阅读说明：本技术 温度补偿有源偏置电路 (Temperature compensation active bias circuit ) 是由 郁发新 陈伟 吴建敏 郑骎 王志宇 *** 于 2019-08-05 设计创作，主要内容包括：本发明公开了温度补偿有源偏置电路,包括开关晶体管、有源偏置晶体管、电压调节电阻R2和栅极限流电阻R5；开关晶体管的一端与电压调节电阻R2的一端连接,电压调节电阻R2的另一端与有源偏置晶体管、栅极限流电阻R5的一端连接；本发明提供可降低工艺敏感度的温度补偿有源偏置,以解决在复杂工作环境中低噪声放大器芯片性能稳定性,并提高低噪声放大器芯片成品率的温度补偿有源偏置电路。(The invention discloses a temperature compensation active bias circuit, which comprises a switching transistor, an active bias transistor, a voltage regulating resistor R2 and a grid current limiting resistor R5; one end of the switching transistor is connected with one end of a voltage regulating resistor R2, and the other end of the voltage regulating resistor R2 is connected with one end of an active bias transistor and one end of a grid current limiting resistor R5; the invention provides a temperature compensation active bias circuit which can reduce the process sensitivity, so as to solve the problem of performance stability of a low-noise amplifier chip in a complex working environment and improve the yield of the low-noise amplifier chip.)

1. The temperature compensation active bias circuit is characterized by comprising a switching transistor, an active bias transistor, a voltage regulating resistor R2 and a grid current limiting resistor R5; one end of the switching transistor is connected with one end of a voltage regulating resistor R2, and the other end of the voltage regulating resistor R2 is connected with one end of an active bias transistor and one end of a grid current limiting resistor R5; the transistor switch comprises a transistor FET1, an external voltage Vc, an external voltage Vdd and a grid current-limiting resistor R1; the gate of the transistor FET1 is connected to one end of a gate current limiting resistor R1, the other end of the gate current limiting resistor R1 is connected to the external voltage Vc, the drain of the transistor FET1 is connected to the external voltage Vdd, and the source of the transistor FET1 is connected to one end of a voltage adjusting resistor R2.

2. The temperature-compensated active bias circuit of claim 1, wherein: the active bias transistor is connected in parallel with a gate current limiting resistor R5.

3. The temperature-compensated active bias circuit of claim 2, wherein: the active bias transistor comprises a transistor FET2, a temperature-sensitive resistor R3 and a temperature-sensitive resistor R4; the grid and the drain of the transistor FET2 are connected, the grid of the transistor FET2 is connected with one end of the temperature-sensitive resistor R3, the other end of the temperature-sensitive resistor R3 is grounded, the source of the transistor FET2 is connected with one end of the temperature-sensitive resistor R4, and the other end of the temperature-sensitive resistor R4 is grounded.

4. The temperature-compensated active bias circuit of claim 1, wherein: the other end of the gate current limiting resistor R5 is connected to an amplifier.

5. The temperature-compensated active bias circuit of claim 1, wherein: the high level of the external voltage Vc is 5 volts, the low level is 0 volts, and the external voltage Vdd is 5V.

Technical Field

The present invention relates to the field of attenuators, and more particularly, to temperature compensated active bias circuits.

Background

With the continuous development of wireless communication technology, people have continuously increased requirements on multi-frequency multi-standard receivers and have deeper research on broadband low-noise amplifiers.

The low-noise amplifier has complex working environment and large temperature span, and the traditional temperature compensation circuit divides voltage and biases, can improve the deterioration of gain flatness caused by temperature fluctuation, but is sensitive to process fluctuation, so that the yield of the low-noise amplifier chip is low. The traditional active bias can reduce the sensitivity of the low-noise amplifier to process fluctuation, but has poor environmental adaptability and weaker temperature compensation capability.

Therefore, the active bias with small circuit area, low power consumption, integrated temperature compensation and reduced threshold voltage sensitivity is researched, and the active bias has important significance and practical application value.

Disclosure of Invention

The invention overcomes the defects of the prior art, and provides the temperature compensation active bias circuit which can reduce the process sensitivity, so as to solve the problem of the performance stability of the low-noise amplifier chip in a complex working environment and improve the yield of the low-noise amplifier chip.

The technical scheme of the invention is as follows:

the temperature compensation active bias circuit comprises a switching transistor, an active bias transistor, a voltage regulating resistor R2 and a grid current limiting resistor R5; one end of the switching transistor is connected with one end of a voltage regulating resistor R2, and the other end of the voltage regulating resistor R2 is connected with one end of an active bias transistor and one end of a grid current limiting resistor R5; the transistor switch comprises a transistor FET1, an external voltage Vc, an external voltage Vdd and a grid current-limiting resistor R1; the gate of the transistor FET1 is connected to one end of a gate current limiting resistor R1, the other end of the gate current limiting resistor R1 is connected to the external voltage Vc, the drain of the transistor FET1 is connected to the external voltage Vdd, and the source of the transistor FET1 is connected to one end of a voltage adjusting resistor R2.

Further, an active bias transistor is connected in parallel with the gate current limiting resistor R5.

Further, the active bias transistor comprises a transistor FET2, a temperature-sensitive resistor R3 and a temperature-sensitive resistor R4; the grid and the drain of the transistor FET2 are connected, the grid of the transistor FET2 is connected with one end of the temperature-sensitive resistor R3, the other end of the temperature-sensitive resistor R3 is grounded, the source of the transistor FET2 is connected with one end of the temperature-sensitive resistor R4, and the other end of the temperature-sensitive resistor R4 is grounded.

Further, the other end of the gate current limiting resistor R5 is connected to the amplifier.

Further, the high level of the external voltage Vc is 5V, the low level is 0V, and the external voltage Vdd is 5V.

Compared with the prior art, the invention has the advantages that: the invention reduces the influence of threshold voltage Vth fluctuation on amplifier gain caused by the process, improves the stability of the amplifier performance under different temperature working environments, and simultaneously reduces the size and the power consumption.

Drawings

FIG. 1 is a schematic circuit diagram of the present invention;

FIG. 2 is a schematic diagram of a circuit board of the present invention;

FIG. 3 is a graph of simulation results of the variation of active bias output voltage with Vth according to the present invention;

FIG. 4 is a graph of simulation results of transistor gain with Vth variation under active bias in accordance with the present invention;

FIG. 5 is a graph of simulation results of the variation of active bias output voltage with temperature in accordance with the present invention;

FIG. 6 is a graph showing the simulation result of the variation of the transistor gain with temperature under the active bias of the present invention.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, wherein like or similar reference numerals refer to like or similar elements or elements of similar function throughout. The embodiments described below with reference to the drawings are exemplary only, and are not intended as limitations on the present invention.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The invention is further described with reference to the following figures and detailed description.

As shown in fig. 1 to 6, the temperature compensation active bias circuit includes a switching transistor, an active bias transistor, a voltage regulation resistor R2 and a gate current limiting resistor R5; one end of the switching transistor is connected with one end of a voltage regulating resistor R2, the other end of the voltage regulating resistor R2 is connected with one end of an active bias transistor and one end of a grid current limiting resistor R5, and the other end of the grid current limiting resistor R5 is connected with the amplifier. The transistor switch comprises a transistor FET1, an external voltage Vc, an external voltage Vdd and a grid current-limiting resistor R1; the gate of the transistor FET1 is connected to one end of a gate current limiting resistor R1, and the other end of the gate current limiting resistor R1 is connected to the external voltage Vc, and the switching of the active bias transistor is controlled by adjusting the level of the external voltage Vc for power supply. The drain of the transistor FET1 is connected to the external voltage Vdd, and the source of the transistor FET1 is connected to one end of the voltage regulating resistor R2. The active bias transistor is connected in parallel with a gate current limiting resistor R5. The whole switch transistor is small in occupied area and low in power consumption, when the switch transistor is started, the driving voltage is small, and the source voltage of the switch transistor is approximately equal to the external voltage Vdd. Transistor FET1 employs a pHEMT tube based on GaAs technology.

The active bias transistors include a transistor FET2, a temperature sensitive resistor R3, and a temperature sensitive resistor R4. The gate and the drain of the transistor FET2 are connected, the voltages of the gate and the drain are equal, the active bias transistor is in a saturation region, the input voltage is converted into the output current and then into the output voltage, and the influence of the output voltage on the fluctuation of the process threshold voltage Vth is further reduced. The grid of the transistor FET2 is connected with one end of the temperature-sensitive resistor R3, the other end of the temperature-sensitive resistor R3 is grounded, the source of the transistor FET2 is connected with one end of the temperature-sensitive resistor R4, and the other end of the temperature-sensitive resistor R4 is grounded. A temperature sensitive resistor R3 and the gate of a transistor FET2, the drain of which is in parallel with a gate current limiting resistor R5.

The transistor FET2 adopts a pseudomorphic high electron mobility field effect transistor based on a T-shaped gate process, and the temperature-sensitive resistor R3 and the temperature-sensitive resistor R4 adopt a positive temperature change coefficient. The resistance values of the temperature-sensitive resistor R3 and the temperature-sensitive resistor R4 are reduced at low temperature, so that the output voltage is reduced, the gain of the amplifier transistor at low temperature is reduced, the output voltage can be increased at high temperature, and the gain of the amplifier transistor at high temperature is increased.

The slope of the output voltage of the active bias transistor changing along with the threshold voltage Vth is adjusted through the resistance values of the voltage adjusting resistor R2 and the temperature sensitive resistor R3, the larger the value of R2 multiplied by R3 is, the closer the change slope of the output voltage of the active bias transistor and the change slope of the threshold voltage Vth is, and the higher the process redundancy of the amplifier is. The slope of the output voltage of the active bias transistor along with the temperature change is controlled by adjusting the resistance values of the temperature-sensitive resistor R3 and the temperature-sensitive resistor R4. The temperature-sensitive resistor R3 influences the sensitivity of the active bias transistor to the threshold voltage Vth, and can adjust the output voltage at different temperatures, so that the reasonable resistance value of the temperature-sensitive resistor R3 can be well compatible with the redundancy of the active bias transistor to the threshold voltage fluctuation and the temperature change.

The transistor size influences the whole power consumption and area of the temperature compensation active bias circuit, the large-size tube core has larger power consumption, the stronger adaptability to temperature and threshold voltage Vth is, the reasonable tube core size can balance the active bias performance and power consumption, and the size is reduced.

The specific scheme and the parameters of each element are as follows: the total gate width of the switching transistor is 50um, the gate index is 2, and the gate length is 150 nm. The sizes of the grid current limiting resistor R1 and the grid current limiting resistor R5 are 5 × 200um and 3 × 500um respectively, and the resistance values are 7 kilo-ohms and 8 kilo-ohms. The voltage regulating resistor R2 is 3 × 210um in size and 3.6 kohm in resistance. The total gate width of the active bias transistor is 200um, and the gate index is 4. The sizes of the temperature-sensitive resistor R3 and the temperature-sensitive resistor R4 are 10 × 90um and 16 × 18um respectively, and the resistance values are 1.5 kilo-ohm and 2 hundred-ohm respectively. The high level of the external voltage Vc is 5 volts, the low level is 0 volts, and the external voltage Vdd is 5V.

And finishing a circuit topological structure according to the specification, and carrying out layout according to a circuit schematic diagram, wherein the size of the active bias area is as follows: 350um to 400um, 5 mW. As can be seen from fig. 3, the output voltage of the temperature compensation active bias circuit is raised from 0.37 v to 0.59 v when the threshold voltage Vth is changed from-0.1 v to 0.1 v, and is substantially consistent with the change slope of the threshold voltage Vth, and can follow the change of the threshold voltage Vth. The current only drops from 9mA to 6mA when the threshold voltage Vth varies from-0.1 volts to 0.1 volts for the active bias transistor under the temperature compensated active bias circuit. As can be seen from FIG. 4, the gain of the active bias transistor of the temperature compensated active bias circuit is reduced from 16dB to 14.7dB, and is only reduced by 1.3 dB. As can be seen from fig. 5, the temperature compensated active bias circuit output voltage varies from 0.47 volts to 0.52 volts with temperature variations from-55 c to 125 c. Under the temperature change of the active bias transistor from-55 ℃ to 125 ℃, the current is increased from 4mA to 11mA, and as can be seen from FIG. 6, the gain is only reduced from 15dB to 14.5dB and is only reduced by 0.5 dB.

The scheme designs a temperature compensation active bias by adopting a GaAs process, but the realization of the active bias is not limited to the process. The structure proposed herein can be used to achieve Vth adjustment and gain stability at different temperatures using different process dies and temperature compensation resistors.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and decorations can be made without departing from the spirit of the present invention, and these modifications and decorations should also be regarded as being within the scope of the present invention.