Tunable output matching circuit and power amplifier

Abstract

This invention relates to the field of wireless communication technology, and provides a tunable output matching circuit and a power amplifier. The circuit includes a first capacitor and a first inductor. A first terminal of the first inductor is used to receive a radio frequency (RF) signal, and a second terminal of the first inductor is connected to the first terminal of the first capacitor and is used to output the impedance-matched RF signal. The second terminal of the first capacitor is grounded. The tunable output matching circuit also includes a first tuning circuit and a second tuning circuit. The first tuning circuit is connected in parallel with the first inductor and is controlled to conduct or disconnect by a first external logic control circuit connected to it. The first tuning circuit is used to perform impedance matching tuning on the first inductor. The second tuning circuit is connected in parallel with the first capacitor and is controlled to conduct or disconnect by a second external logic control circuit connected to it. The second tuning circuit is used to perform impedance matching tuning on the first capacitor. The tunable output matching circuit of this invention can reduce losses and improve the bandwidth performance of the power amplifier.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a tunable output matching circuit and a power amplifier. Background Technology

[0002] In modern wireless communication, electronic countermeasures, radar, and measurement systems, signal complexity and the demand for information transmission rates are growing at an unprecedented rate. From early narrowband voice communication to today's applications supporting 5G / 6G, ultra-wideband radar, spectrum sensing, and software-defined radio, systems are placing higher demands on the performance of core RF front-end components, such as power amplifiers. Achieving broadband power amplifiers has become a crucial research direction and urgent challenge in the field of RF technology. To use a monolithic power amplifier to cover a wide frequency band, the load impedance should be kept near its optimal value throughout the operating frequency band. Using an output matching network with tunable matching elements can improve the impedance tuning range, thereby effectively increasing the power amplifier bandwidth. Traditionally, tunability is achieved by switching different components on and off; the matching elements in the output matching network can achieve this function.

[0003] Existing technology provides a relatively common adjustable inductor solution, such as Figure 1 As shown: Several parallel inductors L1 are set to appropriate inductance values, and the number of parallel inductors is controlled by switch SW1, thereby achieving the purpose of adjusting the inductance value.

[0004] However, existing broadband communications employ multiple power amplifiers optimized for each frequency band, with switches used to switch between them. This approach increases system complexity and cost, requires significant space, and introduces additional insertion losses due to the switches. Directly controlling the conduction or switching of parallel inductors via switches to improve the impedance tuning range of the output matching network also suffers from insertion losses, leading to a decrease in the inductor's quality factor (Q value). This, in turn, lowers the overall quality factor of the matching network and may degrade the power amplifier's bandwidth performance. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, this invention proposes a tunable output matching circuit to solve the problem of poor power amplifier bandwidth performance in existing tunable output matching circuits.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention provides a tunable output matching circuit, comprising a first capacitor and a first inductor. A first terminal of the first inductor is used to receive a radio frequency (RF) signal, and a second terminal of the first inductor is connected to the first terminal of the first capacitor and used to output the RF signal after impedance matching. The second terminal of the first capacitor is grounded. The tunable output matching circuit further includes a first tuning circuit and a second tuning circuit. The first tuning circuit is connected in parallel with the first inductor and is controlled to be turned on or off by a first external logic control circuit connected thereto. The first tuning circuit is used to perform impedance matching tuning on the first inductor. The second tuning circuit is connected in parallel with the first capacitor and is controlled to be turned on or off by a second external logic control circuit connected thereto. The second tuning circuit is used to perform impedance matching tuning on the first capacitor.

[0008] Preferably, the first tuning circuit includes a first choke inductor, a first diode, a second choke inductor, and a first tuning unit; The first end of the first choke inductor is used to connect to the power supply. The second end of the first choke inductor is connected to the positive terminal of the first diode and the first end of the first inductor. The negative terminal of the first diode is connected to the first end of the second choke inductor and the first end of the first tuning unit. The second end of the second choke inductor is used to connect to the first external logic control circuit. The second end of the first tuning unit is connected to the second end of the first inductor. The first external logic control circuit is used to generate a first control voltage to control the conduction and disconnection of the first tuning circuit; the first choke inductor is used to provide a DC bias voltage to the first diode and prevent the radio frequency signal from entering the power supply; the second choke inductor is used to isolate the first control voltage from the radio frequency signal; and the first tuning unit is used to achieve impedance tuning of the series branch. When the first control voltage is greater than or equal to the output voltage of the first diode, the first diode is turned on; when the first control voltage is less than the output voltage of the first diode, the first diode is turned off.

[0009] Preferably, the first tuning unit includes a second inductor and a second capacitor; the first end of the second inductor serves as the first end of the first tuning unit, the second end of the second inductor is connected to the first end of the second capacitor, and the second end of the second capacitor serves as the second end of the first tuning unit.

[0010] Preferably, the second tuning circuit includes a third choke inductor, a second diode, a fourth choke inductor, and a second tuning unit; The first end of the third choke inductor is used to connect to the power supply. The second end of the third choke inductor is connected to the positive terminal of the second diode and the first end of the first capacitor. The negative terminal of the second diode is connected to the first end of the fourth choke inductor and the first end of the second tuning unit. The second end of the fourth choke inductor is used to connect to the second external logic control circuit. The second end of the second tuning unit is connected to the second end of the first capacitor. The second external logic control circuit is used to generate a second control voltage to control the conduction and disconnection of the first tuning circuit; the third choke inductor is used to provide a DC bias voltage for the second diode and prevent the radio frequency signal from entering the power supply; the fourth choke inductor is used to isolate the second control voltage from the radio frequency signal; and the second tuning unit is used to achieve impedance tuning of the parallel branch. When the second control voltage is greater than or equal to the output voltage of the second diode, the second diode is turned on; when the second control voltage is less than the output voltage of the second diode, the second diode is turned off.

[0011] Preferably, the second tuning unit includes a third inductor and a third capacitor; the first end of the third inductor serves as the first end of the second tuning unit, the second end of the third inductor is connected to the first end of the third capacitor, and the second end of the third capacitor serves as the second end of the second tuning unit.

[0012] Secondly, embodiments of the present invention provide a power amplifier, the power amplifier including an input matching circuit, a power amplification circuit, and a tunable output matching circuit as described above, which are connected in sequence. The tunable output matching circuit is used to perform impedance matching on the radio frequency signal amplified by the power amplification circuit for different frequency bands.

[0013] Compared with related technologies, in the embodiments of the present invention, the first end of the first inductor is used to receive the radio frequency signal, and the second end of the first inductor is connected to the first end of the first capacitor and used to output the radio frequency signal after impedance matching. The second end of the first capacitor is grounded. The tunable output matching circuit also includes a first tuning circuit and a second tuning circuit. The first tuning circuit is connected in parallel with the first inductor and is controlled to be turned on or off by a first external logic control circuit connected to it. The first tuning circuit is used to achieve impedance matching tuning of the first inductor. The second tuning circuit is connected in parallel with the first capacitor and is controlled to be turned on or off by a second external logic control circuit connected to it. The second tuning circuit is used to achieve impedance matching tuning of the first capacitor. In this way, the on / off state of the series branch and the parallel branch is controlled by different control voltages, thereby adjusting the capacitance and inductance values ​​of the series branch and the parallel branch of the matching network. This allows for tunable matching network with a smaller area and cost, reduces overall loss, and effectively improves the bandwidth performance of the power amplifier. Attached Figure Description

[0014] 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 Circuit diagram of an adjustable inductor solution provided by the prior art; Figure 2 A circuit diagram of a tunable output matching circuit provided in an embodiment of the present invention; Figure 3 This is a block diagram of a power amplifier provided in an embodiment of the present invention.

[0015] Among them, 100 is a tunable output matching circuit, 1 is a first tuning circuit, 11 is a first tuning unit, 2 is a second tuning circuit, and 21 is a second tuning unit; 200. Power amplifier; 201. Input matching circuit; 202. Power amplifier circuit. Detailed Implementation

[0016] 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.

[0017] 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.

[0018] 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.

[0019] Example 1 Please see Figure 2As shown, this embodiment of the invention provides a tunable output matching circuit 100, which includes a first capacitor C1 and a first inductor L1. A first end of the first inductor L1 is used to receive a radio frequency (RF) signal, which is input through a signal input terminal (RFin). A second end of the first inductor L1 is connected to the first end of the first capacitor C1 and is used to receive the RF signal after output matching impedance. The second end of the first capacitor C1 is grounded, and the RF signal is output through a signal output terminal (RFout). The tunable output matching circuit 100 also includes a first tuning circuit 1 and a second tuning circuit 2. The first tuning circuit 1 is connected in parallel with the first inductor L1 and is controlled to be turned on or off by a first external logic control circuit connected to it. The first tuning circuit 1 is used to achieve impedance matching tuning of the first inductor L1. The second tuning circuit 2 is connected in parallel with the first capacitor C1 and is controlled to be turned on or off by a second external logic control circuit connected to it. The second tuning circuit 2 is used to achieve impedance matching tuning of the first capacitor C1. By controlling the on / off state of the series and parallel branches with different control voltages, the capacitance and inductance values ​​of the series and parallel branches of the matching network can be adjusted. This allows for tunable matching networks with a smaller area and lower cost, reducing overall losses and effectively improving the power amplifier's bandwidth performance.

[0020] In this embodiment, the first tuning circuit 1 includes a first choke inductor Choke1, a first diode PIN1, a second choke inductor Choke2, and a first tuning unit 11. The first terminal of the first choke inductor Choke1 is connected to the power supply VCC. The second terminal of the first choke inductor Choke1 is connected to the positive terminal of the first diode PIN1 and the first terminal of the first inductor L1. The negative terminal of the first diode PIN1 is connected to the first terminal of the second choke inductor Choke2 and the first terminal of the first tuning unit 11. The second terminal of the second choke inductor Choke2 is connected to the first external logic control circuit. The second terminal of the first tuning unit 11 is connected to the second terminal of the first inductor L1.

[0021] The first external logic control circuit generates a first control voltage VT1 to control the conduction and disconnection of the first tuning circuit 1. The first choke inductor Choke1 provides a DC bias voltage to the first diode PIN1 and prevents the radio frequency signal from entering the power supply VCC. The second choke inductor Choke2 isolates the first control voltage VT1 from the radio frequency signal. The first tuning unit 11 is used to achieve impedance tuning of the series branch. The first choke inductor Choke1, connected to the power supply VCC, provides a DC bias voltage to the first diode PIN1 while preventing the radio frequency signal from entering the power supply VCC, thus preventing the radio frequency energy from being absorbed by the power supply. The second choke inductor Choke2 isolates the first control voltage VT1 output by the first external logic control circuit from the radio frequency signal, avoiding radio frequency interference on the control line and ensuring the stability of the bias voltage of the first diode PIN1. The first tuning unit 11, in conjunction with the first inductor L1 of the main matching network, controls the on / off state of the first diode PIN1 to switch the connection state of the branch, thereby changing the equivalent capacitance value of the series branch and realizing the adjustable function of the matching network.

[0022] When the first control voltage VT1 is greater than or equal to the output voltage of the first diode PIN1, the first diode PIN1 is turned on; when the first control voltage VT1 is less than the output voltage of the first diode PIN1, the first diode PIN1 is turned off. By switching between the two states of the first diode PIN1, the matching state of the entire matching network is controlled, thereby realizing the adjustable function of the matching network.

[0023] In this embodiment, the first tuning unit 11 includes a second inductor L2 and a second capacitor C2. The first end of the second inductor L2 serves as the first end of the first tuning unit 11, and the second end of the second inductor L2 is connected to the first end of the second capacitor C2. The second end of the second capacitor C2 serves as the second end of the first tuning unit 11. The series resonant circuit formed by connecting the second inductor L2 and the second capacitor C2 in series is the core topology for realizing output matching and tuning functions. It utilizes the series resonant characteristics to filter the target operating frequency and suppress noise; it utilizes the inductive / capacitive impedance in the detuned state to compensate for the impedance difference between the source and the load, achieving conjugate matching and improving power transmission efficiency. By controlling the on / off state of the first diode PIN1, the capacitive inductance value of the series branch of the matching network is adjusted, thereby achieving tunability of the matching network and improving the power amplifier bandwidth performance.

[0024] In this embodiment, the second tuning circuit 2 includes a third choke inductor Choke3, a second diode PIN2, a fourth choke inductor Choke4, and a second tuning unit 21. The third choke inductor Choke3 is connected to the power supply VCC. The second terminal of the third choke inductor Choke3 is connected to the positive terminal of the second diode PIN2 and the first terminal of the first capacitor C1. The negative terminal of the second diode PIN2 is connected to the first terminal of the fourth choke inductor Choke4 and the first terminal of the second tuning unit 21. The second terminal of the fourth choke inductor Choke4 is connected to the second external logic control circuit. The second terminal of the second tuning unit 21 is connected to the second terminal of the first capacitor C1.

[0025] The second external logic control circuit generates a second control voltage VT2 to control the conduction and disconnection of the first tuning circuit. The third choke inductor Choke3 provides a DC bias voltage to the second diode PIN2 and prevents the radio frequency signal from entering the power supply VCC. The fourth choke inductor Choke4 isolates the second control voltage VT2 from the radio frequency signal. The second tuning unit 21 is used to achieve impedance tuning of the parallel branch. The third choke inductor Choke3, connected to the power supply VCC, provides a DC bias voltage to the second diode PIN2 while preventing the radio frequency signal from entering the power supply VCC, thus preventing the radio frequency energy from being absorbed by the power supply. The fourth choke inductor Choke4 isolates the second control voltage VT2 output by the second external logic control circuit from the radio frequency signal, avoiding radio frequency interference on the control line and ensuring the stability of the bias voltage of the second diode PIN2. The second tuning unit 21, in conjunction with the first capacitor C1 of the main matching network, controls the on / off state of the second diode PIN2 to switch the connection state of the parallel branch, thereby changing the equivalent capacitance value of the parallel branch and realizing the adjustable function of the matching network.

[0026] When the second control voltage VT2 is greater than or equal to the output voltage of the second diode PIN2, the second diode PIN2 is turned on; when the second control voltage VT2 is less than the output voltage of the second diode PIN2, the second diode PIN2 is turned off. By switching between the two states of the second diode PIN2, the matching state of the entire matching network is controlled, thereby realizing the adjustable function of the matching network.

[0027] In this embodiment, the second tuning unit 21 includes a third inductor L3 and a third capacitor C3. The first end of the third inductor L3 serves as the first end of the second tuning unit 21, and the second end of the third inductor L3 is connected to the first end of the third capacitor C3. The second end of the third capacitor C3 serves as the second end of the second tuning unit 21. The series resonant circuit formed by connecting the third inductor L3 and the third capacitor C3 in series is the core topology for realizing output matching and tuning functions. It utilizes the series resonant characteristics to filter the target operating frequency and suppress noise; it utilizes the inductive / capacitive impedance in the detuned state to compensate for the impedance difference between the source and the load, achieving conjugate matching and improving power transmission efficiency. By controlling the on / off state of the second diode PIN2, the capacitive inductance value of the parallel branch of the matching network is adjusted, thereby achieving tunability of the matching network and improving the power amplifier bandwidth performance.

[0028] In this embodiment, the matching state of the entire matching network is controlled by switching the two states of the first diode PIN1 and the second diode PIN2, thus achieving adjustable matching network functionality. In the design of a broadband power amplifier, the values ​​of the first control voltage VT1 and the second control voltage VT2 can be controlled separately for impedance requirements in different frequency bands, thereby achieving superior power amplifier performance over a wider bandwidth. This power amplifier performance includes output power, power gain, efficiency, and linearity.

[0029] Example 2 Please see Figure 3 As shown, this embodiment of the invention provides a power amplifier 200, which includes an input matching circuit 201, a power amplification circuit 202, and a tunable output matching circuit 100 as described above, all connected in sequence. The tunable output matching circuit 100 is used to perform impedance matching on the radio frequency signal amplified by the power amplification circuit 202 at different frequency bands. This power amplifier 200 produces the same technical effects as in Embodiment 1, and will not be described further here.

[0030] 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 tunable output matching circuit comprising a first capacitance and a first inductance, a first end of the first inductance being configured to access a radio frequency signal, a second end of the first inductance being connected to a first end of the first capacitance and configured to output the radio frequency signal after impedance matching, a second end of the first capacitance being connected to ground; characterized in that, The tunable output matching circuit further includes a first tuning circuit and a second tuning circuit. The first tuning circuit is connected in parallel with the first inductor and is controlled to be turned on or off by a first external logic control circuit connected to it. The first tuning circuit is used to achieve impedance matching tuning of the first inductor. The second tuning circuit is connected in parallel with the first capacitor and is controlled to be turned on or off by a second external logic control circuit connected to it. The second tuning circuit is used to achieve impedance matching tuning of the first capacitor. The first tuning circuit includes a first choke inductor, a first diode, a second choke inductor, and a first tuning unit; The first end of the first choke inductor is used to connect to the power supply. The second end of the first choke inductor is connected to the positive terminal of the first diode and the first end of the first inductor. The negative terminal of the first diode is connected to the first end of the second choke inductor and the first end of the first tuning unit. The second end of the second choke inductor is used to connect to the first external logic control circuit. The second end of the first tuning unit is connected to the second end of the first inductor. The first external logic control circuit is used to generate a first control voltage to control the conduction and disconnection of the first tuning circuit; the first choke inductor is used to provide a DC bias voltage to the first diode and prevent the radio frequency signal from entering the power supply; the second choke inductor is used to isolate the first control voltage from the radio frequency signal; and the first tuning unit is used to achieve impedance tuning of the series branch. When the first control voltage is greater than or equal to the output voltage of the first diode, the first diode is turned on; when the first control voltage is less than the output voltage of the first diode, the first diode is turned off.

2. The tunable output matching circuit according to claim 1, characterized in that, The first tuning unit includes a second inductor and a second capacitor; the first end of the second inductor serves as the first end of the first tuning unit, the second end of the second inductor is connected to the first end of the second capacitor, and the second end of the second capacitor serves as the second end of the first tuning unit.

3. The tunable output matching circuit according to claim 1, characterized in that, The second tuning circuit includes a third choke inductor, a second diode, a fourth choke inductor, and a second tuning unit; The first end of the third choke inductor is used to connect to the power supply. The second end of the third choke inductor is connected to the positive terminal of the second diode and the first end of the first capacitor. The negative terminal of the second diode is connected to the first end of the fourth choke inductor and the first end of the second tuning unit. The second end of the fourth choke inductor is used to connect to the second external logic control circuit. The second end of the second tuning unit is connected to the second end of the first capacitor. The second external logic control circuit is used to generate a second control voltage to control the conduction and disconnection of the first tuning circuit; the third choke inductor is used to provide a DC bias voltage for the second diode and prevent the radio frequency signal from entering the power supply; the fourth choke inductor is used to isolate the second control voltage from the radio frequency signal; and the second tuning unit is used to achieve impedance tuning of the parallel branch. When the second control voltage is greater than or equal to the output voltage of the second diode, the second diode is turned on; when the second control voltage is less than the output voltage of the second diode, the second diode is turned off.

4. The tunable output matching circuit according to claim 3, characterized in that, The second tuning unit includes a third inductor and a third capacitor; the first end of the third inductor serves as the first end of the second tuning unit, the second end of the third inductor is connected to the first end of the third capacitor, and the second end of the third capacitor serves as the second end of the second tuning unit.

5. A power amplifier, characterized in that, The power amplifier includes an input matching circuit, a power amplification circuit, and a tunable output matching circuit as described in any one of claims 1-4, which are connected in sequence. The tunable output matching circuit is used to perform impedance matching on the radio frequency signal amplified by the power amplification circuit at different frequency bands.

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