Amplifier device

Abstract

An amplifier device includes an amplifier unit and a bias module. The amplifier unit has a first end coupled to a voltage source for receiving a power supply voltage, a second end for receiving an input signal, and a third end coupled to a first reference potential end. The first reference potential end is used to receive a first reference potential. The first end of the amplifier unit is used to output an output signal amplified by the amplifier unit. The bias module is coupled to the second end of the amplifier unit for receiving a voltage signal to provide a bias current to the amplifier unit. The voltage signal is a variable voltage. A power supply current flows into the amplifier unit, and the power supply current is adjusted according to the voltage signal to maintain the power supply current within a predetermined range.

Description

Technical Field

[0001] The present invention relates to an amplifier device, and more particularly to an amplifier device capable of adjusting bias current according to various factors and providing corresponding compensation. Background Art

[0002] In wireless communication technology, amplifier devices are often used to amplify signals to improve the quality of received and transmitted signals. However, as applications become more and more complex, the factors that need to be considered when designing amplifier devices also increase accordingly to avoid affecting the performance of the amplifier devices. Summary of the invention

[0003] An embodiment of the present invention provides an amplifier device, comprising an amplifier unit and a bias module. The amplifier unit has a first end coupled to a voltage source for receiving a power supply voltage, a second end for receiving an input signal, and a third end coupled to a first reference potential end, wherein the first reference potential end is used to receive a first reference potential, and the first end of the amplifier unit is used to output an output signal amplified by the amplifier unit. The bias module is coupled to the second end of the amplifier unit for receiving a voltage signal to provide a bias current to the amplifier unit, wherein the voltage signal is a variable voltage. The power supply current flows into the amplifier unit, and the power supply current is adjusted according to the voltage signal to maintain the power supply current within a predetermined range. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a schematic diagram of an amplifier device according to an embodiment of the present invention.

[0005] Figure 2 shows the voltage response of the uncompensated supply current.

[0006] FIG. 3 shows a voltage compensation scheme using bias current according to an embodiment of the present invention.

[0007] FIG. 4 is a schematic diagram of the variable current source in FIG. 1 .

[0008] FIG. 5 is a schematic diagram of another variable current source in FIG. 1 .

[0009] FIG. 6 is a schematic diagram of another amplifier device according to an embodiment of the present invention.

[0010] FIG. 7 is a schematic diagram of another amplifier device according to an embodiment of the present invention.

[0011] FIG. 8 is a schematic diagram of another amplifier device according to an embodiment of the present invention.

[0012]

Explanation of symbols

[0013] 2: Amplifier device

[0014] 11: Amplification unit

[0015] 12: Bias module

[0016] 20, 30, 155, 1608: Reference potential terminal

[0017] 24: Voltage Source

[0018] 130, 132: Curve

[0019] 134, 136, 140, 142: Line segments

[0020] 151, 153, 1601 to 1607: Signal terminals

[0021] 152: first resistor selection circuit

[0022] 154: Second resistor selection circuit

[0023] 156: Voltage to Current Converter

[0024] 157, 158: switch control terminal

[0025] 190: Bias voltage source

[0026] 1200: variable current source

[0027] 1201, 1206: Transistor

[0028] 1203, 1207, Rp1 to Rp6, Rn1 to Rn6, RF, RF1: Resistance

[0029] 1204, 1205: diode

[0030] Ibias: bias current

[0031] Icc: Supply current

[0032] OP: Operational Amplifier

[0033] S1: Input signal

[0034] S2: Output signal

[0035] SW1, SW2: switches

[0036] V1: supply voltage

[0037] VBG2, VBG3, Vdet02, Vr5: reference signals

[0038] VCC1: voltage signal

[0039] Vdet2: power signal

[0040] Vo: Output voltage

[0041] VPTAT2, VD0, Vat: temperature signal

[0042] Vref1, Vref5: reference potential

[0043] Vsource: power supply voltage DETAILED DESCRIPTION

[0044] FIG. 1 is a schematic diagram of an amplifier device 2 according to an embodiment of the present invention. The amplifier device 2 includes an amplifier unit 11 and a bias module 12. The amplifier unit 11 can extract a supply current Icc from a voltage source 24, and the voltage source 24 is used to receive a power supply voltage Vsource. The power supply voltage Vsource is a time-varying voltage. When the power supply voltage Vsource changes with time, the supply current Icc will also change accordingly. FIG. 2 shows the voltage response of the uncompensated supply current Icc, where the horizontal axis is the power supply voltage Vsource represented by volt (volt, V), and the vertical axis is the supply current Icc represented by milliampere (mA). Curve 130 represents the ideal supply current Icc, curve 132 represents the actual supply current Icc, and line segments 134 and 136 represent the first and second approximate curves of the actual supply current Icc, respectively. In one embodiment, the power supply voltage Vsource can change from 5.5V to 3.2V within a period of time, and the amplifier unit 11 can operate within the range of the power supply voltage Vsource. Ideally, the supply current Icc should be substantially maintained at 140 mA, as shown by curve 130. In practice, the supply current Icc may vary between 120 mA and 160 mA, as shown by curve 132. For a supply voltage Vsource ranging between 3.2 V and 4.7 V, curve 132 may be approximated by line segment 134, and for a supply voltage Vsource ranging between 4.7 V and 5.5 V, curve 132 may be approximated by line segment 136. Line segments 134 and 136 may have a first slope and a second slope, respectively.

[0045] FIG. 3 shows a voltage compensation scheme using a bias current Ibias in an embodiment of the present invention. Line segments 140 and 142 represent the bias current Ibias generated by the bias module 12 when the power supply voltage Vsource is less than a critical value and exceeds a critical value, respectively. The critical value can be substantially selected as the intersection of line segments 134 and 136 of FIG. 2, such as 4.7V. Line segments 140 and 142 show that the bias current Ibias is negatively correlated with the power supply voltage Vsource of FIG. 2. In addition, line segment 140 has a first inverse slope corresponding to the first slope of line segment 134 of FIG. 2, and line segment 142 has a second inverse slope corresponding to the second slope of line segment 136 of FIG. 2. The first inverse slope can be negatively correlated to the first slope, and the second inverse slope can be negatively correlated to the second slope. The amplifier device 2 can adjust the bias current Ibias according to the line segments 140 and 142 to compensate for the change of the power supply voltage Vsource over time, so that the amplifier unit 11 can maintain operation with a substantially fixed supply current Icc, such as 140mA, and improve the performance of the amplifier device 2. In some embodiments, for a power supply voltage Vsource less than 4.7V, the bias module 12 can adjust the bias current Ibias according to the line segment 140, and for a power supply voltage Vsource exceeding 4.7V, the bias module 12 can adjust the bias current Ibias according to the line segment 142. In some embodiments, the amplifier device 2 can compensate for the change of the power supply voltage Vsource according to the line segment 140 or the line segment 142.

[0046] Although only two line segments 134 and 136 are used to approximate the actual supply current Icc (curve 132) in FIG. 2, those skilled in the art may use more than two approximation curves to approximate the actual supply current Icc, and correspondingly use more than two corresponding lines that are negatively correlated to the more than two approximation curves to simulate the bias current Ibias of the required operating range, and use two or more critical values ​​to determine which of the more than two corresponding lines to use to simulate the bias current Ibias, so as to compensate for the change of the power supply voltage Vsource. The inverse slope and critical value of the line segment simulating the bias current Ibias are not limited to the embodiment in FIG. 3, and can be selected based on actual applications and design requirements.

[0047] Referring to FIG. 1 , the amplifier unit 11 has a first terminal coupled to a voltage source 24 for receiving a power supply voltage Vsource and for flowing a power supply current Icc, a second terminal for receiving an input signal S1, and a third terminal coupled to a reference potential terminal 20. The amplifier unit 11 may be a bipolar junction transistor (BJT), and may be used as a power amplifier or a low noise amplifier. The amplifier unit 11 may be biased by a bias current Ibias to amplify the input signal S1, and an output signal S2 amplified by the amplifier unit 11 may be output from the first terminal of the amplifier unit 11. The reference potential terminal 20 may receive a reference potential Vref1. The reference potential Vref1 may be a ground reference potential or other reference potentials.

[0048] The bias module 12 may be coupled to the second end of the amplifier unit 11, and may receive a voltage signal VCC1 to provide a bias current Ibias to the amplifier unit 11. The voltage signal VCC1 may be substantially positively correlated with the time-varying power supply voltage Vsource, so the voltage signal VCC1 may also be a time-varying variable voltage. In some embodiments, the voltage signal VCC1 may be a portion of the power supply voltage Vsource, and a voltage divider may be used to divide the power supply voltage Vsource to obtain the voltage signal VCC1, wherein VCC1=Vsource*K, and K may be 0.5. In other embodiments, the voltage signal VCC1 may be substantially equal to the power supply voltage Vsource.

[0049] Since the voltage signal VCC1 is substantially positively correlated with the power supply voltage Vsource, in contrast, in FIG. 3 , the line segments 140 and 142 may also indicate that the bias current Ibias is substantially negatively correlated with the voltage signal VCC1, so the bias module 12 may adjust the bias current Ibias according to the voltage signal VCC1. A decrease in the power supply voltage Vsource will increase the bias current Ibias, thereby increasing the power supply current Icc. Conversely, an increase in the power supply voltage Vsource will decrease the bias current Ibias, thereby decreasing the power supply current Icc. In this way, the power supply current Icc that changes with the change in the power supply voltage Vsource may be compensated, and the power supply current Icc may be adjusted according to the voltage signal VCC1 to maintain the power supply current Icc within a predetermined range, such as ±3% of 140 mA.

[0050] The bias module 12 may include a variable current source 1200. In some embodiments, the variable current source 1200 may be a variable resistor for adjusting the bias current Ibias according to the voltage signal VCC1. In other embodiments, as shown in FIG. 4, the variable current source 1200 may include signal terminals 151, 153, a reference potential terminal 155, an operational amplifier OP, a first resistor selection circuit 152, a second resistor selection circuit 154, resistors Rp1, Rn1, RF, RF1, a voltage-to-current converter 156, and switch control terminals 157, 158. In some embodiments, the resistance value of the resistor Rn1 may be adjusted to selectively remove the resistor RF1 from the variable current source 1200. The variable current source 1200 may receive the voltage signal VCC1 and the reference signal VBG2 to generate the bias current Ibias according to the line segments 140 and 142 in FIG. 3. The reference signal VBG2 may be a bandgap reference voltage or other reference voltages. With respect to the change of the power supply voltage Vsource, the reference signal VBG2 may be substantially constant.

[0051] The operational amplifier OP may have a first input terminal, a second input terminal, and an output terminal. The first input terminal is a positive terminal, the second input terminal is a negative terminal, and the output terminal is used to output an output voltage Vo. The first input terminal of the operational amplifier OP may be coupled to the signal terminal 151 and receive a reference signal VBG2, and the second input terminal of the operational amplifier OP may be coupled to the signal terminal 153 and receive a voltage signal VCC1. The output terminal of the operational amplifier OP may output an output voltage Vo according to a difference between the reference signal VBG2 and the voltage signal VCC1. In other embodiments, the operational amplifier OP may be an adder.

[0052] The voltage-to-current converter 156 may include a first terminal coupled to the output terminal of the operational amplifier OP, and a second terminal coupled to the second terminal of the amplifying unit 11. The voltage-to-current converter 156 may convert the output voltage Vo into a bias current Ibias. The voltage-to-current converter 156 may be a metal oxide semiconductor field effect transistor (MOSFET), a BJT, or other types of transistors.

[0053] The resistor RF may include a first end coupled to the second input end of the operational amplifier OP, and a second end coupled to the output end of the operational amplifier OP. The resistor RF1 may include a first end coupled to the first end of the resistor RF, and a second end coupled to the reference potential end 155, and the reference potential end 155 may receive the reference potential Vref5. The reference potential Vref5 may be a ground reference potential or other reference potentials. In some embodiments, the reference potential Vref5 and the reference potential Vref1 may have substantially the same potential. In some embodiments, the resistors RF and RF1 may have substantially the same resistance value. In some embodiments, the resistors RF and RF1 may be variable resistors. In some embodiments, the resistance value of the resistor RF1 may be set to a multiple of the resistance value of the resistor RF to change the slopes of the line segments 140 and 142 in FIG. 3.

[0054] The resistor Rp1 may include a first end coupled to the signal terminal 151 via the first resistor selection circuit 152, and a second end coupled to the first input terminal of the operational amplifier OP. The resistor Rn1 may include a first end coupled to the signal terminal 153 via the second resistor selection circuit 154, and a second end coupled to the second input terminal of the operational amplifier OP. The resistors Rp1 and Rn1 may be variable resistors. The first resistor selection circuit 152 may include a first end coupled to the signal terminal 151, and a second end coupled to the first end of the resistor Rp1. The second resistor selection circuit 154 may include a first end coupled to the signal terminal 153, and a second end coupled to the first end of the resistor Rn1. The first resistor selection circuit 152 may include a switch SW1 and a resistor Rp2. The switch SW1 may include a first end coupled to the first end of the first resistor selection circuit 152, a second end coupled to the second end of the first resistor selection circuit 152, and a control end coupled to the switch control end 157. The switch control terminal 157 may receive a first control signal to turn on or off the switch SW1. The resistor Rp2 may be coupled between the first terminal of the switch SW1 and the second terminal of the switch SW1. The second resistor selection circuit 154 may include a switch SW2 and a resistor Rn2. The switch SW2 may include a first terminal coupled to the first terminal of the second resistor selection circuit 154, a second terminal coupled to the second terminal of the second resistor selection circuit 154, and a control terminal coupled to the switch control terminal 158. The switch control terminal 158 may receive a second control signal to turn on or off the switch SW2. The resistor Rn2 may be coupled between the first terminal of the switch SW2 and the second terminal of the switch SW2. The switches SW1 and SW2 may be MOSFETs, BJTs, or other types of transistors. The resistors Rp2 and Rn2 may be variable resistors. The resistors Rp1 and Rn1 may have substantially the same resistance value, and the resistors Rp2 and Rn2 may have substantially the same resistance value. In some embodiments, the resistor Rp1 and the first resistor selection circuit 152 can be exchanged, that is, the first end of the resistor Rp1 can be coupled to the signal terminal 151, the second end of the resistor Rp1 can be coupled to the first end of the first resistor selection circuit 152, and the second end of the first resistor selection circuit 152 can be coupled to the first input terminal of the operational amplifier OP. Similarly, the resistor Rn1 and the second resistor selection circuit 154 can be exchanged, that is, the first end of the resistor Rn1 can be coupled to the signal terminal 153, the second end of the resistor Rn1 can be coupled to the first end of the second resistor selection circuit 154, and the second end of the second resistor selection circuit 154 can be coupled to the second input terminal of the operational amplifier OP.

[0055] The difference between the reference signal VBG2 and the voltage signal VCC1 can be adjusted using the first resistor selection circuit 152 and the second resistor selection circuit 154 to adjust the change rate of the output voltage Vo and / or the bias current Ibias. Specifically, the switches SW1 and SW2 can be turned on or off together to switch the change rate of the output voltage Vo and / or the bias current Ibias. The output voltage Vo can be expressed by Formula 6:

[0056] Vo=k1*(VBG2-VCC1) Formula 6

[0057] Where VBG2 is a reference signal and has nothing to do with the change of the power supply voltage Vsource;

[0058] VCC1 is a voltage signal;

[0059] When switch SW1 and switch SW2 are closed,

[0060] k1=Res_RF / (Res_Rp1+Res_Rp2)=Res_RF / (Res_Rn1+Res_Rn2);

[0061] When switch SW1 and switch SW2 are turned on,

[0062] k1=Res_RF / Res_Rp1=Res_RF / Res_Rn1; and

[0063] Res_RF, Res_Rp1, Res_Rn1, Res_Rp2, and Res_Rn2 are the resistance values ​​of resistors RF, Rp1, Rn1, Rp2, and Rn2 respectively.

[0064] The output voltage Vo can be determined by the difference (VBG2-VCC1) and the slope k1. Since the reference signal VBG2 is independent of the change of the power supply voltage Vsource, and the voltage signal VCC1 is positively correlated with the power supply voltage Vsource, an increase in the power supply voltage Vsource will reduce the difference (VBG2-VCC1), thereby reducing the output voltage Vo; a decrease in the power supply voltage Vsource will increase the difference (VBG2-VCC1), thereby increasing the output voltage Vo. In this way, the change of the power supply voltage Vsource can be compensated to provide a substantially fixed supply current Icc to the amplifier unit 11.

[0065] 3 , the first reverse slope of the line segment 140 and the second reverse slope of the line segment 142 can be implemented by the first resistor selection circuit 152 and the second resistor selection circuit 154 in the variable current source 1200. When the power supply voltage Vsource is less than the critical value, the switch SW1 can be closed to electrically disconnect the first end of the switch SW1 from the second end of the switch SW1, and the switch SW2 can be closed to electrically disconnect the first end of the switch SW2 from the second end of the switch SW2, so the total resistance value (Res_Rp1+Res_Rp2) of the resistor Rp1 and the resistor Rp2 and the total resistance value (Res_Rn1+Res_Rn2) of the resistor Rn1 and the resistor Rn2 can be used to generate a gentler slope k1, such as the first reverse slope of the line segment 140. When the power supply voltage Vsource exceeds the critical value, the switch SW1 can be turned on to electrically connect the first end of the switch SW1 with the second end of the switch SW1, and the switch SW2 can be turned on to electrically connect the first end of the switch SW2 with the second end of the switch SW2, so the resistance value Res_Rp1 of the resistor Rp1 and the resistance value Res_Rn1 of the resistor Rn1 can be used to generate a steeper slope k1, such as the second reverse slope of the line segment 142. In some embodiments, a line segment with a single reverse slope can be used to simulate the bias current Ibias, and the first resistor selection circuit 152 and the second resistor selection circuit 154 can be removed from the variable current source 1200. In some embodiments, the first resistor selection circuit 152, the second resistor selection circuit 154 and the resistors Rp1 and Rn1 can be removed from the variable current source 1200 and can be moved to an external circuit outside the variable current source 1200.

[0066] The variable current source 1200 is not limited to providing a bias current Ibias that is negatively correlated with the power supply voltage Vsource, and can provide a bias current Ibias that is positively correlated with the power supply voltage Vsource by exchanging the positions of the first resistor selection circuit 152 and the resistor Rp1 with the second resistor selection circuit 154 and the resistor Rn1. Specifically, the first resistor selection circuit 152 and the resistor Rp1 can be coupled between the signal terminal 153 and the second input terminal of the operational amplifier OP, and the second resistor selection circuit 154 and the resistor Rn1 can be coupled between the signal terminal 151 and the first input terminal of the operational amplifier OP. In this configuration, the variable current source 1200 can generate a bias current Ibias that is positively correlated with the power supply voltage Vsource.

[0067] In addition, the variable current source 1200 is not limited to compensating for changes in power supply voltage, but can also be used to compensate for temperature changes and power changes of signals. FIG. 5 is a schematic diagram of another variable current source 1200 in FIG. 1. The variable current source 1200 may include signal terminals 151, 153, a reference potential terminal 155, an operational amplifier OP, a first resistor selection circuit 152, a second resistor selection circuit 154, resistors Rp1, Rn1, RF, RF1, a voltage-to-current converter 156, switch control terminals 157, 158, resistors Rp3 to Rp6, Rn3 to Rn6, signal terminals 1601 to 1607, and a reference potential terminal 1608. The variable current source 1200 may generate a bias current Ibias to compensate for changes in power supply voltage, power changes of input signals or output signals, changes in ambient temperature, and / or changes in temperature of the amplifier unit 11. The configuration and operation of the operational amplifier OP, the first resistor selection circuit 152, the second resistor selection circuit 154, and the resistors Rp1, Rn1, RF, and RF1 are the same as those in FIG. 4. The relevant description has been provided in the previous paragraphs and will not be repeated here. In some embodiments, the resistance value of one of the resistors Rn1, Rn3, Rn4, Rn5, and Rn6 or the resistance value of any combination of the aforementioned resistors can be adjusted to selectively remove the resistor RF1 from the variable current source 1200.

[0068] The resistor Rp3 may include a first end coupled to the signal terminal 1601 to receive the power signal Vdet2, and a second end coupled to the first input terminal of the operational amplifier OP. The resistor Rn3 may include a first end coupled to the signal terminal 1602 to receive the reference signal Vdet02, and a second end coupled to the second input terminal of the operational amplifier OP. The power signal Vdet2 may represent the power of the input signal S1 or the output signal S2. The reference signal Vdet02 may be a reference voltage, and the reference signal Vdet02 may be substantially fixed relative to the power change of the input signal S1 or the output signal S2.

[0069] The resistor Rp4 may include a first end coupled to the signal terminal 1603 to receive the temperature signal VPTAT2, and a second end coupled to the first input terminal of the operational amplifier OP. The resistor Rn4 may include a first end coupled to the signal terminal 1604 to receive the reference signal VBG3, and a second end coupled to the second input terminal of the operational amplifier OP. The temperature signal VPTAT2 may be a proportional to absolute temperature (PTAT) signal. In some embodiments, a complementary to absolute temperature (CTAT) signal may also be used for temperature compensation. In an example using a CTAT signal, the first end of the resistor Rp4 may receive the reference signal VBG3 via the signal terminal 1603, and the first end of the resistor Rn4 may receive the CTAT signal via the signal terminal 1604. The reference signal VBG3 may be a differential reference voltage, and the reference signal VBG3 may be substantially fixed relative to temperature changes, and the reference signal VBG3 may be substantially the same as the reference signal VBG2. In some embodiments, the temperature signal VPTAT2 and the reference signal VBG3 may be generated by circuits disposed on the same die of an integrated circuit (IC).

[0070] The resistor Rp5 may include a first end coupled to the signal terminal 1605 to receive the temperature signal VD0, and a second end coupled to the first input terminal of the operational amplifier OP. The resistor Rn5 may include a first end coupled to the signal terminal 1606 to receive the temperature signal Vat, and a second end coupled to the second input terminal of the operational amplifier OP. The temperature signal VD0 may represent the temperature on the IC including the amplifying unit 11, and is used to indicate the ambient temperature. The temperature signal Vat may represent the temperature of a location near the amplifying unit 11, and is used to indicate the temperature of the amplifying unit 11. In some embodiments, the temperature signal Vat and the temperature signal VD0 may be generated by a temperature detection circuit of the IC disposed on the same die. In other embodiments, the temperature signal Vat and the temperature signal VD0 may be generated by temperature detection circuits of the IC disposed on different dies, respectively. Specifically, the temperature detection circuit for generating the temperature signal Vat and the amplifying unit 11 may be disposed on the same die, and the temperature detection circuit for generating the temperature signal VD0 may be disposed on another die and away from the amplifying unit 11.

[0071] The resistor Rp6 may include a first terminal coupled to the signal terminal 1607 to receive the reference signal Vr5, and a second terminal coupled to the first input terminal of the operational amplifier OP. The resistor Rn6 may include a first terminal coupled to the reference potential terminal 1608 to receive the reference potential Vref5, and a second terminal coupled to the second input terminal of the operational amplifier OP. The reference signal Vr5 may be a reference voltage, and the reference signal Vr5 may be substantially fixed relative to the change of the power supply voltage Vsource.

[0072] Resistors Rp3 to Rp6 and Rn3 to Rn6 may be variable resistors. Resistors Rp3 and Rn3 may have substantially the same resistance value, resistors Rp4 and Rn4 may have substantially the same resistance value, resistors Rp5 and Rn5 may have substantially the same resistance value, and resistors Rp6 and Rn6 may have substantially the same resistance value. The output voltage Vo may be expressed by Formula 7:

[0073] Vo=k1*(VBG2-VCC1)+k2(Vdet2-Vdet02)+k3(VPTAT2-VBG3)+k4(Vr5-Vref5)+k5(VD0-Vat) Formula 7

[0074] Where VBG2 is a reference signal and has nothing to do with the change of the power supply voltage Vsource;

[0075] VCC1 is a voltage signal;

[0076] Vdet2 is the power signal;

[0077] Vdet02 is a reference signal and has nothing to do with the power changes of the input signal S1 or the output signal S2;

[0078] VPTAT2 is the temperature signal;

[0079] VBG3 is a reference signal and has nothing to do with temperature changes;

[0080] Vr5 is a reference signal and has nothing to do with changes in the power supply voltage Vsource;

[0081] Vref5 is the reference potential;

[0082] VD0 is the temperature signal;

[0083] Vat is the temperature signal;

[0084] When the switch SW1 and the switch SW2 are closed, k1=Res_RF / (Res_Rp1+Res_Rp2)=

[0085] Res_RF / (Res_Rn1+Res_Rn2);

[0086] When the switch SW1 and the switch SW2 are turned on, k1 = Res_RF / Res_Rp1 = Res_RF / Res_Rn1; and

[0087] k2=Res_RF / Res_Rp3=Res_RF / Res_Rn3;

[0088] k3=Res_RF / Res_Rp4=Res_RF / Res_Rn4;

[0089] k4=Res_RF / Res_Rp6=Res_RF / Res_Rn6;

[0090] k5=Res_RF / Res_Rp5=Res_RF / Res_Rn5; and

[0091] Res_RF, Res_Rp1 to Res_Rp6, Res_Rn1 to Res_Rn6 are the resistance values ​​of resistors RF, Rp1 to Rp6, Rn1 to Rn6 respectively.

[0092] The output voltage Vo can be determined by the difference (VBG2-VCC1) and the slope k1, the difference (Vdet2-Vdet02) and the slope k2, the difference (VPTAT2-VBG3) and the slope k3, the difference (Vr5-Vref5) and the slope k4, and the difference (VD0-Vat) and the slope k5. The difference (VBG2-VCC1) and the slope k1 have been described in the previous paragraph and will not be repeated here.

[0093] The linearity of the amplifier unit 11 may change with the power of the input signal S1 or the output signal S2, and the power of the input signal S1 or the output signal S2 is estimated by the power signal Vdet2. The difference (Vdet2-Vdet02) may represent the amount of power change and may be used to compensate for the power change. The output end of the operational amplifier OP may also output an output voltage Vo according to the power signal Vdet2 and the reference signal Vdet02. Therefore, the bias module 12 may adjust the bias current Ibias according to the power of the input signal S1 or the power of the output signal S2. In some embodiments, when the power of the input signal S1 or the output signal S2 increases, the bias current Ibias may be increased; when the power of the input signal S1 or the output signal S2 decreases, the bias current Ibias may be reduced, so as to maintain the linearity of the amplifier unit 11 and improve the efficiency of the amplifier unit 11.

[0094] The gain of the amplifier unit 11 may change with the ambient temperature, which is estimated by the temperature signal VPTAT2. Specifically, the gain of the amplifier unit 11 may decrease as the ambient temperature increases, and increase as the ambient temperature decreases. The difference (VPTAT2-VBG3) may represent the amount of change in ambient temperature and may be used to compensate for the change in ambient temperature. The output end of the operational amplifier OP may also output an output voltage Vo based on the temperature signal VPTAT2 and the reference signal VBG3. Therefore, the bias module 12 may adjust the bias current Ibias and maintain the gain of the amplifier unit 11 within a predetermined gain range, such as ±2dB of a specific gain of the amplifier unit 11. For example, the gain of the amplifier unit 11 may be adjusted to 28dB at high temperatures, and the gain of the amplifier unit 11 may be adjusted to 32dB at low temperatures, so as to maintain the gain of the amplifier unit 11 within the range of 30dB±2dB when the temperature changes.

[0095] The gain of the amplifier unit 11 may change with the temperature of the amplifier unit 11, and the temperature of the amplifier unit 11 is estimated by the temperature signal Vat. For example, the temperature of the amplifier unit 11 may increase with the operation time, resulting in a decrease in gain. The difference (VD0-Vat) may represent the amount of change between the ambient temperature and the temperature of the amplifier unit, and may be used to compensate for the temperature change of the amplifier unit 11. The output end of the operational amplifier OP may also output an output voltage Vo according to the temperature signal VD0 and the temperature signal Vat. Therefore, the bias module 12 may adjust the bias current Ibias and maintain the gain of the amplifier unit 11 within a predetermined gain range, such as ±0.2dB of a specific gain of the amplifier unit 11. For example, after the amplifier unit 11 operates for a period of time, the temperature of the amplifier unit 11 will gradually increase, and the gain of the amplifier unit 11 may be adjusted to 29.8dB or 30.2dB to maintain the gain of the amplifier unit 11 within the range of 30dB±0.2dB.

[0096] The difference (Vr5-Vref5) can represent a basic value for generating the bias current Ibias. The basic value of the bias current Ibias can be used, for example, to make the amplifier unit 11 operate at an appropriate operating point. The output terminal of the operational amplifier OP can also output an output voltage Vo according to the reference signal Vr5 and the reference potential Vref5. Therefore, the bias module 12 can adjust the bias current Ibias. In some embodiments, the signal terminal 1607, the reference potential terminal 1608, and the resistors Rp6 and Rn6 can be removed from the variable current source 1200. The basic value of the bias current Ibias can be provided by other bias current generating circuits.

[0097] Although in FIG. 5 , only one slope value is used to implement the slopes k2, k3, k4, and k5, the slopes k2, k3, k4, and k5 can also be implemented with two or more slope values ​​by using a circuit configuration similar to the first resistor selection circuit 152 and the second resistor selection circuit 154 in FIG. 4 .

[0098] The variable current source 1200 in FIGS. 4 and 5 can generate a bias current Ibias to compensate for changes in the power supply voltage, changes in the power of the input / output signal, changes in the ambient temperature and / or changes in the temperature of the amplifying unit, thereby improving the performance of the amplifier device 2.

[0099] In addition, in some embodiments, in addition to using the same circuit configuration as the variable current source 1200 of FIG. 5 , the variable current source 1200 may be changed according to actual applications and design requirements to compensate for changes in the power supply voltage and at the same time compensate for changes in the power of the input / output signal, changes in the ambient temperature, or changes in the temperature of the amplifying unit, or a selected combination of the foregoing items. In some embodiments, the first resistor selection circuit 152, the second resistor selection circuit 154, and the resistors Rp1, Rp3 to Rp6, Rn1, Rn3 to Rn6 may be removed from the variable current source 1200 and may be moved to an external circuit outside the variable current source 1200.

[0100] FIG. 6 is a schematic diagram of another amplifier device 2 according to an embodiment of the present invention. The bias module 12 may include a variable current source 1200 and a transistor 1201. The transistor 1201 may include a first terminal coupled to the bias voltage source 190, a second terminal coupled to the variable current source 1200, and a third terminal coupled to the second terminal of the amplifying unit 11. The bias voltage source 190 may receive a supply voltage V1. The variable current source 1200 may be implemented by the embodiments of FIGS. 4 and 5. In some embodiments, the transistor 1201 may be a MOSFET, a BJT, or other types of transistors.

[0101] FIG. 7 is a schematic diagram of another amplifier device 2 according to an embodiment of the present invention. The bias module 12 may include a transistor 1201, a variable current source 1200, a resistor 1203, and diodes 1204 and 1205. The configuration of the transistor 1201 and the variable current source 1200 is the same as that of FIG. 6 and will not be described again. The resistor 1203 may include a first end coupled to the variable current source 1200 and a second end coupled to the second end of the transistor 1201. The diode 1204 may include a first end coupled to the second end of the resistor 1203 and a second end. The diode 1205 may include a first end coupled to the second end of the diode 1204 and a second end coupled to the reference potential terminal 30. The reference potential terminal 30 may receive a reference potential Vref5. In some embodiments, the diodes 1204 and 1205 may be diode-connected transistors.

[0102] FIG. 8 is a schematic diagram of another amplifier device 2 according to an embodiment of the present invention. The bias module 12 may include a transistor 1201, a variable current source 1200, a resistor 1203, a transistor 1206, and a resistor 1207. The configuration of the transistor 1201, the variable current source 1200, and the resistor 1203 is the same as that of FIG. 7 and will not be described again. The resistor 1207 may include a first terminal and a second terminal coupled to the third terminal of the transistor 1201. The transistor 1206 may include a first terminal coupled to the second terminal of the resistor 1203, a second terminal coupled to the first terminal of the resistor 1207, and a third terminal coupled to the reference potential terminal 30. The reference potential terminal 30 may receive a reference potential Vref5. In some embodiments, the transistor 1206 may be a MOSFET, a BJT, or other types of transistors.

[0103] The amplifier device 2 of Figures 1, 6 to 8 uses the variable current source 1200 of Figures 4 and 5 to generate a bias current Ibias to compensate for changes in the power supply voltage, power changes of the input signal or output signal, ambient temperature changes and / or temperature changes of the amplification unit, thereby improving the performance of the amplifier device 2.

[0104] The amplifier device in the embodiment of the present invention can adjust the bias current of the bias module according to various factors, and can perform power supply voltage compensation, signal power compensation, ambient temperature compensation and / or temperature compensation of the amplification unit on the amplifier device, thereby improving the performance of the amplifier device.

[0105] The above descriptions are only preferred embodiments of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the present invention.

Claims

1. An amplifier device, characterized in that: Include: an amplifier unit having a first terminal coupled to a voltage source for receiving a power supply voltage, a second terminal for receiving an input signal, and a third terminal coupled to a first reference potential terminal, wherein the first reference potential terminal is used to receive a first reference potential, and the first terminal of the amplifier unit is used to output an output signal amplified by the amplifier unit; and a bias module, coupled to the second end of the amplifying unit, for receiving a voltage signal to provide a bias current to the amplifying unit, wherein the voltage signal is a variable voltage; A power supply current flows into the amplifying unit, and the power supply current is adjusted according to the voltage signal to maintain the power supply current within a predetermined range; The bias module is used to provide the bias current according to a first reverse slope, or a second reverse slope, or the first reverse slope and the second reverse slope; The voltage signal is substantially positively correlated with the power supply voltage, and the first reverse slope and the second reverse slope are negatively correlated with the voltage signal; wherein, When the power supply voltage is less than a predetermined value, the relationship between the supply current and the power supply voltage includes a first line segment; When the power supply voltage is greater than the predetermined value, the relationship between the supply current and the power supply voltage includes a second line segment; The first line segment has a first slope; The second line segment has a second slope; The first inverse slope is negatively correlated to the first slope; and the second inverse slope is negatively correlated to the second slope.

2. The amplifier device according to claim 1, characterized in that The bias module includes a variable current source.

3. The amplifier device according to claim 2, characterized in that The variable current source includes a variable resistor.

4. The amplifier device according to claim 2, characterized in that The variable current source comprises: An operational amplifier, comprising a first input terminal coupled to a first signal terminal and used to receive a first reference signal, a second input terminal coupled to a second signal terminal and used to receive the voltage signal, and an output terminal used to output an output voltage; a first resistor (RF) comprising a first terminal coupled to the second input terminal of the operational amplifier, and a second terminal coupled to the output terminal of the operational amplifier; and A voltage-to-current converter comprises a first terminal coupled to the output terminal of the operational amplifier and a second terminal coupled to the second terminal of the amplifying unit and is used for converting the output voltage into the bias current.

5. An amplifier device, characterized in that: Include: an amplifier unit having a first terminal coupled to a voltage source for receiving a power supply voltage, a second terminal for receiving an input signal, and a third terminal coupled to a first reference potential terminal, wherein the first reference potential terminal is used to receive a first reference potential, and the first terminal of the amplifier unit is used to output an output signal amplified by the amplifier unit; and a bias module, coupled to the second end of the amplifying unit, for receiving a voltage signal to provide a bias current to the amplifying unit, wherein the voltage signal is a variable voltage; The bias module includes a variable current source; The variable current source comprises: An operational amplifier, comprising a first input terminal coupled to a first signal terminal and used to receive a first reference signal, a second input terminal coupled to a second signal terminal and used to receive the voltage signal, and an output terminal used to output an output voltage; a first resistor (RF) comprising a first terminal coupled to the second input terminal of the operational amplifier, and a second terminal coupled to the output terminal of the operational amplifier; and a voltage-to-current converter, comprising a first terminal coupled to the output terminal of the operational amplifier and a second terminal coupled to the second terminal of the amplifying unit, and used for converting the output voltage into the bias current; and a second resistor (Rp1) comprising a first terminal coupled to the first signal terminal, and a second terminal coupled to the first input terminal of the operational amplifier; and a third resistor (Rn1) comprising a first terminal coupled to the second signal terminal, and a second terminal coupled to the second input terminal of the operational amplifier; A supply current flows into the amplifying unit, and the supply current is adjusted according to the voltage signal to maintain the supply current within a predetermined range.

6. The amplifier device according to claim 5, characterized in that The second resistor (Rp1) and the third resistor (Rn1) are variable resistors.

7. The amplifier device according to claim 5, characterized in that The variable current source further comprises: a first resistor selection circuit, comprising a first terminal coupled to the first signal terminal, and a second terminal coupled to the first terminal of the second resistor (Rp1); and A second resistor selection circuit includes a first terminal coupled to the second signal terminal and a second terminal coupled to the first terminal of the third resistor (Rn1).

8. The amplifier device according to claim 7, characterized in that in: The first resistance selection circuit comprises: a first switch comprising a first terminal coupled to the first terminal of the first resistor selection circuit, a second terminal coupled to the second terminal of the first resistor selection circuit, and a control terminal; and a fourth resistor (Rp2) coupled between the first end of the first switch and the second end of the first switch; and The second resistance selection circuit comprises: a second switch comprising a first terminal coupled to the first terminal of the second resistor selection circuit, a second terminal coupled to the second terminal of the second resistor selection circuit, and a control terminal; and A fifth resistor (Rn2) is coupled between the first end of the second switch and the second end of the second switch.

9. The amplifier device according to claim 5, characterized in that The variable current source further comprises: a sixth resistor (Rp3), comprising a first terminal coupled to a third signal terminal and used to receive a power signal, and a second terminal coupled to the first input terminal of the operational amplifier; and a seventh resistor (Rn3), comprising a first terminal coupled to a fourth signal terminal and used to receive a second reference signal, and a second terminal coupled to the second input terminal of the operational amplifier; wherein the second reference signal is a fixed voltage and has nothing to do with power changes of the input signal or the output signal; and The output end of the operational amplifier is further used to output the output voltage according to the power signal and the second reference signal.

10. The amplifier device according to claim 5, characterized in that The variable current source further comprises: an eighth resistor (Rp4), comprising a first terminal coupled to a fifth signal terminal and used to receive a first temperature signal, and a second terminal coupled to the first input terminal of the operational amplifier; and a ninth resistor (Rn4), comprising a first terminal coupled to a sixth signal terminal and used to receive a third reference signal, and a second terminal coupled to the second input terminal of the operational amplifier; The third reference signal is a fixed voltage and has nothing to do with temperature changes; and The output end of the operational amplifier is further used to output the output voltage according to the first temperature signal and the third reference signal.

11. The amplifier device according to claim 5, characterized in that The variable current source further comprises: a tenth resistor (Rp5), comprising a first terminal coupled to a seventh signal terminal and used to receive a second temperature signal, and a second terminal coupled to the first input terminal of the operational amplifier; and an eleventh resistor (Rn5), comprising a first terminal coupled to an eighth signal terminal and used to receive a third temperature signal, and a second terminal coupled to the second input terminal of the operational amplifier; The output end of the operational amplifier is further used to output the output voltage according to the second temperature signal and the third temperature signal.

12. The amplifier device according to claim 5, characterized in that The variable current source further comprises: a twelfth resistor (Rp6), comprising a first terminal coupled to a ninth signal terminal and used to receive a fourth reference signal, and a second terminal coupled to the first input terminal of the operational amplifier; and a thirteenth resistor (Rn6), comprising a first end coupled to a second reference potential end and used to receive a second reference potential, and a second end coupled to the second input end of the operational amplifier; wherein the fourth reference signal is a fixed voltage and has nothing to do with the voltage variation of the power supply voltage; and The output end of the operational amplifier is further used to output the output voltage according to the fourth reference signal and the second reference potential.

13. The amplifier device according to claim 5, characterized in that The variable current source further includes a fourteenth resistor (RF1) including a first end coupled to the first end of the first resistor (RF) and a second end coupled to a third reference potential end.

14. The amplifier device according to claim 5, characterized in that The first input terminal of the operational amplifier is a positive terminal, and the second input terminal of the operational amplifier is a negative terminal.

15. The amplifier device according to claim 5, characterized in that The operational amplifier is an adder.

16. The amplifier device according to claim 5, characterized in that The bias module further includes a first transistor including a first terminal coupled to a bias voltage source, a second terminal coupled to the variable current source, and a third terminal coupled to the second terminal of the amplifying unit.

17. The amplifier device according to claim 16, characterized in that The bias module further comprises: a fifteenth resistor (1203), comprising a first terminal coupled to the variable current source, and a second terminal coupled to the second terminal of the first transistor; a first diode comprising a first end coupled to the second end of the fifteenth resistor (1203), and a second end; and A second diode includes a first end coupled to the second end of the first diode and a second end coupled to a fourth reference potential end.

18. The amplifier device according to claim 16, characterized in that The bias module further comprises: a fifteenth resistor (1203), comprising a first terminal coupled to the variable current source, and a second terminal coupled to the second terminal of the first transistor; a seventeenth resistor (1207), comprising a first terminal and a second terminal, coupled to the third terminal of the first transistor; and A second transistor includes a first terminal coupled to the second terminal of the fifteenth resistor (1203), a second terminal coupled to the first terminal of the seventeenth resistor (1207), and a third terminal coupled to a fifth reference potential terminal.

19. The amplifier device according to claim 5, characterized in that The amplifying unit is a power amplifier.

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