Measurement Method and System for Saturation Recovery Time of Low-Noise Amplifier

Abstract

The present invention relates to a method and system for measuring the saturation recovery time of a low-noise amplifier. The method comprises: using a first signal source to generate a first signal with a first frequency and a first power, wherein the power is not less than the saturated input power of the low-noise amplifier; using a second signal source to generate a second signal with a second frequency and a second power, wherein the power is less than the saturated input power of the low-noise amplifier, and the second frequency is unequal to the first frequency; using a test receiver to measure the power of the second signal, wherein the receiver's receiving frequency is equal to the second frequency; using a pulse generator to generate a first pulse and a second pulse; adjusting the pulse parameters of the second pulse according to the difference between the power received by the receiver and a preset power until the power received by the test receiver is equal to the preset power; and determining the saturation recovery time of the low-noise amplifier based on the final pulse parameters of the second pulse and the pulse parameters of the first pulse. This method can accurately measure the saturation recovery time of a low-noise amplifier.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic characteristic testing, and in particular to a method and system for measuring the saturation recovery time of a low-noise amplifier. Background Art

[0002] Currently, target electromagnetic characteristic testing is typically conducted within a compact microwave anechoic chamber, where the transceiver antennas are typically fixed. During testing, the transmitting antenna transmits a test signal toward the target, which then reflects it back to the receiving antenna. Furthermore, to ensure high system dynamics, the transmitting link often incorporates a high-power amplifier, while the receiving link typically incorporates a low-noise amplifier. Ideally, the receiving antenna only receives the low-power echo signal from the target. This low-power signal allows the low-noise amplifier to operate in its linear region, thereby linearly amplifying the echo signal. The amplified signal is then received by the receiver, where the echo signal power is measured.

[0003] However, in actual testing, because the transmitting and receiving antennas are mounted near the focal point of the reflective surface and are very close to each other, some of the signal from the transmitting antenna is directly coupled into the receiving antenna and received by the receiving chain. The coupling between the transmitting and receiving antennas is typically -20dB to -30dB, while the power amplifier power of the transmitting chain typically exceeds +30dBm. Under such circumstances, the coupled signal leaking into the receiving chain typically exceeds +10dBm. Such a large coupled signal typically saturates the low-noise amplifier of the receiving chain. Once saturated, the low-noise amplifier will be unable to amplify the echo signal of the measured target, resulting in incorrect signal power received by the receiver.

[0004] Typically, due to the different arrival times of the direct leakage signal from the transmitting antenna and the echo signal from the target under test at the low-noise amplifier (LNA), the time difference between the two is fixed for a specific microwave anechoic chamber. Furthermore, after saturation, the LNA recovers to a linear operating state after a certain period of time. Therefore, when selecting an LNA, as long as its saturation recovery time is less than the arrival time difference between the direct leakage signal and the echo signal, the LNA will meet the test requirements and ensure the accuracy of electromagnetic testing of the target under test.

[0005] However, the related technology cannot test the saturation recovery time of the low-noise amplifier, so it is difficult to select a suitable low-noise amplifier when testing the electromagnetic characteristics of the target in a microwave darkroom, resulting in inaccurate test results.

[0006] Therefore, there is an urgent need for a method and system for measuring the saturation recovery time of a low noise amplifier to solve the above technical problems. Summary of the Invention

[0007] The embodiments of the present invention provide a method and system for measuring the saturation recovery time of a low noise amplifier, which can accurately measure the saturation recovery time of the low noise amplifier.

[0008] In a first aspect, an embodiment of the present invention provides a method for measuring the saturation recovery time of a low-noise amplifier, which is applied to a measurement system for the saturation recovery time of a low-noise amplifier. The system includes a first transmitting link, a second transmitting link, a receiving link, a pulse generator, and a combiner. The receiving link includes a low-noise amplifier under test and a test receiver connected in sequence. The first transmitting link includes a first signal source and a first RF switch connected in sequence. The second transmitting link includes a second signal source and a second RF switch connected in sequence. The first RF switch and the second RF switch are respectively connected to the inlet end of the combiner, and the outlet end of the combiner is connected to the input end of the low-noise amplifier. The pulse generator is respectively connected to the first RF switch and the second RF switch. The method includes:

[0009] generating a first signal of a first frequency and a first power using the first signal source, wherein the first power is not less than a saturated input power of the low-noise amplifier;

[0010] generating, by the second signal source, a second signal of a second frequency and a second power, wherein the second power is less than a saturated input power of the low-noise amplifier, the first frequency and the second frequency are both within an operating frequency band of the low-noise amplifier, and the second frequency is unequal to the first frequency;

[0011] Measuring the power of the second signal amplified by the low-noise amplifier using the test receiver, wherein the receiving frequency of the test receiver is equal to the second frequency;

[0012] generating a first pulse and a second pulse by using the pulse generator, wherein the first pulse is used to control the on and off of the first radio frequency switch, and the second pulse is used to control the on and off of the second radio frequency switch;

[0013] adjusting the pulse parameters of the second pulse according to the difference between the power received by the test receiver and the preset power until the power received by the test receiver is equal to the preset power, and determining the final pulse parameters of the second pulse;

[0014] A saturation recovery time of the low noise amplifier is determined based on the final pulse parameters of the second pulse and the pulse parameters of the first pulse.

[0015] In one possible design, the pulse parameters include a pulse period, a pulse width, and a pulse delay, and adjusting the pulse parameters of the second pulse based on a difference between the power received by the test receiver and a preset power includes:

[0016] determining whether the power received by the test receiver is less than the preset power under the initial pulse delay of the second pulse;

[0017] If so, continuously increasing the pulse delay of the second pulse according to a preset time interval;

[0018] For each pulse delay of the second pulse, it is determined whether the power received by the test receiver is equal to the preset power under the current pulse delay. If so, the current pulse delay is determined as the final pulse delay of the second pulse; otherwise, it is determined whether the power received by the test receiver is equal to the preset power under the next pulse delay, until the power received by the test receiver is equal to the preset power.

[0019] In one possible design, determining a saturation recovery time of the low-noise amplifier based on a final pulse parameter of the second pulse and a pulse parameter of the first pulse includes:

[0020] A difference between a center time of the second pulse width and a center time of the first pulse width is determined as a saturation recovery time of the low noise amplifier.

[0021] In one possible design, the preset power is calculated by the following method:

[0022] Turn off the first signal source;

[0023] generating a second signal of the second frequency and the second power using the second signal source;

[0024] generating a second pulse using the pulse generator;

[0025] The test receiver is used to measure the power of the second signal amplified by the low noise amplifier to obtain the preset power.

[0026] In one possible design, before measuring the saturation recovery time of the low-noise amplifier using the low-noise amplifier saturation recovery time measurement system, the method further includes:

[0027] The first signal source, the second signal source, the first radio frequency switch, the second radio frequency switch, the low noise amplifier, the test receiver, the pulse generator, and the combiner are turned on to preset each device.

[0028] In one possible design, an attenuator is further provided between the low noise amplifier and the test receiver;

[0029] The attenuator is used to adjust the signal size to prevent the output signal of the low noise amplifier from being too high and damaging the test receiver.

[0030] In one possible design, the first signal and the second signal are both CW waves.

[0031] In a second aspect, an embodiment of the present invention further provides a system for measuring the saturation recovery time of a low noise amplifier, comprising:

[0032] A first transmitting chain, a second transmitting chain, a receiving chain, a pulse generator, and a combiner;

[0033] The receiving link includes a low noise amplifier under test and a test receiver connected in sequence;

[0034] The first transmission chain includes a first signal source and a first radio frequency switch connected in sequence, and the second transmission chain includes a second signal source and a second radio frequency switch connected in sequence, the first signal source is used to generate a first signal with a first frequency and a first power, and the second signal source is used to generate a second signal with a second frequency and a second power, the first frequency and the second frequency are both within the operating frequency band of the low-noise amplifier, and the first frequency is not equal to the second frequency, the first power is not less than the saturated input power of the low-noise amplifier, and the second power is less than the saturated input power of the low-noise amplifier;

[0035] The pulse generator is used to generate a first pulse and a second pulse, and the pulse generator is connected to the first RF switch and the second RF switch respectively. The first pulse is used to control the on and off of the first RF switch, and the second pulse is used to control the on and off of the second RF switch.

[0036] The combiner is used to send the first signal and the second signal to the low noise amplifier;

[0037] The test receiver is used to measure the power of the second signal, and the receiving frequency of the test receiver is equal to the second frequency.

[0038] In one possible design, the first signal and the second signal are both CW waves.

[0039] In one possible design, an attenuator is further provided between the low noise amplifier and the test receiver.

[0040] In this embodiment of the present invention, a first signal is used to simulate a high-power transmit signal that can drive a low-noise amplifier (LNA) to saturation, a second signal is used to simulate a low-power echo signal with normal gain, and a pulse generator is used to generate a first pulse and a second pulse. The first pulse and the second pulse control the first and second radio frequency switches, respectively, to control the delay time for the first and second signals to reach the LNA. Since the LNA enters a saturated state after receiving the high-power first signal, it cannot amplify the second signal in this saturated state, and the power of the second signal cannot be accurately measured. Only when the LNA recovers to a linear operating state can the power of the second signal be accurately measured. Therefore, this embodiment determines whether the LNA has recovered from saturation by observing the difference between the power received by the receiver and a preset power. Specifically, it determines whether the time difference between the first and second signals reaching the LNA under test is equal to the saturation recovery time of the LNA under test. When the power received by the receiver under test is observed to be equal to the preset power, it indicates that the LNA has recovered from saturation to a linear state. At this point, the saturation recovery time of the LNA can be calculated based on the pulse parameters of the first and second pulses. In this way, when conducting an electromagnetic characteristic test of a target to be measured, the time difference between the direct leakage signal of the transmitting antenna and the echo signal of the target to be measured reaching the low-noise amplifier is first determined, and then the method of the present invention can be used to select a low-noise amplifier whose saturation recovery time is not greater than the time difference, thereby ensuring the accuracy of the microwave darkroom test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 This is a flow chart of a method for measuring the saturation recovery time of a low noise amplifier provided by one embodiment of the present invention;

[0043] Figure 2 1 is a graph showing the correspondence between the gain input power and the output power of a low noise amplifier provided by an embodiment of the present invention;

[0044] Figure 3 The figure is a schematic diagram of a system for measuring the saturation recovery time of a low noise amplifier provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] The specific implementation of the above concept is described below.

[0047] Please refer to Figure 1 An embodiment of the present invention provides a method for measuring the saturation recovery time of a low-noise amplifier, which is applied to a system for measuring the saturation recovery time of a low-noise amplifier. The system includes a first transmitting chain, a second transmitting chain, a receiving chain, a pulse generator, and a combiner. The receiving chain includes a low-noise amplifier under test and a test receiver connected in sequence. The first transmitting chain includes a first signal source and a first radio frequency switch connected in sequence. The second transmitting chain includes a second signal source and a second radio frequency switch connected in sequence. The first radio frequency switch and the second radio frequency switch are respectively connected to an input end of the combiner, and an output end of the combiner is connected to an input end of the low-noise amplifier. The pulse generator is respectively connected to the first radio frequency switch and the second radio frequency switch. The method includes:

[0048] Step 100: Generate a first signal of a first frequency and a first power using a first signal source, wherein the first power is not less than a saturated input power of a low noise amplifier;

[0049] Step 102: generating a second signal of a second frequency and a second power using a second signal source, wherein the second power is less than the saturation input power of the low noise amplifier, the first frequency and the second frequency are both within the operating frequency band of the low noise amplifier, and the second frequency is not equal to the first frequency;

[0050] Step 104, using a test receiver to measure the power of the second signal amplified by the low noise amplifier, wherein the receiving frequency of the test receiver is equal to the second frequency;

[0051] Step 106: Generate a first pulse and a second pulse using a pulse generator, wherein the first pulse is used to control the on / off of the first radio frequency switch, and the second pulse is used to control the on / off of the second radio frequency switch;

[0052] Step 108, adjusting the pulse parameters of the second pulse according to the difference between the power received by the test receiver and the preset power until the power received by the test receiver is equal to the preset power, and determining the final pulse parameters of the second pulse;

[0053] Step 110 : determining a saturation recovery time of a low noise amplifier based on the final pulse parameters of the second pulse and the pulse parameters of the first pulse.

[0054] This embodiment uses a first signal to simulate a high-power transmit signal that can drive a low-noise amplifier (LNA) into saturation, and a second signal to simulate a low-power echo signal with normal gain. A pulse generator generates first and second pulses, which control the first and second RF switches, respectively, to control the delay time between the first and second signals reaching the LNA. Since the LNA enters a saturated state after receiving the high-power first signal, it cannot amplify the second signal in this saturated state, and its power cannot be accurately measured. Only when it recovers to a linear operating state can the power of the second signal be accurately measured. Therefore, this embodiment determines whether the LNA has recovered from saturation by observing the difference between the power received by the receiver and a preset power. Specifically, it determines whether the time difference between the first and second signals reaching the LNA under test equals the saturation recovery time of the LNA under test. When the power received by the receiver under test equals the preset power, it indicates that the LNA has recovered from saturation to a linear state. At this point, the saturation recovery time of the LNA can be calculated using the pulse parameters of the first and second pulses. In this way, when conducting an electromagnetic characteristic test of a target to be measured, the time difference between the direct leakage signal of the transmitting antenna and the echo signal of the target to be measured reaching the low-noise amplifier is first determined, and then the method of the present invention can be used to select a low-noise amplifier whose saturation recovery time is not greater than the time difference, thereby ensuring the accuracy of the microwave darkroom test results.

[0055] It should be noted that the first and second signal sources can be dual-source vector network analyzers or other devices capable of generating test signals. The first and second RF switches are PIN switches. The combiner can be a power splitter or other device capable of combining two or more signals. The pulse generator can be another signal generator capable of producing a precisely adjustable pulse waveform. Furthermore, the test system includes cables and other components compatible with each device.

[0056] The following describes Figure 1 How to perform the steps shown.

[0057] First, with respect to step 100 , a first signal source is used to generate a first signal with a first frequency and a first power, where the first power is not less than a saturated input power of a low noise amplifier.

[0058] like Figure 2Figure 2 shows a plot of the gain input power versus output power of a low-noise amplifier. As can be seen from the figure, when the input power exceeds a certain value, the low-noise amplifier enters saturation. In this state, there is no linear relationship between the output signal power and the input signal power. This manifests as cutoff distortion and insufficient gain in the amplifier. Therefore, to simulate the amplifier's distortion state, the first power is no less than the low-noise amplifier's saturated input power, where the saturated input power is determined based on the factory parameters provided by the amplifier manufacturer.

[0059] It should be noted that the saturation recovery time of a low-noise amplifier varies depending on the power of the signal it receives. For example, the saturation recovery time of the low-noise amplifier differs when the first power is +10dBm and +12dBm. Therefore, when determining the first power, the first power can be determined based on the actual target power during testing or according to actual needs.

[0060] Then, for step 102 and step 104, a second signal source is used to generate a second signal with a second frequency and a second power, the second power is less than the saturation input power of the low-noise amplifier, the first frequency and the second frequency are both within the operating frequency band of the low-noise amplifier, and the second frequency is not equal to the first frequency.

[0061] The power of the second signal amplified by the low noise amplifier is measured by using a test receiver, and the receiving frequency of the test receiver is equal to the second frequency.

[0062] In this step, the second signal causes the low noise amplifier to operate as follows Figure 2 In the linear region shown, when the low noise is in a non-saturated state, the second signal can be amplified normally. Therefore, the second power should be less than the saturated input power of the low noise amplifier, such as -30dBm. The specific value is determined according to actual needs and is not specifically limited in this application.

[0063] It should be noted that a test receiver can only receive signals at the same frequency as its operating frequency. Since the present invention only tests the low-noise amplifier's test results for a second signal, the first and second frequencies are different, and the second frequency is equal to the test receiver's receiving frequency. For example, when the low-noise amplifier operates in the 2-18 GHz frequency range, the first and second frequencies can be 3 GHz and 10 GHz, respectively. The test receiver's operating frequency is set to 10 GHz. This allows the low-noise amplifier's saturation recovery time to be measured when the second signal has a frequency of 10 GHz. Of course, by changing the second frequency, the low-noise amplifier's saturation recovery time can be obtained at other frequencies, as long as the first and second frequencies are different and the test receiver's receiving frequency is equal to the second frequency.

[0064] Next, for step 106 , a pulse generator is used to generate a first pulse and a second pulse, wherein the first pulse is used to control the on / off of the first radio frequency switch, and the second pulse is used to control the on / off of the second radio frequency switch.

[0065] In this step, the first and second pulses are used to control the delay time between the first and second signals reaching the low-noise amplifier. The goal is to ensure that the first signal reaches the low-noise amplifier first, causing it to enter a saturated state. Then, after a delay, the second signal reaches the low-noise amplifier, allowing the low-noise amplifier to observe whether its response to the second signal is normal. Based on the response, it is determined whether the low-noise amplifier has recovered from saturation to a linear state within the delay time.

[0066] Then, for step 108, the pulse parameters of the second pulse are adjusted according to the difference between the power received by the test receiver and the preset power until the power received by the test receiver is equal to the preset power, and the final pulse parameters of the second pulse are determined.

[0067] In this step, the pulse parameters include pulse period, pulse width, and pulse delay. According to the difference between the power received by the test receiver and the preset power, the pulse parameters of the second pulse are adjusted, including:

[0068] determining whether the power received by the test receiver is less than a preset power under the initial pulse delay of the second pulse;

[0069] If so, continuously increasing the pulse delay of the second pulse according to a preset time interval;

[0070] For each pulse delay of the second pulse, it is determined whether the power received by the test receiver is equal to the preset power under the current pulse delay. If so, the current pulse delay is determined as the final pulse delay of the second pulse; otherwise, it is determined whether the power received by the test receiver is equal to the preset power under the next pulse delay, until the power received by the test receiver is equal to the preset power.

[0071] In this step, the pulse period and pulse width of the first pulse and the second pulse can be equal, such as the pulse period is 500ns and the pulse width is 50ns. Of course, the pulse period and pulse width of the first pulse and the second pulse can also be unequal, and the present application is not limited thereto.

[0072] The initial pulse delays of the first pulse and the second pulse can be equal, such as 0ns. Under this parameter, it is determined whether the power received by the test receiver is less than the preset power. If it is less than, it means that the low-noise amplifier has not yet recovered from the saturation state to the linear state, resulting in insufficient gain amplification, so the power received by the test receiver is less than the preset power. At this time, the delay time of the second pulse should be increased, and the preset time interval should be increased each time. To ensure the test accuracy, the preset time interval should be as small as possible, such as 5ns. Of course, it can also be other values, which are not specifically limited in this application. By continuously increasing the delay of the second pulse, the power received by the test receiver is eventually equal to or less than the preset power. At this time, it can be determined that the low-noise amplifier has recovered to the linear state.

[0073] In some embodiments, the preset power is calculated by the following method:

[0074] Turn off the first signal source;

[0075] generating a second signal of a second frequency and a second power by a second signal source;

[0076] generating a second pulse using a pulse generator;

[0077] The power of the second signal amplified by the low noise amplifier is measured by using a test receiver to obtain a preset power.

[0078] That is, the preset power is the power received by the test receiver when the noise amplifier operates in the linear region and the second signal has the second frequency and the second power.

[0079] In some embodiments, before measuring the saturation recovery time of the low noise amplifier using the low noise amplifier saturation recovery time measurement system, the method further includes:

[0080] The first signal source, the second signal source, the first radio frequency switch, the second radio frequency switch, the low noise amplifier, the test receiver, the pulse generator, and the combiner are turned on to preset each device.

[0081] By presetting the system, system errors can be eliminated and the accuracy of test results can be guaranteed.

[0082] In some implementations, an attenuator is further provided between the low noise amplifier and the test receiver; the attenuator is used to adjust the signal size to prevent the output signal of the low noise amplifier from being too high and damaging the test receiver.

[0083] In this step, the attenuator after the low-noise amplifier amplifies can be used to protect the test receiver to prevent the amplifier output signal from being too high and damaging the receiver. At the same time, selecting an attenuator with a suitable attenuation value can also prevent the receiver from receiving a signal that is too high and causing saturation or compression of the receiver.

[0084] In some embodiments, the first signal and the second signal are both CW waves.

[0085] Finally, for step 110, determining the saturation recovery time of the low noise amplifier based on the final pulse parameters of the second pulse and the pulse parameters of the first pulse includes:

[0086] The difference between the center time of the second pulse width and the center time of the first pulse width is determined as the saturation recovery time of the low noise amplifier.

[0087] For example, if the pulse period of the first pulse and the second pulse are both 500ns and the pulse width is 50ns, the pulse delay of the first pulse is 0ns, and the pulse delay of the second pulse is 100ns. Therefore, the center time of the first pulse width is 25ns, and the center time of the second pulse width is 125ns. The difference between the center time of the second pulse width and the center time of the first pulse width is 100ns. In other words, the saturation recovery time of the low-noise amplifier is 100ns.

[0088] like Figure 3 As shown, an embodiment of the present invention further provides a system for measuring the saturation recovery time of a low noise amplifier, comprising:

[0089] A first transmitting chain, a second transmitting chain, a receiving chain, a pulse generator, and a combiner;

[0090] The receiving chain includes a low noise amplifier and a test receiver connected in sequence;

[0091] The first transmission chain includes a first signal source and a first radio frequency switch connected in sequence, and the second transmission chain includes a second signal source and a second radio frequency switch connected in sequence, the first signal source is used to generate a first signal with a first frequency and a first power, and the second signal source is used to generate a second signal with a second frequency and a second power, the first frequency and the second frequency are both within an operating frequency band of a low-noise amplifier, and the first frequency is not equal to the second frequency, the first power is not less than a saturated input power of the low-noise amplifier, and the second power is less than the saturated input power of the low-noise amplifier;

[0092] The pulse generator is used to generate a first pulse and a second pulse, and the pulse generator is connected to the first radio frequency switch and the second radio frequency switch respectively. The first pulse is used to control the on and off of the first radio frequency switch, and the second pulse is used to control the on and off of the second radio frequency switch.

[0093] The combiner is used to send the first signal and the second signal to the low noise amplifier;

[0094] The test receiver is used to measure the power of the second signal, and the receiving frequency of the test receiver is equal to the second frequency.

[0095] In a possible design, both the first signal and the second signal are CW waves.

[0096] In a possible design, an attenuator is further provided between the low noise amplifier and the test receiver.

[0097] It should be understood that the system illustrated in the embodiments of the present invention does not constitute a specific limitation on a system for measuring the saturation recovery time of a low-noise amplifier. In other embodiments of the present invention, a system for measuring the saturation recovery time of a low-noise amplifier may include more or fewer components than illustrated, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0098] Since the above system is based on the same concept as the embodiment of the method of the present invention, the specific content can be found in the description of the embodiment of the method of the present invention, and will not be repeated here.

[0099] It should be noted that, in this article, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the presence of other identical factors in the process, method, article or device comprising the elements.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for measuring the saturation recovery time of a low-noise amplifier, applied to a measurement system for the saturation recovery time of a low-noise amplifier, the system comprising a first transmitting chain, a second transmitting chain, a receiving chain, a pulse generator, and a combiner, the receiving chain comprising a low-noise amplifier under test and a test receiver connected in sequence, the first transmitting chain comprising a first signal source and a first radio frequency switch connected in sequence, the second transmitting chain comprising a second signal source and a second radio frequency switch connected in sequence, the first radio frequency switch and the second radio frequency switch being respectively connected to an input end of the combiner, an output end of the combiner being connected to an input end of the low-noise amplifier, and the pulse generator being respectively connected to the first radio frequency switch and the second radio frequency switch; the method comprising: generating, by the first signal source, a first signal of a first frequency and a first power, wherein the first power is not less than a saturated input power of the low-noise amplifier; generating, by the second signal source, a second signal of a second frequency and a second power, wherein the second power is less than a saturated input power of the low-noise amplifier, the first frequency and the second frequency are both within an operating frequency band of the low-noise amplifier, and the second frequency is unequal to the first frequency; Measuring the power of the second signal amplified by the low-noise amplifier using the test receiver, wherein the receiving frequency of the test receiver is equal to the second frequency; generating a first pulse and a second pulse by using the pulse generator, wherein the first pulse is used to control the on and off of the first radio frequency switch, and the second pulse is used to control the on and off of the second radio frequency switch; adjusting the pulse parameters of the second pulse according to the difference between the power received by the test receiver and the preset power until the power received by the test receiver is equal to the preset power, and determining the final pulse parameters of the second pulse; A saturation recovery time of the low noise amplifier is determined based on the final pulse parameters of the second pulse and the pulse parameters of the first pulse.

2. The method according to claim 1, characterized in that The pulse parameters include a pulse period, a pulse width, and a pulse delay, and adjusting the pulse parameters of the second pulse according to a difference between the power received by the test receiver and a preset power includes: determining whether the power received by the test receiver is less than the preset power under the initial pulse delay of the second pulse; If so, continuously increasing the pulse delay of the second pulse according to a preset time interval; For each pulse delay of the second pulse, it is determined whether the power received by the test receiver is equal to the preset power under the current pulse delay. If so, the current pulse delay is determined as the final pulse delay of the second pulse; otherwise, it is determined whether the power received by the test receiver is equal to the preset power under the next pulse delay, until the power received by the test receiver is equal to the preset power.

3. The method according to claim 2, wherein determining the saturation recovery time of the low noise amplifier based on the final pulse parameters of the second pulse and the pulse parameters of the first pulse comprises: A difference between a center time of the second pulse width and a center time of the first pulse width is determined as a saturation recovery time of the low noise amplifier.

4. The method according to claim 1, wherein The preset power is calculated by the following method: Turn off the first signal source; generating a second signal of the second frequency and the second power using the second signal source; generating a second pulse using the pulse generator; The test receiver is used to measure the power of the second signal amplified by the low noise amplifier to obtain the preset power.

5. The method according to claim 1, wherein Before measuring the saturation recovery time of the low noise amplifier using the low noise amplifier saturation recovery time measurement system, the method further includes: The first signal source, the second signal source, the first radio frequency switch, the second radio frequency switch, the low noise amplifier, the test receiver, the pulse generator, and the combiner are turned on to preset each device.

6. The method according to claim 1, characterized in that An attenuator is further provided between the low noise amplifier and the test receiver; The attenuator is used to adjust the signal size to prevent the output signal of the low noise amplifier from being too high and damaging the test receiver.

7. The method according to any one of claims 1 to 6, characterized in that Both the first signal and the second signal are CW waves.

8. A system for measuring the saturation recovery time of a low noise amplifier, characterized in that: include: A first transmitting chain, a second transmitting chain, a receiving chain, a pulse generator, and a combiner; The receiving link includes a low noise amplifier and a test receiver connected in sequence; The first transmission chain includes a first signal source and a first radio frequency switch connected in sequence, and the second transmission chain includes a second signal source and a second radio frequency switch connected in sequence, the first signal source is used to generate a first signal with a first frequency and a first power, and the second signal source is used to generate a second signal with a second frequency and a second power, the first frequency and the second frequency are both within the operating frequency band of the low-noise amplifier, and the first frequency is not equal to the second frequency, the first power is not less than the saturated input power of the low-noise amplifier, and the second power is less than the saturated input power of the low-noise amplifier; The pulse generator is used to generate a first pulse and a second pulse, and the pulse generator is connected to the first RF switch and the second RF switch respectively. The first pulse is used to control the on and off of the first RF switch, and the second pulse is used to control the on and off of the second RF switch. The combiner is used to send the first signal and the second signal to the low noise amplifier; The test receiver is used to measure the power of the second signal, and the receiving frequency of the test receiver is equal to the second frequency.

9. The system according to claim 8, characterized in that Both the first signal and the second signal are CW waves.

10. The system according to claim 8, wherein: An attenuator is further provided between the low noise amplifier and the test receiver.

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