High-frequency band radio frequency power amplification circuit and radio frequency signal input matching circuit

Abstract

The invention relates to a high-frequency band radio frequency power amplification circuit and a radio frequency signal input matching circuit, and relates to the technical field of radio frequency power circuits. The radio frequency signal input matching circuit comprises a third non-polar capacitor C3 and a first resistor R1 which are connected in series, one end of the third non-polar capacitor C1 is used for being connected with the radio frequency signal input end IN of the radio frequency power amplification circuit, the other end of the third non-polar capacitor C1 is connected with one end of the first resistor R1, and the other end of the first resistor R1 is used for being connected with the input end of the radio frequency power amplifier. Compared with the prior art, the conditions of saturation distortion and the like of the output radio-frequency signal and the radio-frequency power amplification circuit due to overlarge amplitude of the input signal are avoided, the interference of the reflection signal on the radio-frequency input signal is reduced, the circuit structure is simple, and the production cost and the labor cost are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency power circuits, and in particular to a high frequency band radio frequency power amplifier circuit and a radio frequency signal input matching circuit. Background Art

[0002] With the rapid development of wireless communication technology, RF circuits have become the core element for the efficient operation of various communication devices, such as mobile phones, base stations, and satellite communication terminals, and their importance has become increasingly prominent. As the "main battlefield" of RF circuits, high-frequency bands have also brought many difficult problems, such as complex impedance matching, strict requirements for signal strength control, and the risk of self-oscillation lurking like a "hidden mine", which poses many challenges to the stable and efficient operation of RF circuits.

[0003] Traditional RF circuit design usually uses passive matching networks to deal with impedance matching problems. Such networks often integrate a large number of inductors and non-polar capacitors, which is like building a sophisticated and complex "circuit maze". It not only takes up considerable physical space, resulting in bloated equipment, but also increases production costs due to its large number of components and complex wiring. The debugging process is even more cumbersome, complicated, time-consuming and labor-intensive. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide a high-frequency band RF power amplifier circuit and a RF signal input matching circuit, which can avoid saturation distortion of the output RF signal and the RF power amplifier circuit due to excessive input signal amplitude, reduce the interference of the reflected signal on the RF input signal, and have the characteristics of simple circuit structure.

[0005] In a first aspect, an embodiment provides a high-frequency band radio frequency power amplifier circuit, including a radio frequency power amplifier U and a matching circuit thereof, wherein the matching circuit includes a radio frequency signal input matching circuit, an amplifier switch matching circuit, a working voltage input matching circuit, and a radio frequency signal output matching circuit; The input signal matching circuit comprises a third non-polar capacitor C3 and a first resistor R1 connected in series, one end of the third non-polar capacitor C3 is connected to the RF signal input terminal IN of the RF power amplifier circuit, and the other end is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the input terminal of the RF power amplifier U; The amplifier switch matching circuit includes a first non-polar capacitor C1, one end of which is grounded GND, and the other end is respectively connected to the input end of the RF power amplifier U and the switch control power supply VGC; the switch control power supply VGC is used to control the RF power amplifier U to be turned on and off.

[0006] In one embodiment, based on the formula Set the resistance value of the first circuit R1; wherein R1 represents the resistance value of the first resistor R1, R L Indicates the load resistance value, R S Indicates the resistance value of the RF signal source.

[0007] In one embodiment, the resistance value of the first resistor R1 is R1=1Ω.

[0008] In one embodiment, the working voltage input matching circuit includes a second non-polar capacitor C2, one end of the second non-polar capacitor C2 is grounded GND, and the other end is respectively connected to the output end of the RF power amplifier U and the working power supply VCC; the working power supply VCC is used to provide a working voltage for the RF power amplifier U.

[0009] In one embodiment, the RF signal output matching circuit includes a fourth non-polar capacitor C4, one end of the fourth non-polar capacitor C4 is connected to the output end of the RF power amplifier U, and the other end is connected to the RF signal output end OUT of the RF power amplifier circuit.

[0010] In a second aspect, a method is provided in an embodiment.

[0011] In one embodiment, based on the formula Set the resistance value of the first circuit R1; wherein R1 represents the resistance value of the first resistor R1, R L Indicates the load resistance value, R S Indicates the resistance value of the RF signal source.

[0012] In one embodiment, the resistance value of the first resistor R1 is R1=1Ω.

[0013] The beneficial effects of the present invention are: Since a resistor is connected in series at the input end of the RF power amplifier, the setting of the first series resistor R1 avoids saturation distortion of the output RF signal and the RF power amplifier circuit due to excessive input signal amplitude, reduces the interference of the reflected signal on the RF input signal, and has a simple circuit structure, reducing production costs and labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a high-frequency band radio frequency power amplifier circuit according to an embodiment of the present application.

[0015] In the diagram: 01, input signal matching circuit, 02, amplifier switch matching circuit, 03, operating voltage input matching circuit, 04, RF signal output matching circuit. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0017] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0018] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0019] In view of the complex impedance matching problem in the current high-frequency band RF power amplifier circuit, a high-frequency band RF power amplifier circuit and a RF signal input matching circuit are provided in the embodiment of the present application. Since a resistor is connected in series at the input end of the RF power amplifier, the setting of the first series resistor R1 avoids saturation distortion of the output RF signal and the RF power amplifier circuit due to excessive input signal amplitude, reduces the interference of the reflected signal on the RF input signal, and the circuit structure is simple, reducing production costs and labor costs.

[0020] The present application provides a high frequency band radio frequency power amplifier circuit, please refer to Figure 1 , including a radio frequency power amplifier U and its matching circuit. The matching circuit includes a radio frequency signal input matching circuit 01, an amplifier switch matching circuit 02, a working voltage input matching circuit 03 and a radio frequency signal output matching circuit 04.

[0021] Among them, the input signal matching circuit 01 includes a third non-polar capacitor C3 and a first resistor R1 connected in series, one end of the third non-polar capacitor C3 is connected to the RF signal input terminal IN of the RF power amplifier circuit, and the other end is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the input terminal of the RF power amplifier U.

[0022] The amplifier switch matching circuit 02 includes a first non-polar capacitor C1, which is a filter capacitor of the switch control power supply VGC, one end of which is grounded GND, and the other end is respectively connected to the input end of the RF power amplifier U and the switch control power supply VGC; the switch control power supply VGC is used to control the opening and closing of the RF power amplifier U.

[0023] The third non-polar capacitor C3 is a coupling capacitor (blocking DC and passing AC). The applicant found in the study that: when the first resistor R1 is not connected in series, on the one hand, taking the operating frequency of the RF power amplifier circuit at 3GHz to 6GHz and the input signal amplitude range of the amplifier being less than 20dBm as an example, when the signal at the RF signal input terminal IN is 21dBm (0.1W), the transistor at the output end of the RF power amplifier U will operate in a nonlinear region, and the signal at the final RF signal output terminal OUT will produce harmonic distortion, affecting the signal quality. On the other hand, when the input stage circuit (including the RF signal input terminal, the first non-polar capacitor C1, the third non-polar capacitor C3 and the switch control power supply VGC) does not match the characteristic impedance of the transmission line, the signal reflection will be more serious, resulting in a low signal amplification factor at the output stage of the RF power amplifier U, and even causing self-excitation in the entire circuit.

[0024] In view of this, we can connect a resistor in series at the input end of the RF power amplifier with a higher output signal amplitude (that is, high frequency band). On the one hand, taking the RF power amplifier circuit operating frequency of 3GHz to 6GHz, and the amplifier input signal amplitude range of less than 20dBm as an example, according to P=V 2 / R,V 2 =PR, after a resistor is connected in series, the total resistance at the input of the RF power amplifier is Ro+R1. At this time, I=V / (Ro+R1), and the power consumption of the series resistor is P1=I 2 R1, if R1 is 1Ω, when the input RF signal passes through the first resistor R1, the first resistor R1 will consume 2.55dBm, thereby reducing the signal amplitude from 21dBm to 18.45 dBm. Avoid saturation distortion of the output RF signal and RF power amplifier circuit due to excessive input signal amplitude. Wherein, P represents power, V represents voltage, R represents resistance, I represents current, P1 represents the power consumption of the first resistor R1, R1 represents the resistance value of the first resistor R1, and Ro represents the transmission line impedance of the RF signal input end.

[0025] On the other hand, assuming that the load resistance of the RF signal output terminal OUT before the first resistor R1 is connected in series is R L , then the load resistance before the first series resistor R1 is R L +R1, according to the reflection coefficient formula, the reflection coefficient d1 before the first resistor R1 is not connected in series = (R L -Ro) / (R L +Ro), the reflection coefficient d2 after the first resistor R1 is connected in series = (R L -Ro+R1) / (R L +Ro), then d1>d2. It can be seen that based on the first series resistor R1, the interference of the reflected signal on the RF input signal is reduced.

[0026] However, the applicant discovered during the research that for the first resistor R1, in the high-frequency band, due to the short wavelength of the signal, the transmission line effect is more obvious. If the first resistor R1 is too large, it will cause transmission absorption and post-oscillation or even mismatch of the entire circuit. If the first resistor R1 is too small, the above-mentioned effect achieved by the present application is not obvious. Therefore, the selection of the resistance value of the first resistor R1 becomes a technical difficulty.

[0027] In view of this, the applicant found in the study that the RF signal source of the RF signal input terminal IN and the load of the RF signal output terminal OUT are both purely resistive. Assuming that the resistance of the RF signal source is R S , then when the resistance of the signal source resistor R S Approaching the load resistance R L In order to make R S =R L , so as to better achieve circuit matching, the calculation formula of the first series resistor R1 can be expressed as , thereby calculating the resistance value R1 of the first resistor R1, and setting the first resistor R1 based on the calculated R1.

[0028] Therefore, in one embodiment, based on the formula Set the resistance value of the first circuit R1.

[0029] In one embodiment, taking the operating frequency of the RF power amplifier circuit as 3 GHz to 6 GHz, and the input signal amplitude range of the amplifier as less than 20 dBm, R S =49Ω, R L =51Ω, then we can get R1≈1Ω.

[0030] In one embodiment, the working voltage input matching circuit 03 includes a second non-polar capacitor C2. The second non-polar capacitor C2 is a filter capacitor for the working power supply VCC voltage, one end of which is grounded GND, and the other end is respectively connected to the output end of the RF power amplifier U and the working power supply VCC; the working power supply VCC is used to provide the RF power amplifier U with a working voltage.

[0031] In one embodiment, the RF signal output matching circuit 04 includes a fourth non-polar capacitor C4. The fourth non-polar capacitor C4 is a coupling capacitor (blocking DC and passing AC) on the RF power amplifier circuit, one end of which is connected to the output end of the RF power amplifier U, and the other end is connected to the RF signal output end OUT of the RF power amplifier circuit.

[0032] In the high-frequency band RF power amplifier circuit based on any of the above embodiments, the setting of the first series resistor R1 avoids saturation distortion of the output RF signal and the RF power amplifier circuit due to excessive input signal amplitude, reduces the interference of the reflected signal on the RF input signal, and has a simple circuit structure, reducing production costs and labor costs.

[0033] In one embodiment of the present application, a high-frequency band RF signal input matching circuit is provided, which can be used as a RF signal input matching circuit of a high-frequency band RF power amplifier circuit, and the RF signal input matching circuit includes a third non-polar capacitor C3 and a first resistor R1 connected in series. One end of the third non-polar capacitor C1 is used to connect to the RF signal input terminal IN of the RF power amplifier circuit, and the other end is connected to one end of the first resistor R1, and the other end of the first resistor R1 is used to connect to the input terminal of the RF power amplifier.

[0034] In one embodiment, based on the formula Set the resistance value of the first circuit R1; wherein R1 represents the resistance value of the first resistor R1, R L Indicates the load resistance value of the RF signal output terminal OUT, R S Indicates the resistance value of the RF signal source.

[0035] In one embodiment, the resistance value of the first resistor R1 is R1=1Ω.

[0036] In the high-frequency band RF signal input matching circuit based on any of the above embodiments, the setting of the first series resistor R1 avoids saturation distortion of the output RF signal and the RF power amplifier circuit due to excessive input signal amplitude, reduces the interference of the reflected signal on the RF input signal, and has a simple circuit structure, reducing production costs and labor costs.

[0037] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A high frequency band radio frequency power amplifier circuit, characterized in that: It includes a radio frequency power amplifier U and a matching circuit thereof, wherein the matching circuit includes a radio frequency signal input matching circuit, an amplifier switch matching circuit, a working voltage input matching circuit and a radio frequency signal output matching circuit; The input signal matching circuit comprises a third non-polar capacitor C3 and a first resistor R1 connected in series, one end of the third non-polar capacitor C3 is connected to the RF signal input terminal IN of the RF power amplifier circuit, and the other end is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the input terminal of the RF power amplifier U; The amplifier switch matching circuit includes a first non-polar capacitor C1, one end of which is grounded GND, and the other end is respectively connected to the input end of the RF power amplifier U and the switch control power supply VGC; the switch control power supply VGC is used to control the RF power amplifier U to be turned on and off.

2. The high frequency band radio frequency power amplifier circuit according to claim 1, characterized in that: Based on the formula Set the resistance value of the first circuit R1; wherein R1 represents the resistance value of the first resistor R1, R L Indicates the load resistance value, R S Indicates the resistance value of the RF signal source.

3. The high frequency band radio frequency power amplifier circuit according to claim 2, characterized in that: The resistance value of the first resistor R1 is R1=1Ω.

4. The high frequency band radio frequency power amplifier circuit according to claim 1, characterized in that: The working voltage input matching circuit includes a second non-polar capacitor C2, one end of which is grounded GND, and the other end is respectively connected to the output end of the RF power amplifier U and the working power supply VCC; the working power supply VCC is used to provide the RF power amplifier U with a working voltage.

5. The high frequency band radio frequency power amplifier circuit according to claim 1, characterized in that: The RF signal output matching circuit comprises a fourth non-polar capacitor C4, one end of which is connected to the output end of the RF power amplifier U, and the other end of which is connected to the RF signal output end OUT of the RF power amplifier circuit.

6. A high frequency band radio frequency signal input matching circuit, characterized in that: It includes a third non-polar capacitor C3 and a first resistor R1 connected in series, one end of the third non-polar capacitor C1 is used to connect to the RF signal input terminal IN of the RF power amplifier circuit, and the other end is connected to one end of the first resistor R1, and the other end of the first resistor R1 is used to connect to the input terminal of the RF power amplifier.

7. The high frequency band RF signal input matching circuit according to claim 6, characterized in that: Based on the formula Set the resistance value of the first circuit R1; wherein R1 represents the resistance value of the first resistor R1, R L Indicates the load resistance value of the RF signal output terminal OUT, R S Indicates the resistance value of the RF signal source.

8. The high frequency band radio frequency power amplifier circuit according to claim 7, characterized in that: The resistance value of the first resistor R1 is R1=1Ω.

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