Radio frequency power amplification circuit and radio frequency choke circuit

Abstract

The invention relates to a radio frequency power amplification circuit and a radio frequency choke circuit, and relates to the technical field of radio frequency power amplifiers, and the adopted radio frequency choke circuit comprises a first inductive circuit and a second inductive circuit which are connected in parallel; wherein the first inductance circuit comprises a first inductor L1 and a second inductor L2 which are connected in series, and the second inductance circuit comprises a third inductor L3. Compared with the prior art, along with the increase of the signal frequency, a capacitor equivalent to the first inductive circuit and the third inductor L3 are in parallel resonance, and the impedance amplitudes of the resonant frequency point and the equivalent circuit of the nearby frequency band are relatively large; therefore, a high impedance amplitude can be provided in a large bandwidth range to prevent radio frequency signals from entering a VDD power supply, and the bandwidth range of the choking effect is obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency power amplifiers, and in particular to a radio frequency power amplifier circuit and a radio frequency choke circuit. Background Art

[0002] The RF power amplifier circuit includes an RF power amplifier (PA) and its matching circuit, wherein the matching circuit includes an RF choke circuit. The function of the RF choke circuit is to provide a DC connection, connecting the drain power supply VDD of the RF power amplifier and the drain signal output terminal to power the drain of the RF power tube, and at the same time provide a larger impedance amplitude within the operating frequency band of the RF power amplifier to prevent the RF signal on the drain of the RF power tube from entering the VDD power supply, thereby preventing the RF signal on the drain of the power tube from interfering with the VDD power supply.

[0003] However, the bandwidth of traditional RF choke circuits is relatively small, and it is difficult to play a choking role within a larger bandwidth range. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide a radio frequency power amplifier circuit and a radio frequency choke circuit, which have the characteristics of being able to increase the bandwidth range of the choke action.

[0005] In a first aspect, an embodiment provides a radio frequency power amplifier circuit, including a radio frequency power amplifier T1 and a matching circuit thereof, wherein the matching circuit includes an input matching circuit IMN, an output matching circuit OMN, a gate bias circuit and a radio frequency choke circuit; wherein the gate signal input terminal of the radio frequency power amplifier T1 is respectively connected to the amplified signal input terminal IN through the input matching circuit IMN, and is connected to the gate power supply VGG through the gate bias circuit; the drain signal output terminal of the radio frequency power amplifier T1 is respectively connected to the amplified signal output terminal OUT through the output matching circuit OMN, and is connected to the drain power supply VDD through the radio frequency choke circuit; The radio frequency choke circuit includes a first inductance circuit and a second inductance circuit connected in parallel; the first inductance circuit includes a first inductance L1 and a second inductance L2 connected in series, and the second inductance circuit includes a third inductance L3.

[0006] In one embodiment, the first inductor L1 and the second inductor L2 are identical discrete inductors.

[0007] In one embodiment, the self-resonant frequencies of the first inductor L1 and the second inductor L2 use the central frequency of the operating frequency of the radio frequency power amplifier T1.

[0008] In one embodiment, the third inductor L3 is an inductor with a parasitic capacitance value less than 0.05 pF.

[0009] In a second aspect, an embodiment provides a radio frequency choke circuit, comprising a first inductance circuit and a second inductance circuit connected in parallel; the first inductance circuit comprises a first inductance L1 and a second inductance L2 connected in series, and the second inductance circuit comprises a third inductance L3.

[0010] In one embodiment, the first inductor L1 and the second inductor L2 are identical discrete inductors.

[0011] In one embodiment, the self-resonant frequencies of the first inductor L1 and the second inductor L2 are the center frequency of the operating frequency of the applied circuit.

[0012] In one embodiment, the third inductor L3 is an inductor with a parasitic capacitance value less than 0.05 pF.

[0013] The beneficial effects of the present invention are: Since the impedance of the equivalent circuit of the first inductor L1 and the second inductor L2 in series is capacitive after the signal frequency exceeds the self-resonant frequency, the series circuit of the first inductor L1 and the second inductor L2 can be equivalent to a capacitor after the signal frequency exceeds the self-resonant frequency of the first inductor L1 and the second inductor L2. As the signal frequency increases, the equivalent capacitor resonates in parallel with the third inductor L3. Since the impedance amplitude of the equivalent circuit of the resonant frequency point and the frequency band nearby is large, a high impedance amplitude can be provided within a larger bandwidth to choke the RF signal from entering the VDD power supply, significantly improving the range of the choke action bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of a traditional and commonly used radio frequency choke circuit structure; Figure 2 yes Figure 1 Schematic diagram of equivalent circuit structure of the circuit shown; Figure 3 is a schematic diagram of a radio frequency choke circuit structure according to an embodiment of the present application; Figure 4 yes Figure 3 Schematic diagram of equivalent circuit structure of the radio frequency choke circuit shown; Figure 5 yes Figure 3 A schematic diagram of an equivalent circuit structure after the operating signal frequency exceeds the self-resonant frequency in the RF choke circuit shown; Figure 6 It is a schematic diagram of the structure of a radio frequency power amplifier circuit according to an embodiment of the present application; Figure 7 yes Figure 3 The RF choke circuit shown is Figure 1The RF choke circuit shown is applied in the RF power amplifier circuit, and is a schematic diagram of the simulation effect of the impedance amplitude changing with the increase of the operating frequency.

[0015] In the figure: 01, the first inductor circuit, 02, the second inductor 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] To facilitate the description of the inventive concept of the present application, the RF choke technology is briefly described below.

[0020] Please refer to Figure 1 In a conventional RF choke circuit, only one separate inductor L4 is used to implement it. When used in a RF power amplifier circuit, one end of the separate inductor L4 is connected to the drain of the RF power amplifier (PA), and the other end is connected to the drain power supply of the RF power amplifier. The separate inductor L4 provides a large impedance amplitude within the operating frequency band of the RF power amplifier to prevent the RF signal on the drain of the RF power tube from entering the VDD power supply, thereby preventing the RF signal on the drain of the power tube from interfering with the VDD power supply.

[0021] However, the applicant found in his research that Figure 2 ,for Figure 1 The equivalent circuit of the RF choke circuit shown in the figure. The equivalent circuit includes a fifth inductor L5 and a fifth capacitor C5 connected in parallel, and the fifth capacitor C5 is a parasitic capacitor caused by the coupling between the inductor coils. Due to the existence of the parasitic capacitor C5 and its parallel connection with L5, the equivalent circuit will undergo parallel self-resonance at a certain frequency point. Although the impedance amplitude at the self-resonance point is particularly large, when the frequency exceeds the self-resonance frequency, the equivalent circuit appears capacitive, and the impedance amplitude decreases with increasing frequency. This results in the poor bandwidth characteristics of the conventional commonly used RF choke circuit, that is, the conventional commonly used RF choke circuit cannot provide a high impedance amplitude within a larger bandwidth range to suppress the RF signal on the drain of the RF power tube from entering the VDD power supply.

[0022] In view of this, an RF power amplifier circuit and an RF choke circuit are provided in an embodiment of the present application, and the RF choke circuit used includes a first inductance circuit and a second inductance circuit connected in parallel; wherein the first inductance circuit includes a first inductance L1 and a second inductance L2 connected in series, and the second inductance circuit includes a third inductance L3. Since the impedance of the equivalent circuits of the first inductance L1 and the second inductance L2 connected in series are respectively capacitive after the signal frequency exceeds the self-resonance frequency, after the signal frequency exceeds the self-resonance frequency of the first inductance L1 and the second inductance L2, the series circuit of the first inductance L1 and the second inductance L2 can be equivalent to a capacitor. As the signal frequency increases, the equivalent capacitor resonates in parallel with the third inductance L3. Since the impedance amplitudes of the equivalent circuits at the resonant frequency point and the frequency band nearby are large, a high impedance amplitude can be provided within a larger bandwidth range to choke the RF signal from entering the VDD power supply, significantly improving the range of the choke action bandwidth.

[0023] The radio frequency choke circuit is first described below.

[0024] Please refer to Figure 3 In one embodiment of the present application, a radio frequency choke circuit is provided, comprising a first inductance circuit 01 and a second inductance circuit 02 connected in parallel. The first inductance circuit 01 comprises a first inductance L1 and a second inductance L2 connected in series, and the second inductance circuit 02 comprises a third inductance L3.

[0025] Please refer to Figure 4 ,for Figure 3The equivalent circuit of the RF choke circuit shown in the figure, wherein the first inductor L1 can be equivalent to the inductor L11 and the capacitor C11 connected in parallel, and the second inductor L2 can be equivalent to the inductor L2 and the capacitor C22 connected in parallel. The capacitor C11 is the parasitic capacitance caused by the direct coupling of the coil of the first inductor L1, and the capacitor C22 is the parasitic capacitance caused by the direct coupling of the coil of the second inductor L2. The impedance of the equivalent circuit of each of the first inductor L1 and the second inductor L2 is capacitive after the working RF signal frequency exceeds the self-resonant frequency. Since it is capacitive, after the signal frequency exceeds the self-resonant frequency of the first inductor L1 and the second inductor L2, the series circuit of the first inductor L1 and the second inductor L2 can be equivalent to a capacitor C3.

[0026] Please refer to Figure 5 ,for Figure 3 In the RF choke circuit shown, the equivalent circuit after the working signal frequency exceeds the self-resonant frequency includes a third inductor L3 and a capacitor C3 connected in parallel. As the working signal frequency increases, the third inductor L3 and the capacitor C3 resonate in parallel. Since the impedance amplitude of the equivalent circuit at the resonant frequency point and the frequency band nearby is large, a high impedance amplitude can be provided within a larger bandwidth range to choke the RF signal from entering the power supply, which significantly improves the range of the choke action bandwidth.

[0027] In one embodiment, to achieve a better radio frequency choke effect, the first inductor L1 and the second inductor L2 are discrete inductors with the same inductance.

[0028] In one embodiment, in order to achieve a better working state, the self-resonant frequencies of the first inductor L1 and the second inductor L2 adopt the central frequency point of the working frequency of the applied circuit (the working circuit).

[0029] In one embodiment, to achieve a better parallel resonance effect, the third inductor L3 uses an inductor with a large inductance and low parasitic capacitance. In one embodiment, the third inductor L3 uses an inductor with a parasitic capacitance value less than 0.05 pF.

[0030] In one embodiment of the present application, a radio frequency power amplifier circuit is provided. Figure 6 The RF power amplifier circuit includes a RF power amplifier T1 and a matching circuit thereof. The matching circuit includes an input matching circuit IMN, an output matching circuit OMN, a gate bias circuit and a RF choke circuit. The gate signal input terminal of the RF power amplifier T1 is respectively connected to the amplified signal input terminal IN through the input matching circuit IMN, and is connected to the gate power supply VGG through the gate bias circuit; the drain signal output terminal of the RF power amplifier T1 is respectively connected to the amplified signal output terminal OUT through the output matching circuit OMN, and is connected to the drain power supply VDD through the RF choke circuit.

[0031] in, Figure 6 The radio frequency choke circuit in the radio frequency power amplifier circuit shown can adopt any one of the radio frequency choke circuits in the above embodiments.

[0032] Those skilled in the art will understand that Figure 6 The hardware structure of the radio frequency power amplifier circuit shown in the figure does not constitute a limitation on the radio frequency power amplifier circuit, and may include more circuit structures than shown in the figure, or combine certain circuit structures.

[0033] In one embodiment, the self-resonant frequency of the first inductor L1 and the second inductor L2 in the RF choke circuit adopts the central frequency of the RF power amplifier operating frequency. Since the impedance amplitude of the equivalent circuit of the resonant frequency and the frequency band nearby is large, a high impedance amplitude can be provided within a large bandwidth to prevent the RF signal in the RF amplifier circuit from entering the VDD power supply.

[0034] Please refer to Figure 7 ,for Figure 3 The RF choke circuit (the present application scheme) shown in Figure 1 The RF choke circuit (traditional solution) shown is used in the RF power amplifier circuit. As the operating frequency increases, the impedance amplitude changes. It can be seen that the impedance amplitude of the RF choke circuit of the present application can be maintained at a high state in the frequency band of 800MHz~1800MHz, and the bandwidth is 1000MHz. The traditional solution can only be in 1200MHz~1400MHz, and the bandwidth is only 200MHz. Therefore, the performance of the RF choke circuit of the present application is significantly better than the traditional solution, and the bandwidth range of the choke effect is improved.

[0035] 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 radio frequency power amplifier circuit, characterized in that: It includes a radio frequency power amplifier T1 and a matching circuit thereof, wherein the matching circuit includes an input matching circuit IMN, an output matching circuit OMN, a gate bias circuit and a radio frequency choke circuit; wherein the gate signal input terminal of the radio frequency power amplifier T1 is respectively connected to the amplified signal input terminal IN through the input matching circuit IMN, and is connected to the gate power supply VGG through the gate bias circuit; the drain signal output terminal of the radio frequency power amplifier T1 is respectively connected to the amplified signal output terminal OUT through the output matching circuit OMN, and is connected to the drain power supply VDD through the radio frequency choke circuit; The radio frequency choke circuit includes a first inductance circuit and a second inductance circuit connected in parallel; the first inductance circuit includes a first inductance L1 and a second inductance L2 connected in series, and the second inductance circuit includes a third inductance L3.

2. The radio frequency power amplifier circuit according to claim 1, characterized in that: The first inductor L1 and the second inductor L2 are identical discrete inductors.

3. The radio frequency power amplifier circuit according to claim 1, characterized in that: The self-resonant frequencies of the first inductor L1 and the second inductor L2 use the central frequency of the operating frequency of the radio frequency power amplifier T1.

4. The radio frequency power amplifier circuit according to claim 1, characterized in that: The third inductor L3 is an inductor with a parasitic capacitance value less than 0.05 pF.

5. A radio frequency choke circuit, characterized in that: It includes a first inductance circuit and a second inductance circuit connected in parallel; the first inductance circuit includes a first inductance L1 and a second inductance L2 connected in series, and the second inductance circuit includes a third inductance L3.

6. The radio frequency choke circuit according to claim 5, characterized in that: The first inductor L1 and the second inductor L2 are identical discrete inductors.

7. The radio frequency choke circuit according to claim 5, characterized in that: The self-resonant frequencies of the first inductor L1 and the second inductor L2 adopt the central frequency point of the operating frequency of the applied circuit.

8. The radio frequency choke circuit according to claim 5, characterized in that: The third inductor L3 is an inductor with a parasitic capacitance value less than 0.05 pF.

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