Output matching circuit, low-noise amplification circuit and radio frequency power amplifier module

Abstract

The utility model provides an output matching circuit, a low noise amplifier circuit and a radio frequency power amplifier module, the output matching circuit comprises a first capacitor, a first inductor, a second capacitor, a series resonance circuit and a second inductor; the input end of the series resonance circuit is connected to the power supply, and the output end of the series resonance circuit is connected to the second end of the second capacitor. The output matching circuit provided by the utility model can form a combined mode of parallel connection and series connection, so that the output matching circuit has higher bandwidth and out-of-band rejection, and the flatness in a passband is better.

Description

Technical Field

[0001] This utility model relates to the field of wireless communication technology, and in particular to an output matching circuit, a low-noise amplifier circuit, and an RF power amplifier module. Background Technology

[0002] Wideband low-noise amplifier circuits are an important component of the RF receiver front end. They need to provide high gain and low noise over a wide frequency band while suppressing out-of-band interference.

[0003] The matching circuit of a high-bandwidth low-noise amplifier circuit is mainly divided into an input matching circuit and an output matching circuit. The input matching circuit is used to efficiently transmit the signal received by the antenna to the input of the low-noise amplifier circuit. It typically needs to consider the antenna impedance, the input impedance of the low-noise amplifier, and the trade-off between noise and power matching. The output matching circuit is also a critical part of the design. It determines whether the amplifier can effectively transmit the amplified signal to subsequent circuits and ensure that the power and spectral characteristics of the output signal meet system requirements. It needs to consider the output impedance of the low-noise amplifier and the input impedance of the next stage circuit, and usually forms a conjugate match with the output impedance of the low-noise amplifier.

[0004] Existing low-noise amplifier circuits typically employ an LCCL connection, which uses two inductors and two capacitors connected in series and parallel. One capacitor (C) is then equivalently transformed into an LCtank circuit (capacitor-inductor series resonant circuit), meaning one capacitor is effectively transformed into an inductor and a capacitor connected in series. Alternatively, the other capacitor (C) can be equivalently transformed into an LCtrap circuit (capacitor-inductor parallel circuit), meaning the other capacitor is effectively transformed into an inductor and a capacitor connected in parallel, in order to achieve out-of-band rejection.

[0005] Although the above design can achieve out-of-band suppression, it can only achieve this effect if the existing bandwidth remains unchanged or even worsens, and the flatness within the passband is poor. Utility Model Content

[0006] To address the shortcomings of the existing technologies, this invention proposes an output matching circuit with high bandwidth, high out-of-band rejection, and better passband flatness, as well as a low-noise amplifier circuit and an RF power amplifier module.

[0007] To solve the above-mentioned technical problems, in a first aspect, the present invention provides an output matching circuit, which includes a first capacitor, a first inductor, a second capacitor, a series resonant circuit, and a second inductor.

[0008] The first terminal of the first capacitor serves as the input terminal of the output matching circuit, and is used to connect to the output terminal of the low-noise amplifier.

[0009] The first end of the first inductor is connected to the power supply, and the second end of the first inductor is connected to the first end of the first capacitor.

[0010] The first terminal of the second capacitor is connected to the power supply, and the second terminal of the second capacitor is connected to the second terminal of the first capacitor.

[0011] The input terminal of the series resonant circuit is connected to the power supply, and the output terminal of the series resonant circuit is connected to the second terminal of the second capacitor.

[0012] The first end of the second inductor is connected to the output end of the series resonant circuit, and the second end of the second inductor serves as the output end of the output matching circuit, which is used to connect to the next stage circuit.

[0013] Preferably, the series resonant circuit includes a third inductor and a third capacitor;

[0014] The first end of the third inductor serves as the input end of the series resonant circuit;

[0015] The first terminal of the third capacitor is connected to the third inductor, and the second terminal of the third capacitor serves as the output terminal of the series resonant circuit.

[0016] Secondly, this utility model provides a low-noise amplifier circuit, which includes a switching unit, a filter, an input matching circuit, a low-noise amplifier, and an output matching circuit as described above.

[0017] The first end of the switching unit is used to connect to the antenna, thereby enabling the channel for receiving signals to be turned on or off.

[0018] The input terminal of the filter is connected to the second terminal of the switching unit;

[0019] The input terminal of the input matching circuit is connected to the output terminal of the filter;

[0020] The first input terminal of the low-noise amplifier is connected to the output terminal of the input matching circuit and is used to connect to the first bias voltage. The second input terminal of the low-noise amplifier is used to connect to the second bias voltage. The ground terminal of the low-noise amplifier is grounded. The output terminal of the low-noise amplifier is connected to the input terminal of the output matching circuit.

[0021] Preferably, the low-noise amplifier includes a first field-effect transistor and a second field-effect transistor;

[0022] The gate of the first field-effect transistor serves as the first input terminal of the low-noise amplifier, and the source of the first field-effect transistor serves as the ground terminal of the low-noise amplifier.

[0023] The gate of the second field-effect transistor serves as the second input terminal of the low-noise amplifier, the source of the second field-effect transistor is connected to the drain of the first field-effect transistor, and the drain of the second field-effect transistor serves as the output terminal of the low-noise amplifier.

[0024] Preferably, the input matching circuit includes a fourth inductor, a fifth inductor, a fourth capacitor, and a sixth inductor;

[0025] The first end of the fourth inductor serves as the input terminal of the input matching circuit, and the second end of the fourth inductor serves as the output terminal of the input matching circuit.

[0026] The first terminal of the fifth inductor is connected to the first terminal of the fourth inductor, and the second terminal of the fifth inductor is grounded.

[0027] The first terminal of the fourth capacitor is connected to the second terminal of the fourth inductor, and the second terminal of the fourth capacitor is connected to the source of the first field-effect transistor.

[0028] The first end of the sixth inductor is connected to the source of the first field-effect transistor, and the second end of the sixth inductor is grounded.

[0029] Preferably, the low-noise amplifier circuit further includes a first resistor; a first end of the first resistor is connected to a first input terminal of the low-noise amplifier, and a second end of the first resistor is used to connect a first bias voltage.

[0030] Preferably, the low-noise amplifier circuit further includes a second resistor; the first end of the second resistor is connected to the output terminal of the output matching circuit, and the second end of the second resistor is grounded.

[0031] Thirdly, this utility model provides an RF power amplifier module, which includes the low-noise amplifier circuit described above.

[0032] Compared with the prior art, the output matching circuit in this utility model adds a series resonant circuit and limits the input terminal of the series resonant circuit to be connected to the power supply, and the output terminal of the series resonant circuit to be connected to the second terminal of the second capacitor. This allows a series and parallel combination mode to be formed in the output matching circuit, so that the output matching circuit has higher bandwidth and out-of-band rejection, and better flatness in the passband. Attached Figure Description

[0033] 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 easier to understand through the detailed description in conjunction with the following drawings. In the drawings:

[0034] Figure 1The circuit diagram of the low-noise amplifier circuit provided in the embodiment of this utility model. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0038] Example 1

[0039] This utility model embodiment provides an output matching circuit 100, such as Figure 1 As shown, it includes a first capacitor C1, a first inductor L1, a second capacitor C2, a series resonant circuit 101, and a second inductor L2.

[0040] The first terminal of the first capacitor C1 serves as the input terminal of the output matching circuit 100, and is used to connect to the output terminal of the low-noise amplifier 203.

[0041] The first terminal of the first inductor L1 is connected to the power supply VDD, and the second terminal of the first inductor L1 is connected to the first terminal of the first capacitor C1.

[0042] The first terminal of the second capacitor C2 is connected to the power supply VDD, and the second terminal of the second capacitor C2 is connected to the second terminal of the first capacitor C1.

[0043] The input terminal of the series resonance circuit 101 is used to connect to the power supply VDD, and the output terminal of the series resonance circuit 101 is connected to the second terminal of the second capacitor C2.

[0044] The first terminal of the second inductor L2 is connected to the output terminal of the series resonance circuit 101, and the second terminal of the second inductor L2 serves as the output terminal of the output matching circuit 100 for connecting to the next-stage circuit.

[0045] In this embodiment, the series resonance circuit 101 includes a third inductor L3 and a third capacitor C3.

[0046] The first terminal of the third inductor L3 serves as the input terminal of the series resonance circuit 101.

[0047] The first terminal of the third capacitor C3 is connected to the third inductor L3, and the second terminal of the third capacitor C3 serves as the output terminal of the series resonance circuit 101.

[0048] In this embodiment, the circuit principle of the output matching circuit 100 applied to the circuit after the low-noise amplifier circuit 200 is as follows: The operating frequency band of the low-noise amplifier circuit 200 has a certain frequency band width (BW) requirement at the center frequency f0, and when f < f0, the out-of-band rejection has a relatively high requirement. First, the series resonance of the third inductor L3 and the content of the third band forms a low-resistance region at the frequency to effectively suppress the signals near the out-of-band f1 signal. In the operating frequency band, its equivalent inductance (Lequal) forms a series resonance with the second capacitor C2, making form a high-resistance region, which can add a high-resistance region of another frequency on the basis of the parallel resonance frequency fs formed by the original first inductor L1, first capacitor C1, second inductor L2, and second capacitor C2 in the circuit, so that a relatively consistent high-resistance region is formed throughout the wideband from fs to f2, effectively improving the gain flatness within the entire band. By reasonably designing the values of fs and f2, the entire output matching circuit 100 can have both high out-of-band rejection and high bandwidth, and at the same time have good in-band flatness.

[0049] Compared with the prior art, the output matching circuit 100 in this embodiment forms a series-plus-parallel combination mode in the output matching circuit 100 by adding a series resonance circuit 101 and specifying that the input terminal of the series resonance circuit 101 is connected to the power supply VDD and the output terminal of the series resonance circuit 101 is connected to the second terminal of the second capacitor C2, so that the output matching circuit 100 has higher bandwidth and out-of-band rejection, and better flatness within the passband.

[0050] Embodiment Two

[0051] This embodiment provides a low-noise amplifier circuit 200, as Figure 1 As shown, it includes a switching unit, a filter, an input matching circuit 202, a low-noise amplifier 203, and the output matching circuit 100 in Embodiment 1.

[0052] The first end of the switching unit is used to connect to the antenna, thereby opening or closing the channel for receiving signals.

[0053] The input of the filter is connected to the second terminal of the switching unit.

[0054] The input terminal of the input matching circuit 202 is connected to the output terminal of the filter.

[0055] The first input terminal of the low-noise amplifier 203 is connected to the output terminal of the input matching circuit 202 and is used to connect the first bias voltage VBCS. The second input terminal of the low-noise amplifier 203 is used to connect the second bias voltage VBCG. The ground terminal of the low-noise amplifier 203 is grounded. The output terminal of the low-noise amplifier 203 is connected to the input terminal of the output matching circuit 100. The voltage values ​​of the first bias voltage VBCS and the second bias voltage VBCG are different.

[0056] In this embodiment, the low-noise amplifier 203 includes a first field-effect transistor M1 and a second field-effect transistor M2.

[0057] The gate of the first field-effect transistor M1 serves as the first input terminal of the low-noise amplifier 203, and the source of the first field-effect transistor M1 serves as the ground terminal of the low-noise amplifier 203.

[0058] The gate of the second field-effect transistor M2 serves as the second input terminal of the low-noise amplifier 203, the source of the second field-effect transistor M2 is connected to the drain of the first field-effect transistor M1, and the drain of the second field-effect transistor M2 serves as the output terminal of the low-noise amplifier 203.

[0059] The input matching circuit 202 includes a fourth inductor L4, a fifth inductor L5, a fourth capacitor Cgs, and a sixth inductor LS;

[0060] The first end of the fourth inductor L4 serves as the input terminal of the input matching circuit 202, and the second end of the fourth inductor L4 serves as the output terminal of the input matching circuit 202.

[0061] The first terminal of the fifth inductor L5 is connected to the first terminal of the fourth inductor L4, and the second terminal of the fifth inductor L5 is grounded.

[0062] The first terminal of the fourth capacitor Cgs is connected to the second terminal of the fourth inductor L4, and the second terminal of the fourth capacitor Cgs is connected to the source of the first field-effect transistor M1.

[0063] The first terminal of the sixth inductor LS is connected to the source of the first field-effect transistor M1, and the second terminal of the sixth inductor LS is grounded.

[0064] The low-noise amplifier circuit 200 also includes a first resistor R1; the first end of the first resistor R1 is connected to the first input terminal of the low-noise amplifier 203, and the second end of the first resistor R1 is used to connect to the first bias voltage VBCS.

[0065] The low-noise amplifier circuit 200 also includes a second resistor R2; the first end of the second resistor R2 is connected to the output terminal of the output matching circuit 100, and the second end of the second resistor R2 is grounded.

[0066] In this embodiment, the low-noise amplifier circuit 200 first receives a radio frequency (RF) signal through an external antenna and converts it into an electrical signal. The converted electrical signal is then input to the input terminal of the low-noise amplifier 203, passing through a switching unit and a filter. It then passes sequentially through a fifth inductor L5 and a fourth inductor L4 connected in parallel to ground. Finally, it resonates in series with the parasitic capacitance of the first field-effect transistor M1 and an external fourth capacitor Cgs, thereby achieving the desired operating frequency. The sixth inductor LS, connected to the source of the first field-effect transistor M1, can adjust the value of the real part of the input signal. By rationally designing the values ​​of the fourth inductor L4, the fifth inductor L5, the fourth capacitor Cgs, and the sixth inductor LS, the power of the input signal can be maximized while the noise power is minimized.

[0067] After the radio frequency signal is amplified by the first field-effect transistor M1 and the second field-effect transistor M2 in the low-noise amplifier 203, it is first powered by the first inductor L1 in the output matching circuit 100, and also participates in the matching. Then, the first capacitor C1 forms a DC blocking path, and then the series resonant circuit 101 formed by the third inductor L3 and the third capacitor C3 is connected in parallel. Finally, it is output through the second inductor L2 in series. The output terminal of the output matching circuit 100 is equivalent to the output terminal of the low-noise amplifier circuit 200, that is, the terd terminal.

[0068] Since the switching unit and filter are conventional devices, therefore... Figure 1 The two were combined into a single module 201.

[0069] Since the low-noise amplifier circuit 200 in this embodiment includes the output matching circuit 100 in the first embodiment above, it can also achieve the same technical effect as the output matching circuit 100 in the first embodiment above, and will not be described in detail here.

[0070] Example 3

[0071] This embodiment provides an RF power amplifier module, which includes the low-noise amplifier circuit 200 described in Embodiment 2. Since the RF power amplifier module in this embodiment includes the low-noise amplifier circuit 200 from Embodiment 2, it can also achieve the same technical effects as the low-noise amplifier circuit 200 in Embodiment 2, and will not be described in detail here.

[0072] It should be noted that the various embodiments described above with reference to the accompanying drawings are only 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 covered within the scope of the present invention. Furthermore, unless the context otherwise requires, singular terms include plural forms, 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. An output matching circuit, characterized in that, The output matching circuit includes a first capacitor, a first inductor, a second capacitor, a series resonant circuit, and a second inductor. The first terminal of the first capacitor serves as the input terminal of the output matching circuit, and is used to connect to the output terminal of the low-noise amplifier. The first end of the first inductor is connected to the power supply, and the second end of the first inductor is connected to the first end of the first capacitor. The first terminal of the second capacitor is connected to the power supply, and the second terminal of the second capacitor is connected to the second terminal of the first capacitor. The input terminal of the series resonant circuit is connected to the power supply, and the output terminal of the series resonant circuit is connected to the second terminal of the second capacitor. The first end of the second inductor is connected to the output terminal of the series resonant circuit, and the second end of the second inductor serves as the output terminal of the output matching circuit.

2. The output matching circuit as described in claim 1, characterized in that, The series resonant circuit includes a third inductor and a third capacitor; The first end of the third inductor serves as the input end of the series resonant circuit; The first terminal of the third capacitor is connected to the third inductor, and the second terminal of the third capacitor serves as the output terminal of the series resonant circuit.

3. A low-noise amplifier circuit, characterized in that, The low-noise amplifier circuit includes a switching unit, a filter, an input matching circuit, a low-noise amplifier, and an output matching circuit as described in claim 1 or 2. The first end of the switching unit is used to connect to the antenna to open or close the channel for receiving signals; The input terminal of the filter is connected to the second terminal of the switching unit; The input terminal of the input matching circuit is connected to the output terminal of the filter; The first input terminal of the low-noise amplifier is connected to the output terminal of the input matching circuit and is used to connect to the first bias voltage. The second input terminal of the low-noise amplifier is used to connect to the second bias voltage. The ground terminal of the low-noise amplifier is grounded. The output terminal of the low-noise amplifier is connected to the input terminal of the output matching circuit.

4. The low-noise amplifier circuit as described in claim 3, characterized in that, The low-noise amplifier includes a first field-effect transistor and a second field-effect transistor; The gate of the first field-effect transistor serves as the first input terminal of the low-noise amplifier, and the source of the first field-effect transistor serves as the ground terminal of the low-noise amplifier. The gate of the second field-effect transistor serves as the second input terminal of the low-noise amplifier, the source of the second field-effect transistor is connected to the drain of the first field-effect transistor, and the drain of the second field-effect transistor serves as the output terminal of the low-noise amplifier.

5. The low-noise amplifier circuit as described in claim 4, characterized in that, The input matching circuit includes a fourth inductor, a fifth inductor, a fourth capacitor, and a sixth inductor; The first end of the fourth inductor serves as the input terminal of the input matching circuit, and the second end of the fourth inductor serves as the output terminal of the input matching circuit. The first terminal of the fifth inductor is connected to the first terminal of the fourth inductor, and the second terminal of the fifth inductor is grounded. The first terminal of the fourth capacitor is connected to the second terminal of the fourth inductor, and the second terminal of the fourth capacitor is connected to the source of the first field-effect transistor. The first end of the sixth inductor is connected to the source of the first field-effect transistor, and the second end of the sixth inductor is grounded.

6. The low-noise amplifier circuit as described in claim 3, characterized in that, The low-noise amplifier circuit further includes a first resistor; the first end of the first resistor is connected to the first input terminal of the low-noise amplifier, and the second end of the first resistor is used to connect to a first bias voltage.

7. The low-noise amplifier circuit as described in claim 3, characterized in that, The low-noise amplifier circuit also includes a second resistor; the first end of the second resistor is connected to the output terminal of the output matching circuit, and the second end of the second resistor is grounded.

8. A radio frequency power amplifier module, characterized in that, The radio frequency power amplifier module includes the low-noise amplifier circuit as described in any one of claims 3 to 7.

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