A broadband noise-eliminating radio frequency low noise amplifier and radio frequency receiver

Abstract

This application provides a broadband denoising RF low-noise amplifier and an RF receiver. The amplifier includes: a broadband input matching and denoising circuit for achieving broadband RF input matching from the antenna to the amplifier; an interstage transformer matching circuit for transforming the input impedance of a subsequent fixed amplifier circuit to be conjugate with the output impedance of the broadband input matching and denoising circuit; a fixed amplifier circuit for amplifying the output signal of the broadband input matching and denoising circuit; and an output transformer matching circuit for transforming the input impedance of a subsequent mixer to be conjugate with the output impedance of the amplifier. The amplifier of this application can improve circuit gain and reduce noise.

Description

Technical Field

[0001] This application relates to the field of circuit technology, and in particular to a broadband noise-reducing radio frequency low-noise amplifier and a radio frequency receiver. Background Technology

[0002] Low-noise amplifiers (LNOA) are a crucial component of radio frequency (RF) receivers, directly determining the receiver's sensitivity and noise figure. With the development of broadband communication systems, there is a growing demand for LNOA to achieve increasingly wider bandwidths without sacrificing gain and noise figure. The design challenge of broadband LNOA lies in balancing bandwidth and the quality factor of the resonant circuit. A high quality factor circuit achieves higher gain and stronger noise suppression, but with limited bandwidth. Conversely, a low quality factor resonant network offers wider bandwidth but suffers from higher losses, reducing circuit gain and worsening circuit noise. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a broadband noise-reducing radio frequency low-noise amplifier and a radio frequency receiver.

[0004] To achieve the above objectives, this application provides a broadband noise-reducing radio frequency low-noise amplifier, comprising:

[0005] Wideband input matching and noise reduction circuitry is used to achieve RF wideband input matching from the antenna to the amplifier; Interstage transformer matching circuit, used to transform the input impedance of the subsequent fixed amplifier circuit to be conjugate with the output impedance of the broadband input matching and noise reduction circuit; A fixed amplifier circuit is used to amplify the output signal of the broadband input matching and denoising circuit; The output transformer matching circuit is used to transform the input impedance of the subsequent mixer to be conjugate with the output impedance of the amplifier.

[0006] Optionally, the broadband input matching and noise reduction circuit includes inductors L1, L2, L3, L4, capacitors C1, C2, C3, C4, and MOSFETs M1, M2, M3, M4. The antenna output is connected to one end of capacitor C1 and inductor L2 via inductor L1, while the other ends of capacitor C1 and inductor L2 are grounded. Signals are transmitted between inductors L2 and L3, between inductors L2 and L4, and between inductors L3 and L4 via electromagnetic coupling. Inductor L3 and capacitor C2 are connected in parallel between the gates of MOSFETs M1 and M3. The center tap of inductor L3 is connected to the bias voltage V. G1The sources of MOSFET M1 and inductors L4 are connected together. The source of MOSFET M3 is connected to one end of capacitor C3 and the other end of inductor L4. The center tap of inductor L4 is grounded. The other end of capacitor C3 is connected to the gate of MOSFET M1 and the other end of capacitor C4 is connected to the gate of MOSFET M3. The drain of MOSFET M1 is connected to the source of MOSFET M2. The gate of MOSFET M2 is connected to power supply VDD. The drain of MOSFET M2 is connected to the input terminal of the interstage transformer matching circuit. The drain of MOSFET M3 is connected to the source of MOSFET M4. The gate of MOSFET M4 is connected to power supply VDD. The drain of MOSFET M4 is connected to the input terminal of the interstage transformer matching circuit.

[0007] Optionally, RF broadband input matching can be achieved by adjusting the values ​​of the three inductors L2, L3, and L4, as well as the coupling coefficients between inductors L2 and L3, between inductors L2 and L4, and between inductors L3 and L4.

[0008] Optionally, the channel current thermal noise of MOSFETs M1 and M3 can be eliminated by adjusting the inductance values ​​of inductors L3 and L4, as well as the coupling coefficient between them.

[0009] Optionally, the interstage transformer matching circuit includes capacitors C5 and C6, and inductors L5 and L6. Capacitor C5 and inductor L5 are connected in parallel between the drains of MOSFETs M2 and M4. The center tap of inductor L5 is connected to the power supply VDD. Signals are transmitted between inductors L5 and L6 through electromagnetic coupling. The center tap of inductor L6 is connected to the bias voltage V. G2 Capacitor C6 and inductor L6 are connected in parallel between the input terminals of the fixed amplifier circuit.

[0010] Optionally, by adjusting the values ​​of capacitors C5 and C6, inductors L5 and L6, and the corresponding coupling coefficients, the conjugate matching between the fixed amplifier circuit and the broadband input matching and noise reduction circuit can be achieved.

[0011] Optionally, the fixed amplifier circuit includes MOSFETs M5, M6, M7, and M8, capacitor C6 and inductor L6 connected in parallel between the gates of MOSFETs M5 and M7, the sources of MOSFETs M5 and M7 grounded, the drains of MOSFETs M5 and M7 connected to the sources of MOSFETs M6 and M8 respectively, the gates of MOSFETs M6 and M8 connected to the power supply VDD, and the drains of MOSFETs M6 and M8 connected to the input terminal of the output transformer matching circuit.

[0012] Optionally, the output transformer matching circuit includes a capacitor C7, inductors L7 and L8. Capacitor C7 and inductor L7 are connected in parallel between the drains of MOSFETs M6 and M8. The center tap of inductor L7 is connected to the power supply VDD. Inductors L7 and L8 transmit signals via electromagnetic coupling. The center tap of inductor L8 is connected to the bias voltage VDD. MIX The two ends of inductor L8 are connected and serve as the output terminals of the amplifier.

[0013] Optionally, conjugate matching between the mixer and amplifier in the later stage can be achieved by adjusting the capacitance value of capacitor C7, the inductance values ​​of inductors L7 and L8, and the corresponding coupling coefficients.

[0014] This application also provides a radio frequency receiver, including the aforementioned broadband noise-reducing radio frequency low-noise amplifier.

[0015] As can be seen from the above description, the broadband noise-reducing RF low-noise amplifier and RF receiver provided in this application include: a broadband input matching and noise reduction circuit for achieving broadband RF input matching from the antenna to the amplifier; an interstage transformer matching circuit for transforming the input impedance of the subsequent fixed amplifier circuit to be conjugate with the output impedance of the broadband input matching and noise reduction circuit; a fixed amplifier circuit for amplifying the output signal of the broadband input matching and noise reduction circuit; and an output transformer matching circuit for transforming the input impedance of the subsequent mixer to be conjugate with the output impedance of the amplifier. The amplifier of this application can improve circuit gain and reduce noise. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a block diagram of the circuit module structure of an embodiment of this application; Figure 2 This is a schematic diagram of the circuit principle of an embodiment of this application; Figure 3 This is a schematic diagram showing the noise figure simulation results of the circuit in an embodiment of this application; Figure 4 This is a schematic diagram of the input matching simulation results of the circuit in an embodiment of this application; Figure 5 This is a schematic diagram illustrating the voltage gain simulation effect of the circuit in an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] like Figure 1 , 2 As shown, the broadband noise-reducing radio frequency low-noise amplifier provided in this application embodiment includes: a broadband input matching and noise reduction circuit 1, an interstage transformer matching circuit 2, a fixed amplifier circuit 3, and an output transformer matching circuit 4. Wideband input matching and noise reduction circuitry is used to achieve RF wideband input matching from the antenna to the amplifier; Interstage transformer matching circuit is used to transform the input impedance of the subsequent fixed amplifier circuit to the output impedance conjugate with the wideband input matching and noise reduction circuit; A fixed amplifier circuit is used to amplify the output signal of a wideband input matching and noise reduction circuit. The output transformer matching circuit is used to transform the input impedance of the subsequent mixer to be conjugate with the output impedance of the amplifier.

[0021] The broadband noise-reducing RF low-noise amplifier provided in this application embodiment utilizes a broadband input matching and noise reduction circuit to achieve input impedance matching from the antenna end to the amplifier (typically 50 ohms antenna impedance matching), achieving maximum power transfer. An interstage transformer matching circuit transforms the input impedance of the subsequent fixed amplifier circuit to be conjugate with the output impedance of the broadband input matching and noise reduction circuit, reducing power reflection caused by impedance mismatch at the output of the broadband input matching and noise reduction circuit and improving signal transmission efficiency. The fixed amplifier circuit adopts a cascode structure, utilizing the high output impedance characteristic of the cascode structure to provide a large voltage gain, amplifying the output signal of the broadband input matching and noise reduction circuit. The output transformer matching circuit is used to transform the input impedance of the subsequent mixer to be conjugate with the output impedance of the broadband noise-reducing RF low-noise amplifier circuit, achieving maximum power transfer between the low-noise amplifier and the subsequent mixer circuit.

[0022] like Figure 2 As shown, the broadband input matching and noise reduction circuit includes inductors L1, L2, L3, and L4; capacitors C1, C2, C3, and C4; and MOSFETs M1, M2, M3, and M4. The antenna output is connected to the circuit input. The input is connected to one end of capacitors C1 and L2 via inductor L1, while the other ends of capacitors C1 and L2 are grounded. The coupling coefficient between inductors L2 and L3 is k1, and they transmit signals through electromagnetic coupling. The coupling coefficient between inductors L2 and L4 is k2, and they transmit signals through electromagnetic coupling. The coupling coefficient between inductors L3 and L4 is k3. Inductor L3 and capacitor C2 are connected in parallel between the gates of MOSFETs M1 and M3. The center tap of inductor L3 is connected to the bias voltage V. G1 (Voltage value is 0.6V) are connected as follows: the source of MOSFET M1 is connected to one end of capacitor C3 and one end of inductor L4; the source of MOSFET M3 is connected to one end of capacitor C4 and the other end of inductor L4; the center tap of inductor L4 is grounded; the other end of capacitor C3 is connected to the gate of MOSFET M1; the other end of capacitor C4 is connected to the gate of MOSFET M3; the drain of MOSFET M1 is connected to the source of MOSFET M2; the gate of MOSFET M2 is connected to power supply VDD (voltage value is 1.2V); the drain of MOSFET M2 is connected to the input terminal of the interstage transformer matching circuit; the drain of MOSFET M3 is connected to the source of MOSFET M4; the gate of MOSFET M4 is connected to power supply VDD; and the drain of MOSFET M4 is connected to the input terminal of the interstage transformer matching circuit.

[0023] The RF low-noise amplifier in this embodiment operates at a frequency of 7-9.2 GHz. Wideband input matching and noise reduction circuitry achieves wideband matching within this range to maximize power transfer and optimize noise performance. Inductor L4 is a source degradation inductor, adjusting the input impedance to approximately 50 Ω without introducing additional noise. Wideband RF input matching of the low-noise amplifier is achieved by adjusting the values ​​of inductors L2, L3, and L4, as well as the coupling coefficients between inductors L2 and L3, between inductors L2 and L4, and between inductors L3 and L4. Meanwhile, by adjusting the inductance values ​​of inductors L3 and L4, as well as the coupling coefficient between them, the magnetic coupling between inductors L4 and L3 is used to couple the channel current thermal noise of MOSFETs M1 and M3 to their gates, and finally superimpose it at the drains of MOSFETs M1 and M3. This achieves broadband matching while eliminating the channel current thermal noise of MOSFETs M1 and M3, thus optimizing the noise performance of the overall circuit. MOSFETs M2 and M4 are used to increase the output resistance and improve the voltage gain of the overall circuit.

[0024] The interstage transformer matching circuit includes capacitors C5 and C6, and inductors L5 and L6. Capacitor C5 and inductor L5 are connected in parallel between the drains of MOSFETs M2 and M4. The center tap of inductor L5 is connected to the power supply VDD. The coupling coefficient between inductors L5 and L6 is k4, and they transmit signals through electromagnetic coupling. The center tap of inductor L6 is connected to the bias voltage V. G2 (Voltage value is 0.6V), capacitor C6 and inductor L6 are connected in parallel between the input terminals of the fixed amplifier circuit. By adjusting the values ​​of capacitors C5 and C6, inductors L5 and L6, and the coupling coefficient k4, the input impedance of the fixed amplifier circuit is transformed into the conjugate of the output impedance of the broadband input matching and denoising circuit. This achieves conjugate matching between the pre-stage broadband input matching and denoising circuit and the subsequent fixed amplifier circuit, reducing power transmission loss. Simultaneously, the inter-stage transformer matching circuit pushes the peak gain of the pre-stage broadband input matching and denoising circuit to higher frequencies.

[0025] The fixed amplifier circuit includes MOSFETs M5, M6, M7, and M8. Capacitor C6 and inductor L6 are connected in parallel between the gates of MOSFETs M5 and M7. The sources of MOSFETs M5 and M7 are grounded. The drains of MOSFETs M5 and M7 are connected to the sources of MOSFETs M6 and M8, respectively. The gates of MOSFETs M6 and M8 are connected to the power supply VDD. The drains of MOSFETs M6 and M8 are connected to the input terminal of the output transformer matching circuit.

[0026] The fixed amplifier circuit employs a cascaded common-source and common-gate amplifier. Through the cascading combination of common-source and common-gate stages, the common-source provides high transconductance for signal amplification, while the common-gate provides high output impedance, facilitating high-gain amplification. The common-gate MOSFETs (M6 and M8) also "clamp" the drain potential of the common-source MOSFETs (M5 and M7), significantly reducing voltage fluctuations between the drain and source of MOSFETs M5 and M7. The Miller effect caused by parasitic capacitance between the gate and drain of MOSFETs M5 and M7 is strongly suppressed, shifting the circuit poles upward and significantly expanding the bandwidth. Simultaneously, the common-gate structure provides excellent reverse isolation, making it difficult for the output signal of the fixed amplifier circuit to couple back to the input, effectively avoiding high-frequency self-oscillation, improving circuit stability and anti-interference capability, and enhancing input-output isolation. The fixed amplifier circuit further amplifies the output signal of the broadband input matching and denoising circuits.

[0027] The output transformer matching circuit includes capacitor C7, inductors L7 and L8. Capacitor C7 and inductor L7 are connected in parallel between the drains of MOSFETs M6 and M8. The center tap of inductor L7 is connected to the power supply VDD. The coupling coefficient between inductors L7 and L8 is k5. They transmit signals through electromagnetic coupling. The center tap of inductor L8 is connected to the bias voltage VDD. MIX (Voltage value is 0.8V) are connected together, and the two ends of inductor L8 serve as the output terminals of the amplifier.

[0028] In RF transceiver systems, a mixer is typically connected after the low-noise amplifier. By adjusting the values ​​of capacitor C7, inductors L7 and L8, and coupling coefficient k5, the input impedance of the mixer circuit is transformed into the conjugate of the output impedance of the broadband denoising RF low-noise amplifier. This achieves maximum power transfer between the broadband denoising RF low-noise amplifier and the mixer circuit, reducing power loss due to reflections. Simultaneously, by using an output transformer matching circuit, the peak gain of the pre-amplifier circuit is adjusted to the low-frequency range. Combined with the broadband input matching and the high-frequency peak gain of the denoising circuit, the entire broadband denoising RF low-noise amplifier circuit can achieve high gain over a wide frequency range.

[0029] The broadband noise-reducing RF low-noise amplifier provided in this application employs source degradation technology in the broadband input matching and noise reduction circuit section. It utilizes a source degradation inductor to adjust the input impedance to approximately 50Ω without introducing additional noise, thus expanding the operating bandwidth. Furthermore, a three-coupling transformer technique (inductors L2, L3, and L4) transforms the input impedance of the low-noise amplifier to 50Ω, achieving broadband matching. Simultaneously, the three-coupling transformer couples the channel current thermal noise of MOSFETs M1 and M3 in the broadband input matching and noise reduction circuit to the drain for superposition and elimination, optimizing the overall circuit noise performance and reducing the noise figure. The active section of the entire low-noise amplifier circuit adopts a common-source, common-gate structure, significantly improving voltage gain while enhancing reverse isolation and expanding the operating bandwidth. By utilizing interstage transformer matching circuits and output transformer matching circuits, the gain resonant peak is pushed to high and low frequencies respectively, achieving broadband high gain without introducing additional power consumption.

[0030] like Figure 3-5 As shown, the broadband noise-reducing RF low-noise amplifier provided in this embodiment can achieve a noise figure of 3.9dB, an input impedance matching degree of 3dB, a bandwidth of 7-9.2 GHz, and a maximum voltage gain of 28.8dB.

[0031] This application also provides a radio frequency receiver, including the broadband noise-reducing radio frequency low-noise amplifier as described above.

[0032] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0033] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this disclosure, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0034] Although this disclosure has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0035] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this disclosure.

Claims

1. A broadband noise-reducing radio frequency low-noise amplifier, characterized in that, include: Wideband input matching and noise reduction circuitry is used to achieve RF wideband input matching from the antenna to the amplifier; Interstage transformer matching circuit, used to transform the input impedance of the subsequent fixed amplifier circuit to be conjugate with the output impedance of the broadband input matching and noise reduction circuit; A fixed amplifier circuit is used to amplify the output signal of the broadband input matching and denoising circuit; The output transformer matching circuit is used to transform the input impedance of the subsequent mixer to be conjugate with the output impedance of the amplifier.

2. The wideband, denoised, RF, low noise amplifier of claim 1, wherein, The broadband input matching and noise reduction circuit includes inductors L1, L2, L3, L4, capacitors C1, C2, C3, C4, and MOSFETs M1, M2, M3, M4. The antenna output is connected to one end of capacitor C1 and inductor L2 via inductor L1, while the other ends of capacitor C1 and inductor L2 are grounded. Signals are transmitted between inductors L2 and L3, between inductors L2 and L4, and between inductors L3 and L4 via electromagnetic coupling. Inductor L3 and capacitor C2 are connected in parallel between the gates of MOSFETs M1 and M3. The center tap of inductor L3 is connected to the bias voltage V. G1 The sources of MOSFET M1 and inductors L4 are connected together. The source of MOSFET M3 is connected to one end of capacitor C3 and the other end of inductor L4. The center tap of inductor L4 is grounded. The other end of capacitor C3 is connected to the gate of MOSFET M1 and the other end of capacitor C4 is connected to the gate of MOSFET M3. The drain of MOSFET M1 is connected to the source of MOSFET M2. The gate of MOSFET M2 is connected to power supply VDD. The drain of MOSFET M2 is connected to the input terminal of the interstage transformer matching circuit. The drain of MOSFET M3 is connected to the source of MOSFET M4. The gate of MOSFET M4 is connected to power supply VDD. The drain of MOSFET M4 is connected to the input terminal of the interstage transformer matching circuit.

3. The broadband noise-reducing radio frequency low-noise amplifier according to claim 2, characterized in that, By adjusting the values ​​of the three inductors L2, L3, and L4, and by adjusting the coupling coefficients between inductors L2 and L3, between inductors L2 and L4, and between inductors L3 and L4, RF broadband input matching can be achieved.

4. The broadband noise-reducing radio frequency low-noise amplifier according to claim 2, characterized in that, By adjusting the inductance values ​​of L3 and L4, as well as the coupling coefficient between them, the channel current thermal noise of MOSFETs M1 and M3 can be eliminated.

5. The wideband, denoised, RF, low noise amplifier of claim 2, wherein, The interstage transformer matching circuit includes capacitors C5 and C6, and inductors L5 and L6. Capacitor C5 and inductor L5 are connected in parallel between the drains of MOSFETs M2 and M4. The center tap of inductor L5 is connected to the power supply VDD. Signals are transmitted between inductors L5 and L6 through electromagnetic coupling. The center tap of inductor L6 is connected to the bias voltage V. G2 Capacitor C6 and inductor L6 are connected in parallel between the input terminals of the fixed amplifier circuit.

6. The broadband noise-reducing radio frequency low-noise amplifier according to claim 5, characterized in that, By adjusting the values ​​of capacitors C5 and C6, inductors L5 and L6, and the corresponding coupling coefficients, conjugate matching between the fixed amplifier circuit and the broadband input matching and noise reduction circuit can be achieved.

7. The wideband, denoised, RF, low noise amplifier of claim 5, wherein, The fixed amplifier circuit includes MOSFETs M5, M6, M7, and M8. Capacitor C6 and inductor L6 are connected in parallel between the gates of MOSFETs M5 and M7. The sources of MOSFETs M5 and M7 are grounded. The drains of MOSFETs M5 and M7 are connected to the sources of MOSFETs M6 and M8, respectively. The gates of MOSFETs M6 and M8 are connected to the power supply VDD. The drains of MOSFETs M6 and M8 are connected to the input terminal of the output transformer matching circuit.

8. The wideband, denoising, low noise amplifier of claim 7, wherein, The output transformer matching circuit includes capacitor C7, inductors L7 and L8. Capacitor C7 and inductor L7 are connected in parallel between the drains of MOSFETs M6 and M8. The center tap of inductor L7 is connected to the power supply VDD. Signals are transmitted between inductors L7 and L8 through electromagnetic coupling. The center tap of inductor L8 is connected to the bias voltage VDD. MIX The two ends of inductor L8 are connected and serve as the output terminals of the amplifier.

9. The broadband noise-reducing RF low-noise amplifier according to claim 8, characterized in that, By adjusting the capacitance value of capacitor C7, the inductance values ​​of inductors L7 and L8, and the corresponding coupling coefficients, conjugate matching between the mixer and amplifier in the subsequent stage can be achieved.

10. A radio frequency receiver, characterized by Includes the broadband noise-reducing radio frequency low-noise amplifier as described in any one of claims 1-9.

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