Common-base amplification circuit, radio-frequency amplifier, and electronic device

Abstract

A common-base amplification circuit, a radio-frequency amplifier, and an electronic device. The common-base amplification circuit comprises: a first transistor, a second transistor and a decoupling unit, wherein a base electrode of the first transistor is connected to a base electrode of the second transistor; and the decoupling unit is connected between the base electrode of the first transistor and the base electrode of the second transistor, and is used for decoupling and adjusting odd harmonics and even harmonics. The decoupling unit is connected between the base electrodes of the first transistor and the second transistor, which have a common base electrode, such that odd harmonic components and even harmonic components can be independently adjusted, and harmonic control can be implemented without the need for additional matching of input and output elements, thereby simplifying the circuit structure and improving the gain of useful signals; and the even harmonic components are independently adjusted, such that a common-mode component of the circuit can also be adjusted while ensuring that a differential-mode gain remains unchanged, thereby enhancing common-mode suppression and improving the common-mode stability and comprehensive performance of a radio-frequency amplifier.

Description

Common base amplifier circuit, radio frequency amplifier and electronic equipment

[0001] Cross-references to related publications

[0002] This disclosure claims priority to a Chinese patent application filed with the State Intellectual Property Office on March 14, 2024, with application number CN202410294640.1 and invention name “Common base amplifier circuit, radio frequency amplifier and electronic device”, the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The embodiments of the present disclosure relate to, but are not limited to, the field of wireless communication technology, and particularly to a common base amplifier circuit, a radio frequency amplifier, and an electronic device. Background Art

[0004] With the continuous development of mobile communications, fifth-generation mobile communications have placed higher demands on transmission rate, latency, and reliability. The cascode (common source, common gate, or common emitter, common base) amplifier structure, featuring high gain, high isolation, and wide output voltage swing, has become a common structure for various amplifiers in RF transceivers. Amplifier stability is the highest priority specification for all amplifiers; all other additional specifications are only meaningful if stability is achieved. Common-mode stability is an extremely important specification for differential RF amplifiers. RF amplifiers with poor common-mode stability will be severely affected by signals at common-mode nodes such as the power supply and ground, causing significant performance fluctuations and even oscillations. Furthermore, the harmonic components at each node of the amplifier have a certain impact on the amplifier's output power, efficiency, and linearity. Furthermore, high requirements are placed on harmonic spurious emissions in variable-frequency systems. Therefore, regulating harmonics in the amplifier is a key technology for improving performance.

[0005] Traditional cascode RF amplifiers suffer from poor common-mode stability. Changes in the cascode capacitance of traditional stack-structured RF amplifiers affect all harmonics, limiting their harmonic suppression capabilities. For LODAs (Local Oscillator Driver Amplifiers) and nonlinear PAs (Power Amplifiers), additional matching of input and output components is required for harmonic control. Summary of the Invention

[0006] The present disclosure provides a common base amplifier circuit, a radio frequency amplifier, and an electronic device.

[0007] In a first aspect, an embodiment of the present disclosure provides a common base amplifier circuit, comprising: a first transistor, a second transistor and a decoupling unit, wherein the base of the first transistor is connected to the base of the second transistor; the decoupling unit is connected between the base of the first transistor and the base of the second transistor, and is used to decouple and adjust odd harmonics and even harmonics.

[0008] On the other hand, an embodiment of the present disclosure further provides a radio frequency amplifier, comprising the common base amplifier circuit as described above.

[0009] On the other hand, an embodiment of the present disclosure further provides an electronic device, comprising the radio frequency amplifier as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1a is a schematic diagram of a radio frequency amplifier with a cascode structure in the related art;

[0011] FIG1b is a schematic diagram of a stack-structured radio frequency amplifier in the related art;

[0012] FIG2 is a schematic diagram of a module structure of a common base amplifier circuit according to an embodiment of the present disclosure;

[0013] FIG3 a is a schematic structural diagram of a common-base amplifier circuit including a π-type decoupling unit according to an embodiment of the present disclosure;

[0014] FIG3 b is a schematic structural diagram of a common-base amplifier circuit including a T-type decoupling unit according to an embodiment of the present disclosure;

[0015] FIG4 is a schematic diagram of a module structure of a radio frequency amplifier according to an embodiment of the present disclosure;

[0016] FIG5 is a schematic diagram of a module structure of a radio frequency amplifier according to an embodiment of the present disclosure;

[0017] FIG6 a is a schematic diagram of a cascode structure radio frequency amplifier according to an embodiment of the present disclosure;

[0018] FIG6 b is a schematic diagram of a stack-structured radio frequency amplifier according to an embodiment of the present disclosure;

[0019] FIG7 is a schematic structural diagram of a cascode structure radio frequency amplifier according to a specific example of the present disclosure;

[0020] FIG8 is a schematic diagram showing how the differential mode gain of the RF amplifier shown in FIG7 changes with the adjustment coefficient;

[0021] FIG9 is a schematic diagram showing how the common-mode stability coefficient of the RF amplifier shown in FIG7 changes with the adjustment coefficient;

[0022] FIG10 is a schematic diagram showing how harmonics of the RF amplifier shown in FIG7 vary with input power at different adjustment coefficients;

[0023] FIG11 is a schematic diagram showing how the OP1dB of the RF amplifier shown in FIG7 changes with the adjustment coefficient;

[0024] FIG12 is a schematic diagram showing how the OP3dB of the RF amplifier shown in FIG7 changes with the adjustment coefficient. DETAILED DESCRIPTION

[0025] Example embodiments will be described more fully hereinafter with reference to the accompanying drawings, but the example embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of this disclosure to those skilled in the art.

[0026] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0027] The terms used herein are used only to describe specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a," "an," and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It will also be understood that when the terms "comprising" and / or "made of" are used in this specification, the presence of the features, wholes, steps, operations, elements, and / or components is specified, but the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groups thereof is not excluded.

[0028] The embodiments described herein may be described with reference to plan views and / or cross-sectional views, with the aid of idealized schematic diagrams of the present disclosure. Thus, the example illustrations may be modified based on manufacturing techniques and / or tolerances. Therefore, the embodiments are not limited to the embodiments shown in the accompanying drawings, but include modifications of the configurations formed based on the manufacturing process. Therefore, the regions illustrated in the accompanying drawings are schematic in nature, and the shapes of the regions shown in the drawings illustrate specific shapes of the regions of the elements, but are not intended to be limiting.

[0029] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted as having an idealized or overly formal meaning unless expressly defined as such herein.

[0030] Traditional differential RF amplifiers can be divided into cascode and stack structures based on the connection method of the base (gate) capacitors in the common base (gate) stage. The circuit of a cascode differential RF amplifier is shown in Figure 1a. The circuit of a stack differential RF amplifier is shown in Figure 1b. Both the cascode and stack structures include a common emitter (source) stage, a common base (gate) stage, and cas capacitors. Traditional RF amplifiers have the following drawbacks: The virtual ground point in the cascode structure provides an ideal differential AC ground, resulting in high differential mode gain. The large cas capacitors typically connected in parallel with the bases of Q3 and Q4 provide power supply filtering, but this reduces the circuit's common-mode stability. The stack structure provides the RF AC ground through the cas capacitors, and the amplifier gain can be controlled by adjusting the cas capacitor value. However, changes in the cas capacitor affect all harmonics, making it impossible to decouple the odd and even harmonic components for independent adjustment. In related technologies, RF amplifier harmonic control is often performed in the input and output matching networks. This requires additional matching components, occupies more area, and also increases the loss of useful signals.

[0031] To address the aforementioned issues, embodiments of the present disclosure provide a common-base amplifier circuit. As shown in Figures 2, 3a, and 3b, the common-base amplifier circuit includes a first transistor Q1, a second transistor Q2, and a decoupling unit. The base of the first transistor Q1 is connected to the base of the second transistor Q2. The decoupling unit is connected between the bases of the first transistor Q1 and the second transistor to decouple and regulate odd and even harmonics.

[0032] The common-base amplifier circuit can be applied to a differential RF amplifier. The emitters of the first transistor Q1 and the second transistor Q2 are respectively connected to the two output terminals of the common-emitter circuit in the RF amplifier. A decoupling unit is connected in series between the bases of Q1 and Q2, and the decoupling unit is grounded. The collectors of Q1 and Q2 are respectively connected to the two output terminals of the RF amplifier, namely, RFout+ and RFout-. The first transistor Q1 and the second transistor Q2 have the same size and can be either a bipolar transistor or a field-effect transistor.

[0033] By connecting a decoupling unit between the bases of the first transistor Q1 and the second transistor Q2 having a common base, the odd and even harmonic components of the stack-structured RF amplifier can be adjusted individually, thereby achieving decoupling adjustment of the odd and even harmonic components. Harmonic control can be achieved without the need for additional matching of input and output components, simplifying the circuit structure and improving the useful signal gain. Moreover, by independently adjusting the even harmonic components, the common-mode components of the circuit can be adjusted while ensuring that the differential-mode gain remains unchanged, that is, the even harmonic components are adjusted to achieve enhanced common-mode suppression, thereby improving the common-mode stability and overall performance of the RF amplifier.

[0034] In some embodiments, the decoupling unit includes a first impedance element, a second impedance element, and a third impedance element, and the first impedance element, the second impedance element, and the third impedance element are arranged in a π-type arrangement or a T-type arrangement. That is, the decoupling unit can be a π-type decoupling unit or a T-type decoupling unit.

[0035] The decoupling unit is configured to adjust odd harmonics by adjusting a target impedance parameter, where the target impedance parameter is obtained based on an impedance parameter of a first impedance element, an impedance parameter of a second impedance element, and an impedance parameter of a third impedance element; and to adjust even harmonics by adjusting a ratio of the impedance parameters of the first impedance element, the second impedance element, and the third impedance element when the target impedance parameter remains unchanged.

[0036] In some embodiments, the first impedance element, the second impedance element or the third impedance element may be one of the following or any combination thereof: capacitance, inductance, and resistance. Accordingly, the impedance parameter may be a capacitance value, an inductance value or a resistance value.

[0037] Taking the impedance elements in the decoupling unit as capacitors as an example, the decoupling unit adjusts the odd harmonics by adjusting the overall capacitance value of the decoupling unit to achieve differential mode adjustment; while ensuring that the overall capacitance value of the decoupling unit remains unchanged, the even harmonics are adjusted by adjusting the capacitance ratio of the above three capacitor elements, that is, common mode adjustment is achieved while ensuring that the differential mode remains unchanged.

[0038] One or more of the first impedance element, the second impedance element, and the third impedance element may be a variable impedance element or a fixed impedance element. For example, when the impedance element is a capacitor, one or more of the first impedance element, the second impedance element, and the third impedance element may be a variable capacitor or a capacitor with a fixed capacitance value; when the impedance element is an inductor, one or more of the first impedance element, the second impedance element, and the third impedance element may be a variable inductor or an inductor with a fixed inductance value; when the impedance element is a resistor, one or more of the first impedance element, the second impedance element, and the third impedance element may be a variable resistor or a resistor with a fixed resistance value. By using a variable impedance element, it is possible to easily adjust the ratio between the target impedance parameter and the impedance parameter of each impedance element.

[0039] In some embodiments, the impedance parameter of the first impedance element is equal to the impedance parameter of the second impedance element. It should be noted that in order to further improve common-mode stability, the impedance parameter of the first impedance element and the impedance parameter of the second impedance element can also be set to be unequal to adjust the balance of the RF amplifier.

[0040] The following describes the structure of the π-type decoupling unit in detail with reference to FIG3a, taking each impedance element as a capacitor as an example. In the π-type decoupling unit, the third impedance element is Cpi As shown in FIG3a, the first impedance element C1, the second impedance element C2 and the third impedance element C pi The first impedance element C1 has one end (first end) connected to the base of the first transistor Q1, and the other end (second end) is grounded; the second impedance element C2 has one end (first end) connected to the base of the second transistor Q2, and the other end (second end) is grounded; the third impedance element C pi The first impedance element C1, the second impedance element C2 and the third impedance element C pi High-Q variable capacitors or capacitor arrays can be used to achieve digital control, multi-speed adjustment, etc.

[0041] It should be noted that the non-grounded end (i.e., the first end) of the first impedance element C1 and the base of the first transistor Q1 are also connected to the first bias resistor Rcasp, and the non-grounded end (i.e., the first end) of the second impedance element C2 and the base of the second transistor Q2 are also connected to the second bias resistor Rcasn. The first bias resistor Rcasp and the second bias resistor Rcasn are used for bias power supply.

[0042] The first impedance element C1, the second impedance element C2 and the third impedance element C pi In the case of capacitance, the following conditions are met: C pi =0.5*(1-α1)*C total Among them, C total is the capacitance value of the decoupling unit, C total =C1+2C pi or C total =C2+2C pi , usually, C1=C2=α1*C total ; C pi is the capacitance value of the third impedance element, α1 is the first adjustment coefficient, and α1≠1.

[0043] When 0≤α1<1, the first impedance element C1, the second impedance element C2 and the third impedance element C pi are all capacitors; when α1>1, the third impedance element C pi The first impedance element C1 and the second impedance element C2 are equivalent to inductors, and the third impedance element C pi For the capacitor.

[0044] The decoupling unit is configured to adjust the even harmonics by adjusting the first adjustment coefficient α1 while keeping the capacitance value of the decoupling unit unchanged. totalAssign C1, C2 and C without changing pi ratio, achieving enhanced common-mode rejection and adjustable harmonics.

[0045] 3b, the structure of the T-type decoupling unit is described in detail by taking each impedance element as a capacitor as an example. T As shown in FIG3b, the first impedance element C1, the second impedance element C2 and the third impedance element C T It is arranged in a T-shape, wherein one end (first end) of the first impedance element C1 is connected to the base of the first transistor Q1, the other end (second end) of the first impedance element C1 is connected to one end (first end) of the second impedance element C2; the other end (second end) of the second impedance element C2 is connected to the base of the second transistor Q2; the third impedance element C T One end of the first impedance element C1 is connected between the second impedance element C2, and the other end is grounded. T High-Q variable capacitors or capacitor arrays can be used to achieve digital control, multi-speed adjustment, etc.

[0046] It should be noted that the first end of the first impedance element C1 and the base of the first transistor Q1 are also connected to the first bias resistor Rcasp, and the second end of the second impedance element C2 and the base of the second transistor Q2 are also connected to the second bias resistor Rcasn. The first bias resistor Rcasp and the second bias resistor Rcasn are used for bias power supply.

[0047] The first impedance element C1, the second impedance element C2 and the third impedance element C T In the case of capacitance, the following conditions are met: C T =α2*C total , where C totle is the capacitance value of the decoupling unit; usually, C1=C2=C total ; C T is the capacitance value of the third impedance element, and α2 is the second adjustment coefficient.

[0048] When α2>0, the first impedance element C1, the second impedance element C2 and the third impedance element C T are all capacitors; when α2<0, the third impedance element C T Equivalent to an inductor.

[0049] The decoupling unit is configured to adjust the even harmonics by adjusting the second adjustment coefficient α2 while maintaining the capacitance of the decoupling unit. This allows the capacitance of the third impedance element to be adjusted while maintaining the differential mode gain, thereby enhancing common-mode rejection and adjusting each harmonic.

[0050] An embodiment of the present disclosure further provides a radio frequency amplifier, comprising the common base amplifier circuit as described above.

[0051] The radio frequency amplifier provided by the embodiment of the present disclosure includes a common base amplifier circuit, which includes a first transistor, a second transistor and a decoupling unit, wherein the base of the first transistor is connected to the base of the second transistor; the decoupling unit is connected between the base of the first transistor and the base of the second transistor, and is used to decouple and adjust odd harmonics and even harmonics. By connecting the decoupling unit between the bases of the first transistor and the second transistor of the common base, the odd harmonic components and the even harmonic components can be adjusted separately, and harmonic control can be achieved without additional matching input and output elements, simplifying the circuit structure and improving the useful signal gain; independently adjusting the even harmonic components can also adjust the common mode components of the circuit while ensuring that the differential mode gain remains unchanged, thereby achieving enhanced common mode rejection and improving the common mode stability and overall performance of the radio frequency amplifier.

[0052] Figure 4 is a schematic diagram of the module structure of an RF amplifier according to an embodiment of the present disclosure, Figure 6a is a schematic diagram of an RF amplifier with a π-type decoupling structure according to an embodiment of the present disclosure, and Figure 6b is a schematic diagram of an RF amplifier with a T-type decoupling structure according to an embodiment of the present disclosure. In combination with Figures 4, 6a, and 6b, the RF amplifier, in addition to including a common-base amplifier circuit 10, may also include a common-emitter circuit 20. The common-emitter circuit 20 includes a third transistor Q3 and a fourth transistor Q4. The emitter of the third transistor Q3 is connected to the emitter of the fourth transistor Q4; the collector of the third transistor Q3 is connected to the emitter of the first transistor Q1, and the collector of the fourth transistor Q4 is connected to the emitter of the second transistor Q2.

[0053] The third transistor Q3 and the fourth transistor Q4 have the same size. The common-emitter circuit 20 adopts a pseudo-differential transistor form. The emitter of the third transistor Q3 and the emitter of the fourth transistor Q4 are connected to each other and grounded. The base of the third transistor Q3 and the base of the fourth transistor Q4 are connected to the radio frequency input terminals RFin+ and RFin-, respectively. The collector of the third transistor Q3 and the collector of the fourth transistor Q4 are connected to the input terminal of the common-base amplifier circuit 10.

[0054] In order to further improve the differential mode stability and isolation, in some embodiments, as shown in FIG5, FIG6a and FIG6b, the RF amplifier may further include a parasitic oscillation suppression module 30, the parasitic oscillation suppression module 30 includes a first neutralization capacitor C C1 and the second neutralizing capacitor C C2 , the first neutralizing capacitor C C1 One end of the second neutralizing capacitor C is connected to the base of the third transistor Q3, and the other end is connected to the collector of the fourth transistor Q4;C2 One end is connected to the base of the fourth transistor Q4, and the other end is connected to the collector of the third transistor Q3. By cross-connecting the neutralizing capacitor and the transistors in the common-emitter circuit, the differential mode stability and isolation of the RF amplifier can be improved.

[0055] Neutralizing capacitors are sensitive and only effective within a narrow range of values. Values ​​outside this range can cause the amplifier to self-excite and degrade common-mode stability to a certain extent. The disclosed embodiment combines the decoupling unit with the parasitic oscillation suppression module 30, balancing differential-mode stability and common-mode stability while enabling independent regulation of odd and even harmonic components.

[0056] In some embodiments, the capacitance of the first neutralizing capacitor is equal to the capacitance of the second neutralizing capacitor. It should be noted that, in order to further improve the common-mode stability and performance of the RF amplifier, the capacitance of the first neutralizing capacitor and the capacitance of the second neutralizing capacitor may also be set to be unequal to adjust the balance of the RF amplifier.

[0057] An embodiment of the present disclosure further provides an electronic device, which includes the radio frequency amplifier as described above.

[0058] To clearly illustrate the solution of the embodiment of the present disclosure, a specific example is described below with reference to FIG7 . As shown in FIG7 , the RF amplifier includes a common-emitter circuit, a common-base amplifier circuit, and a parasitic oscillation suppression module. The common-base amplifier circuit includes a π-type decoupling unit. In this example, the π-type decoupling unit is a π-type capacitor.

[0059] The common-base amplifier circuit consists of transistors Q1 and Q2, both of identical size. Q1's emitter is connected to the collector of Q3 in the common-emitter circuit, which in turn is connected to one end of the primary winding of the output transformer balun TF2. Q2's emitter is connected to the collector of Q4 in the common-emitter circuit, and Q2's collector is connected to the other end of the primary winding of the output transformer balun TF2. The center tap of TF2's primary winding is connected to power supply VDD, providing a DC path for the circuit. One end of the secondary winding is grounded, and the other end is connected to the RF output. By properly designing the size, number of turns, and coupling coefficient of the primary and secondary windings of transformer TF2, impedance matching or power matching can be achieved at the output port. The base of Q1 is connected to the bias voltage Vcas through bias resistor Rcasp, while the base of Q2 is connected to the bias voltage Vcas through bias resistor Rcasn. The bases of Q1 and Q2 are connected to the two ends of a pi-type capacitor, respectively.

[0060] The common-emitter circuit consists of transistors Q3 and Q4, which are of identical size. The differential RF signals RFin+ and RFin- are connected to the primary winding of transformer TF1. The secondary winding serves as the input to the common-emitter circuit, connected to the bases of Q3 and Q4, respectively. The center tap of the secondary winding is connected to the bias voltage Vgm, providing a DC bias for the common-emitter circuit. The emitters of Q3 and Q4 are connected to each other and to ground, providing a DC path. The collector of Q3 is connected to the emitter of transistor Q1 in the common-base amplifier circuit, while the collector of Q4 is connected to the emitter of Q2 in the common-base amplifier circuit. Impedance matching at the input port can be achieved by properly designing the size, number of turns, and coupling coefficient of the primary and secondary windings of transformer TF1.

[0061] The π-type decoupling unit consists of capacitors C1, C2 and C pi In general, C1=C2, and the balance of the differential circuit can be adjusted by making C1≠C2. pi The value of adjusts the circuit harmonic energy. One end of C1 is connected to the base of transistor Q1 in the common base amplifier circuit, and the other end of C1 is connected to the ground; pi One end is connected to the base of Q1, and the other end is connected to the base of Q2; one end of C2 is connected to the base of Q2, and the other end is connected to ground.

[0062] The parasitic oscillation suppression module consists of neutralizing capacitors Cc1 and Cc2. One end of neutralizing capacitor Cc1 is connected to the base of transistor Q3 in the common-emitter circuit, and the other end is connected to the collector of transistor Q4. One end of neutralizing capacitor Cc2 is connected to the base of transistor Q4 in the common-emitter circuit, and the other end is connected to the collector of transistor Q3 in the common-emitter circuit. This cross-connection creates a neutralizing capacitor structure. By adjusting the capacitance of neutralizing capacitors Cc1 and Cc2, the differential-mode stability and isolation of the RF amplifier can be improved.

[0063] In the example of FIG7, according to C total =C+2C pi , we get C1=C2=C=α1*C total , C pi =0.5*(1-α1)*C total , C total =1p. Among them, when α1=1, then C pi =0, the RF amplifier is equivalent to the traditional RF amplifier shown in FIG1b; when 0<α1≤1, it is the new RF amplifier disclosed in the present invention; when α1>1, then C pi Equivalent to an inductor.

[0064] Differential RF signals RFin+ and RFin- are input from the base of the common-emitter circuit. After neutralizing capacitors Cc1 and Cc2 offset some of the coupled signals between the transistor base and collector, improving differential-mode stability and isolation, they are output from the collector of the common-emitter circuit to the common-base amplifier circuit. After harmonics are processed by the π-type capacitor in the common-base amplifier circuit, they are output from the collector of the common-base amplifier circuit. Bias resistors Rcasp and Rcasn provide bias power for the common-base amplifier circuit. The bias of the common-emitter circuit (not shown) can be flexibly used depending on the input matching type. The entire RF amplifier is powered by the output matching network, which can be powered by a differential inductor, a transformer, or a balun.

[0065] FIG8 is a schematic diagram showing the differential mode gain of the RF amplifier shown in FIG7 as a function of the adjustment coefficient. The horizontal axis in FIG8 is the adjustment coefficient α1, and the vertical axis is the differential mode gain. As shown in FIG8, when α1 is adjusted, the differential mode equivalent capacitance C total unchanged, so the differential mode gain does not change when adjusting α1.

[0066] FIG9 is a schematic diagram showing how the common-mode stability coefficient of the RF amplifier shown in FIG7 changes with the adjustment coefficient. The horizontal axis in FIG9 is the frequency, and the vertical axis is the common-mode stability coefficient. FIG9 shows the frequency of the same C total The comparison results of the common mode stability of the RF amplifier of the embodiment of the present disclosure and the traditional RF amplifier are shown in FIG9 , where α(α1)=1 is the traditional RF amplifier. total If they are equal, by adjusting C1, C2 and C pi With the improved capacitance distribution, the circuit common-mode stability coefficient Mu and kf are significantly improved, with Mu increased by 20% and kf increased by 121%.

[0067] FIG10 is a schematic diagram of the change of harmonics with input power under different adjustment coefficients of the RF amplifier shown in FIG7. The horizontal axis in FIG10 is the adjustment coefficient α1, and the vertical axis is the harmonic output power. FIG10 shows the change of the second harmonic and the third harmonic corresponding to different first adjustment coefficients α(α1) with input power at a frequency of 28 GHz. When α1>1, the π-type capacitor is equivalent to an inductor. It can be clearly seen from the figure that the second harmonic component and the third harmonic component can be adjusted by α1, that is, while maintaining the equivalent total capacitance C total Under the same conditions, by reasonably allocating C1, C2 and C pi The capacitance value can be used to adjust the output harmonic components of the RF amplifier. As can be seen from Figure 10, the adjustment range of the second and third harmonics is greater than 10dB.

[0068] Figure 11 is a schematic diagram of the OP1dB of the RF amplifier shown in Figure 7 changing with the adjustment coefficient, and Figure 12 is a schematic diagram of the OP3dB of the RF amplifier shown in Figure 7 changing with the adjustment coefficient. The horizontal axis in Figures 11 and 12 is the first adjustment coefficient α1, and the vertical axis is the output power of the useful signal. Figures 11 and 12 show the changes in OP1dB (output 1dB compression power) and OP3dB (output 3dB compression power) at different frequencies with the first adjustment coefficient α1. According to Figures 11 and 12, it can be seen that by adjusting the value of the first adjustment coefficient α1, the OP1dB and OP3dB of each frequency point will fluctuate to a certain extent, and the output power of α1 has a relatively average value in the 0.3-0.5 range.

[0069] The embodiment of the present disclosure provides a common-mode suppression enhanced harmonic controllable radio frequency amplifier, which can improve common-mode stability and realize adjustable harmonic components. The decoupling unit of the common-base amplifier circuit of the radio frequency amplifier adopts a π-type capacitor or a T-type capacitor. When the π-type capacitor is used, the base capacitance value C of the common-base amplifier circuit of the traditional differential radio frequency amplifier is increased. total Reasonably distribute it to the π-type capacitor of the RF amplifier to meet C total =C1(or C2)+2C pi (Under normal circumstances, C1=C2). total Under the same conditions, assign C1, C2 and C pi When using T-type capacitors, ensure that C1=C2=C total , C T =αC total Setting up a decoupling unit can achieve enhanced common-mode rejection and adjustable harmonics while ensuring that the differential-mode gain remains unchanged.

[0070] The proportion of π-type capacitors or T-type capacitors can be adjusted according to the main function of the circuit in the system. For example, when used in a power amplifier in a radio frequency transceiver system, the proportion of C1, C2 and C in the π-type capacitor network can be adjusted accordingly. pi or adjust the ratio of C in the T-type capacitor network. T To obtain the maximum OP1dB and PAE (power additional efficiency); when used in the local oscillator driver amplifier in the RF transceiver system, the C1, C2 and C in the π-type capacitor network can be adjusted. pi or adjust the ratio of C in the T-type capacitor network. T Achieve minimum harmonic output and improve harmonic suppression capability.

[0071] To improve the stability of the RF amplifier, the embodiment of the present disclosure solves the problem from the following two aspects: 1. Using neutralizing capacitors to improve the stability and isolation of the differential mode; 2. By adjusting C1, C2 and Cpi The ratio of C1 and C2 can be adjusted accordingly without affecting the differential mode signal; pi It can achieve common mode rejection enhancement and improve common mode stability; or, adjust the C in the T-type capacitor T The common mode component of the circuit can be adjusted accordingly, using a low Q capacitor C T Enhanced common mode stability can be achieved.

[0072] To solve the problem of independent regulation of odd / even harmonic components of RF amplifier, the embodiment of the present disclosure adjusts C in π-type capacitor. total The capacitance value of the π-type capacitor can be used to adjust the odd harmonic components of the RF amplifier. pi The ratio of the π-type capacitor C can be used to adjust the even harmonic components of the RF amplifier separately; total The capacitance value of the T-type capacitor can be used to adjust the odd harmonic components of the RF amplifier. T The capacitance value can independently adjust the even harmonic components of the RF amplifier, thereby achieving decoupling adjustment of odd and even harmonics.

[0073] The RF amplifier of the embodiment of the present disclosure can be applied to various types of RF amplifiers in RF millimeter wave communication systems and radar systems. For example, it can be a power amplifier, a driver amplifier, a low noise amplifier, a variable gain amplifier, etc., to achieve amplification of RF signals. It is not limited to the RF millimeter wave frequency band, and can also be used in Sub-6G and terahertz frequency bands. The RF amplifier includes a differential input port (RFin+ and RFin-) and a differential output port (RFout+ and RFout-). The differential input port is connected to the output of the previous module through an input matching network, and the differential output port connects the amplified RF signal to the input of the next module through an output matching network. The embodiment of the present disclosure aims to improve the common-mode stability of various types of RF amplifiers, regulate the harmonic components to improve the overall performance of the RF amplifier, and thus improve the performance of the entire transceiver system.

[0074] It will be appreciated by those skilled in the art that all or some of the steps in the method disclosed above, and the functional modules / units in the device can be implemented as software, firmware, hardware, and appropriate combinations thereof. In a hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As is well known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media generally embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0075] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and should be interpreted only in a general illustrative sense and not for purposes of limitation. In some instances, it will be apparent to those skilled in the art that, unless otherwise expressly indicated, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A common base amplifier circuit, comprising: a first transistor, a second transistor, and a decoupling unit, wherein the base of the first transistor is connected to the base of the second transistor; The decoupling unit is connected between the base of the first transistor and the base of the second transistor, and is configured to perform decoupling and regulation on odd harmonics and even harmonics.

2. The common base amplifier circuit according to claim 1, wherein: The decoupling unit includes a first impedance element, a second impedance element and a third impedance element; The decoupling unit is further configured to adjust odd harmonics by adjusting a target impedance parameter, where the target impedance parameter is obtained based on the impedance parameter of the first impedance element, the impedance parameter of the second impedance element, and the impedance parameter of the third impedance element; and to adjust even harmonics by adjusting a ratio of the impedance parameters of the first impedance element, the second impedance element, and the third impedance element while keeping the target impedance parameter unchanged.

3. The common base amplifier circuit according to claim 2, wherein: The first impedance element, the second impedance element or the third impedance element is one of the following or any combination thereof: a capacitor, an inductor, and a resistor.

4. The common base amplifier circuit according to claim 2 or 3, wherein: The first impedance element, the second impedance element and the third impedance element are arranged in a π shape, one end of the first impedance element is connected to the base of the first transistor, and the other end is grounded; one end of the second impedance element is connected to the base of the second transistor, and the other end is grounded; the third impedance element is connected between the base of the first transistor and the base of the second transistor.

5. The common base amplifier circuit according to any one of claims 2 to 4, wherein: The first impedance element, the second impedance element and the third impedance element are capacitors and meet the following conditions: C pi =0.5*(1-α1)*C total ; Among them, C total is the capacitance value of the decoupling unit, C pi is the capacitance value of the third impedance element, α1 is the first adjustment coefficient, α1≠1; The decoupling unit is configured such that the capacitance value C of the decoupling unit total When the first adjustment coefficient remains unchanged, the even harmonics are adjusted.

6. The common base amplifier circuit according to claim 2 or 3, wherein: The first impedance element, the second impedance element and the third impedance element are arranged in a T shape, one end of the first impedance element is connected to the base of the first transistor, and the other end is connected to one end of the second impedance element; the other end of the second impedance element is connected to the base of the second transistor; one end of the third impedance element is connected between the first impedance element and the second impedance element, and the other end is grounded.

7. The common base amplifier circuit according to claim 2, 3 or 6, wherein: The first impedance element, the second impedance element and the third impedance element are capacitors and meet the following conditions: C T =α2*C total ; Among them, C total is the capacitance value of the decoupling unit, C T is the capacitance value of the third impedance element, and α2 is the second adjustment coefficient; The decoupling unit is configured such that the capacitance value C of the decoupling unit total When the second adjustment coefficient remains unchanged, the even harmonics are adjusted.

8. The common base amplifier circuit according to any one of claims 2 to 7, wherein: At least one of the first impedance element, the second impedance element, and the third impedance element is a variable impedance element or a fixed impedance element.

9. The common base amplifier circuit according to any one of claims 2 to 8, wherein: The impedance parameter of the first impedance element is equal to or different from the impedance parameter of the second impedance element.

10. A radio frequency amplifier, comprising the common base amplifier circuit according to any one of claims 1 to 9.

11. The radio frequency amplifier according to claim 10, further comprising a common-emitter circuit, the common-emitter circuit comprising a third transistor and a fourth transistor, the emitter of the third transistor being connected to the emitter of the fourth transistor; the collector of the third transistor being connected to the emitter of the first transistor, and the collector of the fourth transistor being connected to the emitter of the second transistor.

12. The radio frequency amplifier according to claim 11, further comprising a parasitic oscillation suppression module, the parasitic oscillation suppression module comprising a first neutralization capacitor and a second neutralization capacitor, wherein one end of the first neutralization capacitor is connected to the base of the third transistor, and the other end is connected to the collector of the fourth transistor; one end of the second neutralization capacitor is connected to the base of the fourth transistor, and the other end is connected to the collector of the third transistor.

13. The radio frequency amplifier according to claim 12, wherein: The capacitance of the first neutralization capacitor is equal to or different from the capacitance of the second neutralization capacitor.

14. An electronic device comprising the radio frequency amplifier according to any one of claims 10 to 13.

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