阅读说明：本技术 一种包络阻抗控制结构、功率放大器结构 (Envelope impedance control structure and power amplifier structure ) 是由 代志江 冉雄博 李明玉 靳一 徐常志 于 2020-05-22 设计创作，主要内容包括：本发明涉及电子信息技术领域,公开了一种包络阻抗控制结构、功率放大器结构。包络阻抗控制结构包括供匹配网络、供电网络、包络阻抗控制网络,所述匹配网络的一端为信号输入端,另一端为信号输出端,所述匹配网络用于阻抗变换；所述供电网络的一端接入匹配网络中,另一端接电源,所述供电网络用于为晶体管提供直流偏置；所述包络阻抗控制网络的一端连接匹配网络,另一端接地,所述包络阻抗控制网络用于控制包络频带的阻抗。所述功率放大器结构在晶体管输入端和输出端设置包络阻抗控制结构。本发明的包络阻抗控制网络在不影响功率放大器基波工作频带的情况下,灵活地控制包络阻抗,能使包络阻抗始终在宽频带范围内低于某一阈值。(The invention relates to the technical field of electronic information, and discloses an envelope impedance control structure and a power amplifier structure. The envelope impedance control structure comprises a matching network, a power supply network and an envelope impedance control network, wherein one end of the matching network is a signal input end, the other end of the matching network is a signal output end, and the matching network is used for impedance transformation; one end of the power supply network is connected into the matching network, the other end of the power supply network is connected with a power supply, and the power supply network is used for providing direct current bias for the transistor; one end of the envelope impedance control network is connected with the matching network, the other end of the envelope impedance control network is grounded, and the envelope impedance control network is used for controlling the impedance of an envelope frequency band. The power amplifier structure is provided with an envelope impedance control structure at the input end and the output end of the transistor. The envelope impedance control network flexibly controls the envelope impedance under the condition of not influencing the fundamental wave operating frequency band of the power amplifier, and can enable the envelope impedance to be lower than a certain threshold value in a wide frequency band range all the time.)

1. An envelope impedance control structure is characterized by comprising a matching network, a power supply network and an envelope impedance control network, wherein one end of the matching network is a signal input end, the other end of the matching network is a signal output end, and the matching network is used for impedance transformation; one end of the power supply network is connected into the matching network, the other end of the power supply network is connected with a power supply, and the power supply network is used for providing direct current bias for a transistor of the power amplifier; one end of the envelope impedance control network is connected with the matching network, the other end of the envelope impedance control network is grounded, and the envelope impedance control network is used for controlling the impedance of an envelope frequency band.

2. The envelope impedance control structure of claim 1, wherein the envelope impedance control network comprises an envelope control circuit, the envelope control circuit comprises a microstrip line, a radio frequency capacitor, a first capacitor and a first resistor, one end of the microstrip line is connected to the matching network, the other end of the microstrip line is respectively connected to the radio frequency capacitor and the first resistor, the radio frequency capacitor is grounded, and the first resistor is connected to the first capacitor and then grounded.

3. An envelope impedance control structure as claimed in claim 2, wherein one or more radio frequency capacitors are connected in parallel between the microstrip line and ground.

4. An envelope impedance control structure as claimed in claim 3, wherein said radio frequency capacitance is replaced by an equivalent microstrip capacitance.

5. The envelope impedance control structure of claim 2, wherein the microstrip line is replaced by a radio frequency inductor.

6. An envelope impedance control structure as claimed in claim 2, wherein said first resistor is connected in series with a second inductor, or said first resistor is connected in parallel with a second capacitor.

7. An envelope impedance control structure according to claim 2, wherein the envelope impedance control network comprises three parallel envelope control circuits, the microstrip lines of the three parallel envelope control circuits being connected to the matching network, respectively.

8. An envelope impedance control structure as claimed in claim 7, wherein the first capacitors of the three parallel envelope control circuits differ in capacitance.

9. An envelope impedance control architecture according to claim 1, wherein the matching network is connected to one or more power supply networks, the power supply networks comprising a supply circuit comprising a supply line and a bias network in series, the supply line being connected to the matching network.

10. A power amplifier arrangement comprising a transistor, the input of which is provided with the envelope impedance control arrangement of any of claims 1 to 9, and the output of which is provided with the envelope impedance control arrangement of any of claims 1 to 9.

Technical Field

The invention relates to the technical field of electronic information, in particular to an envelope impedance control structure and a power amplifier structure.

Background

With the development of mobile communication, the information quantity is increasing continuously, the bandwidth of a transmitting signal is required to be increased to improve the information transmission quantity in unit time, a power amplifier (called a power amplifier for short) is required to have the broadband signal transmitting capacity, and the total bandwidth of signal envelope reaches 500 MHz; indexes such as power, efficiency and linearity of the power amplifier determine the working distance and size of the wireless communication equipment, and the power amplifier design method with excellent comprehensive performance has great research value. With the continuous change of user requirements in future 6G communication, the envelope bandwidth of signals in a multi-frequency point and multi-signal mode is greatly expanded, an envelope impedance control technology needs to be adopted in power amplifier design, otherwise indexes such as output power, efficiency and gain of the power amplifier are seriously deteriorated, and the overall performance of the system is reduced. For example, the signal bandwidth of more than 20MHz is respectively arranged at two frequency points of 1.8GHz and 2.1 GHz.

The signal envelope impedance (or called baseband impedance) directly affects various indexes (linearity, power and efficiency) of the power amplifier. Although the envelope impedance in the prior art has a decisive influence on the nonlinear characteristic of the power amplifier, it is only reported how to design a broadband bias network meeting the conditions. The bias network needs to have an approximate short circuit function on full-band radio frequency signals, for example, a bias circuit formed by a pure LC network, and according to the theory of the circuit network, the function value of the driving point input impedance of the network is a pure imaginary number, and the zero poles of the network are alternately arranged along with the increase of the frequency. That is, the reactance is large or small in the entire frequency band, and the impedance of the entire frequency band is not smaller than a certain threshold.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: in order to solve the problem of impedance difference in the whole frequency band, the invention provides an envelope impedance control structure and a power amplifier structure.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: an envelope impedance control structure comprises a matching network, a power supply network and an envelope impedance control network, wherein one end of the matching network is a signal input end, the other end of the matching network is a signal output end, and the matching network is used for impedance transformation; one end of the power supply network is connected into the matching network, the other end of the power supply network is connected with a power supply, and the power supply network is used for providing direct current bias for a transistor of the power amplifier; one end of the envelope impedance control network is connected with the matching network, the other end of the envelope impedance control network is grounded, and the envelope impedance control network is used for controlling the impedance of an envelope frequency band.

Furthermore, the envelope impedance control network comprises an envelope control circuit, the envelope control circuit comprises a microstrip line, a radio frequency capacitor, a first capacitor and a first resistor, one end of the microstrip line is connected to the matching network, the other end of the microstrip line is respectively connected with the radio frequency capacitor and the first resistor, the radio frequency capacitor is grounded, and the first resistor is connected with the first capacitor and then grounded.

Furthermore, one or more parallel radio frequency capacitors are arranged between the microstrip line and the grounding end.

Further, the radio frequency capacitor is replaced by an equivalent microstrip capacitor.

Further, the microstrip line is replaced by a radio frequency inductor.

Further, the first resistor is connected in series with a second inductor, or the first resistor is connected in parallel with the second inductor, or the first resistor is connected in parallel with a second capacitor.

Furthermore, the envelope impedance control network comprises three envelope control circuits connected in parallel, and microstrip lines of the three envelope control circuits connected in parallel are respectively connected with the matching network.

Further, the capacitance of the second capacitors of the three parallel envelope control circuits is different.

Further, the matching network connects one or more power supply networks, the power supply network comprising a power supply circuit comprising a power supply line and a bias network connected in series, the power supply line being connected to the matching network.

The invention also discloses a power amplifier structure which comprises a transistor, wherein the input end of the transistor is provided with an envelope impedance control structure, and the output end of the transistor is provided with an envelope impedance control structure.

Compared with the prior art, the invention has the following beneficial effects: the matching network of the invention enables the load of the input or output port to be matched with the ideal impedance transformation of the transistor; the bias network provides a power supply transmission channel for the transistor; the envelope impedance control network enables the transistor to exhibit a low impedance characteristic over the envelope frequency band. Based on the technical scheme of the invention, the envelope impedance control network flexibly controls the envelope impedance under the condition of not influencing the fundamental wave operating frequency band of the power amplifier, so that the envelope impedance is always lower than a certain threshold value in a wide frequency band range; the technical scheme of the invention meets the requirement of wider and wider signal envelope bandwidth.

Drawings

Fig. 1 is a schematic diagram of an envelope impedance control structure according to the present invention.

Fig. 2(a) is a schematic diagram of one structure of the envelope impedance control network according to the present invention.

Fig. 2(b) is a schematic diagram of one structure of the envelope impedance control network according to the present invention.

Fig. 2(c) is a schematic diagram of one structure of the envelope impedance control network according to the present invention.

Fig. 2(d) is a schematic diagram of one structure of the envelope impedance control network according to the present invention.

Fig. 2(e) is a schematic diagram of one structure of the envelope impedance control network according to the present invention.

Fig. 3 is a schematic structural diagram of an envelope impedance control structure according to an embodiment of the present invention.

Fig. 4 is a diagram illustrating comparison of envelope impedance values of the envelope network of the embodiment of fig. 3.

Fig. 5 is a schematic diagram of a power amplifier structure in which envelope impedance control networks are introduced into both the input and output terminals of the transistor in the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Similar to the control of the rf frequency in the bias network, the linearity index of the power amplifier is strongly related to the memory effect of the power amplifier itself, and therefore the control of the envelope impedance is crucial.

In one embodiment, as shown in fig. 1, an envelope impedance control structure includes a supply matching network 101, a supply network 102, and an envelope impedance control network 103, where one end of the matching network 101 is a signal input end a, the other end of the matching network 101 is a signal output end B, and the matching network 101 is used for impedance transformation; one end of the power supply network 102 is connected into the matching network 101, the power supply network 102 and the matching network 101 are connected by leading out a line through the matching network 101, the other end of the power supply network 102 is connected with a power supply, and the power supply network 102 is used for providing direct current bias for a transistor of the power amplifier; one end of the envelope impedance control network 103 is connected to a matching network, and the other end of the envelope impedance control network 103 is grounded, and the envelope impedance control network is used for controlling the impedance of an envelope frequency band. The structure can flexibly control the envelope impedance under the condition of not influencing the fundamental wave operating frequency band of the power amplifier. The matching network enables the load of the input end or the output end to be matched with the ideal impedance transformation of the transistor; the bias network provides a power supply transmission channel for the transistor; the envelope impedance control network enables the transistor to exhibit a low impedance characteristic over the envelope frequency band.

In one embodiment, the envelope impedance control network comprises an envelope control circuit, such as the envelope control circuit shown in fig. 2(a) comprising a microstrip line TL_BBRadio frequency capacitor C_RFA first capacitor C_BBA first resistor R_BBOne end of the microstrip line is connected to a matching network, and the microstrip line is connected to a matching networkThe other ends are respectively connected with a radio frequency capacitor C_RFAnd a first resistor R_BBSaid radio frequency capacitor C_RFGround, the first resistor R_BBIs connected with a first capacitor C_BBAnd then grounded.

In one embodiment, one or more parallel rf capacitors are provided between the microstrip line and the ground. When a plurality of radio frequency capacitors are connected in parallel, each working frequency point is in an approximate short circuit state (the modulus value of the capacitive reactance is less than 20).

In one embodiment, the rf capacitor is replaced with an equivalent microstrip capacitor, such as a microstrip sector capacitor.

In one embodiment, as shown in fig. 2(b), the microstrip line TL_BBBy a radio frequency inductor L_RFAnd (4) replacing.

In one embodiment, the first resistor R_BBA second inductor L connected in series_AOr the first resistor R_BBParallel second inductor L_AOr the first resistor R_BBA second capacitor C connected in parallel_A；

In one case, as shown in FIG. 2(c), the microstrip line TL_BBOne end connected to a matching network 101, the microstrip line TL_BBThe other ends are respectively connected with a radio frequency capacitor C_RFAnd a second inductance L_ASaid second inductance L_ASequentially connected with a first resistor R_BBA first capacitor C_BBAnd then grounded.

In one case, as shown in FIG. 2(d), the microstrip line TL_BBOne end connected to a matching network 101, the microstrip line TL_BBThe other ends are respectively connected with a radio frequency capacitor C_RFAnd a first resistor R_BBThe first resistor R_BBIs connected with a first capacitor C_BBThen grounded, the first resistor R_BBParallel second inductor L_A。

In one case, as shown in fig. 2(e), the microstrip line TL_BBOne end connected to a matching network 101, the microstrip line TL_BBThe other ends are respectively connected with a radio frequency capacitor C_RFAnd a first resistor R_BBThe first resistor R_BBConnect the first electricContainer C_BBThen grounded, the first resistor R_BBA second capacitor C connected in parallel_A。

In one embodiment, as shown in fig. 3, the envelope impedance control network includes three parallel envelope control circuits, and microstrip lines of the three parallel envelope control circuits are respectively connected to the matching network. In the embodiment of fig. 3, the three parallel envelope control circuits comprise microstrip lines TL_BBRadio frequency capacitor C_RFA first capacitor C_BBA first resistor R_BBOne end of the microstrip line is connected to the matching network, and the other end of the microstrip line is respectively connected with the radio frequency capacitor C_RFAnd a first resistor R_BBSaid radio frequency capacitor C_RFGround, the first resistor R_BBIs connected with a first capacitor C_BBAnd then grounded. It should be noted that the structure of the envelope control circuit in this embodiment is not limited to the structure shown in fig. 3, and the structure of the envelope control circuit in other embodiments of the present invention should also be applied to this embodiment. In the embodiment of fig. 3, the matching network 101 is composed of microstrip lines, and signals flow in from point a, flow out from point B and flow into the transistor; one end of the power supply network 102 leads out a power supply line from the matching network, the lead-out power supply line is respectively connected with a 27pF capacitor and a power supply filter network, the 27pF capacitor is grounded, and the other end of the power supply filter network is connected with a power supply; the length of the microstrip lines of the three parallel envelope control circuits is 15mm, and the width of the microstrip lines is 0.3 mm; radio frequency capacitor C of three parallel envelope control circuits_RAll have a capacitance value of 27pF, and the first resistors R of the three envelope control circuits connected in parallel_BBAll resistance values of (2) omega, three parallel first capacitors C of envelope control circuit_BBWherein the first capacitor C of the first envelope control circuit_BBHas a capacitance value of 80pF, and a first capacitor C of the second envelope control circuit_BBThe capacitance value of the third envelope control circuit is 200pF, and the first capacitor C of the third envelope control circuit_BBHas a capacitance value of 500 pF. The radio frequency signal passes through a radio frequency capacitor C_RFShort-circuited to ground, while the envelope frequency passes through the first capacitor C_BBAnd a first resistor R_BBTo ground. Wherein C is_BBTransmission lines TL connected to each other_BBForming resonance in envelope frequency bandReducing the envelope impedance value of the transistor to ground; introducing a resistance R_BBThe method avoids the phenomenon that the envelope frequency band generates pure LC network resonance, so that a great impedance value occurs in the envelope frequency band of a signal. And the first capacitor C with different capacitance values_BBAnd microstrip line TL_BBSeries resonance is formed near frequency points of 80MHz, 120MHz and 200MHz, and an imaginary part of impedance Zin seen from a point B at the resonance point is close to zero.

According to the structure shown in fig. 3, the envelope impedance values in a wide frequency band are all very small, and after the envelope impedance control network of the present embodiment is introduced, the envelope impedance values are as shown in fig. 4. The envelope impedance of the present embodiment is in the frequency band of 0-500MHz, and the impedance modulus is lower than 8. If more envelope impedance control branches are introduced into the circuit, the first capacitor C is flexibly adjusted_BBOr microstrip line TL_BBThe envelope impedance control function at an ideal frequency point can be realized.

In one embodiment, the power supply network comprises a power supply circuit comprising a power supply line and a bias network connected in series, as shown in fig. 3, the bias network comprises a 27pF rf capacitor and a power filter network connected in parallel, the 27pF rf capacitor is grounded, the power filter network is connected to a power supply terminal, and the power supply line is connected to a matching network.

In another embodiment, a power amplifier structure comprises a transistor, wherein an input end of the transistor is provided with the envelope impedance control structure according to any one of the embodiments of the present invention, and an output end of the transistor is provided with the envelope impedance control structure according to any one of the embodiments of the present invention, and a signal is input from a matching network at the input end of the transistor and output from a matching network at the output end of the transistor. As in the embodiment of fig. 5, the envelope impedance control structures provided at the transistor input and output each comprise two envelope control circuits connected in parallel. The envelope impedance control structure arranged at the input end of the transistor comprises a matching network 1, wherein the power supply network comprises a grid power supply line connected with the matching network 1, the grid power supply line is connected with a grid bias network and then connected with a grid voltage end Vg, two lines led out from the matching network 1 are respectively connected with an envelope impedance control circuit 1 and an envelope impedance control circuit 2, and a microstrip line TL of the envelope impedance control circuit 1_BB，1One end connected to a matching network 1, the microstrip line TL_BB，1The other ends are respectively connected with a radio frequency capacitor C_RF，1And a first resistor R_BB，1Said radio frequency capacitor C_RF，1Ground, the first resistor R_BB，1Is connected with a first capacitor C_BB，1Then grounding; microstrip line TL of envelope impedance control circuit 2_BB，2One end connected to a matching network 1, the microstrip line TL_BB，2The other ends are respectively connected with a radio frequency capacitor C_RF，2And a first resistor R_BB，2Said radio frequency capacitor C_RF，2Ground, the first resistor R_BB，2Is connected with a first capacitor C_BB，2And then grounded. In the envelope impedance control structure arranged at the output end of the transistor, the envelope impedance control structure comprises a matching network 2, the power supply network comprises a drain electrode power supply line connected with the matching network 2, the drain electrode power supply line is connected with a drain electrode biasing network and then connected with a drain electrode voltage end Vd, two lines led out from the matching network 2 are respectively connected with an envelope impedance control circuit 3 and an envelope impedance control circuit 4, and a microstrip line TL of the envelope impedance control circuit 3_BB，3One end connected to a matching network 2, the microstrip line TL_BB，3The other ends are respectively connected with a radio frequency capacitor C_RF，3And a first resistor R_BB，3Said radio frequency capacitor C_RF，3Ground, the first resistor R_BB，3Is connected with a first capacitor C_BB，3Then grounding; microstrip line TL of envelope impedance control circuit 4_BB，4One end connected to a matching network 2, the microstrip line TL_BB，4The other ends are respectively connected with a radio frequency capacitor C_RF，4And a first resistor R_BB，4Said radio frequency capacitor C_RF，4Ground, the first resistor R_BB，4Is connected with a first capacitor C_BB，4And then grounded.

Finally, it should be noted that: the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, but not to limit the technical solutions, and certainly not to limit the patent scope of the present invention; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; that is, the technical problems to be solved by the present invention, which are not substantially changed or supplemented by the spirit and the concept of the main body of the present invention, are still consistent with the present invention and shall be included in the scope of the present invention; in addition, the technical scheme of the invention is directly or indirectly applied to other related technical fields, and the technical scheme is included in the patent protection scope of the invention.