A low-noise amplifier equivalent noise temperature measurement system and method

Abstract

The application discloses a kind of low-noise amplifier equivalent noise temperature measurement system and method, measurement system includes: load component, for providing thermal noise signal, including first load and second load, the first load and the second load are located in temperature different first temperature zone and second temperature zone respectively;The input end of the low-noise amplifier to be measured is electrically connected with the first load or the second load and receives thermal noise signal;Second amplification component is connected with the output end of the low-noise amplifier, amplifies the output signal of the low-noise amplifier, and the second amplification component meets impedance matching with the low-noise amplifier;Measuring device is used to measure the signal output by second amplification component, and obtain the equivalent noise temperature of the low-noise amplifier.The end of the low-noise amplifier connected with load is switched in different temperature zones, and the uncertainty factor in measurement is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of low temperature measurement, and particularly relates to a low-noise amplifier equivalent noise temperature measurement system and method. BACKGROUND

[0002] In the field of low temperature measurement, the real effective signal of a sample to be measured is very weak relative to the system environmental noise, and it is difficult to be directly collected and processed by a measuring instrument. Generally, the real signal of the sample to be measured can be effectively extracted by increasing the signal-to-noise ratio of the output signal through in-situ signal amplification.

[0003] Taking a quantum computer as an example, a quantum processor runs a quantum computing task and outputs an operation result signal. The control and reading signal of a quantum chip is very weak, generally below-110 dBm, and it is difficult to be directly collected and processed by a measuring instrument. The effective signal of the chip needs to be amplified in-situ. While amplifying the effective signal, the noise needs to be suppressed, so as to improve the signal-to-noise ratio. Generally, a low-temperature low-noise amplifier is arranged in a certain temperature zone adjacent to the quantum chip in a cryogenic system, for in-situ signal amplification of the quantum chip, and the low equivalent noise temperature of the amplifier itself maximally suppresses the noise.

[0004] The noise figure is a quantity used to measure the amount of random noise added to a signal by a component, such as a DUT, due to the irregular thermal motion of electrons in the device. In order to measure the degree of deterioration of the control signal, the concept of noise figure NF is introduced, that is, the noise figure quantifies the degree of reduction of the signal-to-noise ratio of the DUT. Generally, when the noise is very small, the noise performance of a low-noise amplifier is measured by equivalent noise temperature , which has the following relationship with the noise figure:

[0005]

[0006] In the formula, =290K, representing the equivalent noise temperature at room temperature.

[0007] The noise figure is a quality factor used to describe the amount of excessive noise in a system, so the smaller the noise figure is, the better. Designers strive to optimize the signal-to-noise ratio (SNR) of the entire system, and generally have two choices: to improve the signal power and to reduce the noise figure. Generally, the improvement of the signal power means greater thermal load, and waste of cost and performance, while the reduction of the noise figure is more economical and easier to achieve. SUMMARY

[0008] ​In order to improve the measurement accuracy of the equivalent noise temperature, the application provides a low-noise amplifier equivalent noise temperature measurement system and method, and the technical scheme is as follows:

[0009] A low-noise amplifier equivalent noise temperature measurement system comprises:

[0010] A load component is used to provide a thermal noise signal, and comprises a first load and a second load, wherein the first load and the second load are respectively located in a first temperature zone and a second temperature zone with different temperatures; an input end of the low-noise amplifier to be measured is electrically connected to the first load or the second load to receive the thermal noise signal;

[0011] A secondary amplification component is connected to the output end of the low-noise amplifier, amplifies the output signal of the low-noise amplifier, and the secondary amplification component and the low-noise amplifier satisfy impedance matching;

[0012] A measurement device is used to measure the signal output by the secondary amplification component and obtain the equivalent noise temperature of the low-noise amplifier.

[0013] Optionally, the temperature zone ratio of the temperature zones where the first load and the second load are located is at least one order of magnitude.

[0014] Optionally, the low-noise amplifier is connected to the first load and the second load through the same first cable, and the measurement device obtains two corresponding measurement signals.

[0015] Optionally, the first load and the second load are the same load.

[0016] Optionally, the low-noise amplifier and the secondary amplification component are arranged in the corresponding lowest temperature zone in the working environment temperature requirement.

[0017] Optionally, the gain of the secondary amplification component and the low-noise amplifier as a whole is such that the system noise power after two-stage amplification is greater than the noise floor of the measurement device.

[0018] A low-noise amplifier equivalent noise temperature measurement method comprises:

[0019] The measurement system of the low-noise amplifier is built, the load serving as a noise source is located in the first temperature zone and the second temperature zone, the measurement device correspondingly measures the first noise signal and the second noise signal, and the first relationship and the second relationship corresponding to the fixed parameters of the elements in the measurement system are obtained from the first noise signal and the second noise signal; the elements comprise the load component, the low-noise amplifier, the secondary amplification component, the measurement device, the first cable and the second cable.

[0020] determining a third relationship representing an equivalent noise temperature of the low noise amplifier based on the first relationship, the second relationship and a Y factor, wherein the Y factor is a ratio of the first noise signal and the second noise signal;

[0021] According to the noise after amplification of the low noise amplifier and the secondary amplification assembly respectively according to the load of different temperature zones, the noise is much larger than the noise floor of the measuring device, and a fourth relationship is obtained by simplifying the third relationship;

[0022] According to the fourth relationship, the equivalent noise temperature of the low noise amplifier is obtained.

[0023] Optionally, the first relationship and the second relationship of the first noise signal and the second noise signal and the fixed parameters of the elements in the measuring system are obtained, and the first relationship and the second relationship are respectively:

[0024] *k*B

[0025] *k*B

[0026] wherein, , are equivalent noise temperatures of the first load and the second load as source noise respectively, , are attenuation multiples of the first cable and loss of the second cable, , is a gain multiple and an equivalent noise temperature of the low noise amplifier, , is a gain and an equivalent noise temperature of the secondary amplification assembly, is a noise floor of the measuring device, k is a Boltzmann constant, B represents a resolution bandwidth.

[0027] Optionally, the third relationship representing the equivalent noise temperature of the low noise amplifier is determined based on the first relationship, the second relationship and the Y factor, and specifically includes that the equivalent noise temperature of the low noise amplifier and the Y factor are respectively determined as:

[0028]

[0029]

[0030] ​​​​

[0031] wherein Y is a Y-factor, used to characterize the amplification factor.

[0032] Optionally, the noise of the first load and the second load after being amplified by the low-noise amplifier and the secondary amplification component is much larger than the noise floor of the measuring device, and a fourth relationship is obtained according to the third relationship, and the fourth relationship is:

[0033] .

[0034] Optionally, the equivalent noise temperature of the low-noise amplifier is obtained according to the fourth relationship, and the equivalent noise temperature of the low-noise amplifier is:

[0035] .

[0036] The application has the following beneficial effects:

[0037] (1) The application reduces the uncertain interference factors of the front end of the low-noise amplifier to be measured; for example, the same cable and 50-ohm impedance are used in the front end of the low-noise amplifier to be measured, the consistency of impedance matching is ensured, the uncertain factors are greatly reduced, and in addition, the first load and the second load can use the same load, so that the same load only needs to be moved in different temperature zones, and the uncertain factors are greatly reduced.

[0038] (2) The gain of the secondary amplification component and the low-noise amplifier to be measured as a whole is large, so that the system noise power after two-stage amplification is much larger than the noise floor of the spectrum analyzer, the accuracy of the measurement data is ensured, and for the secondary amplification component, more stages of amplification can also be used to ensure the accuracy of the measurement data.

[0039] (3) The influence of the first cable and the second cable is introduced into the calculation of the measurement system, and the accuracy of the measurement system is further improved.

[0040] (4) The measurement method of the equivalent noise temperature of the low-noise amplifier provided by the application uses the above measurement system, and therefore has the same beneficial effects, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a schematic structural diagram of an amplifier equivalent noise temperature characterization system in the prior art;

[0042] Figure 2 is a schematic structural diagram of a measurement system of the equivalent noise temperature of a low-noise amplifier DUT in the application;

[0043] Figure 3A table comparing the measured equivalent noise temperature with the data in the specification book for two identical commercial low-temperature low-noise amplifiers DUTs used according to the application. DETAILED DESCRIPTION

[0044] In order to enable persons skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should fall within the scope of protection of the present application. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be interpreted as a limitation on the present application.

[0045] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0046] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0047] In the field of low-temperature measurement, the real effective signal of the sample to be measured is very weak relative to the system environmental noise, and it is difficult to be directly collected and processed by the measuring instrument. Usually, through in-situ signal amplification, the signal-to-noise ratio of the output signal is improved to effectively extract the real signal of the sample to be measured. In the existing technology, the mainstream methods of noise measurement are Y-factor method and cold source method. Taking a quantum computer as an example, as shown in the accompanying Figure 1As shown in the prior art, an amplifier equivalent noise temperature characterization system includes a signal amplifier D to be measured and located in a first temperature zone in a refrigeration device, a microwave switch K, and a first load Z1, a second load Z2 located in a second temperature zone in the refrigeration device, and a measuring device 21 located in a third temperature zone, an input end of the signal amplifier D is connected to the first load Z1 or the second load Z2 through the microwave switch K, and an output end of the signal amplifier D is connected to the measuring device 21; the first temperature zone and the second temperature zone are both preset temperature zones in the refrigeration device. The microwave switch K is used to switch different thermal noise sources, and this method can realize rapid measurement, but the measurement accuracy is not high enough and has the following defects:

[0048] 1) The microwave switch K is an active device, which can introduce certain noise to the test system;

[0049] 2) When the microwave switch K is switched to different temperature zones, the cables connected to different temperature zones are not completely the same, and the impedance matching before and after switching is also not completely the same, and the impedance mismatch can greatly affect the measurement accuracy;

[0050] 3) This scheme uses one-stage amplification, if the gain multiple of the amplifier is not enough, the effective signal of the thermal noise after amplification cannot be much larger than the noise floor of the measuring instrument, and then the test data will lose significance, and the equivalent noise temperature cannot be effectively calculated.

[0051] In summary, in the measurement of quantum chips, the signal is very weak and difficult to improve, and is easily overwhelmed by system noise, so an excellent low-temperature and low-noise amplifier can realize in-situ signal amplification while reducing system noise and improving the signal-to-noise ratio of the measurement system. Improving the measurement accuracy of the noise figure can refine the system model during product development, and better optimize the system performance.

[0052] To improve the measurement accuracy, as shown in the prior art, Figure 2 As shown in the embodiment of the present application, a low-noise amplifier equivalent noise temperature measurement system is disclosed, which comprises:

[0053] A load assembly is used to provide a thermal noise signal, which includes a first load Z1 and a second load Z2, and the first load Z1 and the second load Z2 are located in a first temperature zone and a second temperature zone with different temperatures, respectively; an input end of a low-noise amplifier DUT to be measured is electrically connected to the first load Z1 or the second load Z2 to receive a thermal noise signal; the present application is suitable for a wide test frequency band of the low-noise amplifier DUT and has no limitation in application field.

[0054] A second amplification component is connected to the output end of the low-noise amplifier DUT and amplifies the output signal of the low-noise amplifier DUT, and the second amplification component satisfies impedance matching with the low-noise amplifier DUT; in order to test the effect, each second amplifier in the second amplification component is of the same model specification as the low-noise amplifier DUT.

[0055] A measuring device is configured to measure the signal output by the second amplification component and obtain the equivalent noise temperature of the low-noise amplifier.

[0056] Preferably, the temperature ratio of the two temperature zones in the present application is at least one order of magnitude. Compared with the prior art in which the first temperature zone is 4K and the second temperature zone is 1K, the greater the temperature difference between the first temperature zone and the second temperature zone in the present application, the closer the obtained equivalent noise temperature is to the true value. The first temperature zone in which the first load Z1, the low-noise amplifier DUT, and the second amplification component are located is 4K, and the second temperature zone in which the second load Z2 is located is 50K.

[0057] In this scheme, the resistance values of the first load Z1 and the second load Z2 are both 50 ohms. A 50-ohm impedance is used for optimal matching of the amplifier, and at the same time, as a passive device, its return loss characteristic is not sensitive to temperature changes, which also helps to improve the measurement accuracy.

[0058] In order to realize the measurement environment, the system is arranged in a refrigeration device 1, which is optionally a dilution refrigerator, and a plurality of temperature zones are arranged inside the refrigeration device 1, each temperature zone is isolated from each other, the temperature of each temperature zone is realized by a refrigeration disc, and the first load Z1 and the second load Z2 are arranged on the refrigeration disc of the corresponding temperature zone. The refrigeration device 1 of the present scheme is not limited to a dilution refrigerator, and can meet the differential arrangement and stable temperature control of the temperature zones in the present application.

[0059] Optionally, the low-noise amplifier DUT is connected to the first load Z1 and the second load Z2 through a first cable respectively, and the first cable The end portion of the first cable is used for conveniently switching the connection of the load in different temperature zones, and the low-noise amplifier DUT is alternately connected to the first load Z1 and the second load Z2 through the same first cable , which can reduce the uncertainty factors in the measurement. When two cables are respectively connected to the corresponding loads and the low-noise amplifier DUT through a microwave switch K, the materials and lengths of the two cables cannot be guaranteed to be exactly the same, and therefore will affect the calculation of the equivalent noise temperature as an uncertainty factor.

[0060] Preferably, the first load Z1 and the second load Z2 are the same load, and after obtaining the first measurement result, only the load connected with the cable needs to be moved to another temperature zone, which minimizes the uncertainty factors, including that the two different loads cannot be completely consistent due to the process, the structures at the connection positions of the cable and the two loads are different, and the like.

[0061] Optionally, the first cable is as short as possible, which reduces the influence of the first cable on the measurement, so that the data measured by the measurement device is closer to the real value of the equivalent noise temperature of the low-noise amplifier DUT.

[0062] Optionally, the secondary amplification assembly uses multi-stage amplification, which can ensure the accuracy of the measurement data. The secondary amplification assembly is arranged to reduce the introduction of other noises. The secondary amplification assembly at least includes one secondary amplifier. For the convenience of description, the secondary amplification assembly uses one secondary amplifier LNA2. It should be noted that the application is not limited to using one secondary amplifier LNA2. The secondary amplifier LNA2 satisfies impedance matching with the low-noise amplifier DUT. The overall gain of the secondary amplification assembly and the low-noise amplifier makes the system noise power after two-stage amplification greater than the noise floor of the measurement device. In order to improve the accuracy of the measurement, the overall gain is at least 10 dB greater than the noise floor of the measurement device. In detail, the greater the gain of the secondary amplifier LNA2 and the overall gain of the low-noise amplifier DUT, the smaller the noise influence at the rear end of the amplifier, the smaller the error caused by the low noise itself, and the closer the data measured by the measurement device to the real value.

[0063] Optionally, the low-noise amplifier and the secondary amplification assembly are arranged in the corresponding lowest temperature zone in the working environment temperature requirement. In this embodiment, the low-noise amplifier DUT and the secondary amplifier LNA2 are arranged in the first temperature zone (the temperature zone corresponding to 4K in this scheme), which can ensure that the system measures the minimum equivalent noise temperature, compared with being arranged in the second temperature zone (the temperature zone corresponding to 50K in this scheme).

[0064] Optionally, the output end of the secondary amplifier LNA2 is connected with the input end of the measurement device 21 through the second cable . The measurement device 21 is a spectrum analyzer in this scheme, and can also be other measurement devices such as a high-precision power meter in other schemes.

[0065] Optionally, the application uses a cascade system, so that the amplified noise is much greater than the noise floor of the measurement device, which ensures the accuracy of the measurement data.

[0066] In addition, the measurement system further comprises power supplies for the low-noise amplifier DUT and the secondary amplifier LNA2, which support the low-noise amplifier DUT and the secondary amplifier LNA2 to normally work as active devices.

[0067] The measurement system of the present application greatly improves the measurement accuracy of the system and has great significance for characterizing low-temperature low-noise amplifiers with better performance.

[0068] The measurement method of the above-mentioned low-noise amplifier equivalent noise temperature measurement system comprises:

[0069] S10, a measurement system of the above-mentioned low-noise amplifier DUT is built, the first load and the second load as noise sources in the measurement system are located in the first temperature zone and the second temperature zone respectively, the measurement device 21 corresponds to the measured first noise signal and the second noise signal, and the first relationship and the second relationship between the first noise signal and the second noise signal and the fixed parameters of the elements in the measurement system are obtained; wherein the first noise signal is the total noise of the output signal when the input end of the low-noise amplifier DUT is connected to the first load Z1, and the second noise signal is the total noise of the output signal when the input end of the low-noise amplifier DUT is connected to the second load Z2; the elements include a load assembly, a low-noise amplifier, a secondary amplification assembly, a measurement device, a first cable, and a second cable; the first load and the second load in the load assembly are the same load.

[0070] S20, a third relationship representing the equivalent noise temperature of the low-noise amplifier DUT is determined based on the first relationship, the second relationship, and a Y factor, wherein the Y factor is the ratio of the first noise signal and the second noise signal.

[0071] The first relationship and the second relationship are two loads located in a large temperature difference region as noise sources, the relative relationship between the noise signal in the output signal of the measurement system and the fixed parameters of each element in the measurement system is measured, and the first relationship and the second relationship are converted and processed in combination with the ratio Y factor of the first noise signal and the second noise signal, to obtain the third relationship between the equivalent noise temperature of the to-be-measured low-noise amplifier DUT and the fixed parameters of each element in the measurement system and the Y factor.

[0072] The first relationship and the second relationship are relative relationships between noise signals of a measurement system output signal and fixed parameters of the low-noise amplifier DUT and a secondary amplification component, and the third relationship is obtained by converting the first relationship and the second relationship, and is a relationship between an equivalent noise temperature of the low-noise amplifier DUT and a fixed parameter of the secondary amplification component in the measurement system. The fixed parameters of each element in the measurement system correspond to the first noise signal and the second noise signal, and therefore the third relationship can also be expressed as a function of the first noise signal and the second noise signal. For a low-gain amplifier, the secondary amplification component uses multi-stage amplification, which can ensure the accuracy of the measurement data. The secondary amplification component at least includes one secondary amplifier LNA2, and for the convenience of description, the secondary amplification component uses one secondary amplifier LNA2, and it should be noted that the application is not limited to using one secondary amplifier LNA2.

[0073] S30: According to the noise amplified by the low-noise amplifier DUT and the secondary amplifier LNA2 through the first load Z1 and the second load Z2 as the thermal noise source, the noise is much larger than the noise floor of the measuring device 2, and the third relationship is simplified to obtain a fourth relationship;

[0074] S40: According to the fourth relationship, the equivalent noise temperature of the low-noise amplifier DUT is obtained.

[0075] As an embodiment of the application, the measurement system of the low-noise amplifier DUT is built in step S10, the first cable is connected to the first load Z1 or the second load Z2, and the measuring device 21 corresponds to the measured first noise signal and the second noise signal. Here, the first cable is connected to the second load Z2 first and then connected to the first load Z1, and the first cable is connected to the first load Z1 first and then connected to the second load Z2, which will not be described here.

[0076] The above system is used to measure the equivalent noise temperature of the low-noise amplifier DUT, and the first cable is connected to the second load Z2 first and then connected to the first load Z1, and the first cable

[0077] S11, the input end of the low-noise amplifier DUT is connected to the second load Z2 on the 50K disk (the second temperature zone) through the first cable ;

[0078] S12, the output end of the low-noise amplifier DUT is directly connected to the input end of the secondary amplifier LNA2, and the low-noise amplifier DUT and the secondary amplifier LNA2 are impedance matched, thereby reducing the introduction of other noise;

[0079] S13, placing the low-noise amplifier DUT and the secondary amplifier LNA2 on the 4K disk (first temperature zone) and connecting the output end of the secondary amplifier LNA2 and the input end of the spectrum analyzer through the second cable ;

[0080] S14, completing the measurement of the second noise signal power by the measuring device;

[0081] S15, moving the end of the first cable located in the second temperature zone to the 4K disk (first temperature zone) and connecting with the first load Z1;

[0082] S16, completing the measurement of the first noise signal power by the spectrum analyzer.

[0083] As an embodiment of the present application, the first noise signal and the second noise signal output by the measuring system have the first relationship and the second relationship with the fixed parameters of the elements in the measuring system, respectively:

[0084] * * * k*B

[0085] * * * k*B

[0086] wherein, , are the equivalent noise temperatures of the first load Z1 and the second load Z2 as the source noise, respectively, , are the attenuation multiples of the first cable and the loss of the second cable, , are the gain multiple and the equivalent noise temperature of the low-noise amplifier DUT, , are the gain and the equivalent noise temperature of the secondary amplifier LNA2, is the noise floor of the spectrum analyzer as the measuring device, k is the Boltzmann constant, B and the bandwidth. The attenuation multiple of the first cable in the formula and the gain multiple of the low-noise amplifier DUT need to be converted into the attenuation loss in units of dB and gain value converted into corresponding multiple relationship, conversion formula is , wherein the gain of the low noise amplifier DUT and the secondary amplifier LNA2 is positive value, and the cable attenuation should be recorded as -0.1dB gain, not 0.1dB.

[0087] As an embodiment of the present application, a third relationship representing the equivalent noise temperature of the low noise amplifier is determined based on the first relationship, the second relationship and the Y factor, specifically comprising: the equivalent noise temperature of the low noise amplifier and the Y factor are determined as follows respectively:

[0088]

[0089]

[0090] wherein Y can be understood as Y factor, which can be used to represent amplification coefficient. The Y factor is the ratio of the first noise signal and the second noise signal, and in combination with the first relationship and the second relationship, the equivalent noise temperature of the low noise amplifier to be measured can be obtained as It can be found from the above formula that the equivalent noise temperature of the low noise amplifier DUT is related to the fixed parameters of each element of the measurement system and Y. In the calculation of the equivalent noise temperature in the present application, the noise calculation caused by the first cable and the second cable is introduced, which further reduces the noise error caused by the first cable and the second cable .

[0091] As an embodiment of the present application, according to the fact that the noise of the first load and the second load after being amplified by the low noise amplifier and the secondary amplification assembly is much larger than the noise floor of the measurement device, a fourth relationship is obtained by simplifying the third relationship, and the fourth relationship is

[0092]

[0093] As an embodiment of the present application, according to the fourth relationship, the equivalent noise temperature of the low noise amplifier is obtained as:

[0094] .

[0095] The different schemes in the above measurement system and measurement method can realize the measurement effect in different combination ways.

[0096] Based on the above measurement system and measurement method, the equivalent noise temperature of the low noise amplifier can be obtained as Figure 3According to the measured data and the calculation results of the table, two same commercial low-temperature low-noise amplifiers DUTs are used in the test, and the measured equivalent noise temperature is compared with the data in the specification book, wherein the sixth column represents the nominal value of the equivalent noise temperature of the commercial secondary amplifier LNA2 in the specification book, and the last column represents the laboratory measured value of the equivalent noise temperature of the commercial secondary amplifier LNA2. Since the model specifications of the secondary amplifier LNA2 and the low-noise amplifier DUT to be measured are the same, the measured value of the secondary amplifier LNA2 in the table is the measured value of the low-noise amplifier DUT.

[0097] (1) The frequency band measured this time is 0.1GHz~2GHz, and 0.1 / 0.3 / 0.5 / 0.7 / 0.9 / 1.1 / 1.3 / 1.5 / 1.7 / 1.9GHz points are taken;

[0098] (2) The actual temperature of the 50K temperature zone is 48.31K, and the actual temperature of the 4K temperature zone is 3.59K;

[0099] (3) The noise power of different temperature zones is measured according to different frequency points, and the corresponding Y factor is calculated;

[0100] (4) According to the formula , the equivalent noise temperature of different frequency points is calculated;

[0101] (5) According to the data comparison, the difference between the test data and the nominal data is about 1~2K.

[0102] In the description of the present specification, the description of the reference terms "some embodiments" or "examples" and the like means that the specific features, structures, materials or characteristics described in combination with the embodiments or examples are contained in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present specification.

[0103] The above is only the preferred embodiment of the present application, and does not limit the present application in any way. Any person skilled in the art can make any form of equivalent replacement or modification of the technical solutions and technical contents disclosed in the present application without departing from the scope of the technical solutions of the present application, and still belongs to the protection scope of the present application.

Claims

1. A system for measuring the equivalent noise temperature of a low-noise amplifier, characterized in that, include: A load component for providing thermal noise signals includes a first load and a second load, the first load and the second load being located in a first temperature zone and a second temperature zone, respectively; the input terminal of the low-noise amplifier under test is electrically connected to the first load or the second load to receive the thermal noise signals. A secondary amplification component is connected to the output terminal of the low-noise amplifier to amplify the output signal of the low-noise amplifier. The secondary amplification component and the low-noise amplifier satisfy impedance matching. Measuring equipment used to measure the signal output of the secondary amplifier component and obtain the equivalent noise temperature of the low-noise amplifier; The overall gain of the secondary amplification component and the low-noise amplifier makes the system noise power after two stages of amplification greater than the noise floor of the measuring device.

2. The measurement system as described in claim 1, characterized in that, The temperature range ratio of the temperature ranges where the first load and the second load are located is at least one order of magnitude.

3. The measurement system as described in claim 1, characterized in that, The low-noise amplifier is connected to the first load and the second load respectively through the same first cable, and the measuring device obtains two corresponding measurement signals.

4. The measurement system as described in claim 1, characterized in that, The first load and the second load are the same load.

5. The measurement system as described in claim 1, characterized in that, The low-noise amplifier and the secondary amplification component are set in the lowest temperature range corresponding to the operating environment temperature requirements.

6. A method for measuring the equivalent noise temperature of a low-noise amplifier, characterized in that, include: A measurement system for the low-noise amplifier as described in any one of claims 1-5 is constructed, wherein the load, serving as a noise source, is located in a first temperature zone and a second temperature zone, respectively, and the measuring device measures the first noise signal and the second noise signal accordingly, thereby obtaining a first relationship and a second relationship between the first noise signal and the second noise signal and the fixed parameters of the components in the measurement system; the components include a load component, a low-noise amplifier, a secondary amplification component, a measuring device, a first cable, and a second cable. A third relationship representing the equivalent noise temperature of the low-noise amplifier is determined based on the first relationship, the second relationship, and the Y factor, wherein the Y factor is the ratio of the first noise signal to the second noise signal. Since the noise amplified by the low-noise amplifier and the secondary amplification component for loads in different temperature zones is much greater than the noise floor of the measuring device, the third relationship is simplified to obtain the fourth relationship. The equivalent noise temperature of the low-noise amplifier is obtained according to the fourth relation.

7. The measurement method as described in claim 6, characterized in that, Obtain a first relationship and a second relationship between the first noise signal, the second noise signal, and the fixed parameters of the components in the measurement system. The first relationship and the second relationship are as follows: * * *k*B * * *k*B in, , The equivalent noise temperatures, taking the first load and the second load as the source noise, are respectively. , The first cable The attenuation factor and the loss of the second cable, , The gain factor and equivalent noise temperature of the low-noise amplifier are given. , The gain and equivalent noise temperature of the secondary amplifier component. To reduce the background noise of the measuring equipment. k It is the Boltzmann constant. B This indicates the resolution bandwidth.

8. The method as described in claim 7, characterized in that, Based on the first relationship, the second relationship, and the Y factor, a third relationship representing the equivalent noise temperature of the low-noise amplifier is determined, specifically including: the equivalent noise temperature and the Y factor of the low-noise amplifier are respectively determined as follows: Where Y is the Y factor, used to characterize the amplification factor.

9. The method as described in claim 8, characterized in that, Since the noise from the first and second loads amplified by the low-noise amplifier and the secondary amplification component is much greater than the noise floor of the measuring device, the third relationship is simplified to obtain the fourth relationship, which is: 。 10. The method as described in claim 9, characterized in that, The equivalent noise temperature of the low-noise amplifier is obtained according to the fourth relation as follows: 。

Images