Radio-frequency power amplifier and radio-frequency chip module

Abstract

The present invention relates to the technical field of radio frequency. Disclosed in the present invention are a radio-frequency power amplifier and a radio-frequency chip module. The radio-frequency power amplifier comprises a signal input end, an input matching circuit, a power amplifier, a bias circuit, and a signal output end, wherein the signal input end, the input matching circuit, the power amplifier and the signal output end are electrically connected in sequence; an input end of the bias circuit is connected to a reference voltage source, and an output end of the bias circuit is connected between the input matching circuit and the power amplifier; the bias circuit comprises a first resistor, a first triode, a second triode, a second resistor, a third triode, a third resistor, a first capacitor and a second capacitor; and a collector of the third triode is connected to a first end of the second capacitor, and an emitter of the third triode is connected to a second end of the second capacitor. The radio-frequency power amplifier in the present invention can increase output power, and can also effectively reduce power consumption and improve the efficiency.

Description

RF power amplifier and RF chip module Technical Field

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

[0002] With the development of 5G mobile communication technology and the widespread adoption of 5G mobile phones both domestically and internationally, requirements for 5G signal quality are increasing year by year, posing significant challenges to 5G chip design. The RF front-end (RFF), comprising the low-noise amplifier (LNA), power amplifier (PA), filters, switches, and antennas, is the module most impacting mobile communications. The PA is a crucial component. The PA amplifies weak output signals before transmitting them. Its performance directly determines signal quality, with performance indicators such as output power, efficiency, gain, linearity, operating bandwidth, and reflection coefficient all determined by the PA. Therefore, the question of how to improve 5G signal quality can be translated into how to enhance PA performance.

[0003] Improving 5G signal quality requires reducing PA output power distortion. The higher the PA's output power 1dB compression point (P1dB), the lower the signal distortion. A higher P1dB leads to higher PA power consumption, a conflict that is impossible to reconcile while maintaining efficiency. Currently, domestic and international PA design requirements require a balance between output power and power consumption, making efficiency improvements paramount.

[0004] The RF power amplifier of the related art includes a signal input terminal, an input matching terminal, a bias circuit network, a final amplifier, and a signal output terminal. The bias circuit can compensate for the voltage Vbe of the final amplifier when the final amplifier is operating in a high-power state, and can filter out the RF signal leaking from the final amplifier to the bias circuit network through a capacitor. However, the RF signal leaked from the bias circuit network passes through the emitter and base of the corresponding transistor, which will have a significant impact on the impedance on the collector of the transistor. The voltage swing of the collector on the transistor is determined by the impedance at that point, and the current size of the emitter of the transistor will be affected by the voltage swing of the collector on the transistor. The current fluctuation will cause the output power of the final amplifier, that is, the output power of the RF power amplifier, to decrease, especially at high frequencies. In the design of 5G RF power amplifiers with relatively high frequencies, the output power drop at high frequencies is a very serious problem, which will directly lead to a decrease in signal quality or an increase in power consumption, thereby reducing efficiency.

[0005] Summary of the Invention

[0006] The purpose of the embodiment of the present invention is to provide a radio frequency power amplifier, which adds a corresponding second capacitor in the bias circuit to solve the problem of high power consumption and low efficiency of the radio frequency signal output by the existing radio frequency power amplifier.

[0007] In order to solve the above technical problems, an embodiment of the present invention provides a radio frequency power amplifier, which includes a signal input terminal, an input matching circuit, a power amplifier, a bias circuit, and a signal output terminal; the signal input terminal, the input matching circuit, the power amplifier, and the signal output terminal are electrically connected in sequence, the input terminal of the bias circuit is connected to a reference voltage source, and the output terminal of the bias circuit is connected between the input matching circuit and the power amplifier;

[0008] The bias circuit includes a first resistor, a first transistor, a second transistor, a second resistor, a third transistor, a third resistor, a first capacitor, and a second capacitor; the emitter of the first transistor is connected in series with the first resistor and then grounded, the base of the first transistor is connected to the collector of the first transistor and is connected to the emitter of the second transistor;

[0009] The base of the second transistor is connected to the collector of the second transistor, the collector of the second transistor is connected to the first end of the second resistor, and the second end of the second resistor serves as the input end of the bias circuit; the base of the second transistor is also connected to the first end of the first capacitor and the base of the third transistor respectively, and the second end of the first capacitor is grounded;

[0010] The collector of the third transistor is used to connect to a battery voltage source, the emitter of the third transistor is connected to the first end of the third resistor, the second end of the third resistor serves as the output end of the bias circuit, the collector of the third transistor is also connected to the first end of the second capacitor, and the emitter of the third transistor is connected to the second end of the second capacitor.

[0011] Preferably, the RF power amplifier further includes a fourth resistor, a first end of the fourth resistor is connected to the emitter of the third transistor, and a second end of the fourth resistor is connected to the first end of the third resistor.

[0012] Preferably, the RF power amplifier further includes a third capacitor, a first end of the third capacitor is connected between the third resistor and the fourth resistor, and a second end of the third capacitor is grounded.

[0013] Preferably, the RF power amplifier further includes a fourth capacitor, a first end of the fourth capacitor is connected to the collector of the third transistor, and a second end of the fourth capacitor is grounded.

[0014] Preferably, the power amplifier is a fourth transistor, the base of the fourth transistor is connected to the output end of the bias circuit, the output end of the bias circuit is used to provide a base bias current for the fourth transistor, the collector of the fourth transistor is used to connect to a power supply voltage source, the power supply voltage source is used to provide a collector current for the fourth transistor, the emitter of the fourth transistor is grounded, and the collector of the fourth transistor is also connected to the signal output end.

[0015] Preferably, the RF power amplifier further includes a first inductor, a first end of the first inductor is connected to the power supply voltage source, and a second end of the first inductor is connected to the collector of the fourth transistor.

[0016] Preferably, the input matching circuit is a fifth capacitor, a first end of the fifth capacitor is connected to the signal input end, and a second end of the fifth capacitor is connected to the base of the fourth transistor.

[0017] Preferably, the RF power amplifier further includes an output matching circuit, a first end of the output matching circuit is connected to the collector of the fourth transistor, and a second end of the output matching circuit is connected to the signal output end.

[0018] Preferably, the output matching circuit is a sixth capacitor, a first end of the sixth capacitor is connected to the collector of the fourth transistor, and a second end of the sixth capacitor is connected to the signal output end.

[0019] In a second aspect, an embodiment of the present invention provides a radio frequency chip module, wherein the radio frequency chip module includes the radio frequency power amplifier as described above.

[0020] Compared with the prior art, the radio frequency power amplifier in the present invention is characterized by electrically connecting a signal input terminal, an input matching circuit, a power amplifier, and a signal output terminal in sequence, connecting the input terminal of the bias circuit to a reference voltage source, and connecting the output terminal of the bias circuit to between the input matching circuit and the power amplifier; the emitter of the first transistor is connected to ground after being connected in series with a first resistor, the base of the first transistor is connected to the collector of the first transistor and is connected to the emitter of the second transistor; the base of the second transistor is connected to the collector of the second transistor, the collector of the second transistor is connected to the first end of the second resistor, and the second end of the second resistor serves as the bias circuit. The input terminal; the base of the second transistor is also connected to the first terminal of the first capacitor and the base of the third transistor respectively, and the second terminal of the first capacitor is grounded; the collector of the third transistor is used to connect to the battery voltage source, the emitter of the third transistor is connected to the first terminal of the third resistor, the second terminal of the third resistor serves as the output terminal of the bias circuit, the collector of the third transistor is also connected to the first terminal of the second capacitor, and the emitter of the third transistor is connected to the second terminal of the second capacitor; the RF signal leaked from the power amplifier to the third transistor is filtered out by the second capacitor, and the output power of the RF power amplifier can be increased; at the same time, power consumption is effectively reduced and efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0022] FIG1 is a circuit diagram of a radio frequency power amplifier provided in an embodiment of the present invention;

[0023] FIG2 is a graph showing the output power of a conventional radio frequency power amplifier;

[0024] FIG3 is an interpolation chart of FIG2 during gain compression;

[0025] FIG4 a is an interpolation chart 1 under the output power of FIG2 ;

[0026] FIG4 b is a second interpolation chart of the output power of FIG2 ;

[0027] FIG5 is an output power curve diagram of a radio frequency power amplifier without a fourth resistor provided in an embodiment of the present invention;

[0028] FIG6 is an interpolation chart of FIG5 during gain compression;

[0029] FIG7 a is an interpolation chart 1 under output power of FIG5 ;

[0030] FIG7 b is a second interpolation chart of the output power of FIG5 ;

[0031] FIG8 is a graph showing the output power of a radio frequency power amplifier according to an embodiment of the present invention;

[0032] FIG9 is an interpolation chart of FIG8 during gain compression;

[0033] FIG10 a is an interpolation chart 1 under output power of FIG8 ;

[0034] FIG10 b is a second interpolation chart of FIG8 under output power.

[0035] In the figure, 100, RF power amplifier, 1, signal input terminal, 2, input matching circuit, 3, power amplifier, 4, bias circuit, 5, output matching circuit, 6, signal output terminal. DETAILED DESCRIPTION

[0036] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] Example 1

[0038] 1 to 7 b, an embodiment of the present invention provides a radio frequency power amplifier 100, the radio frequency power amplifier 100 includes a signal input terminal 1 (RF in ), input matching circuit 2, power amplifier 3, bias circuit 4 and signal output terminal 6 (RF out ); the signal input terminal 1, the input matching circuit 2, the power amplifier 3 and the signal output terminal 6 are electrically connected in sequence, and the input terminal of the bias circuit 4 is connected to the reference voltage source V reg , the output end of the bias circuit 4 is connected between the input matching circuit 2 and the power amplifier 3. After the RF signal output from the signal input terminal 1 is inter-stage matched by the input matching circuit 2, it is output to the power amplifier 3 for power amplification and output to the corresponding load through the signal output terminal 6. Among them, the bias circuit 4 is used to output the corresponding bias current to the power amplifier 3, and at the same time, effectively filter out the RF signal leaked from the power amplifier 3. Furthermore, the circuit design of the overall RF power amplifier 100 is simple and does not occupy the layout area.

[0039] The bias circuit 4 includes a first resistor R1, a first transistor Q1, a second transistor Q2, a second resistor R2, a third transistor Q3, a third resistor R3, a first capacitor C1, and a second capacitor C2; the emitter of the first transistor Q1 is connected in series with the first resistor R1 and then grounded, the base of the first transistor Q1 is connected to the collector of the first transistor Q1 and is jointly connected to the emitter of the second transistor Q2; the base of the second transistor Q2 is connected to the collector of the second transistor Q2, the collector of the second transistor Q2 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 serves as the input end of the bias circuit 4; the base of the second transistor Q2 is also connected to the first end of the first capacitor C1 and the base of the third transistor Q3, respectively, and the second end of the first capacitor C1 is grounded; the collector of the third transistor Q3 is used to connect to the battery voltage source V bat The emitter of the third transistor Q3 is connected to the first end of the third resistor R3, the second end of the third resistor R3 serves as the output end of the bias circuit 4, the collector of the third transistor Q3 is also connected to the first end of the second capacitor C2, and the emitter of the third transistor Q3 is connected to the second end of the second capacitor C2.

[0040] Specifically, connecting the third transistor Q3 via the third resistor R3 can act as a ballast resistor for the output bias current, ensuring stable bias current output. The bias circuit 4 can compensate for the Vbe of the power amplifier 3 when the power amplifier 3 is operating in a high-power state, and can filter out the RF signal leaked from the power amplifier 3 to the third transistor Q3 through the first capacitor C1. By connecting the second capacitor C2 between the base and collector of the third transistor Q3, the RF signal can be further filtered out, improving the filtering effect of the RF signal. At the same time, the second capacitor C2 set on the third transistor Q3 can also play a role in increasing P1dB and is the most important capacitor in the entire circuit. Generally, the larger the capacitance value, the faster the output power curve rises, and the larger the P1dB, further increasing the capacitance value after reaching about 10pF has no obvious effect. At the same time, adding the second capacitor C2 can also effectively reduce power consumption and improve efficiency.

[0041] In this embodiment, the RF power amplifier 100 further includes a fourth resistor R4, a first end of which is connected to the emitter of the third transistor Q3, and a second end of which is connected to the first end of the third resistor R3. Since increasing output power increases power consumption, thereby preventing efficiency from being improved, the fourth resistor R4 is added and connected between the emitter of the third transistor Q3 and the third resistor R3. By utilizing the similar ballast effects of the fourth resistor R4 and the third resistor R3, increasing the fourth resistor R4 increases the output power curve, reduces P1dB, and reduces power consumption.

[0042] In this embodiment, the RF power amplifier 100 further includes a third capacitor C3 , a first end of the third capacitor C3 is connected between the third resistor R3 and the fourth resistor R4 , and a second end of the third capacitor C3 is grounded.

[0043] In this embodiment, the RF power amplifier 100 further includes a fourth capacitor C4 , a first end of the fourth capacitor C4 is connected to the collector of the third transistor Q3 , and a second end of the fourth capacitor C4 is grounded.

[0044] Specifically, by adding a second capacitor C2, a third capacitor C3, and a fourth capacitor C4 to the bias circuit 4, the RF signal leaking from the power amplifier 3 to the third transistor Q3 is first partially filtered out by the third capacitor C3, and then filtered out by the fourth capacitor C4 after passing through the second capacitor C2. The remaining RF signal passes through the third transistor Q3 and is filtered out by the first capacitor C1. The third capacitor C3 generally has a relatively small capacitance and can filter out low-frequency RF signals; the fourth capacitor C4 generally has a relatively large capacitance and can filter out high-frequency RF signals. In addition to filtering signals, the second capacitor C2 can also improve P1dB. Therefore, in the bias circuit 4, the three capacitors, namely the third capacitor C3, the second capacitor C2, and the fourth capacitor C4, are first introduced to increase P1dB, and then the fourth resistor R4 is introduced to slightly reduce P1dB. At this point, the power consumption can be quickly reduced to the original power consumption or even lower.

[0045] In this embodiment, the power amplifier 3 is a fourth transistor Q4. The base of the fourth transistor Q4 is connected to the output end of the bias circuit 4. The output end of the bias circuit 4 is used to provide a base bias current for the fourth transistor Q4. The collector of the fourth transistor Q4 is used to be connected to a power supply voltage source VCC. The power supply voltage source VCC is used to provide a collector current for the fourth transistor Q4. The emitter of the fourth transistor Q4 is grounded. The collector of the fourth transistor Q4 is also connected to the signal output end 6.

[0046] In this embodiment, the RF power amplifier 100 further includes a first inductor L1, wherein a first end of the first inductor L1 is connected to the power supply voltage source VCC, and a second end of the first inductor L1 is connected to the collector of the fourth transistor Q4. The power supply voltage source VCC provides a collector current to the fourth transistor Q4 through the first inductor L1.

[0047] In this embodiment, the input matching circuit 2 is a fifth capacitor C5 , a first end of the fifth capacitor C5 is connected to the signal input terminal 1 , and a second end of the fifth capacitor C5 is connected to the base of the fourth transistor Q4 .

[0048] In this embodiment, the RF power amplifier 100 further includes an output matching circuit 5 , a first end of the output matching circuit 5 is connected to the collector of the fourth transistor Q4 , and a second end of the output matching circuit 5 is connected to the signal output end 6 .

[0049] In this embodiment, the output matching circuit 5 is a sixth capacitor C6 , a first end of the sixth capacitor C6 is connected to the collector of the fourth transistor Q4 , and a second end of the sixth capacitor C6 is connected to the signal output terminal 6 .

[0050] In this embodiment, the corresponding simulation parameters of the RF power amplifier 100 include: Gain Compression, Fundamental Output Power, Transducer Power Gain, Power-Added Efficiency, DC Power Consumpt, High Supply Current, Thermal Dissipation, second harmonic, Third Harmonic, Fourth Harmonic, Fifth Harmonic, Input Return Loss, and Output Return Loss.

[0051] Please refer to Figures 2-4b. In the prior art, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fourth capacitor R4 are not added; at this time, the P1dB of the RF power amplifier 100 operating in the 5G n79 frequency band (4.4-5.0GHz) is 30.1 to 30.7dB, and the ICC (operating current) at the output linear power of 29dBm is 883.5 to 919.6mA.

[0052] Please refer to Figures 5-7b. When the fourth resistor R4 is not added to the bias circuit 4, the output power curve of the RF power amplifier 100 is shown in Figure 2. At this time, the P1dB of the RF power amplifier 100 operating in the 5G n79 frequency band (4.4-5.0GHz) is 30.3 to 31.2dB, and the ICC (operating current) at an output linear power of 29dBm is 930.8 to 983.0mA. Compared with the prior art, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are not added in the prior art. Therefore, the P1dB of the RF power amplifier 100 increases by 1.1, 0.5, and 0.1dB at 4.4, 4.7, and 5.0GHz, respectively, but the ICC increases by a maximum of 63.4mA, increasing power consumption.

[0053] Please refer to Figures 8-10b. When the fourth resistor R4 is added, the P1dB of the RF power amplifier 100 operating in the 5G n79 frequency band (4.4-5.0GHz) is 30.4 to 31.4dB, and the ICC (operating current) at the output linear power of 29dBm is 847.6 to 874.1mA. Compared with the prior art, the P1dB of the RF power amplifier 100 increases by 0.2, 0.7, and 0.9dB at 4.4, 4.7, and 5.0GHz, respectively, but the maximum ICC decreases by 45.5mA, and power consumption is reduced. That is, after using the bias circuit 4 of Figure 1, P1dB increases while power consumption decreases, thereby improving efficiency. Therefore, the RF power amplifier 100 is simple in design and does not occupy layout area, and can simultaneously increase P1dB and reduce power consumption, effectively improving efficiency.

[0054] Example 2

[0055] An embodiment of the present invention provides a radio frequency chip module, which includes the radio frequency power amplifier 100 of the first embodiment. The radio frequency chip module can improve output power and effectively reduce power consumption and improve efficiency.

[0056] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0057] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A radio frequency power amplifier, comprising a signal input terminal, an input matching circuit, a power amplifier, a bias circuit and a signal output terminal; the signal input terminal, the input matching circuit, the power amplifier and the signal output terminal are electrically connected in sequence, the input terminal of the bias circuit is connected to a reference voltage source, and the output terminal of the bias circuit is connected between the input matching circuit and the power amplifier; characterized in that: The bias circuit includes a first resistor, a first triode, a second triode, a second resistor, a third triode, a third resistor, a first capacitor and a second capacitor; the emitter of the first triode is connected in series with the first resistor and then grounded, and the base of the first triode is connected to the collector of the first triode and is connected to the emitter of the second triode; The base of the second transistor is connected to the collector of the second transistor, the collector of the second transistor is connected to the first end of the second resistor, and the second end of the second resistor serves as the input end of the bias circuit; the base of the second transistor is also connected to the first end of the first capacitor and the base of the third transistor respectively, and the second end of the first capacitor is grounded; The collector of the third transistor is used to connect to a battery voltage source, the emitter of the third transistor is connected to the first end of the third resistor, the second end of the third resistor serves as the output end of the bias circuit, the collector of the third transistor is also connected to the first end of the second capacitor, and the emitter of the third transistor is connected to the second end of the second capacitor.

2. The radio frequency power amplifier according to claim 1, characterized in that: The RF power amplifier further includes a fourth resistor, a first end of the fourth resistor is connected to the emitter of the third transistor, and a second end of the fourth resistor is connected to the first end of the third resistor.

3. The radio frequency power amplifier according to claim 2, characterized in that: The RF power amplifier further includes a third capacitor, a first end of the third capacitor is connected between the third resistor and the fourth resistor, and a second end of the third capacitor is grounded.

4. The radio frequency power amplifier according to claim 3, characterized in that: The radio frequency power amplifier further includes a fourth capacitor, a first end of the fourth capacitor is connected to the collector of the third transistor, and a second end of the fourth capacitor is grounded.

5. The radio frequency power amplifier according to claim 1, characterized in that: The power amplifier is a fourth transistor, the base of the fourth transistor is connected to the output end of the bias circuit, the output end of the bias circuit is used to provide a base bias current for the fourth transistor, the collector of the fourth transistor is used to connect to a power supply voltage source, the power supply voltage source is used to provide a collector current for the fourth transistor, the emitter of the fourth transistor is grounded, and the collector of the fourth transistor is also connected to the signal output end.

6. The radio frequency power amplifier according to claim 5, characterized in that: The RF power amplifier further includes a first inductor, a first end of the first inductor is connected to the power supply voltage source, and a second end of the first inductor is connected to the collector of the fourth transistor.

7. The radio frequency power amplifier according to claim 5, characterized in that: The input matching circuit is a fifth capacitor, a first end of the fifth capacitor is connected to the signal input end, and a second end of the fifth capacitor is connected to the base of the fourth transistor.

8. The radio frequency power amplifier according to claim 5, characterized in that: The radio frequency power amplifier further includes an output matching circuit, a first end of the output matching circuit is connected to the collector of the fourth transistor, and a second end of the output matching circuit is connected to the signal output end.

9. The radio frequency power amplifier according to claim 8, characterized in that: The output matching circuit is a sixth capacitor, a first end of the sixth capacitor is connected to the collector of the fourth transistor, and a second end of the sixth capacitor is connected to the signal output end.

10. A radio frequency chip module, characterized in that: The radio frequency chip module includes the radio frequency power amplifier as described in any one of claims 1-9.

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