Amplifier circuit with temperature compensated bias circuit

Abstract

The invention provides an amplifier circuit with a temperature compensation bias circuit. An emitter of a third germanium-silicon heterojunction bipolar transistor is grounded, and a collector of the third germanium-silicon heterojunction bipolar transistor is connected with mirror input current; the temperature positive correlation current compensation module and the temperature negative correlation current compensation module are used for carrying out mirror image current temperature compensation so as to realize the temperature positive correlation characteristic of mirror image input current, so that the collector bias current temperature positive correlation is realized; and the third germanium-silicon heterojunction bipolar transistor outputs a temperature positive correlation mirror image bias voltage through a temperature positive correlation bias module connected between the base electrode and the collector electrode of the third germanium-silicon heterojunction bipolar transistor, and biases the input-stage bias voltage of the amplifier circuit after voltage drop of a temperature negative correlation bias voltage drop module. The negative temperature characteristic of transconductance is compensated, the gain shows that the temperature stability is not reduced any more along with temperature increase, the gain stability is improved, and therefore the temperature stability of other radio frequency characteristics such as noise of a system is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to an amplifier circuit with a temperature compensation bias circuit. Background Art

[0002] SiGe HBT (heterojunction bipolar) transistors have advantages in radio frequency applications such as high frequency, high speed, high gain, low noise, and low power consumption. They have been widely used in the design of low noise amplifiers, power amplifiers, transceivers, etc. in the fields of wired and wireless communication systems, and play an increasingly important role in modern electronic systems such as sensor networks, vehicle networks, and radio frequency front-ends.

[0003] When designing a radio frequency amplifier, its bias circuit generally adopts existing technologies such as Figure 1 the mirror bias design, which mirrors the reference current according to the physical size ratio to bias the operating state of the amplifier to maintain a stable bias current and be immune to the influence of process, voltage, temperature, etc., so as to obtain stable radio frequency characteristics.

[0004] From the transconductance and gain characteristics of the HBT amplifier, when maintaining a constant collector bias current, its transconductance and gain show a negative temperature correlation, such as Figure 2 , the gain decreases with the increase of temperature, showing a gain change of ±1 dB within the temperature range, which will affect the temperature stability of other radio frequency characteristics such as the noise of the system. Therefore, a systematic temperature compensation design of the gain is required to obtain temperature-stable radio frequency characteristics such as the gain and noise of the system.

[0005] To solve the above problems, a new type of amplifier circuit with a temperature compensation bias circuit needs to be proposed. Summary of the Invention

[0006] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide an amplifier circuit with a temperature compensation bias circuit, which is used to solve the problem that the transconductance and gain of the HBT amplifier in the prior art show a negative temperature correlation, which will affect the temperature stability of other radio frequency characteristics such as the noise of the system.

[0007] To achieve the above purpose and other related purposes, the present invention provides an amplifier circuit with a temperature compensation bias circuit, including:

[0008] The amplifier circuit includes:

[0009] A first germanium-silicon heterojunction bipolar transistor and a second germanium-silicon heterojunction bipolar transistor;

[0010] The base of the first germanium-silicon heterojunction bipolar transistor serves as the input stage of the amplifier circuit. A first inductor is connected between the emitter of the first germanium-silicon heterojunction bipolar transistor and the ground terminal. The collector of the first germanium-silicon heterojunction bipolar transistor is connected to the emitter of the second germanium-silicon heterojunction bipolar transistor. A second inductor and a first resistor connected in parallel are connected between the collector of the second germanium-silicon heterojunction bipolar transistor and the power supply voltage.

[0011] The input terminal of the radio frequency signal is connected to the base of the first germanium-silicon heterojunction bipolar transistor through a series-connected third inductor and a first capacitor. The output terminal of the radio frequency signal is connected to the collector of the second germanium-silicon heterojunction bipolar transistor through a second capacitor.

[0012] The temperature compensation bias circuit includes:

[0013] A temperature positively correlated current compensation module, a temperature negatively correlated current compensation module, a temperature negatively correlated bias voltage drop module, a temperature positively correlated bias module, and a third germanium-silicon heterojunction bipolar transistor.

[0014] The emitter of the third germanium-silicon heterojunction bipolar transistor is grounded, and the collector of the third germanium-silicon heterojunction bipolar transistor is connected to the mirrored input current.

[0015] The temperature positively correlated current compensation module and the temperature negatively correlated current compensation module are used to perform mirrored current temperature compensation to achieve the temperature positively correlated characteristic of the mirrored input current, so that the collector bias current is temperature positively correlated.

[0016] The third germanium-silicon heterojunction bipolar transistor realizes an output temperature positively correlated mirrored bias voltage through the temperature positively correlated bias module connected between its base and collector, and biases the input stage bias voltage of the amplifier circuit after voltage drop through the temperature negatively correlated bias voltage drop module.

[0017] Preferably, the temperature positively correlated characteristic of the mirrored input current Iref(Tk) = Iref + ITC(Tk) - ITC(1 / Tk), where Iref is the mirrored input current, ITC(Tk) is the mirrored current temperature compensation of the temperature positively correlated current compensation module, and ITC(1 / Tk) is the mirrored current temperature compensation of the temperature negatively correlated current compensation module.

[0018] Preferably, the temperature positively correlated current compensation module includes: a PMOS and a first negative temperature coefficient resistor. The source and substrate electrodes of the PMOS are both connected to the power supply voltage. The first end of the first negative temperature coefficient resistor is connected to the drain of the PMOS, and the second end of the first negative temperature coefficient resistor is connected to the gate of the PMOS and then connected to the temperature negatively correlated current compensation module.

[0019] Preferably, the temperature negatively correlated current compensation module is a first positive temperature coefficient resistor.

[0020] Preferably, the temperature positively correlated bias module is a second positive temperature coefficient resistor.

[0021] Preferably, the temperature negatively correlated bias voltage drop module is a second negative temperature coefficient resistor.

[0022] Preferably, the first negative temperature coefficient resistor and the second negative temperature coefficient resistor have a negative temperature characteristic.

[0023] Preferably, the first negative temperature coefficient resistor and the second negative temperature coefficient resistor are non-silicided resistors.

[0024] Preferably, the first positive temperature coefficient resistor and the second positive temperature coefficient resistor have a positive temperature characteristic.

[0025] Preferably, the first positive temperature coefficient resistor and the second positive temperature coefficient resistor are silicided resistors.

[0026] Preferably, a second resistor is connected in series between the substrate electrode of the first germanium-silicon heterojunction bipolar transistor and the ground terminal; the second resistor and a third resistor are connected in series between the substrate electrode of the second germanium-silicon heterojunction bipolar transistor and the ground terminal.

[0027] As described above, the amplifier circuit with a temperature compensation bias circuit of the present invention has the following beneficial effects:

[0028] The collector current of the present invention is positively related to temperature, which preferably compensates for the negative temperature characteristic of the transconductance. The gain shows temperature stability and does not decrease with increasing temperature. The gain changes by ±0.1 dB within the temperature range, significantly improving the gain stability, and thus improving the temperature stability of other radio frequency characteristics such as the noise of the system. Description of the Drawings

[0029] Figure 1 Schematic diagram of a mirror bias HBT amplifier shown as the prior art;

[0030] Figure 2 Schematic diagram showing the relationship between the gain and the bias current temperature of an HBT amplifier shown as the prior art;

[0031] Figure 3 Schematic diagram showing the design of the temperature compensation bias circuit and the amplifier of the present invention;

[0032] Figure 4 Schematic diagram showing the design implementation of the temperature compensation bias circuit and the amplifier of the present invention;

[0033] Figure 5 It shows a schematic diagram comparing the gain and bias current temperature relationship of the HBT amplifier of the present invention. Detailed implementation manners

[0034] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0035] Please refer to Figure 3 , the present invention provides an amplifier circuit with a temperature compensation bias circuit, including:

[0036] The amplifier circuit 10 includes:

[0037] A first germanium-silicon heterojunction bipolar transistor Q1 and a second germanium-silicon heterojunction bipolar transistor Q2;

[0038] The base of the first germanium-silicon heterojunction bipolar transistor Q1 serves as the input stage of the amplifier circuit 10. A first inductor Ls is connected between the emitter of the first germanium-silicon heterojunction bipolar transistor Q1 and the ground terminal. The collector of the first germanium-silicon heterojunction bipolar transistor Q1 is connected to the emitter of the second germanium-silicon heterojunction bipolar transistor Q2. A parallel combination of a second inductor Ld and a first resistor Rd is connected between the collector of the second germanium-silicon heterojunction bipolar transistor Q2 and the power supply voltage Vdd;

[0039] The input terminal of the radio frequency signal is connected to the base of the first germanium-silicon heterojunction bipolar transistor Q1 through a series connection of a third inductor Lg and a first capacitor Ci; the output terminal of the radio frequency signal is connected to the collector of the second germanium-silicon heterojunction bipolar transistor Q2 through a second capacitor Co;

[0040] In an embodiment of the present invention, a second resistor is connected in series between the substrate electrode of the first germanium-silicon heterojunction bipolar transistor Q1 and the ground terminal; a second resistor and a third resistor are connected in series between the substrate electrode of the second germanium-silicon heterojunction bipolar transistor Q2 and the ground terminal.

[0041] The temperature compensation bias circuit 20 includes:

[0042] A temperature positively correlated current compensation module ITC(Tk), a temperature negatively correlated current compensation module ITC(1 / Tk), a temperature negatively correlated bias voltage drop module R(1 / Tk), a temperature positively correlated bias module R(Tk), and a third germanium-silicon heterojunction bipolar transistor Q3;

[0043] The emitter of the third germanium-silicon heterojunction bipolar transistor Q3 is grounded, and the collector of the third germanium-silicon heterojunction bipolar transistor Q3 is connected to the mirror input current Iref;

[0044] The temperature positively correlated current compensation module ITC(Tk) and the temperature negatively correlated current compensation module ITC(1 / Tk) are used for mirror current temperature compensation to achieve the temperature positively correlated characteristic of the mirror input current Iref, so that the collector bias current is temperature positively correlated;

[0045] The third germanium-silicon heterojunction bipolar transistor Q3 realizes the output temperature positively correlated mirror bias voltage through the temperature positively correlated bias module R(Tk) connected between its base and collector, and biases the input stage bias voltage of the amplifier circuit 10 after the voltage drop of the temperature negatively correlated bias voltage drop module R(1 / Tk), comprehensively strengthening the positive temperature characteristic of Vb, realizing the temperature positively correlated mirror ratio compensation characteristic of the bias network of the mirror bias circuit, and equivalently designing the collector bias current temperature positively correlated.

[0046] By compensating the negative temperature correlation of the collector current transconductance with temperature positive correlation, the temperature stability of the amplifier gain is improved, thereby improving the temperature stability of the system radio frequency characteristics.

[0047] In the embodiment of the present invention, the temperature positively correlated characteristic of the mirror input current Iref is Iref(Tk) = Iref + ITC(Tk) - ITC(1 / Tk), where Iref is the mirror input current Iref, ITC(Tk) is the mirror current temperature compensation of the temperature positively correlated current compensation module ITC(Tk), and ITC(1 / Tk) is the mirror current temperature compensation of the temperature negatively correlated current compensation module ITC(1 / Tk).

[0048] In integrated circuits, various corresponding resistors often have temperature coefficients. Usually, the resistors in integrated circuits include two temperature coefficients, namely negative temperature coefficient and positive temperature coefficient.

[0049] The resistance value of the resistor with a negative temperature coefficient often decreases with the increase of temperature. The resistors with a negative temperature coefficient usually include: unsalicided P-poly resistor (RPPOLYU), three-terminal unsalicided P-poly resistor (RPPOLYU3). RPPOLYU and RPPOLYU3 are common technical terms in the field of integrated circuit manufacturing.

[0050] The resistance value of a positive temperature coefficient resistor often increases with the increase in temperature. Positive temperature coefficient resistors typically include: a P-poly resistor with metal silicide (Salicided P-Poly Resistor, RPPOLYS), an unsalicided P+ diffusion resistor (RPDIFFU), a third metal layer resistor (RM3), and a second metal layer resistor (RM2). RPPOLYS, RPDIFFU, RM2, and RM3 are common technical terms in the field of integrated circuit manufacturing.

[0051] Please refer to Figure 4 , in an embodiment of the present invention, the temperature positively correlated current compensation module ITC(Tk) includes: PMOS P1 and a first negative temperature coefficient resistor 201. The source and substrate electrodes of PMOS P1 are both connected to the power supply voltage Vdd. The first end of the first negative temperature coefficient resistor 201 is connected to the drain of PMOS P1. The second end of the first negative temperature coefficient resistor 201 is connected to the gate of PMOS P1 and then connected to the temperature negatively correlated current compensation module ITC(1 / Tk). PMOS P1 pulls down the self-bias of the first negative temperature coefficient resistor 201 to achieve this.

[0052] In an embodiment of the present invention, the temperature negatively correlated current compensation module ITC(1 / Tk) is a first positive temperature coefficient resistor 202, and it is achieved by pulling down the first positive temperature coefficient resistor 202 network.

[0053] In an embodiment of the present invention, the temperature positively correlated bias module R(Tk) is a second positive temperature coefficient resistor 203.

[0054] In an embodiment of the present invention, the temperature negatively correlated bias voltage drop module R(1 / Tk) is a second negative temperature coefficient resistor 204.

[0055] In an embodiment of the present invention, the first negative temperature coefficient resistor 201 and the second negative temperature coefficient resistor 204 have negative temperature characteristics.

[0056] In an embodiment of the present invention, the first negative temperature coefficient resistor 201 and the second negative temperature coefficient resistor 204 are non-silicided resistors.

[0057] In an embodiment of the present invention, the first positive temperature coefficient resistor 202 and the second positive temperature coefficient resistor 203 have positive temperature characteristics.

[0058] In an embodiment of the present invention, the first positive temperature coefficient resistor 202 and the second positive temperature coefficient resistor 203 are silicided resistors.

[0059] Specifically, the second end of the first negative temperature coefficient resistor 201 is connected to the gate of the PMOS P1 and then connected to the first end of the first positive temperature coefficient resistor 202. The second end of the first positive temperature coefficient resistor 202 is grounded. The first end of the second positive temperature coefficient resistor 203 is connected to the base of the third germanium-silicon heterojunction bipolar transistor Q3. The second end of the second positive temperature coefficient resistor 203 is respectively connected to the second end of the first negative temperature coefficient resistor 201, the first end of the first positive temperature coefficient resistor 202, and the first end of the second negative temperature coefficient resistor 204. The second end of the second negative temperature coefficient resistor 204 is connected to the base of the first germanium-silicon heterojunction bipolar transistor Q1.

[0060] Please refer to Figure 5 , the collector current of the present invention is positively turned off with temperature, which better compensates for the negative temperature characteristic of the transconductance. The gain shows temperature stability and no longer decreases with the increase of temperature. The gain changes by ±0.1 dB within the temperature range, significantly improving the gain stability, thereby improving the temperature stability of other radio frequency characteristics such as the noise of the system.

[0061] It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0062] In summary, the collector current of the present invention is positively turned off with temperature, which better compensates for the negative temperature characteristic of the transconductance. The gain shows temperature stability and no longer decreases with the increase of temperature. The gain changes by ±0.1 dB within the temperature range, significantly improving the gain stability, thereby improving the temperature stability of other radio frequency characteristics such as the noise of the system. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0063] The above embodiments are only illustrative of the principles and effects of the present invention and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. An amplifier circuit having a temperature compensation bias circuit, characterized in that: include: The amplifier circuit comprises: A first silicon-germanium heterojunction bipolar transistor and a second silicon-germanium heterojunction bipolar transistor; The base of the first silicon-germanium heterojunction bipolar transistor serves as the input stage of the amplifier circuit, a first inductor is connected between the emitter of the first silicon-germanium heterojunction bipolar transistor and a ground terminal, a collector of the first silicon-germanium heterojunction bipolar transistor is connected to the emitter of the second silicon-germanium heterojunction bipolar transistor, and a second inductor and a first resistor are connected in parallel between the collector of the second silicon-germanium heterojunction bipolar transistor and a power supply voltage; The input end of the radio frequency signal is connected to the base of the first germanium-silicon heterojunction bipolar transistor through a third inductor and a first capacitor connected in series; the output end of the radio frequency signal is connected to the collector of the second germanium-silicon heterojunction bipolar transistor through a second capacitor; The temperature compensation bias circuit comprises: A temperature positively correlated current compensation module, a temperature negatively correlated current compensation module, a temperature negatively correlated bias voltage drop module, a temperature positively correlated bias module and a third germanium-silicon heterojunction bipolar transistor; The emitter of the third germanium-silicon heterojunction bipolar transistor is grounded, and the collector of the third germanium-silicon heterojunction bipolar transistor is connected to the mirror input current; The temperature positive correlation current compensation module and the temperature negative correlation current compensation module are used to perform temperature compensation of the mirror current to realize the temperature positive correlation characteristic of the mirror input current, thereby making the collector bias current temperature positively correlated; The third germanium-silicon heterojunction bipolar transistor outputs a temperature-positively correlated mirror bias voltage through the temperature-positively correlated bias module connected between its base and collector, and biases the input stage bias voltage of the amplifier circuit after being voltage-dropped by the temperature-negatively correlated bias voltage drop module.

2. The amplifier circuit with a temperature compensation bias circuit according to claim 1, characterized in that: The temperature positive correlation characteristic of the mirror input current is Iref(Tk)=Iref+ITC(Tk)-ITC(1 / Tk), wherein Iref is the mirror input current, ITC(Tk) is the mirror current temperature compensation of the temperature positive correlation current compensation module, and ITC(1 / Tk) is the mirror current temperature compensation of the temperature negative correlation current compensation module.

3. The amplifier circuit with a temperature compensation bias circuit according to claim 1, characterized in that: The temperature positively correlated current compensation module includes: a PMOS and a first negative temperature coefficient resistor, wherein the source and substrate electrodes of the PMOS are both connected to a power supply voltage, the first end of the first negative temperature coefficient resistor is connected to the drain of the PMOS, and the second end of the first negative temperature coefficient resistor is connected to the gate of the PMOS and then connected to the temperature negatively correlated current compensation module.

4. The amplifier circuit with a temperature compensation bias circuit according to claim 1, characterized in that: The temperature negatively correlated current compensation module is a first positive temperature coefficient resistor.

5. The amplifier circuit with a temperature compensation bias circuit according to claim 1, characterized in that: The temperature positive correlation bias module is a second positive temperature coefficient resistor.

6. The amplifier circuit with a temperature compensation bias circuit according to claim 1, characterized in that: The temperature negatively correlated bias voltage drop module is a second negative temperature coefficient resistor.

7. The amplifier circuit with a temperature compensation bias circuit according to claim 1 or 6, characterized in that: The first negative temperature coefficient resistor and the second negative temperature coefficient resistor have negative temperature characteristics.

8. The amplifier circuit with a temperature compensation bias circuit according to claim 7, characterized in that: The first negative temperature coefficient resistor and the second negative temperature coefficient resistor are non-silicided resistors.

9. The amplifier circuit with a temperature compensation bias circuit according to claim 4 or 5, characterized in that: The first positive temperature coefficient resistor and the second positive temperature coefficient resistor have positive temperature characteristics.

10. The amplifier circuit with a temperature compensation bias circuit according to claim 9, characterized in that: The first positive temperature coefficient resistor and the second positive temperature coefficient resistor are silicide resistors.

11. The amplifier circuit with a temperature compensation bias circuit according to claim 1, characterized in that: A second resistor is connected in series between the substrate electrode and the ground terminal of the first germanium-silicon heterojunction bipolar transistor; and the second resistor and a third resistor are connected in series between the substrate electrode and the ground terminal of the second germanium-silicon heterojunction bipolar transistor.

Images