the second switched capacitor assembly; The first end of the fifth resistor is used to connect to the third control voltage; The gate of the third field-effect transistor is connected to the second terminal of the fifth resistor, the drain of the third field-effect transistor is connected to the second terminal of the second capacitor, and the source of the third field-effect transistor serves as the second terminal of the second switched capacitor assembly. The two ends of the sixth resistor are respectively connected to the source and the drain of the third field-effect transistor.

4. The low-noise amplifier as described in claim 1, characterized in that, The output matching circuit includes a fourth field-effect transistor, a second inductor, a third inductor, a third capacitor, a third switched capacitor assembly, and a fourth switched capacitor assembly. The source of the fourth field-effect transistor serves as the first input terminal of the output matching circuit, and the gate of the fourth field-effect transistor is used to connect to the second bias voltage. The first terminal of the second inductor is connected to the drain of the fourth field-effect transistor; The first end of the third inductor is connected to the second end of the second inductor, and the second end of the third inductor serves as the second input end of the output matching circuit; the third inductor and the second inductor are coupled to each other. The first terminal of the third capacitor is connected to the second terminal of the second inductor, and the second terminal of the third capacitor serves as the output terminal of the output matching circuit. The first terminal of the third switched capacitor assembly is connected to the drain of the fourth field-effect transistor, and the second terminal of the third switched capacitor assembly is connected to the second terminal of the third capacitor; the third switched capacitor assembly is used to control the conduction or cutoff of its capacitor according to the radio frequency signal in different frequency bands. The first terminal of the fourth switched capacitor assembly is connected to the second terminal of the third inductor, and the second terminal of the fourth switched capacitor assembly is connected to the second terminal of the third capacitor; the fourth switched capacitor assembly is used to control the conduction or de-conduction of its capacitor according to the radio frequency signal in different frequency bands.

5. The low-noise amplifier as described in claim 4, characterized in that, The third switched capacitor assembly is a third variable capacitor; or, the third switched capacitor assembly includes a fourth capacitor, a seventh resistor, a fifth field-effect transistor, and an eighth resistor. The first terminal of the fourth capacitor serves as the first terminal of the third switched capacitor assembly. The first terminal of the seventh resistor is used to connect to the fourth control voltage; The gate of the fifth field-effect transistor is connected to the second terminal of the seventh resistor, the source of the fifth field-effect transistor is connected to the second terminal of the fourth capacitor, and the drain of the fifth field-effect transistor serves as the second terminal of the third switched capacitor assembly. The two ends of the eighth resistor are respectively connected to the source and the drain of the fifth field-effect transistor; The fourth switched capacitor assembly is a fourth variable capacitor; or, the fourth switched capacitor assembly includes a fifth capacitor, a ninth resistor, a sixth field-effect transistor, and a tenth resistor. The first terminal of the fifth capacitor serves as the first terminal of the fourth switched capacitor assembly. The first terminal of the ninth resistor is used to connect to the fifth control voltage; The gate of the sixth field-effect transistor is connected to the second terminal of the ninth resistor, the drain of the sixth field-effect transistor is connected to the second terminal of the fifth capacitor, and the source of the sixth field-effect transistor serves as the second terminal of the fourth switched capacitor assembly. The two ends of the tenth resistor are respectively connected to the source and the drain of the sixth field-effect transistor.

6. The low-noise amplifier as described in claim 4, characterized in that, The low-noise amplifier also includes an eleventh resistor and a twelfth resistor; The input terminal of the power amplifier circuit is connected in series with the eleventh resistor and then connected to the first bias voltage. The gate of the fourth field-effect transistor is connected in series with the twelfth resistor and then connected to the second bias voltage.

7. The low-noise amplifier as claimed in claim 1, characterized in that, The low-noise amplifier includes a sixth capacitor and a fourth inductor; The input terminal of the power amplifier circuit is connected in series with the sixth capacitor and the fourth inductor, and then connected to the output terminal of the tunable input matching circuit.

8. The low-noise amplifier as described in claim 1, characterized in that, The power amplifier circuit includes a seventh field-effect transistor; the gate of the seventh field-effect transistor serves as the input terminal of the power amplifier circuit, the drain of the seventh field-effect transistor serves as the output terminal of the power amplifier circuit, and the source of the seventh field-effect transistor is grounded. The low-noise amplifier also includes a fifth inductor; the source of the power amplifier circuit is grounded after being connected in series with the fifth inductor.

9. A radio frequency front-end module, characterized in that, The radio frequency front-end module includes the low-noise amplifier as described in any one of claims 1 to 8.

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