CN111900939A - A monolithic low-noise amplifier with externally matched input port for liquid helium temperature region - Google Patents

Abstract

The invention relates to a single-chip low-noise amplifier for externally matching input ports in a liquid helium temperature zone, comprising an input-end matching circuit and a wide-band single-chip low-noise amplifier circuit. The input end matching circuit is cascaded with the monolithic low-noise amplifier circuit, and the input port of the monolithic amplifier circuit is matched mainly through capacitors C1, C2, inductance L1 and resistor R1 to optimize the noise and port return loss performance of the amplifier; monolithic The low-noise amplifying circuit consists of three-stage strain high electron mobility transistor, matching circuit and bias circuit. By using the low-noise amplifier disclosed in the present invention, the liquid helium temperature region of ultra-low temperature can be stably used. In the wide frequency range of 2GHz to 15GHz, the gain is greater than 32dB, and the noise temperature is less than 10K. For excellent narrowband performance, the device has the characteristics of low noise, small size, and convenient matching, and can be used in receiving systems in the fields of deep space exploration and radio astronomy.

Description

A monolithic low-noise amplifier with externally matched input port for liquid helium temperature region

technical field

The invention relates to the technical field of microwave devices, in particular to a single-chip low-noise amplifier with externally matched input ports in a liquid helium temperature region.

Background technique

The sensitivity of the receiver system is limited by the system noise, and the system noise is determined by the noise of the device used and the background noise of the environment. In general microwave receiving systems, the requirements for noise indicators are not very high, and conventional microwave amplifiers can meet their needs. , but for systems such as radio astronomy, deep space exploration, and low-temperature physics, the background noise of the received signal is only a few K. In this case, the noise requirements of the system itself are very strict, and ultra-low temperature low-noise amplifiers must be used. The best performance of the receiver system can be achieved by cooling the receiving front end to minimize the noise generated by the device.

Strained High Electron Mobility Transistors (mHEMTs) have the best noise and excellent high frequency characteristics, high carrier velocities can be obtained at lower drain voltages, and at ultra-low temperatures due to the large quantum well potential The energy required to excite electrons must be higher than normal temperature, and the mHEMT technology can not suffer from the carrier freezing effect during electron migration at ultra-low temperature, and only needs a slight increase in the temperature region of liquid helium (about -269 °C). A little gate voltage can ensure proper operation of the device.

Noise performance is the most concerned indicator of low-noise amplifiers, which is determined by the noise impedance matching between the input circuit and the first-stage mHEMT device. The matching circuit of conventional monolithic low-noise amplifiers is integrated with other circuits on the chip. It cannot be debugged when the working frequency band drifts, and even more serious self-oscillation occurs. The invention designs a single-chip low-noise amplifier with external matching for the input port of the liquid helium temperature region based on the low-temperature characteristics of the mHEMT device and the characteristics of the single-chip circuit.

SUMMARY OF THE INVENTION

The invention proposes a single-chip low-noise amplifier with external matching for the input port of the liquid helium temperature region, which can meet the needs of the fields of radio astronomy, deep space exploration and low-temperature physics for broadband low-noise amplifiers. The circuit can be optimized and adjusted according to the actual frequency band used to maximize the use range of the amplifier.

To achieve the above object, the present invention has adopted the following technical solutions:

A single-chip low-noise amplifier for externally matching input ports in a liquid helium temperature region comprises an input-end matching circuit and a single-chip low-noise amplifying circuit, wherein the input-end matching circuit is cascaded with the single-chip low-noise amplifying circuit;

Wherein, the input end matching circuit includes a capacitor C1, a capacitor C2, an inductor L1, a resistor R1, a microstrip line TL7, a microstrip line TL8 and a gate bias circuit, and the microstrip line TL8 and the monolithic circuit PAD1 pass through a diameter 25μm length 350μm to 400μm gold wire connection. The input port of the monolithic amplifier circuit can be matched to optimize the performance of the amplifier's noise and port return loss, which is also conducive to the optimization and debugging of the circuit performance in the liquid helium environment.

Further, the monolithic low-noise amplifier circuit includes a first stage mHEMT transistor T1, a second stage mHEMT tube T2, a third stage mHEMT tube T3, and the gate of the first stage mHEMT tube T1 is connected to the input end matching circuit through PAD1, The source is grounded through the microstrip lines TL1 and TL2, and the drain is connected to the second-stage mHEMT transistor T2 through an inter-stage matching circuit. The matching circuit is connected to the third stage mHEMT transistor T3, the gate of the third stage mHEMT tube T3 is connected to the input matching circuit, the source is grounded through the microstrip lines TL5 and TL6, and the drain is connected to the output port PAD2 through the output matching circuit. Among them, TL1~TL6 improve the stability of the circuit, TL7 and TL8 are microstrip transmission lines with 50Ω impedance, and the monolithic low-noise amplifier circuit adopts 130nm process. There is a big difference. In the design, the ultra-low temperature microwave probe station was used to extract the scattering parameters (S parameters) and DC parameters of the mHEMT tube in the liquid helium temperature region. The S-parameters of the temperature region were established, and the model circuit of the mHEMT tube and the passive device liquid helium temperature region was established for the simulation design of the low-noise monolithic circuit to improve the design efficiency of the monolithic amplifier.

Further, the gate width of the first-stage mHEMT transistor T1 is 2×100 μm, the gate width of the second-stage mHEMT transistor T2 is 2×50 μm, and the gate width of the third-stage mHEMT transistor T3 is 2×50 μm.

Further, the gates and drains of the three-stage mHEMT tubes T1, T2, and T3 are independently powered by bias circuits composed of B1 to B6, and the gates and drains of the mHEMT tubes are powered separately, which is conducive to room temperature and liquid helium temperature. Area debugging and testing.

Further, the signal input port and the signal output port can be connected to SMA or K-type coaxial connectors, or a microstrip line can be used to integrate with other microwave devices to form a multifunctional ultra-low temperature microwave component.

It can be known from the above technical solutions that a single-chip low-noise amplifier for externally matching input ports in a liquid helium temperature region of the present invention is mainly composed of an input-end matching circuit and a single-chip low-noise amplifier circuit. The monolithic low-noise amplifier circuit ensures the gain, in-band flatness and noise performance of the amplifier over a wide frequency range; the external matching circuit can match the input port of the amplifier to optimize the amplifier's performance such as noise and port return loss, and A narrow-band low-noise amplifier designed to work in the liquid helium temperature region. To sum up, the present invention has the characteristics of small size and low noise temperature, and can be applied to receiver systems with extreme requirements for noise performance, such as deep space exploration, radio astronomy, and low-temperature physics research.

Description of drawings

Fig. 1 is the circuit schematic diagram of the present invention;

Fig. 2 is the gain test result figure of the present invention;

FIG. 3 is a graph of the noise temperature test result of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments.

This embodiment provides a single-chip low-noise amplifier for externally matching input ports in a liquid helium temperature region, as shown in FIG. 1 , including an input-end matching circuit and a single-chip low-noise amplifier circuit, wherein the input-end matching circuit and Monolithic low-noise amplifier circuits are cascaded.

Specifically, the input end matching circuit includes a capacitor C1, a capacitor C2, an inductor L1, a resistor R1, a microstrip line TL7, a microstrip line TL8 and a gate bias circuit. The microstrip line TL8 and the monolithic circuit PAD1 pass through a A gold wire connection with a diameter of 25 μm and a length of 350 μm to 400 μm. The input port of the monolithic amplifier circuit can be matched to optimize the performance of the amplifier's noise and port return loss, which is also conducive to the optimization and debugging of the circuit performance in the liquid helium environment.

The monolithic low-noise amplifier circuit includes the gate width of the first-stage mHEMT transistor T1 is 2×100 μm, the gate width of the second-stage mHEMT transistor T2 is 2×50 μm, and the gate width of the third-stage mHEMT transistor T3 is 2×50 μm. The gate of the first-stage mHEMT transistor T1 is connected to the input matching circuit through PAD1, the source is grounded through the microstrip lines TL1 and TL2, and the drain is connected to the second-stage mHEMT transistor T2 through the inter-stage matching circuit, and the second-stage mHEMT transistor T2 The source is grounded through the microstrip lines TL3 and TL4, the drain is connected to the third stage mHEMT tube T3 through the inter-stage matching circuit, the gate of the third stage mHEMT tube T3 is connected to the input matching circuit, and the source is connected through the microstrip line TL5. And TL6 is grounded, and the drain is connected to the output port PAD2 through the output matching circuit. Among them, TL1~TL6 improve the stability of the circuit, TL7 and TL8 are microstrip transmission lines with 50Ω impedance, and the monolithic low-noise amplifier circuit adopts 130nm process. There is a big difference. In the design, the ultra-low temperature microwave probe station was used to extract the scattering parameters (S parameters) and DC parameters of the mHEMT tube in the liquid helium temperature region. The S-parameters of the temperature region were established, and the model circuit of the mHEMT tube and the passive device liquid helium temperature region was established for the simulation design of the low-noise monolithic circuit to improve the design efficiency of the monolithic amplifier.

The gates and drains of the three-stage mHEMT tubes T1, T2, and T3 are independently powered by bias circuits composed of B1 to B6, and the gates and drains of the mHEMT tubes are powered separately, which is conducive to debugging in normal temperature and liquid helium temperature regions. According to the actual situation, the drain voltage and current of the three-stage mHEMT tube are: T1 drain voltage 1.5V, current 8mA; T2 drain voltage 1.2V, current 6mA; T3 drain voltage 1.2V, current 6mA The drain voltage is 1.2V, and the current is 6mA.

The signal input port can be connected to an SMA or K-type coaxial connector, or a microstrip line can be used to connect other microwave devices. The signal output port can be bonded to SMA and K-type coaxial connectors with two gold wires with a diameter of 25 μm and a length of less than 300 μm, or can be bonded to a microstrip line and then connected to other microwave devices.

The model of the internal components in the monolithic low-noise amplifier for external matching of the input port of the liquid helium temperature region provided by the embodiment of the present invention can be selected according to the actual situation. Exemplarily, the capacitive element of the input end matching circuit can be selected Chip capacitor, the value of capacitor C1 is 12pF, and the value of capacitor C2 is 33pF; the inductance element is an air-core coil inductance, and the value of inductance L1 is 39nH; the resistance element can be a chip resistor, and the value of R1 is 20Ω; microstrip line TL7, microstrip line The impedance of TL8 is all 50Ω. The monolithic low-noise amplifier circuit adopts 130nm gallium arsenide GaAs-based process, and the standard thickness of the circuit is 100μm.

The working range of a single-chip low-noise amplifier designed for externally matching input ports in a liquid helium temperature region provided by the embodiment of the present invention can be 2 GHz to 15 GHz. After calibrating the instrument during testing, the amplifier is installed in a low-temperature dewar, and sealed , Refrigerate after evacuating. When the working temperature of the device drops to the helium temperature region, continue to keep warm for 1 hour. Use a vector network analyzer to test the gain of the device. The measured curve is shown in Figure 2. Use a high-precision noise test platform to test the noise temperature of the device. , the measured curve is shown in Figure 3. From Figures 2 and 3, it can be seen that the gain of the device is greater than 32dB, and the noise temperature is less than 10K.

The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (6)

1. A monolithic low noise amplifier for external matching of an input port of a liquid helium temperature zone is characterized in that:

the broadband low-noise amplifier comprises an input end matching circuit and a broadband monolithic low-noise amplifying circuit which can work at 269 ℃ below zero, wherein the input end matching circuit is cascaded with the broadband monolithic low-noise amplifying circuit;

the input end matching circuit comprises a capacitor C1, a capacitor C2, an inductor L1, a resistor R1, a microstrip line TL7, a microstrip line TL8 and a gate bias circuit, wherein the microstrip line TL8 and the single chip PAD1 are connected through a gold wire with the diameter of 25 mu m and the length of 350 mu m to 400 mu m.

2. The monolithic low noise amplifier for external matching of an input port of a liquid helium temperature zone of claim 1, wherein: the broadband monolithic low-noise amplification circuit comprises a first-stage mHEMT tube T1, a second-stage mHEMT tube T2 and a third-stage mHEMT tube T3, the grid of the first-stage mHEMT tube T1 is connected with an input end matching circuit through a PAD1, the source is grounded through microstrip lines TL1 and TL2, the drain is connected with the second-stage mHEMT tube T2 through an interstage matching circuit, the source of the second-stage mHEMT tube T2 is grounded through microstrip lines TL3 and TL4, the drain is connected with the third-stage mHEMT tube T3 through the interstage matching circuit, the grid of the third-stage mHEMT tube T3 is connected with the input end matching circuit, the source is grounded through microstrip lines TL5 and TL6, and the drain is connected with an output port PAD.

3. The monolithic low noise amplifier for external matching of an input port of a liquid helium temperature zone of claim 2, wherein: the grid width of the first-stage mHEMT tube T1 is 2 x 100 mu m, the grid width of the second-stage mHEMT tube T2 is 2 x 50 mu m, and the grid width of the third-stage mHEMT tube T3 is 2 x 50 mu m.

4. The monolithic low noise amplifier for external matching of an input port of a liquid helium temperature zone of claim 3, wherein: the grids and the drains of the three-stage mHEMT tubes T1, T2 and T3 are independently powered by a bias circuit consisting of B1-B6.

5. The monolithic low noise amplifier for external matching of an input port of a liquid helium temperature zone of claim 4, wherein:

the capacitance element of the input end matching circuit is a chip capacitor, the value of the capacitor C1 is 12pF, and the value of the capacitor C2 is 33 pF;

the inductance element of the input end matching circuit is an air-core coil inductance, and the value of the inductance L1 is 39 nH;

the resistor element of the input end matching circuit is a chip resistor, and the value of the resistor R1 is 20 omega; the impedances of the microstrip line TL7 and the microstrip line TL8 are both 50 Ω.

6. The monolithic low noise amplifier for external matching of an input port of a liquid helium temperature zone of claim 5, wherein:

the broadband monolithic low-noise amplification circuit adopts a 130nm gallium arsenide (GaAs) based process, and the standard thickness of the circuit is 100 mu m.

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