WO2023040201A1

WO2023040201A1 - Radio-frequency power amplifier based on transformer matching network

Info

Publication number: WO2023040201A1
Application number: PCT/CN2022/078358
Authority: WO
Inventors: 谢志远; 赵宇霆; 郭嘉帅
Original assignee: 深圳飞骧科技股份有限公司
Priority date: 2021-09-16
Filing date: 2022-02-28
Publication date: 2023-03-23
Also published as: CN113556092A; CN113556092B

Abstract

Disclosed in the embodiments of the present invention is a radio-frequency power amplifier based on a transformer matching network. The radio-frequency power amplifier comprises an input matching network, a first-stage one-way amplification circuit, a first inter-stage matching network, a second-stage two-way amplification circuit, a second inter-stage matching network, a third-stage four-way amplification circuit and an output matching network, which are connected in sequence, wherein the first inter-stage matching network comprises a first transformer T1, the second inter-stage matching network comprises two second transformers T2, and the output matching network comprises two third transformers T3 and a fourth transformer T4. Transformer matching is utilized in both inter-stage matching and output matching, such that the layout area is effectively reduced, and no extra insertion loss is brought about; and the effect of optimizing the gain and the output return loss is significantly improved.

Description

A RF Power Amplifier Based on Transformer Matching Network

technical field

The invention relates to the technical field of power amplifiers, in particular to a radio frequency power amplifier based on a transformer matching network.

Background technique

As an important part of the transmitter, the RF power amplifier is located at the final stage of the transmitter. Its main function is to amplify the RF signal of the previous stage without distortion, and send the amplified signal from the antenna end. According to different application scenarios, the power amplifier needs to achieve different output power, linearity, efficiency, etc., and thus ensure that the signal can be received safely, effectively and reliably at an appropriate distance. The existing traditional impedance matching network can be composed of reactive components with lumped parameters (such as capacitors and inductors) or components with distributed parameters (such as microstrip lines and striplines). The typical matching network topology consists of "L", "Π" and "T" matching networks composed of lumped elements, as well as distributed transmission line matching networks.

In the N77 (3.3GHz-4.2GHz) frequency band of 5G mobile communication technology, because each component at high frequency will produce different degrees of parasitic effects, and in the case of high output power, a larger transistor emitter is required The total area means that multiple transistors need to be connected in parallel to achieve the output power required by the design. The parallel connection of multiple transistors will result in very small impedance values at the input and output terminals, and it will be very difficult to design matching. Whether it is an "L" type, "Π" type or "T" type matching network, multiple topologies are required. Structural cascading or adding reactive elements can be matched. However, adding cascaded topological structures or reactive components will not only increase the layout area, but also increase the cost of tape-out; each additional topology or reactive components will also increase the insertion loss of the matching structure, which will affect the overall The gain and output power of the circuit have a great influence.

Contents of the invention

Embodiments of the present invention provide a radio frequency power amplifier based on a transformer matching network, which can effectively reduce the layout area without causing additional insertion loss, and significantly improve the optimization effect of gain and output return loss.

In order to solve the above technical problems, the present invention provides a radio frequency power amplifier based on a transformer matching network on the one hand, including an input matching network connected in sequence, a first-stage single-channel amplifier circuit, a first-stage inter-stage matching network, a second-stage dual-channel Amplifying circuit, second-stage inter-stage matching network, third-stage four-way amplifying circuit and output matching network;

The first interstage matching network includes a first transformer T1, the second interstage matching network includes two second transformers T2, and the output matching network includes two third transformers T3 and a fourth transformer T4;

After the single-ended radio frequency input signal RFin passes through the input matching network and the first-stage single-channel amplifier circuit in sequence, it becomes two-channel differential signals through the first transformer T1 and outputs them to the second-stage dual-channel amplifier circuit respectively. The two input terminals of the two differential signals are respectively output to the two second transformers T2 after being amplified by the second-stage dual-channel amplifier circuit, and become four-channel differential signals through the two second transformers T2 The signals are respectively output to the four input terminals of the third-stage four-way amplifier circuit, and the four-way differential signals are respectively output to the two third transformers T3 after being amplified by the third-stage four-way amplifier circuit. The third transformer T3 becomes two differential signals and outputs them to the two input terminals of the fourth transformer T4 respectively, and the fourth transformer T4 synthesizes the two differential signals into one radio frequency output signal RFout for output.

Furthermore, the four input terminals of the third-stage four-way amplifier circuit form a group of two, and the two output terminals corresponding to the two input terminals of each group form a group of output terminals;

The two input ends of the first transformer T1 are respectively connected to the output end of the first-stage single-channel amplifier circuit and the power signal Vcc1, and the two output ends of the first transformer T1 are respectively connected to the second-stage dual amplifier circuit. The two input terminals of the two-way amplifying circuit are connected; the two second transformers T2 correspond to the two output terminals of the second-stage dual amplifying circuit respectively, and one input terminal of each of the second transformer T2 It is connected to the corresponding output end of the second-stage dual-channel amplifier circuit, the other input end of the second transformer T2 is connected to the power signal Vcc2, and the two output ends of each second transformer T2 are respectively connected to the The two input ends of the same group of the third-stage four-way amplifying circuit are connected; the two input ends of each of the third transformer T3 are respectively connected with the two output ends of the same group of the third-stage four-way amplifying circuit, and each Two output terminals of the third transformer T3 are respectively connected to an input terminal of the fourth transformer T4 and a ground terminal, one output terminal of the fourth transformer T4 is used to output the radio frequency output signal RFout, and the other output end grounded.

Furthermore, the first-stage single-channel amplifying circuit includes a first transistor Q1, the second-stage dual-channel amplifying circuit includes two second transistors Q2, and the third-stage four-channel amplifying circuit includes four fourth Three transistors Q3, the base and collector of the first transistor Q1 correspond to the input and output of the first-stage single-channel amplifier circuit, and the bases of the two second transistors Q2 correspond to the first transistor Q2 The two input terminals of the two-stage dual-channel amplifier circuit, the collectors of the two second transistors Q2 correspond to the two output terminals of the second-stage dual-channel amplifier circuit, and the bases of the four third transistor Q3 The poles correspond to the four input terminals of the third-stage four-way amplifier circuit, and the collectors of the four third transistors Q3 correspond to the four output terminals of the third-stage four-way amplifier circuit. The emitters of the transistor Q1, the second transistor Q2 and the third transistor Q3 are all grounded.

Furthermore, the radio frequency power amplifier further includes a negative feedback network connected between the base and the collector of the first transistor Q1, the negative feedback network includes a first resistor R1 and a first capacitor C1 connected in series;

The RF power amplifier further includes a second resistor R2, which is connected in series between the input matching network and the base of the first transistor Q1, and connected in parallel with the negative feedback network.

Furthermore, the input matching network includes inductors L1, L2 and capacitors C2, C3, one end of the capacitor C2 is connected in parallel with one end of the inductor L1 and is used to input the single-ended radio frequency input signal RFin, and the other end of the capacitor C2 One end is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the base of the first transistor Q1, the other end of the inductor L1 is grounded, and one end of the inductor L2 is connected to the capacitors C2 and C3 Between, the other end of the inductor L2 is grounded.

Furthermore, the first transformer T1 and the second transformer T2 are symmetrical interwound transformers, the third transformer T3 and the fourth transformer T4 are laminated step-up transformers, and the symmetrical interwound transformer and the The turns ratio of the primary coil to the secondary coil of the laminated step-up transformer is between 2:1 and 1:1.

Furthermore, the laminated step-up transformer includes first to third metal layers stacked in sequence, each metal layer has two connection terminals, and an insulating layer is arranged between adjacent two metal layers, so There is a through hole on the insulating layer, wherein the first metal layer and the third metal layer are secondary coils, and one end of the first metal layer is connected to one end of the third metal layer through the through hole, and the second metal layer Layer is the primary coil.

Furthermore, each metal layer is ring-shaped, thereby defining a middle area surrounded by the metal layer, the through hole is located on the middle area, one end of the first metal layer and the second One end of the three metal layers is bent and extended to the middle area, so as to be connected through the through hole in the middle area.

Furthermore, the bent portion at one end of the first metal layer overlaps with the bent portion at one end of the third metal layer in the stacking direction.

Furthermore, projections of the bent portion at one end of the first metal layer and the bent portion at one end of the third metal layer in the stacking direction are on a straight line.

Beneficial effects: The RF power amplifier based on the transformer matching network of the present invention includes an input matching network, a first-stage amplification circuit, a first-stage inter-stage matching network, a second-stage amplifying circuit, a second-stage inter-stage matching network, and a third-stage amplification circuit and an output matching network; the first-stage amplifying circuit includes a first amplifier, the second-stage amplifying circuit includes two second amplifiers, and the third-stage amplifier includes four third amplifiers, and the four The third amplifier is divided into two groups, the first inter-stage matching network includes a first transformer T1, the second inter-stage matching network includes two second transformers T2, and the output matching network includes two first Three transformers T3 and a fourth transformer T4; the single-ended radio frequency input signal RFin passes through the input matching network and the first-stage amplifier in turn, and becomes two differential signals via the first transformer T1, and is respectively input to the two first-stage amplifiers. Two amplifiers, the two second transformers T2 are respectively connected to the two second amplifiers in one-to-one correspondence, and each of the second transformers T2 converts the single-ended signal from the corresponding second amplifier into two differential signals And respectively input into the two third amplifiers of the same group, the two third transformers T3 are respectively connected with two groups of the third amplifiers, each of the third transformers T3 will come from two of the same group The differential signal of the third amplifier is synthesized into a single-ended signal and output to the fourth transformer T4, and the fourth transformer T4 synthesizes the single-ended signals from the two third transformers T3 into a radio frequency output signal RFout Therefore, in this solution, by using transformer matching for both inter-stage matching and output matching, compared with the existing cascade of multiple matching topologies, the layout area is effectively reduced, and no additional insertion loss is brought , the effect of optimizing the gain and output return loss is significantly improved; finally, through the 4-way power synthesis of the final amplifier circuit, a higher output power is obtained without affecting or deteriorating other indicators.

Description of drawings

The technical solution and beneficial effects of the present invention will be apparent through the detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings.

Fig. 1 is the circuit diagram of the radio frequency power amplifier provided by the embodiment of the present invention;

Fig. 2 is a schematic diagram of a symmetrical interwound transformer provided by an embodiment of the present invention;

Fig. 3 is a layout of a symmetrical interwound transformer provided by an embodiment of the present invention;

Fig. 4 is a schematic diagram of the connection structure when the third transformer and the fourth transformer provided by the embodiment of the present invention are laminated step-up transformers;

Fig. 5 is an exploded schematic view of the laminated step-up transformer shown in Fig. 4;

Fig. 6 is another structural schematic diagram of a laminated step-up transformer provided by an embodiment of the present invention;

Fig. 7 is a cross-sectional view of the laminated step-up transformer shown in Fig. 6;

Fig. 8 is a phase simulation waveform diagram of the laminated step-up transformer shown in Fig. 6;

Fig. 9 is a simulation waveform diagram of insertion loss and amplitude of the laminated step-up transformer shown in Fig. 6;

FIG. 10 is a standing wave simulation waveform diagram of the laminated step-up transformer shown in FIG. 6 .

Detailed ways

Referring to the drawings, wherein like reference numerals represent like components, the principles of the present invention are exemplified when implemented in a suitable computing environment. The following description is based on illustrated specific embodiments of the invention, which should not be construed as limiting other specific embodiments of the invention not described in detail herein.

Referring to Fig. 1, a radio frequency power amplifier 100 based on a transformer matching network provided by an embodiment of the present invention specifically includes an input matching network 10 connected in sequence, a first-stage single-channel amplification circuit 20, a first-stage inter-stage matching network 30, a second The second-stage two-way amplifying circuit 40 , the second inter-stage matching network 50 , the third-stage four-way amplifying circuit 60 and the output network matching 70 .

Wherein, the first interstage matching network 30 includes a first transformer T1, the second interstage matching network 50 includes two second transformers T2, and the output matching network 70 includes two third transformers T3 and a A fourth transformer T4.

After the single-ended radio frequency input signal RFin passes through the input matching network 10 and the first-stage single-channel amplifier circuit 20 in sequence, it becomes two-way differential signals through the first transformer T1 and outputs them to the second-stage two-way amplifier circuit respectively. The two input terminals of the amplifying circuit 40, the two differential signals are amplified by the second-stage dual amplifying circuit 40 and output to the two second transformers T2 respectively, and then transformed by the two second transformers T2 The four differential signals are respectively output to the four input terminals of the third stage four amplifier circuit 60, and the four differential signals are amplified by the third stage four amplifier circuit 60 and output to the two respectively. The third transformer T3, through the third transformer T3, becomes two differential signals and outputs them to the two input ends of the fourth transformer T4 respectively, and the fourth transformer T4 synthesizes the two differential signals into one radio frequency The output signal RFout is output.

Thus, through the inter-stage matching network and the output matching network of the present invention, the input single-ended signal can be changed into two-way differential signals first, then the two-way differential signals can be changed into four-way differential signals, and then the four-way differential signals can be converted into four-way differential signals. The signal is synthesized into two differential signals, and finally synthesized into a single-ended signal output, which obtains higher output power without affecting or deteriorating other indicators; in addition, the inter-stage matching network and output matching network are realized through transformers Compared with the cascading of multiple matching topological structures in the prior art, the layout area is effectively reduced, and at the same time, no additional insertion loss is brought, and the optimization effect of gain and output return loss is significantly improved.

In some embodiments, the first to third stage amplifying circuits can all be realized by using HBT transistors, specifically as shown in FIG. 40 includes two second transistors Q2, and the third stage four-way amplifier circuit 60 includes four third transistors Q3. Wherein, the base and collector of the first transistor Q1 correspond to the input and output of the first-stage single-channel amplifier circuit 20, and the bases of the two second transistors Q2 correspond to the second The two input ends of the first-stage dual-channel amplifier circuit 40, the collectors of the two second transistors Q2 correspond to the two output terminals of the second-stage dual-channel amplifier circuit 40, and the four third transistors Q3 The bases correspond to the four input terminals of the third-stage four-way amplifier circuit 60 , and the collectors of the four third transistors Q3 correspond to the four output terminals of the third-stage four-way amplifier circuit 60 . Wherein, the four input terminals of the third-stage four-way amplifier circuit 60 form a group in pairs, and the two output terminals corresponding to the two input terminals of each group are a group of output terminals, that is, two third transistors Q3 is a group.

In a specific implementation, the two input terminals of the first transformer T1 are respectively connected to the collector of the first transistor Q1 and the power signal Vcc1, and the two output terminals of the first transformer T1 are respectively connected to the bases of the two second transistors Q2. The two second transformers T2 correspond to the two output ends of the second-stage dual-channel amplifier circuit 40 respectively, that is, the two second transformers T2 correspond to the two second transistors Q2 respectively. , the two input terminals of each second transformer T2 are respectively connected to the collector of the corresponding second transistor Q2 and the power supply signal Vcc2, and the two output terminals of a second transformer T2 are respectively connected to the two third transistors Q3 of the same group The base of the other second transformer T2 is connected to the two output terminals of the other second transformer T2 respectively connected to another group of two third transistors Q3. The two input terminals of one third transformer T3 are respectively connected to the collectors of the two third transistors Q3 of the same group, and the two input terminals of the other third transformer T3 are respectively connected to the collectors of the two third transistors Q3 of another group. collector connection. In addition, one of the output terminals of the two third transformers T3 is grounded, the other output terminals of the two third transformers T3 are respectively connected to the two input terminals of the fourth transformer T4, and one output terminal of the fourth transformer T4 is grounded, The other output terminal is used to output the radio frequency output signal RFout.

For the third-stage four-way amplifier circuit 60 , this embodiment uses two parallel connections of two transistors, which is beneficial to increase the impedance value of the transistor base input terminal, effectively reduce the difficulty of inter-stage matching, and complete impedance transformation. Moreover, for the first inter-stage matching network 30, it is implemented by using a transformer, and the single-ended signal is changed into two differential signals, which are respectively input to the two transistors Q2 of the second-stage dual-channel amplifying circuit 40, which can effectively reduce the inter-stage matching difficulty, and the second transistor Q2 does not need to be connected in series with a base resistor, so its gain, output power and linearity of output power are greatly improved.

It can be seen from FIG. 1 that in the embodiment of the present invention, the first-stage single-channel amplifying circuit 20 adopts the first transistor Q1 to realize one-channel amplifying circuit. In other embodiments, the number of the first transistor Q1 is not limited to one, and can be adopted A plurality of first transistors Q1 connected in parallel realizes the first-stage single-channel amplifier circuit 20, and the way in which the plurality of first transistors Q1 are connected in parallel is that the bases of the plurality of first transistors Q1 are respectively connected in series with a second resistor R2 and then connected in parallel, The collectors of the first transistor Q1 are connected in parallel as the output terminal of the first-stage single-channel amplifier circuit 20 , and the emitters of the first transistor Q1 are both grounded. Similarly, in the embodiment shown in FIG. 1 , the second-stage dual-channel amplifier circuit 40 adopts two second transistors Q2 to implement two-channel amplifier circuits respectively. In other real-time modes, the second-stage dual-channel amplifier circuit 40 Each amplifying circuit can be realized by a plurality of second transistors Q2 connected in parallel, the bases of the plurality of second transistors Q2 connected in parallel are connected in parallel, the collectors are connected in parallel, and the emitters are grounded. In addition, in the embodiment shown in FIG. 1 , the third-stage four-way amplifier circuit 60 uses four third transistors Q3 to realize the four-way amplifier circuit respectively. In other real-time modes, each of the third-stage four-way amplifier circuits 60 The amplifying circuit can be realized by using a plurality of third transistors Q3 connected in parallel, the bases of the third transistors Q3 connected in parallel in each channel are connected in parallel, the collectors are connected in parallel, and the emitters are all grounded. Amplification is realized by connecting multiple transistors in parallel, which can improve the performance of the amplifying circuit.

It can be understood that the amplifying circuit in the embodiment of the present invention is not limited to be realized by using HBT transistors, but also can be realized by using CMOS transistors, or can also be realized by a combination of transistors, as long as the power amplification is realized.

Continuing to refer to FIG. 1 , in the embodiment of the present invention, the radio frequency power amplifier 100 further includes a negative feedback network 80 connected between the base and the collector of the first transistor Q1 . The negative feedback network 80 includes a first resistor R1 and a first capacitor C1 connected in series. The RF power amplifier 100 further includes a second resistor R2, the second resistor R2 is connected in series between the input matching network 10 and the base of the first transistor Q1, and connected in parallel with the negative feedback network 80.

Through the function of the second resistor R2, the stability of the first-stage amplifying circuit 20 can be further improved and the input return loss can be optimized. And by adding a negative feedback network 80 between the collector and the base of the first transistor Q1, the first resistor R1 in the negative feedback network 80 can adjust the feedback depth, increase the stability and at the same time make the gain of the first stage amplifier circuit 20 and The output power is reduced.

In the embodiment of the present invention, the input matching network 10 is realized by two-stage LC matching. As shown in FIG. One end of L1 is connected in parallel and is used to input a single-ended radio frequency input signal RFin, the other end of the capacitor C2 is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the base of the first transistor Q1, and the inductor The other end of L1 is grounded, one end of the inductor L2 is connected between the capacitors C2 and C3, and the other end of the inductor L2 is grounded. The input matching is realized by adopting two-stage LC matching, which is beneficial to optimize the input return loss of the overall circuit.

Wherein, the first inter-stage matching network 30 also includes filter capacitors C4 and C5 with the same capacitance value, two DC blocking capacitors C6 and a choke inductor L3, one end of the two filter capacitors C4 and C5 is respectively connected to two ends of the first transformer T1 The other ends of the two filter capacitors C4 and C5 are respectively grounded, and the two DC blocking capacitors C6 are respectively connected in series between the two output terminals of the first transformer T1 and the bases of the correspondingly connected second transistor Q2. The choke inductor L3 is connected in series between the power signal Vcc1 and the input terminal of the first transformer T1 connected to the power signal Vcc1.

The second interstage matching network 50 also includes two filter capacitors C7 and four DC blocking capacitors C8, wherein one filter capacitor C7 is connected in series between the collector of a second transistor Q2 and the input terminal of the second transformer T2 connected thereto , another filter capacitor C7 is connected in series between the collector of another second transistor Q2 and the input terminal of another second transistor Q2 connected to it, and each output terminal of each second transformer T2 is connected to the third transistor Q2 connected to it. The DC blocking capacitor C8 is connected in series between the bases of the transistor Q3.

In addition, the output matching network 70 also includes four first filter capacitors C9, two second filter capacitors C10 and two inductors L4, one terminal of the four first filter capacitors C9 is connected to the collectors of the four third transistors Q3 Corresponding connections, the other ends of the four first filter capacitors C9 are respectively grounded, one ends of the two second filter capacitors C10 are respectively connected to the two input ends of the fourth transformer T4, and the other ends of the two second filter capacitors C10 are respectively grounded, and the inductance L4 is connected in series between the input end of the fourth transformer T4 and the correspondingly connected output end of the third transformer T3.

In the embodiment of the present invention, the first transformer T1 and the second transformer T2 are symmetrical interwound transformers, the third transformer T3 and the fourth transformer T4 are stacked step-up transformers, and the symmetrical interwound transformers The turn ratios of the primary coil and the secondary coil of the laminated step-up transformer are all between 2:1 and 1:1.

Referring to Fig. 3, the symmetrical interwound transformer of the embodiment of the present invention has an axisymmetric structure, and the grounding point is on the symmetrical axis, so that the phase can be ensured to be accurate enough during the phase conversion of the output signal, which has great advantages in transmitting differential signals. In addition, the symmetrical interwound transformer has a large mutual inductance, so its coupling coefficient K value is 0.7 to 0.9. The larger the K value, the closer the transformer is to the ideal state, and its bandwidth is wider and the insertion loss is smaller. Moreover, the ports of the primary coil and the secondary coil of the transformer are at both ends of the transformer, so it is very suitable for the cascade connection of the front and rear circuits. For example, taking the second transformer T2 as an example, the E and F terminals of the transformer are respectively connected to the output terminal and the isolation terminal of the second transistor Q2 (that is, the DC power supply terminal Vcc2), and the E, F terminals and their connected coils are primary coils, M, The N terminal is connected to the input terminals of the two differential signals of the third-stage amplifying circuit, the M, N and their connected coils are secondary coils, and the turns ratio of the primary and secondary coils is between 2:1 and 1:1.

As shown in Figures 4 to 5, the laminated step-up transformer according to the embodiment of the present invention includes a first metal layer A, a second metal layer B and a third metal layer C stacked in sequence, and each metal layer has two An insulating layer (not shown in the figure) is arranged between two adjacent metal layers, and a through hole D is formed on the insulating layer. Wherein the first metal layer A and the third metal layer C are secondary coils, and one end of the first metal layer A is connected to one end of the third metal layer C through the through hole D, and the second metal layer B is primary coil. As shown in FIG. 4, each metal layer is ring-shaped, thereby defining a middle area surrounded by the metal layer, a through hole D is located on the middle area, and one end of the first metal layer A and one end of the third metal layer C are bent Extend to the middle area to be connected through the through hole D in the middle area. Wherein, the bent portion A1 at one end of the first metal layer A overlaps with the bent portion C1 at one end of the third metal layer C in the stacking direction. Among them, FIG. 4 shows a schematic diagram of the connection structure of two third transformers T3 and one fourth transformer T4 in the output matching network 70. In the figure, "IN-" and "IN+" indicate the input terminals, and "GND" indicates Grounded, GND can keep the phase difference of the two output signals at 180°; under the coupling of the first and third metal layers A, C and the second metal layer B, the signal is induced to combine the two signals into one signal After the signals synthesized by the two third transformers T3 are output, the signals are synthesized again after entering the fourth transformer T4, and finally output as an RFout signal, achieving the purpose of four-way synthesis.

In some other embodiments, as shown in FIG. 6 and FIG. 7 , the projections of the bent portion A1 at one end of the first metal layer A and the bent portion C1 at one end of the third metal layer C in the stacking direction are also It can be roughly on a straight line, through the transformer of this structure, as shown in Figure 8 to Figure 10, Figure 8 is the phase simulation waveform diagram of the laminated step-up transformer shown in Figure 6, and Figure 9 is the phase simulation waveform diagram of Figure 6 The simulation waveform diagram of the insertion loss and amplitude of the laminated step-up transformer shown, where the curve S(3,1) represents the amplitude curve, and S(3,2) represents the insertion loss curve, and Figure 10 is the laminated layer shown in Figure 6 The standing wave simulation waveform diagram of the step-up transformer. It can be seen from the figure that the transformer can synthesize the output power while having very good amplitude and phase consistency, and has a small insertion loss and a good standing wave .

The radio frequency power amplifier based on the transformer matching network provided by the embodiment of the present invention has been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above embodiment is only for helping Understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be construed as a limitation of the invention.

Claims

A radio frequency power amplifier based on a transformer matching network is characterized in that it includes an input matching network connected in sequence, a first-stage single-channel amplifier circuit, a first-stage inter-stage matching network, a second-stage dual-channel amplifier circuit, and a second-stage inter-stage amplifier circuit. Matching network, third stage four-way amplifier circuit and output matching network;

The first interstage matching network includes a first transformer T1, the second interstage matching network includes two second transformers T2, and the output matching network includes two third transformers T3 and a fourth transformer T4;

After the single-ended radio frequency input signal RFin passes through the input matching network and the first-stage single-channel amplifier circuit in sequence, it becomes two-channel differential signals through the first transformer T1 and outputs them to the second-stage dual-channel amplifier circuit respectively. The two input terminals of the two differential signals are respectively output to the two second transformers T2 after being amplified by the second-stage dual-channel amplifier circuit, and become four-channel differential signals through the two second transformers T2 The signals are respectively output to the four input terminals of the third-stage four-way amplifier circuit, and the four-way differential signals are respectively output to the two third transformers T3 after being amplified by the third-stage four-way amplifier circuit. The third transformer T3 becomes two differential signals and outputs them to the two input terminals of the fourth transformer T4 respectively, and the fourth transformer T4 synthesizes the two differential signals into one radio frequency output signal RFout for output.
The radio frequency power amplifier according to claim 1, wherein the four input terminals of the third stage four-way amplifier circuit form a group in pairs, and the two output terminals corresponding to the two input terminals of each group are a set of outputs;

The two input ends of the first transformer T1 are respectively connected to the output end of the first-stage single-channel amplifier circuit and the power signal Vcc1, and the two output ends of the first transformer T1 are respectively connected to the second-stage dual amplifier circuit. The two input terminals of the two-way amplifying circuit are connected; the two second transformers T2 correspond to the two output terminals of the second-stage dual amplifying circuit respectively, and one input terminal of each of the second transformer T2 It is connected to the corresponding output end of the second-stage dual-channel amplifier circuit, the other input end of the second transformer T2 is connected to the power signal Vcc2, and the two output ends of each second transformer T2 are respectively connected to the The two input ends of the same group of the third-stage four-way amplifying circuit are connected; the two input ends of each of the third transformer T3 are respectively connected with the two output ends of the same group of the third-stage four-way amplifying circuit, and each Two output terminals of the third transformer T3 are respectively connected to an input terminal of the fourth transformer T4 and a ground terminal, one output terminal of the fourth transformer T4 is used to output the radio frequency output signal RFout, and the other output end grounded.
The radio frequency power amplifier according to claim 2, wherein the first-stage single-channel amplifying circuit includes a first transistor Q1, and the second-stage dual-channel amplifying circuit includes two second transistors Q2, the The third-stage four-way amplifier circuit includes four third transistors Q3, the base and collector of the first transistor Q1 correspond to the input and output ends of the first-stage single-way amplifier circuit, and the two third transistors Q1 The bases of the second transistor Q2 correspond to the two input terminals of the second-stage dual amplifier circuit, and the collectors of the two second transistors Q2 correspond to the two output terminals of the second-stage dual amplifier circuit. , the bases of the four third transistors Q3 correspond to the four input terminals of the third-stage four-way amplifier circuit, and the collectors of the four third transistors Q3 correspond to the four input terminals of the third-stage four-way amplifier circuit. For the four output terminals of the circuit, the emitters of the first transistor Q1, the second transistor Q2 and the third transistor Q3 are all grounded.
The radio frequency power amplifier according to claim 3, wherein the radio frequency power amplifier further comprises a negative feedback network connected between the base and the collector of the first transistor Q1, and the negative feedback network includes a series The first resistor R1 and the first capacitor C1;

The RF power amplifier further includes a second resistor R2, which is connected in series between the input matching network and the base of the first transistor Q1, and connected in parallel with the negative feedback network.
The radio frequency power amplifier according to claim 3, wherein the input matching network includes inductors L1, L2 and capacitors C2, C3, and one end of the capacitor C2 is connected in parallel with one end of the inductor L1 and is used for inputting a single-ended RF input signal RFin, the other end of the capacitor C2 is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the base of the first transistor Q1, the other end of the inductor L1 is grounded, and the inductor One end of L2 is connected between the capacitors C2 and C3, and the other end of the inductor L2 is grounded.
The radio frequency power amplifier according to claim 1, wherein the first transformer T1 and the second transformer T2 are symmetrical interwound transformers, and the third transformer T3 and the fourth transformer T4 are laminated booster transformers. For the transformer, the turn ratios of the primary coil and the secondary coil of the symmetrical interwound transformer and the laminated step-up transformer are all between 2:1 and 1:1.
The radio frequency power amplifier according to claim 6, wherein the laminated step-up transformer includes first to third metal layers stacked in sequence, each metal layer has two connection terminals, two adjacent An insulating layer is arranged between the metal layers, and a through hole is provided on the insulating layer, wherein the first metal layer and the third metal layer are secondary coils, and one end of the first metal layer is connected to the second through the through hole. One end of the three metal layers is connected, and the second metal layer is the primary coil.
The radio frequency power amplifier according to claim 7, wherein each layer of the metal layer is ring-shaped, thereby defining a middle area surrounded by the metal layer, and the through hole is located on the middle area, so One end of the first metal layer and one end of the third metal layer are bent and extended to the middle area, so as to be connected through the through hole in the middle area.
The radio frequency power amplifier according to claim 8, wherein the bent portion at one end of the first metal layer overlaps with the bent portion at one end of the third metal layer in a stacking direction.
The radio frequency power amplifier according to claim 8, wherein projections of the bent portion at one end of the first metal layer and the bent portion at one end of the third metal layer in the stacking direction are on a straight line.