阅读说明：本技术 一种用于光通信设备中的放大器及其方法 (Amplifier used in optical communication equipment and method thereof ) 是由 卢卡·皮亚宗 于 2017-12-15 设计创作，主要内容包括：本发明提供了一种用于光通信设备的放大器(100)。所述放大器(100)包括放大级(101)、连接到所述放大级(101)的阻抗匹配级(102)和电压控制器(103)。所述电压控制单元(103)用于根据接收到的差分输入信号(104)生成用于控制所述放大级(101)的第一控制信号(105)和生成用于控制所述阻抗匹配级(102)的第二控制信号(106)。其中,所述第一控制信号(105)和所述第二控制信号(106)之间的比值中存在预定义值。(The invention provides an amplifier (100) for an optical communication device. The amplifier (100) comprises an amplification stage (101), an impedance matching stage (102) connected to the amplification stage (101), and a voltage controller (103). The voltage control unit (103) is configured to generate a first control signal (105) for controlling the amplification stage (101) and to generate a second control signal (106) for controlling the impedance matching stage (102) in dependence on the received differential input signal (104). Wherein there is a predefined value in the ratio between the first control signal (105) and the second control signal (106).)

1. An amplifier (100) for an optical communication device, the amplifier (100) comprising:

an amplification stage (101);

an impedance matching stage (102) connected to the amplification stage (101);

a voltage controller (103) for generating a first control signal (105) for controlling the amplification stage (101) and for generating a second control signal (106) for controlling the impedance matching stage (102) depending on a received differential input signal (104), wherein

There is a predefined value in the ratio between the first control signal (105) and the second control signal (106).

2. The amplifier (100) according to claim 1, wherein a ratio between the amplitude of the first control signal (105) and the amplitude of the second control signal (106) is related to a voltage gain of the amplification stage (101).

3. The amplifier (300) according to claim 1 or 2, wherein the amplification stage (101) comprises a first transistor (301), the impedance matching stage (102) comprises a second transistor (302), and the first control signal (105) and the second control signal (106) are out of phase.

4. The amplifier (300) of any of claims 1 to 3, wherein the amplitude of the first control signal (105) is proportional to the amplitude of the second control signal (106), wherein the first control signal (105) and the second control signal (106) are 180 degrees out of phase.

5. The amplifier (300) according to any of claims 1 to 4, wherein the voltage controller (103) comprises a first voltage control circuit (303) and a second voltage control circuit (304), wherein the first voltage control circuit (303) is configured to output the first control signal (105) in dependence of the differential input signal (104) and the second voltage control circuit (304) is configured to output the second control signal (106) in dependence of the differential input signal (104).

6. The amplifier (300) according to claim 5, wherein the first voltage control circuit (303) comprises a first resistor (305) and the second voltage control circuit (304) comprises a second resistor (306), wherein the voltage controller (103) is further configured to define the ratio of the first control signal (105) and the second control signal (106) in dependence on a ratio of the first resistor (305) and the second resistor (306).

7. The amplifier (300) according to claim 5 or 6, wherein the first voltage control circuit (303) comprises a third transistor (307) and the second voltage control circuit (304) comprises a fourth transistor (308), wherein the voltage controller (103) is further configured to define the ratio of the first control signal (105) and the second control signal (106) in dependence on a ratio of the third transistor (307) and the fourth transistor (308).

8. The amplifier (300) according to claim 6 or 7, wherein the ratio of the first resistor (305) and the second resistor (306) is configured according to the type and/or configuration of the first transistor (301) and the second transistor (302), and/or wherein the ratio of the third transistor (307) and the fourth transistor (308) is configured according to the type and/or configuration of the first transistor (301) and the second transistor (302).

9. Amplifier (300) according to claim 7 or 8, characterized in that the voltage controller (103) comprises a current source (309), wherein in the third transistor (307), preferably the third transistor (307) input port (307i) is connected to the current source (309); the fourth transistor (308), preferably the input port (308i) of the fourth transistor (308), is connected to the current source (309), wherein the current source (309) is preferably connected to ground potential.

10. Amplifier (400) according to claim 7 or 8, characterized in that the input port (307i) of the third transistor (307), preferably the third transistor (307), is connected to the ground potential; the fourth transistor (308), preferably the input port (308i) of the fourth transistor (308), is connected to the ground potential.

11. The amplifier (300, 400) according to claim 9 or 10, wherein the third transistor (307) and the fourth transistor (308) have the same configuration.

12. An amplifier (500) as claimed in claim 5, characterized in that the first voltage control circuit (303) comprises a first attenuator (501) and the second voltage control circuit (304) comprises a second attenuator (502), wherein the voltage controller (103) is further adapted to define the ratio of the first control signal (105) and the second control signal (106) in dependence on the ratio of the first attenuator (501) and the second attenuator (502).

13. Amplifier (300, 400, 500) according to any of claims 3 to 12, characterized in that the voltage control unit (103) further comprises a first control output port (310) for outputting the first control signal (105) and a second control output port (311) for outputting the second control signal (106), wherein the first transistor (301), preferably the control port (301c) of the first transistor (301), is connected to the first control output port (310); the second transistor (302), preferably a control port (302c) of the second transistor (302), is connected to the second control output port (311), wherein the amplifier (300, 400, 500) further comprises a first input port (312), preferably connected to an output port (302o) of the second transistor (302), for receiving an external supply Voltage (VDD).

14. An amplifier (300, 400, 500) according to any of claims 3 to 13, characterized in that the amplifier (300, 400, 500) further comprises an output port (313) for outputting a single ended output signal (314), wherein the output port (313) is connected to the first transistor (301), preferably to the output port (301o) of the first transistor, and to the second transistor (302), preferably to the input port (302i) of the second transistor (302).

15. A method (600) of operating an amplifier (100) for an optical communication device, characterized in that the amplifier (100) comprises an amplification stage (101), an impedance matching stage (102) connected to the amplification stage (101), and a voltage controller (103); the method (600) comprises the steps of:

the voltage control unit (103) generates a first control signal (105) for controlling the amplification stage (101) and a second control signal (106) for controlling the impedance matching stage (102) depending on the received differential input signal (104), wherein a predefined value is present in the ratio between the first control signal (105) and the second control signal (106).

Technical Field

The invention relates to the technical field of optical communication, in particular to an amplifier for optical communication equipment and a method thereof.

Background

A conventional transmitter for high-speed optical communication is basically implemented by concatenating three blocks as shown in fig. 8. The first block shows a digital source, which typically provides a differential signal to improve speed and quality compared to conventional signals. The second block shows a driver amplifier for increasing the power level of the signal. The third block shows an electro-optical modulator that converts an electrical signal into an optical signal that is to be transmitted, for example, over an optical fiber.

Finally, if the driver amplifier employed exhibits a matched output impedance, the electro-optic module is less susceptible to signal degradation as the matched output impedance of the driver amplifier absorbs reflections from the interconnection between the driver amplifier and the electro-optic modulator, such as wire bonds, pads, etc., this is very important for achieving high speed and high data rate optical communications.

In summary, the driver amplifier has high performance, and has characteristics of differential input/single-ended output, dc-coupled output, and matched output impedance, and is one of the key components for realizing an extremely high-speed and highly integrated optical communication transmitter.

Conventional schemes for implementing the driver amplifier can be divided into three categories: a lossy termination, an active termination, and a single ended push-pull. Taking an active termination amplifier as an example, the following exemplarily describes the disadvantages of the conventional scheme.

Conventional active termination driver amplifiers typically implement amplifiers with differential input, dc-coupled, and single-ended output characteristics and with matched outputs through active termination.

It is noted that none of the conventional solutions is based on the auxiliary technique in a part of the amplifier operating at high frequencies. This is because the cutoff frequencies of p-channel Field Effect Transistors (FETs) and pnp bipolar transistors (BJTs) are low. Therefore, FETs and BJTs cannot be used to implement driver amplifiers that must reach the high frequency range, as is required in optical communication systems.

Therefore, there is a need for a driver amplifier that overcomes the above-mentioned disadvantages.

Disclosure of Invention

In view of the above problems and disadvantages, the present invention is directed to improving the conventional driver amplifier. The amplifier of the present invention can maximize the performance of the optical communication transmitter.

More specifically, there is provided an amplifier for an optical communication device, comprising: an amplification stage, an impedance matching stage and a voltage controller (hereinafter also referred to as a voltage control unit). The voltage control unit generates a first control signal for controlling the amplification stage and a second control signal for controlling the impedance matching stage according to the received differential input signal. The ratio between the first control signal and the second control signal may be a predefined value, which helps to overcome the above mentioned disadvantages.

More specifically, the amplifier of the invention has the following advantages over conventional solutions:

1. no output power loss: the amplifier in the present invention dissipates any output power during signal transmission compared to conventional schemes based on lossy termination and single-ended push-pull. Thus, the solution maximizes the gain and output voltage, with minimal dc power consumption.

2. Linear operation: compared to conventional schemes based on active termination, the amplifier of the present invention can be used for both switched mode and linear amplifiers.

3. Instantaneous reaction: in contrast to conventional schemes based on active termination, the amplifier of the present invention does not require time to present a matched output impedance because the amplifier does not include an operational amplifier in the circuit.

4. High integration level: compared to conventional schemes based on active termination, the proposed scheme can be easily implemented in GaAs or GaN MMIC technology, since no operational amplifier is included in the scheme.

The object of the invention is achieved by the solution provided in the independent claims. Advantageous embodiments of the invention are further defined in the dependent claims.

In a first aspect, the present invention provides an amplifier for an optical communication device, the amplifier comprising: the circuit comprises an amplification stage, an impedance matching stage connected to the amplification stage and a voltage control unit, wherein the voltage control unit is used for generating a first control signal for controlling the amplification stage and a second control signal for controlling the impedance matching stage according to a received differential input signal, and a ratio of the first control signal to the second control signal has a predefined value.

In an embodiment of the amplifier according to the first aspect, a ratio between the amplitude of the first control signal and the amplitude of the second control signal may be related to a voltage gain of the amplifier stage.

In another implementation of the amplifier according to the first aspect, the amplification stage may comprise a first transistor, the impedance matching stage may comprise a second transistor, and the first control signal and the second control signal may be out of phase.

In another embodiment of the amplifier according to the first aspect, the amplitude of the first control signal may be proportional to the amplitude of the second control signal, and the first and second control signals may be 180 degrees out of phase.

According to the first aspect, in another embodiment of the amplifier, the voltage control unit may comprise a first voltage control circuit (hereinafter also referred to as first voltage control means) and a second voltage control circuit (hereinafter also referred to as second voltage control means), wherein the first voltage control means may be adapted to output the first control signal in dependence of the differential input signal and the second voltage control means may be adapted to output the second control signal in dependence of the differential input signal.

In another implementation of the amplifier according to the first aspect, the first voltage control means may comprise a first resistor and the second voltage control means may comprise a second resistor. The voltage control unit may be further configured to define the ratio of the first control signal and the second control signal according to a ratio of the first resistor and the second resistor.

In another implementation of the amplifier according to the first aspect, the first voltage control means may comprise a third transistor and the second voltage control means may comprise a fourth transistor. The voltage control unit may be further configured to define the ratio of the first control signal and the second control signal according to a ratio of the third transistor and the fourth transistor.

In another implementation of the amplifier according to the first aspect, the ratio of the first and second resistors may be configured according to the type and/or configuration of the first and second transistors, and/or the ratio of the third and fourth transistors may be configured according to the type and/or configuration of the first and second transistors.

In another implementation of the amplifier according to the first aspect, the voltage control unit may comprise a current source. The third transistor, for example, an input port of the third transistor may be connected to the current source; the input port of the fourth transistor, e.g. the fourth transistor, may be connected to the current source, wherein the current source may be connected to ground potential.

In another embodiment of the amplifier according to the first aspect, the input port of the third transistor, e.g. the third transistor, may be connected to the ground potential; the input port of the fourth transistor, e.g. the fourth transistor, may be connected to the ground potential.

In another implementation of the amplifier according to the first aspect, the third transistor and the fourth transistor may have the same configuration.

In another embodiment of the amplifier according to the first aspect, the first voltage control means may comprise a first attenuator and the second voltage control means may comprise a second attenuator. The voltage control unit may be further configured to define the ratio of the first control signal and the second control signal according to a ratio of the first attenuator and the second attenuator.

According to the first aspect, in another implementation of the amplifier, the voltage control unit may further include a first control output port for outputting the first control signal and a second control output port for outputting the second control signal. The first transistor, e.g. a control port of the first transistor, may be connected to the first control output port; a control port of the second transistor, e.g. the second transistor, may be connected to the second control output port. The amplifier may further comprise a first input port connected to the second transistor, e.g. to an output port of the second transistor, for receiving an external supply voltage.

In another implementation of the amplifier according to the first aspect, the amplifier may further comprise an output port for outputting a single-ended output signal. The output port may be connected to the first transistor, e.g. to an output port of the first transistor, and to the second transistor, e.g. to an input port of the second transistor.

In another embodiment of the amplifier according to the first aspect, the amplifier may comprise a second input port and a third input port. The amplifier may be further configured to receive the differential input signal at the second input port and the third input port and then provide the received differential input signal to the voltage control unit.

In a second aspect, the present invention provides a method of operating an amplifier for an optical communication device, the amplifier comprising an amplification stage, an impedance matching stage connected to the amplification stage, and a voltage controller (also referred to as a voltage control unit); the method comprises the following steps: the voltage control unit generates a first control signal for controlling the amplification stage and a second control signal for controlling the impedance matching stage depending on the received differential input signal, wherein a predefined value is present in the ratio between the first control signal (105) and the second control signal (106).

In an embodiment of the method according to the second aspect, the ratio between the amplitude of the first control signal and the amplitude of the second control signal may be related to the voltage gain of the amplifier stage.

In another embodiment of the method according to the second aspect, the amplification stage may comprise a first transistor, the impedance matching stage may comprise a second transistor, and the first control signal and the second control signal may be out of phase.

In another embodiment of the method according to the second aspect, the amplitude of the first control signal may be proportional to the amplitude of the second control signal, and the first and second control signals may be 180 degrees out of phase.

According to the second aspect, in another embodiment of the method, the voltage control unit may comprise a first voltage control means operable to output the first control signal in dependence on the differential input signal and a second voltage control means operable to output the second control signal in dependence on the differential input signal.

According to the second aspect, in another embodiment of the method, the first voltage control device may comprise a first resistor and the second voltage control device may comprise a second resistor. The voltage control unit may be further configured to define the ratio of the first control signal and the second control signal according to a ratio of the first resistor and the second resistor.

In another embodiment of the method according to the second aspect, the first voltage control means may comprise a third transistor and the second voltage control means may comprise a fourth transistor. The voltage control unit may be further configured to define the ratio of the first control signal and the second control signal according to a ratio of the third transistor and the fourth transistor.

In another embodiment of the method according to the second aspect, the ratio of the first and second resistors may be configured according to the type and/or configuration of the first and second transistors, and/or the ratio of the third and fourth transistors may be configured according to the type and/or configuration of the first and second transistors.

In another embodiment of the method according to the second aspect, the voltage control unit may comprise a current source. The third transistor, for example, an input port of the third transistor may be connected to the current source; the input port of the fourth transistor, e.g. the fourth transistor, may be connected to the current source, wherein, e.g. the current source may be connected to ground potential.

In another embodiment of the method according to the second aspect, the input port of the third transistor, e.g. the third transistor, may be connected to the ground potential; the input port of the fourth transistor, e.g. the fourth transistor, may be connected to the ground potential.

In another embodiment of the method according to the second aspect, the third transistor and the fourth transistor may have the same configuration.

In another embodiment of the method according to the second aspect, the first voltage control device may comprise a first attenuator and the second voltage control device may comprise a second attenuator. The voltage control unit may be further configured to define the ratio of the first control signal and the second control signal according to a ratio of the first attenuator and the second attenuator.

According to the second aspect, in another implementation of the method, the voltage control unit may further include a first control output port for outputting the first control signal and a second control output port for outputting the second control signal. The first transistor, e.g. a control port of the first transistor, may be connected to the first control output port; a control port of the second transistor, e.g. the second transistor, may be connected to the second control output port. The amplifier may further comprise a first input port connected to the second transistor, e.g. to an output port of the second transistor, for receiving an external supply voltage.

In another embodiment of the method according to the second aspect, the amplifier may further comprise an output port for outputting a single ended output signal. The output port may be connected to the first transistor, e.g. to an output port of the first transistor, and to the second transistor, e.g. to an input port of the second transistor.

In another embodiment of the method according to the second aspect, the amplifier may comprise a second input port and a third input port. The amplifier may be further configured to receive the differential input signal at the second input port and the third input port and then provide the received differential input signal to the voltage control unit.

The method and its embodiments in the second aspect achieve the same advantages as the amplifier and its corresponding embodiments in the first aspect.

A third aspect of the invention provides an optical communication device comprising the amplifier according to the first aspect or any embodiment of the first aspect, and an electro-optical modulator.

The optical communication apparatus of the third aspect achieves the same advantages as the amplifier of the first aspect and the corresponding implementation forms of the first aspect.

It should be noted that all devices, elements, units and means described in the present application may be implemented in software or hardware elements or any combination thereof. All steps performed by the various entities and functions performed by the various entities described in this application are intended to indicate that the various entities are adapted or used to perform the various steps and functions. Even in the following description of specific embodiments, the specific functions or steps performed by an external entity are not reflected in the description of specific detailed elements of the specific entity performing the specific steps or functions. It should be clear to the skilled person that these methods and functions can be implemented in corresponding software or hardware elements or any combination thereof.

Drawings

The above aspects and embodiments of the present invention are described in detail below by way of specific examples in conjunction with the accompanying drawings.

FIG. 1 illustrates an amplifier provided by an embodiment of the present application;

FIG. 2 shows a schematic model of a transistor;

FIG. 3 illustrates an amplifier provided by an embodiment of the present application in more detail;

FIG. 4 illustrates another amplifier provided by embodiments of the present application;

FIG. 5 illustrates another amplifier provided by embodiments of the present application;

FIG. 6 shows a schematic overview of a method provided by an embodiment of the invention;

fig. 7 illustrates an optical communication apparatus provided by an embodiment of the present invention;

fig. 8 shows a schematic diagram of a conventional optical transmitter.

Detailed Description

Fig. 1 shows an amplifier 100 provided in an embodiment of the present application. The amplifier 100 is particularly suitable for optical communication devices, i.e. the amplifier 100 is suitable for handling frequencies used for optical communication. The amplifier 100 is particularly illustrated by the rectangle shown in fig. 1, which contains further circuitry. The rectangle specifically illustrates that the amplifier 100 may in principle be a conventional amplifier comprising non-conventional circuitry, wherein the advantageous effects of the invention are based on the non-conventional circuitry.

The amplifier 100 comprises an amplification stage 101, an impedance matching stage 102 and a voltage controller (hereinafter also referred to as voltage control unit) 103. As shown in fig. 1, the impedance matching stage 102 and the amplification stage 101 are connected to each other. The amplification stage 101 may be implemented by a transistor, and the impedance matching stage 102 may be implemented by a transistor, a resistor, or a combination of the transistor and the resistor.

The core of the invention is to modify a received differential input signal 104 (received by the amplifier 100 and then provided to the voltage control unit 103 in the amplifier 100) to generate a first control signal 105 and a second control signal 106 having a predefined relationship. The first control signal 105 and the second control signal 106 are generated by the voltage control unit 103, and the voltage control unit 103 can adjust the amplitude and the phase of the generated signals respectively. The first control signal 105 is fed to the amplification stage 101 and the second control signal 106 is fed to the impedance matching stage 102. The function of the amplification stage 101 is to amplify the signal provided by a single output port of the amplifier 100, i.e. the signal Vout shown in fig. 1, while the function of the impedance matching stage 102 is to absorb external interfering signals. The specific relation of the second control signal 106 in the impedance matching stage 102 and the first control signal 105 in the amplification stage 101 allows to drive the impedance matching stage 102 in such a way that the impedance matching stage 102 attenuates the signal generated by the amplification stage 101 during transmission. Further, the ratio of the amplitude of the first control signal 105 to the amplitude of the second control signal 106 is related to the voltage gain of the amplifier stage 101. Thus, the amplifier 100 provides an amplifier with differential input, dc coupling, single ended output characteristics, and with matched outputs.

In other words, according to an embodiment of the present invention, the control voltage of the impedance matching stage 102 (i.e. the second control signal 106) is selected in a defined relationship according to the control voltage of the amplification stage 101 (i.e. the first control signal 105) such that the impedance matching stage 102 does not attenuate the output signal Vout during transmission.

In case the amplification stage 101 and/or the impedance matching stage 102 comprise transistors, these transistors may be implemented using any type of transistors known in the art. Also, all other transistors to be described herein can be implemented by using any type of transistor known in the art. More specifically, a Bipolar Junction Transistor (BJT) or a Field Effect Transistor (FET) may be used in the amplifier 100. All transistors used in the amplifier 100 are not of the same type, and any combination of different types of transistors may be used.

In case of BJT, the basic port of the BJT can be considered as the control port, the emission port of the BJT as the input port, and the collection port of the BJT as the output port.

In the case of a FET, the gate port of the FET may be considered as a control port, the drain port of the FET may be considered as an input port, and the source port of the FET may be considered as an output port.

The amplifier 100 may also use transistor types such as Heterojunction Bipolar Transistors (HBTs), darlington transistors, schottky transistors, multi-emitter transistors, double-gate MOSFETs, junction FET transistors, avalanche transistors, or diffusion transistors.

In a preferred embodiment, the amplifier stage 101 and the impedance matching stage 102 are implemented by transistors. In this case, the first control signal 105 and the second control signal 106 may be out of phase, i.e. phase shifted from each other.

The transistors of the amplifier stage 101 and the matching stage 102 may be both FET transistors or both BJT transistors. The transistors may have the same channel definition. For example, if FET transistors are employed, both transistors are n-channel transistors; if BJT transistors are used, both transistors are npn transistors. Schemes based on the p-channel of the FET or the pnp of the BJT are technically feasible, but their practical significance is not great due to the low cut-off frequency of the p-channel FET and the pnp BJT. Throughout, further example embodiments of the amplifier 100 are based on n-channel FET transistors. However, these example embodiments may also be based on npn bjt transistors or any combination thereof.

Further alternatively, the voltage control unit 103 may be regarded as an assembly having four terminals, i.e. 2 input ports and 2 output ports, the constitutive behavior of which can be described by the following equation (equation 1):

V_OUT1＝A·V_IN1

V_OUT2＝B·V_IN2

wherein, V_IN1And V_IN2Is the voltage at the input port (Vin + and Vin-in FIG. 1), and V_OUT1And V_OUT2Is the voltage of the output ports (e.g., the first control signal 105 and the second control signal 106 in fig. 1). In addition, the parameters "a" and "B" are real values and may be defined independently.

The differential input signal 104 of the amplifier 100 is represented by Vin + and Vin- (see fig. 1). The single ended output of the amplifier is denoted Vout (see fig. 1).

To use the amplifier 100 in an optical communication device, the output signal may be dc coupled to an electro-optical modulator such as EM L.

Fig. 1 only shows the components of the amplifier 100 that are relevant for the core effect on which embodiments of the invention are based. Any other components of the amplifier 100, in particular those to be described below, such as in fig. 3, 4 and 5, may be considered optional features. Any variation of amplifiers known in the art is suitable for use with the present invention, particularly the amplifier as described in fig. 1.

Fig. 2 shows a schematic model of a transistor that may be used for amplifier 100. Although the function of the amplifier 100 can be implemented by any type of transistor, it is now demonstrated by using the well-known simplified model, in which the transistor is assumed to be a FET.

Section a of fig. 2 shows the correlation between the output, control and input ports of the above general transistor and the drain, gate and source ports of the FET.

Part B of FIG. 2 shows the control of the current source (I) by voltage_ds＝g_m×V_gs) The equivalent circuit of the composed FET.

For the FETThe equivalent circuit, the voltage gain (A) of amplifier 100 in FIG. 1_V) And output impedance (Z)_OUT) The calculation can be performed as shown in the following formulas 2 and 3.

Equation 2:

equation 3:

wherein, g_m1And g_m2Is the transconductance of the FETs used to implement the amplifier stage 101 and the impedance matching stage 102, as shown in fig. 1. R_LRepresents the equivalent resistance of an electro-optic modulator D (which may be EM L, which may be connected to the output port of the amplifier 100, also shown in fig. 3, 4 and 5), where "K ═ V_g2/V_g1"is the voltage magnitude V of the transistor gate terminals for realizing the amplification stage 101 and the impedance matching stage 102_g2And V_g1The ratio of (a) to (b). That is, V_g2Is the second control signal 106, V_g1Is the first control signal 105.

More specifically, in case the amplification stage 101 is implemented by a transistor, the first control signal 105 is provided to a control port of the transistor and the first control signal 105 is provided to an output port to output an output signal Vout connected to the output port of the transistor. In case the impedance matching stage 102 is implemented by a transistor, the second control signal 106 is provided to a control port of the transistor and the second control signal 106 is provided to an output port for outputting the output signal Vout connected to the input port of the transistor.

This general concept applies to the amplifier stage 101 and the impedance matching stage 102 as described in fig. 1, as well as to the first transistor 301 and the second transistor 302 in fig. 3, 4 and 5.

In order to achieve matching output impedance by the amplifier 100, it is necessary to satisfy“Z_OUT＝R_L". The matched output impedance can be achieved by appropriate selection of the transistors used to implement the impedance matching stage 102, satisfying "g", according to equation 3_m2＝1/R_L". In addition, in order to avoid power loss during signal transmission, the transistor for implementing the impedance matching stage 102 needs to have constant current source characteristics. According to equation 2, the matched output impedance may be determined by selecting "K ═ g_m1×R_L"to achieve. The matching of the output impedance is achieved by the voltage control unit 103, since "K ═ B/a", where a and B are parameters in equation 1 (see above).

In other words, the core of the invention is that the transistors used to implement the amplification stage 101 and the impedance matching stage 102 have input voltages (V) of different magnitudes_g1And V_g2) And are all out of phase (wherein, V_g1Is said first control signal 105, V_g2The second control signal 106). By appropriate amplitude ratio (K ═ g)_m1×R_L) The matched output impedance can be obtained without consuming output power during signal transmission.

Fig. 3 shows amplifier 300 provided by an embodiment of the present application in more detail. The amplifier 300 includes all of the features and functions of the amplifier 100. All additional features and functions of the amplifier 300 may be considered optional features.

The amplifier 300 may specifically include a first transistor 301, a second transistor 302, a first voltage control circuit (hereinafter also referred to as a first voltage control device) 303, a second voltage control circuit (hereinafter also referred to as a second voltage control device) 304, a first resistor 305, a second resistor 306, a third transistor 307, a fourth transistor 308, a current source 309, a first control output port 310, a second control output port 311, a first input port 312, an output port 313, a second input port 315, and a third input port 316.

In fig. 3, the first transistor 301 implements the amplifier stage 101 and the second transistor 302 implements the impedance matching stage 102. To this end, a first control signal 105 is received by the first transistor 301 and a second control signal 106 is received by the second transistor 302. This is achieved by the control port 301c of the first transistor 301 being connected to the first control output port 310 and the control port 302c of the second transistor 302 being connected to the second control output port 311. The first transistor 301 and the second transistor 302 may be both FETs.

In the embodiment shown in fig. 3, in a preferred embodiment, the amplitude (which may be considered as an absolute value) of the second control signal 106 is proportional to the amplitude of the first control signal 105, wherein the two signals are out of phase by 180 degrees (V)_g2＝-g_m1R_L×V_g1) For example. In particular, the second control signal 106 at the control port 302c of the second transistor 302 is phase shifted by 180 degrees with respect to the first control signal 105. Thus, if the second control signal 106 is out of phase with the first control signal 105, the signals at the input port 302i of the second transistor 302 and at the output port 301o of the first transistor 301 will again be in phase and the matching stage 102 (i.e. the second transistor 302) will not attenuate the output signal 314 during the transmit phase.

As also shown in fig. 3, the input port 301i of the first transistor 301 is connected to ground potential, the output port 302o of the second transistor is connected to the first input port 312, the output port 313 is used for outputting the single-ended output signal 314, to this end, the output port 313 is also connected to the first transistor 301, for example to the output port 301o of the first transistor, and to the second transistor 302, for example to the input port 302i of the second transistor 302, through the input port 312 an external supply voltage VDD can be supplied to the amplifier 300 via an external source not included in the amplifier 300, through the output port 313 the output signal 314 can be supplied to an external electro-optical modulator, i.e. a device capable of converting electronic information into optical information, for example EM L, which is not included in the amplifier 300.

The voltage control unit 103 may further optionally comprise a first voltage control means 303 and a second voltage control means 304, as shown in fig. 3.

The first voltage control means 303 is arranged to output the first control signal 105 in dependence of a differential input signal 104. The second voltage control means 304 is configured to output the second control signal 106 according to the differential input signal 104. For outputting the first control signal 105, the first voltage control means 303 is connected to the first control output port 310; for outputting the second control signal 106, the second voltage control means 304 is connected to the second control output port 311. To receive the differential input signal 104, the first voltage control means 303 is connected to the second input port 315 and the second voltage control means 304 is connected to the third input port 316. Thus, the amplifier 300 may be configured to receive the differential input signal 104 at the second input port 315 and the third input port 316 and to provide the received differential input signal 104 to the voltage control unit 103. The differential input signal 104 may include two differential components, Vin-and Vin +.

Further optionally, the first voltage control means 303 may comprise the first resistor 305 and the second voltage control means 304 may comprise the second resistor 306. The voltage control unit 103 defines the ratio of the first control signal 105 and the second control signal 106 in particular in dependence on the ratio of the first resistor 305 and the second resistor 306, in particular in dependence on the ratio of the resistances in these two resistors. More specifically, the first resistor 305 and the second resistor 306 are both connected to the first input port 312.

Further optionally, the first voltage control means 303 may comprise the third transistor 307 and the second voltage control means 304 may comprise the fourth transistor 308. In addition, the voltage control unit 103 may define the ratio of the first control signal 105 and the second control signal 106 according to a ratio of the third transistor 307 and the fourth transistor 308, especially according to a ratio of operating characteristics of the two transistors. More specifically, the first resistor 305 is connected to the third transistor 307, for example, to an output port 307o of the third transistor 307. More specifically, the second resistor 306 is connected to the fourth transistor 308, for example to an output port 308o of the fourth transistor 308.

More specifically, the ratio of the first resistor 305 and the second resistor 306 is configured according to the type and/or configuration of the first transistor 301 and the second transistor 302. More specifically, the ratio of the third transistor 307 and the fourth transistor 308 is configured according to the type and/or configuration of the first transistor 301 and the second transistor 302. I.e. the first control signal 105 and the second control signal 106 may be fine-tuned according to the type and/or configuration of the first transistor 301 and/or the second transistor 302.

To generate the first control signal 105, the third transistor 307, e.g. the control port 307c of the third transistor 307, is connected to the second input port 315 based on the received differential input signal 104. The second input port 315 may receive the Vin + component of the differential input signal 104.

To generate the second control signal 106, the fourth transistor 308, e.g. the control port 308c of the fourth transistor 308, is connected to the third input port 316 based on the received differential input signal 104. The third input port 316 may receive the Vin-component of the differential input signal 104.

For outputting the first control signal 105, the first control output port 310 is connected to the third transistor 307, for example to the output port 3070 of the third transistor 307, and to the first resistor 305. For outputting the second control signal 106, the second control output port 311 is connected to the fourth transistor 308, e.g. to the output port 3080 of the fourth transistor 308, and to the second resistor 305.

As shown in fig. 3, the voltage control unit 103 may further include an optional current source 309. In this case, the third transistor 307, for example, the input port 307i of the third transistor 307, is connected to the current source 309; the fourth transistor 308, for example the input port 308i of the fourth transistor 308, is connected to the current source 309, wherein the current source 309 may also be connected to ground potential.

More specifically, the third transistor 307 and the fourth transistor 308 may have the same configuration, i.e., they may be of the same type and/or provide the same operating characteristics.

In other words, the embodiment of fig. 3 comprises said first transistor 301, said second transistor 302 and said voltage control unit 103, said voltage control unit 103 being implemented by a differential amplifier with unequal load resistors (i.e. said first resistor 305 and said second resistor 306). In a specific implementation example, the differential amplifier includes two equal transistors (i.e., the third transistor 307 and the fourth transistor 308), two resistors (i.e., the first resistor 305 and the second resistor 306), and a constant current source 309. The first resistor may also be referred to as R₁Said second resistor may also be called R₂. In this example, the first control signal 105 may also be referred to as V_g1The second control signal 106 may also be referred to as V_g2. I.e. the selection resistor R₁And R₂To obtain a suitable V_g1And V_g2The ratio of (a) to (b). In particular, R is selected₂/R₁＝V_g2/V_g1＝g_m1×R_LTo obtain the advantageous effects of the present invention. In particular, the embodiment depicted in fig. 3 is considered to be the simplest way to fully integrate the present invention in MMIC technology.

Fig. 4 shows another amplifier 400 provided by an embodiment of the present application. The amplifier 400 includes all the features and functions of the amplifier 100 and the amplifier 300 described above, except that the amplifier 400 does not include the current source 309. Instead, the third transistor 307, e.g., the input port 307i of the third transistor 307, is connected to ground potential; the fourth transistor 308, for example, the input port 308i of the fourth transistor 308, is connected to the ground potential.

In other words, in the embodiment shown in fig. 4, the voltage control units 103 are implemented by unequal single-ended amplifiers. Voltage V_g1And V_g2(i.e., the first control signal 105 and the second control signal 106) may be scaled by selecting an appropriate resistor R₁And R₂(i.e., the first resistor 305 and the second resistor 306); or by selecting the appropriate transistor Q₃And Q₄(i.e., the third transistor 307 and the fourth transistor 308); or by selecting a resistor (R)₁，R₂The first resistor 305 and the second resistor 306) and a transistor (Q)₃，Q₄The third transistor 307 and the fourth transistor 308) to obtain the following equation:

wherein gm1, gm3 and gm4 represent FETQ in FIG. 4₁、Q₃And Q₄Of (2), wherein Q₁The first transistor 301 is denoted by Q3, the third transistor 307 is denoted by Q4, and the fourth transistor 308 is denoted by Q4.

Fig. 5 shows another amplifier 500 provided in the embodiments of the present application. The amplifier 500 comprises all the features and functions of the amplifier 100 and 300 described above, with the difference that the amplifier 500 does not comprise the current source 309, the first voltage control means 303 does not comprise the first resistor 305 and the third transistor 307, and the second voltage control means 304 does not comprise the second resistor 306 and the fourth transistor 308. Instead, the first voltage control means 303 comprises a first attenuator 501 and the second voltage control means 304 comprises a second attenuator 502. The voltage control unit 103 defines the ratio of the first control signal 105 and the second control signal 106, i.e. the ratio of the operating characteristics of the two attenuators, in dependence on the ratio of the first attenuator 501 and the second attenuator 502. The first attenuator 501 is connected to the second input port 315 and the first control output port 310. The second attenuator 502 is connected to the third input port 316 and the second control output port 311.

In other words, in the embodiment as shown in fig. 5, the voltage control unit 103 is implemented by unequal attenuators. Selecting the attenuation levels of the first attenuator 501 and the second attenuator 502 to obtain a suitable V_g1And V_g2(i.e., the first control signal 105 and the second control signal 106). Any method of implementing an attenuator is suitable for use with the present invention. In one particular example embodiment, the attenuator may be a reduced signal power electronic device that does not significantly distort the signal waveform.

Fig. 6 shows a schematic diagram of a method 600 for the amplifier 100. The method 600 corresponds to the amplifier 100 of fig. 1 and is accordingly used to operate the amplifier 100.

The method 600 comprises the steps 601: the voltage control unit 103 of the amplifier 100 generates a first control signal 105 for controlling the amplification stage 101 in the amplifier 100 and a second control signal 106 for controlling the impedance matching stage 102 in the amplifier 100 from the received differential input signal 104, wherein a predefined value exists in the ratio of the first control signal 105 and the second control signal 106.

Fig. 7 shows an optical communication device 700 provided by an embodiment of the present invention, the optical communication device 700 includes an amplifier 100 and an electro-optical modulator the optical communication device 700 may also be implemented by any of the amplifiers 200, 300 or 400, the electro-optical modulator may be EM L.

The invention has been described by way of example and implementation in connection with various embodiments. Other variations will become apparent to those skilled in the art upon a study of the drawings, the disclosure, and the independent claims, when practicing the claimed invention. In the claims, the term "comprising" does not exclude other elements or steps, and the "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.