A voltage bias generating circuit with controllable temperature coefficient and radio frequency power amplifier

Abstract

The present invention relates to a voltage bias generating circuit with a controllable temperature coefficient and a radio frequency power amplifier, comprising an amplifying unit and a feedback unit. The feedback unit feeds back the bias voltage at the output of the amplifying unit to the positive input of the amplifying unit, and the negative input of the amplifying unit is connected to a reference voltage. The feedback unit is also connected to a current temperature control unit, which provides a regulating current with a controllable temperature coefficient to the feedback unit, thereby changing the feedback voltage input by the feedback unit to the amplifying unit, thereby causing the amplifying unit to output a bias voltage with a controllable temperature coefficient. The voltage bias generating circuit with a controllable temperature coefficient of the present invention has the following beneficial effects: while stabilizing the output bias voltage Vreg, by providing a regulating current with a controllable temperature coefficient, the temperature coefficient of the output bias voltage Vreg is controllable, thereby enabling more precise control of the bias voltage Vreg of the radio frequency power amplifier circuit, thereby improving the high linearity and high efficiency of the radio frequency power amplifier circuit.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency power amplification, and more particularly to a voltage bias generating circuit with a controllable temperature coefficient and a radio frequency power amplifier. Background Art

[0002] A voltage bias generator circuit generates a bias voltage that provides a stable bias for each module in an integrated circuit. In RF power operational amplifier (PA) design, the bias voltage provides the PA with a suitable operating point, enabling high efficiency and high linearity.

[0003] Because the current of the power tube (HBT) of the RF PA is shown in Formula 1:

[0004] Formula 1: Ic = Is * exp(Vbe / Vt)

[0005] Where Is is the reverse saturation current of the HBT, Vbe is the base-emitter bias voltage, and Vt is the thermal voltage, which is 25mV at room temperature. The negative temperature coefficient of the diode junction voltage requires that the base-emitter bias voltage of the HBT also maintain a negative temperature coefficient to ensure that the output current Ic remains consistent over temperature. Therefore, the voltage bias generation circuit requires a negative temperature coefficient. However, existing voltage bias generation circuits either provide a voltage with a zero temperature coefficient, meaning that the bias voltage remains constant despite temperature changes, or they can only provide a single negative temperature coefficient. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to propose a voltage bias generating circuit and a radio frequency power amplifier with a controllable temperature coefficient in response to the above-mentioned defects of the prior art.

[0007] The technical solution adopted by the present invention to solve its technical problem is: proposing a voltage bias generating circuit with a controllable temperature coefficient, including: an amplifying unit and a feedback unit, the feedback unit feeds back the bias voltage at the output end of the amplifying unit to the positive input end of the amplifying unit, the negative input end of the amplifying unit is connected to a reference voltage, the feedback unit is also connected to a current temperature control unit, the current temperature control unit provides a regulating current with a controllable temperature coefficient to the feedback unit, changes the feedback voltage input by the feedback unit to the amplifying unit, and thereby enables the amplifying unit to output a bias voltage with a controllable temperature coefficient.

[0008] In some embodiments, the amplifying unit includes: an operational amplifier circuit Amp1 and a MOSFET Mp1;

[0009] The negative input terminal of the operational amplifier circuit Amp1 is connected to the reference voltage, the positive input terminal of the operational amplifier circuit Amp1 is connected to the output terminal of the feedback unit, the output terminal of the operational amplifier circuit Amp1 is connected to the gate of the MOSFET Mp1, the source of the MOSFET Mp1 is connected to the system power supply, and the drain of the MOSFET Mp1 outputs a bias voltage and is connected to the input terminal of the feedback unit.

[0010] In some embodiments, the feedback unit includes: a resistor R1, a resistor R2, and a resistor R3;

[0011] The first end of the resistor R3 is connected to the drain of the MOS tube Mp1, the second end of the resistor R3 is connected to the first end of the resistor R2 and the current temperature control unit, the second end of the resistor R2 is connected to the first end of the resistor R1 and the positive input end of the operational amplifier circuit Amp1, and the second end of the resistor R1 is grounded.

[0012] In some embodiments, the current temperature control unit includes: a first current subtraction circuit, a second current subtraction circuit, a first proportional amplification circuit, a second proportional amplification circuit, and a current addition circuit;

[0013] The first input terminal and the second input terminal of the first current subtraction circuit are connected to the current source Ip and the current source Iz1 respectively, and the output signal of the first current subtraction circuit is amplified by the first proportional amplifier circuit and then input into the current addition circuit;

[0014] The first input terminal and the second input terminal of the second current subtraction circuit are respectively connected to the current source Iz2 and the current source Ip, and the output signal of the second current subtraction circuit is amplified by the second proportional amplifier circuit and then input into the current addition circuit;

[0015] The input end of the current adding circuit is further connected to the current source Iz3, and the output end of the current adding circuit is connected to the second end of the resistor R3 and the first end of the resistor R2.

[0016] In some embodiments, the first current subtraction circuit includes: MOSFET M1a, MOSFET M2a, MOSFET M3a, MOSFET M4a, MOSFET M5a and MOSFET M6a;

[0017] The gate and drain of the MOSFET M1a are short-circuited and connected to the power supply Ip, and the source of the MOSFET M1a is grounded;

[0018] The MOSFET M2a is connected to the MOSFET M1a in common gate connection, the MOSFET M2a is connected to the MOSFET M3a in common drain connection and is connected to the input end of the first proportional amplifier circuit, and the source of the MOSFET M2a is grounded;

[0019] The MOSFET M3a and the MOSFET M4a are connected to the same source and connected to the system power supply, the MOSFET M3a and the MOSFET M4a are connected to the same gate, and the gate and drain of the MOSFET M4a are short-circuited;

[0020] The MOSFET M4a and the MOSFET M5a are connected to each other in a common drain mode, the MOSFET M5a and the MOSFET M6a are connected to each other in a common gate mode, and the source of the MOSFET M5a is grounded.

[0021] The gate and drain of the MOSFET M6a are short-circuited and connected to the current source Iz1, and the source of the MOSFET M6a is grounded.

[0022] In some embodiments, the second current subtraction circuit includes: MOSFET m1b, MOSFET m2b, MOSFET m3b, MOSFET m4b, MOSFET m5b and MOSFET m6b;

[0023] The gate and drain of the MOSFET m1b are short-circuited and connected to the current source Iz2. The gates of the MOSFET m1b and the MOSFET m2b are connected in common. The source of the MOSFET m1b is grounded.

[0024] The MOSFET M2b and the MOSFET M3b are connected to a common drain and are connected to the input end of the second proportional amplifier circuit, and the source of the MOSFET M2b is grounded;

[0025] The MOSFET M3b and the MOSFET M4b are connected to the same source and connected to the system power supply, the MOSFET M3b and the MOSFET M4b are connected to the same gate, and the gate and drain of the MOSFET M4b are short-circuited;

[0026] The MOSFET m5b is connected to the MOSFET m4b in common drain, the MOSFET m5b is connected to the MOSFET m6b in common gate, and the source of the MOSFET m5b is grounded;

[0027] The gate and drain of the MOSFET M6b are short-circuited and connected to the current source Ip. The gate and drain of the MOSFET M6b are short-circuited, and the source of the MOSFET M6b is grounded.

[0028] In some embodiments, the first proportional operational amplifier circuit includes: MOSFET Mo, MOSFET M1, MOSFET Mm, where m is an integer greater than 1;

[0029] The MOSFET Mo is connected to the drain of the MOSFET m2a and the MOSFET m3a, the gate and drain of the MOSFET Mo are short-circuited, and the source of the MOSFET Mo is grounded;

[0030] The MOSFETs M1-MOSFET Mm are connected to the MOSFET Mo in common gate connection, the sources of the MOSFETs M1-MOSFET Mm are grounded, the drains of the MOSFETs M1-MOSFET Mm are connected in common, and the drains of the MOSFETs M1-MOSFET Mm are also connected to the input end of the current adding circuit and the output end of the second proportional amplification circuit.

[0031] In some embodiments, the second proportional operational amplifier circuit includes: MOSFET Qo, MOSFET Q1 ... MOSFET Qn, where n is an integer greater than 2;

[0032] The MOSFET Qo is connected to the drain of the MOSFET M2b and the MOSFET M3b, the gate and drain of the MOSFET Qo are short-circuited, and the MOSFET Mo is connected to the source of the MOSFETs Q1 to Qn and connected to the system power supply.

[0033] The MOSFETs Q1 to Qn are connected to the gate of the MOSFET Qo, and the MOSFETs Q1 to Qn are connected to the drain of the MOSFETs M1 to Mm and are connected to the input end of the current adding circuit.

[0034] In some embodiments, the current adding circuit includes: a MOSFET V1 and a MOSFET V2;

[0035] The MOSFET V1 is connected to a common drain with the MOSFETs Q1-Qn and the MOSFETs M1-Mm. The drain of the MOSFET V1 is also connected to the current Iz3. The gate and drain of the MOSFET V1 are short-circuited. The MOSFET V1 is connected to a common gate with the MOSFET V2. The sources of the MOSFET V1 and the MOSFET V2 are grounded. The drain of the MOSFET V2 is connected to the second end of the resistor R3 and the first end of the resistor R2.

[0036] The present invention further provides a radio frequency power amplifier, comprising: a voltage bias generating circuit with controllable temperature coefficient as described in any one of the above items.

[0037] The voltage bias generating circuit with a controllable temperature coefficient of the present invention has the following beneficial effects: on the basis of stabilizing the output bias voltage Vreg, by providing a regulating current with a controllable temperature coefficient, the temperature coefficient of the output bias voltage Vreg is controllable, thereby enabling the bias voltage Vreg of the radio frequency power amplifier circuit to be more finely and precisely controlled, thereby improving the high linearity and high efficiency operation of the radio frequency power amplifier circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0039] Figure 1It is a schematic diagram of a voltage bias generating circuit with controllable temperature coefficient of the present invention;

[0040] Figure 2 It is a partial circuit diagram of a voltage bias generating circuit with controllable temperature coefficient of the present invention;

[0041] Figure 3 yes Figure 1 The schematic diagram of the current temperature control unit shown;

[0042] Figure 4 yes Figure 1 The relationship diagram of part of the power supply and temperature of the current temperature control unit shown;

[0043] Figure 5 yes Figure 3 The circuit diagram of the current temperature control unit shown;

[0044] Figure 6 The simulation curve of the current regulation with controllable temperature coefficient of the present invention;

[0045] Figure 7 The voltage bias of the controllable temperature coefficient of the present invention generates a circuit simulation curve. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] like Figure 1 As shown, a voltage bias generating circuit with a controllable temperature coefficient includes: an amplifying unit 100 and a feedback unit 200. The feedback unit 200 feeds back the bias voltage Vreg at the output end of the amplifying unit 100 to the positive input end of the amplifying unit 100. The negative input end of the amplifying unit 100 is connected to the reference voltage Vref. The feedback unit 200 is also connected to a current temperature control unit 300. The current temperature control unit 300 provides a regulating current with a controllable temperature coefficient to the feedback unit 200, changes the feedback voltage Vf input by the feedback unit 200 to the amplifying unit 100, and thereby causes the amplifying unit 100 to output a bias voltage Vreg with a controllable temperature coefficient.

[0048] The reference voltage Vref is the reference voltage output by the bandgap (bandgap reference), which is approximately 1.2V in silicon processes. The regulated current Io can be positive or negative. If the regulated current Io flows to the current temperature control unit 300, the regulated current Io is positive. If the regulated current Io flows to the feedback unit 200, the regulated current Io is negative. The regulated current Io increases or decreases the current of the feedback unit 200, thereby changing the magnitude of the feedback voltage Vf output by the feedback unit 200 to the amplifier unit 100, thereby correspondingly changing the bias voltage Vreg output by the amplifier unit 100. Because the temperature coefficient of the regulated current Io is controllable, the temperature coefficient of the bias voltage Vreg controlled by the regulated current Io is also controllable.

[0049] Furthermore, in some embodiments, the amplifying unit 100 includes: an operational amplifier circuit Amp1 and a MOSFET Mp1.

[0050] Specifically, if Figure 2 As shown, the negative input terminal of the operational amplifier circuit Amp1 is connected to the reference voltage, the positive input terminal of the operational amplifier circuit Amp1 is connected to the output terminal of the feedback unit 200, the output terminal of the operational amplifier circuit Amp1 is connected to the gate of the MOSFET Mp1, the source of the MOSFET Mp1 is connected to the system power supply, and the drain of the MOSFET Mp1 outputs the bias voltage Vreg and is connected to the input terminal of the feedback unit 200.

[0051] Among them, the MOSFET Mp1 is a pmos transistor. When the output voltage of the operational amplifier circuit Amp1 is low, the MOSFET Mp1 is turned on to output the bias voltage Vreg. At this time, the positive input terminal voltage of the operational amplifier circuit Amp1, that is, the feedback voltage Vf output by the feedback unit 200, is equal to the reference voltage Vref.

[0052] Furthermore, in some embodiments, the feedback unit 200 includes a resistor R1 , a resistor R2 , and a resistor R3 .

[0053] Specifically, the first end of the resistor R3 is connected to the drain of the MOS tube Mp1, the second end of the resistor R3 is connected to the first end of the resistor R2 and the current temperature control unit 300, the second end of the resistor R2 is connected to the first end of the resistor R1 and the positive input end of the operational amplifier circuit Amp1, and the second end of the resistor R1 is grounded.

[0054] Since the feedback voltage Vf is equal to the reference voltage, the value of the bias voltage Vreg can be obtained, specifically, as shown in Formula 2:

[0055] Formula 2:

[0056] Assuming that the temperature coefficient of the reference voltage Vref output by the bandgap is 0, the temperature coefficient of the bias voltage Vreg can be derived, as shown in Formula 3:

[0057] Formula 3:

[0058] Wherein, T is temperature, Vreg and Io are the output voltage of the amplifier unit 100 and the output current of the current temperature control unit 300 under normal temperature. Once the normal temperature value is determined, is a constant, It is the temperature coefficient of the regulating current Io.

[0059] Therefore, it can be concluded that tc_Vreg=const*tc_io, and the temperature coefficient of the bias voltage Vreg is controlled by the regulation current Io.

[0060] Furthermore, in some embodiments, the current temperature control unit 300 includes: a first current subtraction circuit 310 , a second current subtraction circuit 320 , a first proportional amplification circuit 330 , a second proportional amplification circuit 340 and a current addition circuit 350 .

[0061] Specifically, if Figure 3 As shown, the first input terminal and the second input terminal of the first current subtraction circuit 310 are respectively connected to the current source Ip and the current source Iz1, and the output signal of the first current subtraction circuit 310 is amplified by the first proportional amplifier circuit 330 and then input into the current addition circuit 350; the first input terminal and the second input terminal of the second current subtraction circuit 320 are respectively connected to the current source Iz2 and the current source Ip, and the output signal of the second current subtraction circuit 320 is amplified by the second proportional amplifier circuit 340 and then input into the current addition circuit 350; the input terminal of the current addition circuit 350 is also connected to the current source Iz3, and the output terminal of the current addition circuit 350 is connected to the second end of the resistor R3 and the first end of the resistor R2 (i.e., the input feedback unit 200).

[0062] Specifically, the current temperature control unit 300 divides the entire temperature region into a low temperature region, a high temperature region, and a normal temperature region, wherein the current source Ip is a current with an original positive temperature coefficient, and the current sources Iz1, Iz2, and Iz3 are three currents with zero temperature coefficients, and the value of Iz1 is the highest value of Ip in the low temperature segment, the value of Iz2 is the lowest value of Ip in the low temperature segment, and Iz3 is a certain value corresponding to Ip in the normal temperature segment. Specifically, the relationship between the current sources Ip, Iz1, Iz2, and Iz3 is as follows: Figure 4 shown.

[0063] Furthermore, in some embodiments, the first current subtraction circuit 310 includes: a MOSFET M1a, a MOSFET M2a, a MOSFET M3a, a MOSFET M4a, a MOSFET M5a, and a MOSFET M6a.

[0064] Specifically, if Figure 5 As shown, the gate and drain of MOSFET M1a are short-circuited and connected to the power supply Ip, and the source of MOSFET M1a is grounded; MOSFET M2a and MOSFET M1a are connected in common gate, MOSFET M2a and MOSFET M3a are connected in common drain and connected to the input end of the first proportional amplifier circuit 330, and the source of MOSFET M2a is grounded; MOSFET M3a and MOSFET M4a are connected in common source and connected to the system power supply, MOSFET M3a and MOSFET M4a are connected in common gate, and the gate and drain of MOSFET M4a are short-circuited; MOSFET M4a and MOSFET M5a are connected in common drain, MOSFET M5a and MOSFET M6a are connected in common gate, and the source of MOSFET M5a is grounded; the gate and drain of MOSFET M6a are short-circuited and connected to the current source Iz1, and the source of MOSFET M6a is grounded.

[0065] Among them, m1a, m2a, m5a, and m6a are N-type MOSFETs, and m3a and m4a are P-type MOSFETs. MOSFET m1a and MOSFET m2a, MOSFET m3a and MOSFET m4a, and MOSFET m5a and MOSFET m6a form three current mirror circuits. MOSFETs m1a, m4a, and m6a are equivalent to diodes. When MOSFET m2a is turned on and its drain current is Ip, MOSFET m5a is turned on and its drain current is Iz1, and MOSFET m3a is turned on and its drain current is Iz1, the output current of the drains of MOSFETs m2a and m3a (i.e., the output current of the first current subtraction circuit 310) is Iz1-Ip.

[0066] Furthermore, in some embodiments, the second current subtraction circuit 320 includes: a MOSFET m1b, a MOSFET m2b, a MOSFET m3b, a MOSFET m4b, a MOSFET m5b, and a MOSFET m6b.

[0067] The gate and drain of MOSFET M1b are short-circuited and connected to the current source Iz2. MOSFET M1b and MOSFET M2b are connected in common gate, and the source of MOSFET M1b is grounded. MOSFET M2b and MOSFET M3b are connected in common drain and connected to the input end of the second proportional amplifier circuit 340. The source of MOSFET M2b is grounded. MOSFET M3b and MOSFET M4b are connected in common source and connected to the system power supply. MOSFET M3b and MOSFET M4b are connected in common gate, and the gate and drain of MOSFET M4b are short-circuited. MOSFET M5b and MOSFET M4b are connected in common drain. MOSFET M5b and MOSFET M6b are connected in common gate, and the source of MOSFET M5b is grounded. The gate and drain of MOSFET M6b are short-circuited and connected to the current source Ip. The gate and drain of MOSFET M6b are short-circuited, and the source of MOSFET M6b is grounded.

[0068] Among them, m1b, m2b, m5b, and m6b are N-type MOSFETs, and m3b and m4b are P-type MOSFETs. MOSFET m1b and MOSFET m2b, MOSFET m3b and MOSFET m4b, and MOSFET m5b and MOSFET m6b form three current mirror circuits. MOSFETs m1b, m4b, and m6b act as diodes. When MOSFET m2b is turned on and its drain current is Iz2, when MOSFET m5b is turned on and its drain current is Iz2, when MOSFET m3b is turned on and its drain current is Ip, the output current of the drains of MOSFETs m2b and m3b (i.e., the output current of the second current subtraction circuit 320) is Ip-Iz2.

[0069] Furthermore, in some embodiments, the first proportional operational amplifier circuit includes: MOSFET Mo, MOSFET M1 . . . MOSFET Mm, where m is an integer greater than 1.

[0070] Specifically, MOSFET Mo is connected to a common drain with MOSFET m2a and MOSFET m3a, the gate and drain of MOSFET Mo are short-circuited, and the source of MOSFET Mo is grounded; MOSFETs M1-MOSFET Mm are connected to a common gate with MOSFET Mo, the sources of MOSFETs M1-MOSFET Mm are grounded, and MOSFETs M1-MOSFET Mm are connected to a common drain, and the drains of MOSFETs M1-MOSFET Mm are also connected to the input end of the current adding circuit 350 and the output end of the second proportional amplification circuit 340.

[0071] MOSFET Mo, MOSFETs M1-MOSFET Mm are all N-type MOSFETs. The gate and drain of MOSFET Mo are short-circuited, acting as diodes. MOSFETs M1-MOSFET Mm are conductive and output a current at their drains equal to the gate current (i.e., the output current Iz1-Ip of the first current subtraction circuit 310). That is, each drain of MOSFETs M1-MOSFET Mm outputs a current Iz1-Ip. Therefore, the output of the first proportional amplifier circuit 330 outputs m currents, and the output current value of the first proportional amplifier circuit 330 is m(Iz1-Ip).

[0072] Furthermore, in some embodiments, the second proportional operational amplifier circuit includes: MOSFET Qo, MOSFET Q1 . . . MOSFET Qn, where n is an integer greater than 2.

[0073] Specifically, MOSFET Qo is connected to a common drain with MOSFET M2b and MOSFET M3b, the gate and drain of MOSFET Qo are short-circuited, MOSFET Mo is connected to a common source with MOSFET Q1-MOSFET Qn and connected to the system power supply; MOSFET Q1-MOSFET Qn is connected to a common gate with MOSFET Qo, and MOSFET Q1-MOSFET Qn is connected to a common drain with MOSFET M1-MOSFET Mm and connected to the input end of the current adding circuit 350.

[0074] MOSFET Qo, MOSFETs Q1-Qn are all P-type MOSFETs. The gate and drain of MOSFET Qo are short-circuited, acting as a diode. MOSFETs Q1-Qn are conductive and output a current at their drains equal to their gate current (i.e., the output current Ip-Iz2 of the first current subtraction circuit 310). That is, each drain of MOSFETs Q1-Qn outputs a current Ip-Iz2. Therefore, the output of the second proportional amplifier circuit 340 outputs n currents, and the output current value of the second proportional amplifier circuit 340 is n(Ip-Iz2).

[0075] Furthermore, in some embodiments, the current adding circuit 350 includes: a MOSFET V1 and a MOSFET V2; the MOSFET V1 is connected to a common drain with MOSFETs Q1 to Qn, and MOSFETs M1 to Mm; the drain of the MOSFET V1 is also connected to the current Iz3; the gate and drain of the MOSFET V1 are short-circuited; the MOSFET V1 and the MOSFET V2 are connected to a common gate; the sources of the MOSFET V1 and the MOSFET V2 are grounded; and the drain of the MOSFET V2 is connected to the second end of the resistor R3 and the first end of the resistor R2.

[0076] Both MOSFET V1 and MOSFET V2 are N-type MOSFETs. The drain and gate of MOSFET V1 are short-circuited, which is equivalent to a diode. MOSFET V2 is turned on and the drain outputs a bias current Io. The value of current Io is equal to the current value of the gate of MOSFET V2, that is, the input value of the current adding circuit 350. The value of bias current source Io is shown in Formula 4:

[0077] Formula 4: Io=Iz3-m(Iz1-Ip)+n(Ip-Iz2)

[0078] In the low temperature range, the current source Iz2>Iz1>Ip. At this time, the MOSFET M3b pulls its own node to the system power supply Vcc, so that Ip-Iz2=0, and the MOSFET Qo is turned off. That is, the output current of the second current subtraction circuit 320200 is 0, and the output current of the second proportional amplifier circuit 340 is 0. The lower the temperature, the smaller the Ip value, the larger the difference (Iz1-Ip), and the larger the output current of the first current subtraction circuit 310. The value of the bias current Io is shown in Formula 4:

[0079] Formula 4: Io = Iz3 - m(Iz1 - Ip)

[0080] When the value of Ip gradually approaches the lower limit Iz1 of the normal temperature range, the output of the first current subtraction circuit 310 approaches 0. At this time, the value of the output bias current Io in the low temperature range is: Io=Iz3.

[0081] According to formula 4, the temperature coefficient of the bias current source Io in the low temperature range can be deduced as shown in formula 5:

[0082] Formula 5:

[0083] Where Ip and Io are the currents at room temperature, and their values ​​are equal. T is the temperature, and tcp is the positive temperature coefficient of the current Ip. Therefore, the temperature coefficient of the bias current Io in the low temperature range is a positive temperature coefficient, and this value can be controlled to be m times the positive temperature coefficient of the initial current Ip.

[0084] In the high temperature range, Ip>Iz2>Iz1. At this time, the MOSFET M2a pulls the drain node down to the system ground GND, so that Iz1-Ip=0, and the MOSFET Mo is turned off. That is, the output current of the first current subtraction circuit 310100 is 0, and the output current of the first proportional amplifier circuit 330300 is 0. The higher the temperature, the larger the Ip value, the larger the difference (Ip-Iz2), and the larger the output value of the second current subtraction circuit 320200. The value of the bias current Io is shown in Formula 6:

[0085] Formula 6: Io = Iz3 + n(Ip - Iz2)

[0086] When the value of Ip approaches the upper limit Iz2 of the normal temperature section, the output of the second current subtraction circuit 320200 approaches 0. At this time, the value of the output bias current Io in the low temperature section is: Io=Iz3.

[0087] According to formula 6, the temperature coefficient of the bias current source Io in the high temperature section can be deduced as shown in formula 7:

[0088] Formula 7:

[0089] Among them, Ip and Io are the currents at room temperature, and their values ​​are equal. T is the temperature, and tcp is the positive temperature coefficient of the current Ip. Therefore, the temperature coefficient of the bias current Io in the high temperature range is a positive temperature coefficient, and this value can be controlled to be n times the positive temperature coefficient value of the initial current Ip.

[0090] In the normal temperature range, the current source Iz2>Ip>Iz1, the output currents of the first current subtraction circuit 310 and the second current subtraction circuit 320 are both 0. At this time, the output bias current Io=Iz3.

[0091] It is understandable that, according to actual needs, the upper and lower range values ​​of the normal temperature section can be adjusted by adjusting the amplitudes of Iz1 and Iz2.

[0092] Optionally, each circuit in the current temperature control unit 300 may adopt a simple current mirror circuit or a cascode current mirror circuit.

[0093] Specifically, if Figure 6 As shown, Figure 6 This is a simulation curve of the regulation current with a controllable temperature coefficient of the present invention, wherein, in the low temperature section, the temperature coefficient of the bias current Io is m times the positive temperature coefficient value of the initial current Ip, that is, the amplification factor of the first proportional amplifier circuit 330 is different, and the slope of the curve in the low temperature section is different; in the high temperature section, the temperature coefficient of the bias current Io is n times the positive temperature coefficient value of the initial current Ip, that is, the amplification factor of the second proportional amplifier circuit 340 is different, and the slope of the curve in the low temperature section is different; in the normal temperature stage, the bias current Io=Iz3, the normal temperature stage is a horizontal line segment, and the two endpoint values ​​of the line segment are the values ​​of Iz1 and Iz2.

[0094] Therefore, according to tc_Vreg=const*tc_io, the temperature coefficient of the regulating current Io is controllable, and the temperature coefficient of the bias voltage Vreg becomes controllable by controlling the temperature coefficient of the regulating current Io.

[0095] Specifically, if Figure 7 As shown, Figure 7The voltage bias of the controllable temperature coefficient of the present invention generates a circuit simulation curve. In this curve, each simulation curve corresponds to three stages, namely the low temperature stage, the normal temperature stage and the high temperature stage. The slopes of the curves in these three stages are different, and the temperature coefficients of the corresponding adjustment current Io in these three stages are also different, thereby realizing the controllable temperature coefficient of the bias voltage Vreg. The temperature coefficient can be a single zero temperature coefficient, a single negative temperature coefficient, and any multiple selected negative temperature coefficients.

[0096] The voltage bias generating circuit with a controllable temperature coefficient of the present invention has the following beneficial effects: on the basis of stabilizing the output bias voltage Vreg, by providing a regulating current with a controllable temperature coefficient, the temperature coefficient of the output bias voltage Vreg is controllable, thereby enabling the bias voltage Vreg of the radio frequency power amplifier circuit to be more finely and precisely controlled, thereby improving the high linearity and high efficiency operation of the radio frequency power amplifier circuit.

[0097] The present invention also provides a radio frequency power amplifier, comprising: a voltage bias generating circuit with a controllable temperature coefficient disclosed in an embodiment of the present invention.

[0098] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. All equivalent variations and modifications within the scope of the claims of the present invention are intended to be covered by the claims of the present invention.

[0099] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A voltage bias generating circuit with a controllable temperature coefficient, comprising: an amplifying unit and a feedback unit, wherein the feedback unit feeds back the bias voltage of the output end of the amplifying unit to the positive input end of the amplifying unit, and the negative input end of the amplifying unit is connected to a reference voltage. The feature is that the feedback unit is further connected to a current temperature control unit, which provides a regulating current with a controllable temperature coefficient to the feedback unit, changes the feedback voltage input by the feedback unit to the amplification unit, and thereby causes the amplification unit to output a bias voltage with a controllable temperature coefficient; The current temperature control unit includes: a first current subtraction circuit, a second current subtraction circuit, a first proportional amplification circuit, a second proportional amplification circuit and a current addition circuit; The first input terminal and the second input terminal of the first current subtraction circuit are connected to the current source Ip and the current source Iz1 respectively, and the output signal of the first current subtraction circuit is amplified by the first proportional amplifier circuit and then input into the current addition circuit; The first input terminal and the second input terminal of the second current subtraction circuit are respectively connected to the current source Iz2 and the current source Ip, and the output signal of the second current subtraction circuit is amplified by the second proportional amplifier circuit and then input into the current addition circuit; The input end of the current adding circuit is further connected to the current source Iz3, and the output end of the current adding circuit is connected to the second end of the resistor R3 and the first end of the resistor R2; The first current subtraction circuit includes: MOSFET M1a, MOSFET M2a, MOSFET M3a, MOSFET M4a, MOSFET M5a and MOSFET M6a; The gate and drain of the MOSFET M1a are short-circuited and connected to the current source Ip, and the source of the MOSFET M1a is grounded; The MOSFET M2a is connected to the MOSFET M1a in common gate connection, the MOSFET M2a is connected to the MOSFET M3a in common drain connection and is connected to the input end of the first proportional amplifier circuit, and the source of the MOSFET M2a is grounded; The MOSFET M3a and the MOSFET M4a are connected to the same source and connected to the system power supply. The MOSFET M3a and the MOSFET M4a are connected to the same gate, and the gate and drain of the MOSFET M4a are short-circuited. The MOSFET M4a and the MOSFET M5a are connected to each other in a common drain mode, the MOSFET M5a and the MOSFET M6a are connected to each other in a common gate mode, and the source of the MOSFET M5a is grounded. The gate and drain of the MOSFET M6a are short-circuited and connected to the current source Iz1, and the source of the MOSFET M6a is grounded; The current source Ip is a current with an original positive temperature coefficient, and the current sources Iz1, Iz2 and Iz3 are three currents with zero temperature coefficients respectively.

2. The voltage bias generating circuit with controllable temperature coefficient according to claim 1, wherein: The amplifying unit includes: an operational amplifier circuit Amp1 and a MOS tube Mp1; The negative input terminal of the operational amplifier circuit Amp1 is connected to the reference voltage, the positive input terminal of the operational amplifier circuit Amp1 is connected to the output terminal of the feedback unit, the output terminal of the operational amplifier circuit Amp1 is connected to the gate of the MOSFET Mp1, the source of the MOSFET Mp1 is connected to the system power supply, and the drain of the MOSFET Mp1 outputs a bias voltage and is connected to the input terminal of the feedback unit.

3. The voltage bias generating circuit with controllable temperature coefficient according to claim 2, wherein: The feedback unit includes: a resistor R1, a resistor R2 and a resistor R3; The first end of the resistor R3 is connected to the drain of the MOS tube Mp1, the second end of the resistor R3 is connected to the first end of the resistor R2 and the current temperature control unit, the second end of the resistor R2 is connected to the first end of the resistor R1 and the positive input end of the operational amplifier circuit Amp1, and the second end of the resistor R1 is grounded.

4. The voltage bias generating circuit with controllable temperature coefficient according to claim 1, wherein: The second current subtraction circuit includes: MOSFET m1b, MOSFET m2b, MOSFET m3b, MOSFET m4b, MOSFET m5b and MOSFET m6b; The gate and drain of the MOSFET m1b are short-circuited and connected to the current source Iz2. The gates of the MOSFET m1b and the MOSFET m2b are connected in common. The source of the MOSFET m1b is grounded. The MOSFET M2b and the MOSFET M3b are connected to a common drain and are connected to the input end of the second proportional amplifier circuit, and the source of the MOSFET M2b is grounded; The MOSFET M3b and the MOSFET M4b are connected to the same source and connected to the system power supply, the MOSFET M3b and the MOSFET M4b are connected to the same gate, and the gate and drain of the MOSFET M4b are short-circuited; The MOSFET m5b is connected to the MOSFET m4b in common drain, the MOSFET m5b is connected to the MOSFET m6b in common gate, and the source of the MOSFET m5b is grounded; The gate and drain of the MOSFET M6b are short-circuited and connected to the current source Ip. The gate and drain of the MOSFET M6b are short-circuited, and the source of the MOSFET M6b is grounded.

5. The voltage bias generating circuit with controllable temperature coefficient according to claim 4, characterized in that: The first proportional amplifying circuit includes: MOSFET Mo, MOSFET M1 ... MOSFET Mm, where m is an integer greater than 1; The MOSFET Mo is connected to the drain of the MOSFET m2a and the MOSFET m3a, the gate and drain of the MOSFET Mo are short-circuited, and the source of the MOSFET Mo is grounded; The MOSFETs M1-MOSFET Mm are connected to the MOSFET Mo in common gate connection, the sources of the MOSFETs M1-MOSFET Mm are grounded, the drains of the MOSFETs M1-MOSFET Mm are connected in common, and the drains of the MOSFETs M1-MOSFET Mm are also connected to the input end of the current adding circuit and the output end of the second proportional amplification circuit.

6. The voltage bias generating circuit with controllable temperature coefficient according to claim 5, characterized in that: The second proportional amplifying circuit includes: MOSFET Qo, MOSFET Q1 ... MOSFET Qn, where n is an integer greater than 2; The MOSFET Qo is connected to the drain of the MOSFET M2b and the MOSFET M3b, the gate and drain of the MOSFET Qo are short-circuited, and the MOSFET Mo is connected to the source of the MOSFETs Q1 to Qn and connected to the system power supply. The MOSFETs Q1 to Qn are connected to the gate of the MOSFET Qo, and the MOSFETs Q1 to Qn are connected to the drain of the MOSFETs M1 to Mm and are connected to the input end of the current adding circuit.

7. The voltage bias generating circuit with controllable temperature coefficient according to claim 4, characterized in that: The current adding circuit includes: MOSFET V1 and MOSFET V2; The MOSFET V1 is connected to a common drain with the MOSFETs Q1-Qn and the MOSFETs M1-Mm. The drain of the MOSFET V1 is also connected to the current source Iz3. The gate and drain of the MOSFET V1 are short-circuited. The MOSFET V1 is connected to a common gate with the MOSFET V2. The sources of the MOSFET V1 and the MOSFET V2 are grounded. The drain of the MOSFET V2 is connected to the second end of the resistor R3 and the first end of the resistor R2.

8. A radio frequency power amplifier circuit, characterized in that: include: A voltage bias generating circuit with controllable temperature coefficient according to any one of claims 1 to 7.

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