Efficient test method and test system for millimeter-wave terahertz mixers

Abstract

The present invention belongs to the technical field of terahertz mixer testing, and relates to an efficient test method and test system for millimeter-wave terahertz mixers. The test system comprises a vector network analyzer and terahertz S-parameter test modules. On the basis of different radio frequencies and local oscillator frequencies caused by the mixing order of a mixer under test, test platforms having two structures are provided, wherein a first-type test platform comprises a vector network analyzer, and a first terahertz S-parameter test module and a second terahertz S-parameter test module that are connected to the vector network analyzer; and a second-type test platform comprises a vector network analyzer and a terahertz S-parameter test module connected to the vector network analyzer. The test method provided by the present invention implements efficient testing of terahertz-band mixers on the basis of combining a microwave-band vector network analyzer main unit with terahertz S-parameter test modules, and solves the problems of low test efficiency, complicated test processes and high costs of existing terahertz mixers.

Description

Efficient test method and test system for millimeter wave terahertz mixer TECHNICAL FIELD

[0001] The present application belongs to the technical field of terahertz mixer testing, and particularly relates to an efficient test method and test system for a millimeter wave terahertz mixer. BACKGROUND

[0002] At present, terahertz technology has been widely applied in the fields of biomedical, safety detection, space exploration and communication. The terahertz mixer is a three-port device capable of realizing up-conversion and down-conversion functions, and is an important component of the front end of a terahertz transceiver, and its performance characteristics have an important influence on the entire system. As a key core component of the entire system, how to quickly and accurately test the performance of the terahertz mixer is one of the key problems faced by designers in the research and production process.

[0003] The main performance indicators of the terahertz mixer include frequency range, conversion loss, noise figure, isolation, conversion compression, third-order intermodulation, and port standing wave. The traditional test method for the above-mentioned indicators of the terahertz mixer requires three kinds of system platforms. The first kind of platform can test the frequency range, conversion loss, and compression point, i.e., two microwave signal generators and a terahertz frequency multiplication source module are used to provide the radio frequency and local oscillator signals for the terahertz mixer, and a microwave frequency spectrum analyzer is used to measure the amplitude of the intermediate frequency signal. By calculating the amplitudes of the radio frequency input signal and the intermediate frequency output signal, the frequency range, conversion loss, and compression point of the terahertz mixer can be obtained. The down-conversion test system can be changed to an up-conversion test platform by exchanging the test interfaces of the RF and IF ports. The second kind of platform is used to test the port standing wave of the mixer, which mainly uses a signal generator and a terahertz frequency multiplication source to provide the local oscillator signal for the mixer, and then uses a vector network analyzer host to test the intermediate frequency port standing wave. In the case of connecting a frequency expansion device, the radio frequency port can be tested. The matching load is terminated according to the test requirements of the RF and IF ports. The third kind of platform is mainly used to test the isolation. Considering that the RF and LO working frequency bands of the millimeter wave terahertz mixer are generally quite different from the IF working frequency band, and the interface forms are also quite different, the main test is the leakage from the local oscillator to the radio frequency port. The test platform mainly needs a signal source and a frequency expansion device to provide the local oscillator port excitation for the mixer, and then uses a power meter or a frequency spectrum analyzer with an expansion module to test the power leakage of the LO frequency band at the RF port. The intermediate frequency port is terminated with a load, and the isolation from the LO to the RF port can be tested and obtained.

[0004] As a three-port device, the test system is relatively complex due to the numerous test parameters, and a large number of instruments are required. On the one hand, this leads to low test efficiency, and on the other hand, the test cost is also quite high.

[0005] The millimeter wave terahertz mixer test generally includes chip die test and package test. Compared with the mixer test in the microwave frequency band, the millimeter wave terahertz mixer test often needs to be completed by combining a microwave frequency band test host and an external frequency expansion device, and the test is more complex. In addition to the host, a frequency expansion device is needed, and a suitable test environment needs to be built according to different frequency bands and test requirements. Taking the mixer conversion loss test as an example, a microwave signal source and a corresponding frequency expansion module, a local oscillator signal source and a corresponding frequency expansion module, and an intermediate frequency spectrum analyzer are needed. On the one hand, many test instruments are needed, and on the other hand, the test efficiency is low, and manual calculation and instrument operation are needed.

[0006] SUMMARY

[0007] In view of the above technical problems, the present application provides a kind of millimeter wave terahertz mixer's high efficiency test method and test system, this test method is based on the vector network analyzer host of microwave frequency band combines terahertz S parameter test module (frequency expansion device), to realize terahertz frequency band mixer high efficiency test;Solve the problems of low test efficiency, test complexity and high cost of existing terahertz mixer.

[0008] The present application is realized by the following technical solutions:

[0009] A kind of millimeter wave terahertz mixer's high efficiency test system, the test system includes vector network analyzer and terahertz S parameter test module;According to the difference of the radio frequency and local oscillator frequency caused by the mixing frequency of the mixer to be tested, two kinds of test platforms are set;

[0010] The first test platform includes a vector network analyzer and a first terahertz S parameter test module and a second terahertz S parameter test module connected to the vector network analyzer;The RF and LO ports of the mixer to be tested are connected to the first terahertz S parameter test module and the second terahertz S parameter test module respectively, and the IF port of the mixer to be tested is connected to the vector network analyzer;

[0011] The second test platform includes a vector network analyzer and a terahertz S parameter test module connected to the vector network analyzer;The RF port of the mixer to be tested is connected to the terahertz S parameter test module;The IF and LO ports of the mixer to be tested are connected to the vector network analyzer.

[0012] Further, when the mixing frequency of the mixer to be tested is more than twice and the local oscillator operating frequency of the mixer to be tested is higher than the host frequency of the vector network analyzer, and when the mixing frequency of the mixer to be tested is one mixing, the first test platform is used;

[0013] When the mixing times of the to-be-tested mixer is more than twice and the local oscillator operating frequency of the to-be-tested mixer is lower than the host frequency of the vector network analyzer, the second test platform is adopted.

[0014] Further, the operating frequency of the vector network analyzer is greater than or equal to the highest value of the operating frequency band of the IF port of the to-be-tested mixer.

[0015] In the first test platform, the operating frequency of the first terahertz S parameter test module is equal to the operating frequency band of the RF port of the to-be-tested mixer; and the operating frequency of the second terahertz S parameter test module is equal to the operating frequency band of the LO port of the to-be-tested mixer.

[0016] In the second test platform, the operating frequency of the first terahertz S parameter test module is equal to the operating frequency band of the RF port of the to-be-tested mixer.

[0017] A high-efficiency test method of a millimeter wave terahertz mixer, the method comprising:

[0018] Confirming the test frequency band and building the test platform: confirming the operating frequency bands of the RF, LO and IF ports of the to-be-tested mixer, and building the first test platform or the second test platform according to the operating frequency band information of the to-be-tested mixer;

[0019] Based on the communication between the vector network analyzer host and the terahertz S parameter test module, the output power of the terahertz S parameter test module is controlled, and the characteristics of the to-be-tested mixer under different port output powers are tested, including the frequency conversion loss test, the compression point test, the port standing wave test and the isolation test.

[0020] Further, when the frequency conversion loss test is performed by using the first test platform:

[0021] The host of the vector network analyzer is set to a sweep frequency mode; the working frequency of the first terahertz S parameter test module is equal to the working frequency band of the RF port of the to-be-tested frequency mixer; the output power of the RF output port of the first terahertz S parameter test module is set so that the to-be-tested frequency mixer works in a non-compressed state; the output power of the RF output port of the second terahertz S parameter test module is set to meet the local oscillator driving power requirement of the to-be-tested frequency mixer; the intermediate frequency frequency is reasonably set; the to-be-tested frequency mixer works in a normal state, the transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the to-be-tested frequency mixer, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the to-be-tested frequency mixer; the output power of the RF output port of the second terahertz S parameter test module is adjusted to adjust the local oscillator input power of the frequency mixer, and the conversion loss change of the to-be-tested frequency mixer under different local oscillator driving powers is obtained; different intermediate frequency working frequency bands are set by setting the working frequency of the first terahertz S parameter test module or the second terahertz S parameter test module, and the conversion loss change of the frequency mixer under different intermediate frequency working frequency bands is obtained.

[0022] When the second test platform is used to test the conversion loss:

[0023] The host of the vector network analyzer is set to a sweep frequency mode; the working frequency of the first terahertz S parameter test module is equal to the working frequency band of the RF port of the to-be-tested frequency mixer; the output power of the RF output port of the first terahertz S parameter test module is set so that the to-be-tested frequency mixer works in a non-compressed state; the output power of the RF output port of the first terahertz S parameter test module is set so that the to-be-tested frequency mixer works in a non-compressed state; the output power of the third port of the vector network analyzer is set to meet the local oscillator driving power requirement of the to-be-tested frequency mixer; the intermediate frequency frequency is reasonably set; the to-be-tested frequency mixer works in a normal state, the transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the to-be-tested frequency mixer, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the to-be-tested frequency mixer; different local oscillator port powers PLO are set to obtain the conversion loss change of the frequency mixer under different local oscillator driving powers, and different intermediate frequency working frequency bands are set to obtain the conversion loss change of the frequency mixer under different intermediate frequency working frequency bands.

[0024] Further, the method for testing the compression point by using the first test platform is:

[0025] The host of the vector network analyzer is set to a sweep frequency mode; the working frequency of the first terahertz S parameter test module is equal to the working frequency band of the RF port of the to-be-tested frequency mixer;

[0026] The first terahertz S-parameter test module is set to meet the power scanning range of the compression test of the to-be-tested mixer; and the output power of the second terahertz S-parameter test module is set to meet the local oscillator driving power for normal operation of the to-be-tested mixer.

[0027] The intermediate frequency frequency of the to-be-tested mixer is set: intermediate frequency frequency = radio frequency frequency - N*local oscillator frequency, N is the mixing number; the intermediate frequency frequency of the mixer is adjusted by setting the working frequencies of the first S-parameter test module and the two-port of the vector network analyzer host, to obtain the required intermediate frequency frequency, which is not higher than the working frequency of the vector network analyzer host;

[0028] The transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the to-be-tested mixer, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the to-be-tested mixer;

[0029] After the power scanning of the first terahertz S-parameter test module is completed, the radio frequency power scanning and the change curve of the conversion loss of the to-be-tested mixer in the corresponding frequency band are obtained, and then the 1dB compression point parameter is obtained; different local oscillator powers and intermediate frequency working frequencies are set, and then the change information of the compression point parameters of the mixer under different conditions is obtained;

[0030] The method for performing the compression point test by using the second test platform is as follows:

[0031] The host of the vector network analyzer is set to the sweep point frequency mode; and the terahertz S-parameter test module is set to have a working frequency equal to the working frequency band of the RF port of the to-be-tested mixer;

[0032] The terahertz S-parameter test module is set to meet the power scanning range of the compression test of the to-be-tested mixer; and the output power of the third port of the vector network analyzer is set to meet the local oscillator driving power for normal operation of the to-be-tested mixer;

[0033] The intermediate frequency working frequency of the to-be-tested mixer is set; the transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the to-be-tested mixer, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the to-be-tested mixer;

[0034] After the power scanning of the terahertz S-parameter test module is completed, the radio frequency power scanning and the change curve of the conversion loss of the to-be-tested mixer in the corresponding frequency band are obtained, and then the 1dB compression point parameter is obtained; different local oscillator powers and intermediate frequency working frequencies are set, and then the change information of the compression point parameters of the mixer under different conditions is obtained.

[0035] Further, the method for performing the port standing wave test by using the first test platform is as follows:

[0036] The host of the vector network analyzer is set to sweep mode; the first terahertz S parameter test module is a test module with a working frequency equal to the working frequency band of the RF port of the mixer to be tested;

[0037] The output power of the first and second terahertz S parameter test modules and the frequency range of the test intermediate frequency output port are set so that the mixer to be tested works in a normal state, at this time, the reflection parameters of the second port of the vector network analyzer host tested by the first and second terahertz S parameter test modules are the standing waves of the RF port, the LO port and the IF port of the mixer to be tested respectively;

[0038] The method for testing the standing wave of the port by using the second test platform is as follows:

[0039] The host of the vector network analyzer is set to sweep mode; the terahertz S parameter test module is a test module with a working frequency equal to the working frequency band of the RF port of the mixer to be tested;

[0040] The output power of the terahertz S parameter test module and the third port of the vector network analyzer and the frequency range of the test intermediate frequency output port are set so that the mixer to be tested works in a normal state, at this time, the reflection parameters of the third port and the second port of the vector network analyzer are the standing waves of the RF port, the LO port and the IF port of the mixer to be tested respectively.

[0041] Further, the method for testing the isolation of the fundamental harmonic mixer by using the first test platform is as follows:

[0042] The host of the vector network analyzer is set to sweep mode; the first and second S parameter test modules should work in the same frequency band, and the IF port of the mixer to be tested is connected with a matching load; the transmission characteristic between the second terahertz S parameter test module and the first terahertz S parameter test module is the isolation parameter of the LO port to the RF port of the mixer to be tested;

[0043] The method for testing the isolation of the second and higher harmonic mixer by using the first test platform is as follows:

[0044] The host of the vector network analyzer is set to sweep mode; the first terahertz S parameter test module is replaced by a test module with a working frequency equal to the working frequency band of the LO port of the mixer to be tested;

[0045] The IF port of the mixer to be tested is connected with a matching load; the transmission characteristic between the second terahertz S parameter test module and the first terahertz S parameter test module is the isolation parameter of the LO port to the RF port of the mixer to be tested;

[0046] The method for testing the isolation of the Nth harmonic frequency mixer by using the second test platform is as follows:

[0047] The host of the vector network analyzer is set to the sweep mode; the first terahertz S parameter test module is removed, and the waveguide output port of the mixer is converted into a coaxial output port by using a waveguide-coaxial converter and is connected to a port of the vector network analyzer; the IF port of the to-be-tested mixer is connected to a matching load; and the transmission characteristic between the second port and the first port of the vector network analyzer is the isolation parameter from the LO port to the RF port of the to-be-tested mixer.

[0048] The beneficial technical effects of the present application are as follows:

[0049] The present application provides an efficient test method for the frequency range, frequency conversion loss, frequency conversion compression, port standing wave index and isolation that are frequently tested for mixers; the purpose of the present application is to solve the problems of low test efficiency, complex test and high cost of the existing terahertz mixer test, and the present application realizes efficient test of the terahertz frequency band mixer based on the vector network analyzer host of the microwave frequency band and the terahertz S parameter test module of the frequency expansion device. The vector network analyzer can set and program control the output power of the terahertz S parameter test module port, and can set the related test parameters of the mixer, such as the working frequency, power requirement and scanning step of the three ports, and the vector network analyzer host can control the work of two S parameter test modules of different frequency bands at the same time.

[0050] Based on the test platform provided by the present application, the general and key parameters (frequency conversion loss, compression point, port standing wave and isolation) of the millimeter wave terahertz mixer can be efficiently and accurately obtained, and the test platform has high universality and compatibility, fully considers the technical characteristics of the mixer and the port frequency change caused by different harmonic frequencies, has high practical value, can be widely applied to the test of mixers with different harmonic frequencies and different port forms, and greatly reduces the time cost and equipment cost caused by the test. The test platform is mainly for the millimeter wave terahertz mixer test, and has high reference value for similar millimeter wave terahertz chip test. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 is a first test platform architecture in the embodiment of the present application (the local oscillator working frequency is higher than the frequency of the vector network analyzer host);

[0052] Fig. 2 is a second test platform architecture in the embodiment of the present application (the local oscillator working frequency is lower than the frequency of the vector network analyzer host);

[0053] Fig. 3 is a 110GHz-170GHz sub-harmonic frequency conversion loss test platform in the embodiment of the present application;

[0054] Figure 4 shows the 110GHz-170GHz subharmonic mixing isolation test platform in an embodiment of the present invention.

[0055] Figure 5 shows the 110GHz-170GHz fundamental frequency mixing test platform in an embodiment of the present invention;

[0056] Figure 6 shows the 110GHz-170GHz tenth harmonic mixing test platform in an embodiment of the present invention;

[0057] Figure 7 shows the frequency conversion loss test platform of the 220GHz-330GHz second harmonic mixer in an embodiment of the present invention.

[0058] Figure 8 shows the isolation test platform for the 220GHz-330GHz second harmonic mixer in an embodiment of the present invention. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0060] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0061] Example 1: A high-efficiency test system for millimeter-wave terahertz mixers, the test system including a vector network analyzer and a terahertz S-parameter test module; two test platforms with different structures are set up according to the different radio frequency and local oscillator frequencies caused by the mixing number of the mixer under test;

[0062] The first test platform includes a vector network analyzer and a first terahertz S-parameter test module and a second terahertz S-parameter test module connected to the vector network analyzer; the RF and LO ports of the mixer under test are connected to the first terahertz S-parameter test module and the second terahertz S-parameter test module, respectively, and the IF port of the mixer under test is connected to the vector network analyzer;

[0063] The second type of test platform includes a vector network analyzer and a terahertz S-parameter test module connected to the vector network analyzer; the RF port of the mixer under test is connected to the terahertz S-parameter test module; the IF and LO ports of the mixer under test are both connected to the vector network analyzer.

[0064] In the embodiment, when the mixing times of the to-be-tested mixer is more than twice and the local oscillator working frequency of the to-be-tested mixer is higher than the host frequency of the vector network analyzer, and when the mixing times of the to-be-tested mixer is once, the first test platform is adopted;

[0065] When the mixing times of the to-be-tested mixer is more than twice and the local oscillator working frequency of the to-be-tested mixer is lower than the host frequency of the vector network analyzer, the second test platform is adopted.

[0066] In the embodiment, the working frequency of the vector network analyzer is greater than or equal to the highest value of the working frequency band of the IF port of the to-be-tested mixer;

[0067] In the first test platform, the working frequency of the first terahertz S parameter test module is equal to the working frequency band of the RF port of the to-be-tested mixer, and the working frequency of the second terahertz S parameter test module is equal to the working frequency band of the LO port of the to-be-tested mixer.

[0068] In the second test platform, the working frequency of the first terahertz S parameter test module is equal to the working frequency band of the RF port of the to-be-tested mixer.

[0069] Specifically, as shown in FIG. 1, in the first test platform, the first port and the third port of the vector network analyzer are connected with the radio frequency input port of the first terahertz S parameter test module and the radio frequency input port of the second terahertz S parameter test module respectively, so as to provide radio frequency signals for the two terahertz S parameter test modules; the local oscillator output signal of the vector network analyzer is divided into two paths and input into the local oscillator input port of the two terahertz S parameter test modules; the vector network analyzer simultaneously receives the reference intermediate frequency signals R1 and R2 and the test intermediate frequency signals A and B of the two terahertz S parameter test modules; the radio frequency output port of the first terahertz S parameter test module is connected with the RF port of the to-be-tested mixer, the radio frequency output port of the second terahertz S parameter test module is connected with the LO port of the to-be-tested mixer, and the IF port of the to-be-tested mixer is connected with the second port of the vector network analyzer.

[0070] The second test platform comprises a vector network analyzer and a terahertz S parameter test module; the first port of the vector network analyzer is connected with the radio frequency input port of the terahertz S parameter test module, so as to provide radio frequency signals for the terahertz S parameter test module; the local oscillator output signal of the vector network analyzer is input into the local oscillator input port of the terahertz S parameter test module; the vector network analyzer receives the reference intermediate frequency signal R1 and the test intermediate frequency signal A of the terahertz S parameter test module; the radio frequency output port of the terahertz S parameter test module is connected with the RF port of the to-be-tested mixer; the IF port and the LO port of the to-be-tested mixer are connected with the second port and the third port of the vector network analyzer respectively.

[0071] Specifically, the S parameter test module in the application adopts the terahertz spread spectrum module in the patent with application number 202310424859.4, which is a conventional test module, and the vector network analyzer used in the application is a conventional device.

[0072] Embodiment 2: An efficient test method for a millimeter wave terahertz mixer, which adopts the efficient test system in Embodiment 1. The method comprises:

[0073] Confirming the test frequency band and building the test platform: confirming the working frequency bands of the RF, LO, and IF ports of the mixer to be tested, and building the first test platform or the second test platform according to the working frequency band information of the mixer to be tested;

[0074] Based on the communication between the host of the vector network analyzer and the terahertz S parameter test module, the output power of the terahertz S parameter test module is controlled, and the characteristics of the mixer to be tested under different port output powers are tested, including frequency conversion loss test, compression point test, port standing wave test, and isolation test.

[0075] In this embodiment, when the first test platform is used for frequency conversion loss test, the method is:

[0076] The host of the vector network analyzer is set to sweep frequency mode; the working frequency of the first terahertz S parameter test module is equal to the working frequency band of the RF port of the mixer to be tested; the output power of the RF output port of the first terahertz S parameter test module is set so that the mixer to be tested works in an uncompressed state; the output power of the RF output port of the second terahertz S parameter test module is set to meet the local oscillator driving power requirement of the mixer to be tested; the intermediate frequency frequency is reasonably set (specifically, intermediate frequency frequency = radio frequency frequency - N*local oscillator frequency, N is the number of frequency conversion; the required intermediate frequency frequency can be obtained by setting the working frequencies of the two S parameter modules; the condition that the intermediate frequency needs to meet is that it cannot be higher than the working frequency of the host of the vector network analyzer); the mixer to be tested works in a normal state, the transmission parameters from the first port to the second port of the vector network analyzer are the down-conversion loss of the mixer to be tested, and the transmission parameters from the second port to the first port of the vector network analyzer are the up-conversion loss of the mixer to be tested; by adjusting the output power of the RF output port of the second terahertz S parameter test module, the local oscillator input power of the mixer is adjusted to obtain the frequency conversion loss change of the mixer to be tested under different local oscillator driving powers; different intermediate frequency working frequency bands are set by setting the working frequencies of the first terahertz S parameter test module or the second terahertz S parameter test module to obtain the frequency conversion loss change of the mixer under different intermediate frequency working frequency bands.

[0077] When the second test platform is used for frequency conversion loss test:

[0078] The host of the vector network analyzer is set to a sweep frequency mode; the terahertz S parameter test module adopts a test module with a working frequency equal to the working frequency band of the RF port of the to-be-tested frequency mixer; the output power of the RF output port of the terahertz S parameter test module is set so that the to-be-tested frequency mixer works in a non-compressed state; the output power of the third port of the vector network analyzer is set to meet the local oscillator driving power requirement of the to-be-tested frequency mixer; the intermediate frequency frequency is set reasonably (intermediate frequency frequency = RF frequency - N*LO frequency, N is the frequency mixing number; the required intermediate frequency frequency can be obtained by setting the working frequencies of the two S parameter modules; the condition that the intermediate frequency needs to meet is that it cannot be higher than the working frequency of the host of the vector network analyzer); the to-be-tested frequency mixer works in a normal state, and the transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the to-be-tested frequency mixer, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the to-be-tested frequency mixer; different local oscillator port powers PLO are set to obtain the conversion loss changes of the frequency mixer under different local oscillator driving powers, and different intermediate frequency working frequency bands are set to obtain the conversion loss changes of the frequency mixer under different intermediate frequency working frequency bands.

[0079] In this embodiment, when the first test platform is used to test the compression point:

[0080] The host of the vector network analyzer is set to a sweep frequency mode; the first terahertz S parameter test module adopts a test module with a working frequency equal to the working frequency band of the RF port of the to-be-tested frequency mixer;

[0081] The first terahertz S parameter test module is set to meet the power scanning range of the compression test of the to-be-tested frequency mixer; and the output power of the RF output port of the second terahertz S parameter test module is set to meet the local oscillator driving power of the normal working of the to-be-tested frequency mixer;

[0082] The intermediate frequency frequency of the to-be-tested frequency mixer is set: intermediate frequency frequency = RF frequency - N*LO frequency, N is the frequency mixing number; the intermediate frequency frequency of the frequency mixer is adjusted by setting the working frequencies of the first S parameter test module and the second S parameter test module to obtain the required intermediate frequency frequency; the intermediate frequency frequency is not higher than the working frequency of the host of the vector network analyzer;

[0083] The transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the to-be-tested frequency mixer, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the to-be-tested frequency mixer;

[0084] After the power scanning of the first terahertz S parameter test module is completed, the variation curves of the RF power scanning and the frequency conversion loss of the to-be-tested mixer in the corresponding frequency band are obtained, and then the 1dB compression point parameter is obtained; different LO powers and IF working frequency points are set, and then the variation information of the compression point parameter of the mixer under different conditions is obtained.

[0085] When the second test platform is used to test the compression point:

[0086] The host of the vector network analyzer is set to the frequency sweeping point frequency mode; the terahertz S parameter test module uses a test module with the working frequency equal to the working frequency band of the RF port of the to-be-tested mixer;

[0087] The power scanning range of the terahertz S parameter test module is set to meet the compression test of the to-be-tested mixer; the output power of the third port of the vector network analyzer is set to meet the LO driving power for the normal working of the to-be-tested mixer;

[0088] The IF working frequency point of the to-be-tested mixer is set; the transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the to-be-tested mixer, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the to-be-tested mixer;

[0089] After the power scanning of the terahertz S parameter test module is completed, the variation curves of the RF power scanning and the frequency conversion loss of the to-be-tested mixer in the corresponding frequency band are obtained, and then the 1dB compression point parameter is obtained; different LO powers and IF working frequency points are set, and then the variation information of the compression point parameter of the mixer under different conditions is obtained.

[0090] In the embodiment, when the first test platform is used to test the compression port standing wave:

[0091] The host of the vector network analyzer is set to the frequency sweeping mode; the first terahertz S parameter test module uses a test module with the working frequency equal to the working frequency band of the RF port of the to-be-tested mixer;

[0092] The output powers of the RF output ports of the first terahertz S parameter test module and the second terahertz S parameter test module and the frequency range of the test IF output port are set so that the to-be-tested mixer works in the normal state, at this time, the reflection S parameters tested by the first terahertz S parameter test module and the second terahertz S parameter test module are the RF port, LO port and IF port standing waves of the to-be-tested mixer.

[0093] In the embodiment, when the second test platform is used to test the compression port standing wave:

[0094] The host of the vector network analyzer is set to the frequency sweeping mode; the terahertz S parameter test module uses a test module with the working frequency equal to the working frequency band of the RF port of the to-be-tested mixer;

[0095] The output power of the third port of the terahertz S parameter test module and the vector network analyzer and the frequency range of the test intermediate frequency output port are set so that the to-be-tested frequency mixer works in a normal state, at which time the reflection parameters of the third port and the second port of the terahertz S parameter test module and the vector network analyzer are standing waves of the RF port, the LO port and the IF port of the to-be-tested frequency mixer.

[0096] In the embodiment, the method for testing the isolation degree of the fundamental frequency mixer (i.e., the to-be-tested frequency mixer with a mixing frequency of one time, at which time the radio frequency of the frequency mixer is equal to the local oscillation frequency) by using the first test platform is as follows:

[0097] The host of the vector network analyzer is set to a sweep mode; the first S parameter test module and the second S parameter test module should work in the same frequency band, i.e., the radio frequency or the local oscillation working frequency band of the frequency mixer, and the IF port of the to-be-tested frequency mixer is connected to a matching load (the connection between the IF port of the to-be-tested frequency mixer and the vector network analyzer is disconnected); the transmission characteristic between the second terahertz S parameter test module and the first terahertz S parameter test module is the isolation degree parameter from the LO port to the RF port of the to-be-tested frequency mixer.

[0098] The method for testing the isolation degree of the frequency mixer with a mixing frequency of two or more times by using the first test platform is as follows:

[0099] The host of the vector network analyzer is set to a sweep mode; the first terahertz S parameter test module is replaced by a test module with a working frequency equal to the working frequency band of the LO port of the to-be-tested frequency mixer.

[0100] The IF port of the to-be-tested frequency mixer is connected to a matching load (the connection between the IF port of the to-be-tested frequency mixer and the vector network analyzer is disconnected); the transmission characteristic between the second terahertz S parameter test module and the first terahertz S parameter test module is the isolation degree parameter from the LO port to the RF port of the to-be-tested frequency mixer.

[0101] Without loss of generality, when the harmonic number N of the frequency mixer is large enough and the radio frequency port and the local oscillation port of the frequency mixer are both waveguide ports, the waveguide has a high-pass characteristic and can well suppress the signal in the local oscillation frequency band, so it can be determined that the isolation degree from the local oscillation port to the radio frequency port of the frequency mixer is good.

[0102] The method for testing the isolation degree of the frequency mixer with a mixing frequency of N times by using the second test platform is as follows:

[0103] The host of the vector network analyzer is set to sweep mode; the first terahertz S parameter test module is removed, and the waveguide output port of the mixer is converted into a coaxial output port by using a waveguide-coaxial converter and is connected to a port of the vector network analyzer; the IF port of the mixer under test is matched with a load (the connection between the IF port of the mixer under test and the vector network analyzer is disconnected); and the transmission characteristic between the second port and the first port of the vector network analyzer is the isolation parameter of the LO port to the RF port of the mixer under test.

[0104] Without loss of generality, when the harmonic number N of the mixer is large enough and the RF port of the mixer is a waveguide port, the waveguide has a high-pass characteristic and can well suppress the signal of the LO frequency band, so it can be determined that the isolation of the LO port to the RF port of the mixer is good.

[0105] In the application, different test schemes are set according to the different RF and LO frequencies caused by the mixing frequency of the mixer, including fundamental wave mixing, second harmonic mixing, third harmonic mixing, etc.

[0106] For fundamental wave mixing: at this time, the RF frequency of the mixer is the same as the LO frequency, and the configuration scheme is shown in FIG. 1. The frequencies of the two S parameter test modules are the same, and the conversion loss, port standing wave, compression point, isolation and other index tests of the mixer can be obtained by one-time connection after the connection in the figure.

[0107] For second harmonic mixing: at this time, the RF frequency of the mixer is twice the LO frequency, and the configuration scheme is also shown in FIG. 1. At this time, the working frequency of the S parameter test module connected to the RF port of the mixer should be twice the working frequency of the S parameter test module connected to the LO port, and should be consistent with the working frequency of the RF and LO of the mixer. If the LO working frequency of the mixer has fallen into the working frequency of the vector network analyzer, the configuration scheme at this time is shown in FIG. 2, and port 3 or 4 of the vector network analyzer directly provides a driving signal for the LO working frequency of the mixer.

[0108] For other harmonic mixing (the harmonic number is N, N>2); at this time, the RF frequency of the mixer is N times the LO frequency. According to the LO frequency, the configuration scheme of FIG. 1 or FIG. 2 is selected, the working frequency of the S parameter test module connected to the RF port is consistent with the working frequency of the RF of the mixer, and the working frequency of the S parameter test module connected to the RF or from the host (3 / 4) port is consistent with the working frequency of the LO of the mixer.

[0109] The following is an enumeration of actual test cases:

[0110] Embodiment 1: Test method of 110-170GHz mixer second harmonic mixer:

[0111] The following is an example of a 110-170GHz second harmonic mixer test, which specifically illustrates the test process of the test platform.

[0112] (1) Confirm the test frequency band and build the test platform: First, confirm the working frequency of the three ports (RF, LO, IF) of the mixer to be tested, and build the test platform according to the working frequency band information. The RF working frequency band is 110GHz-170GHz, the LO working frequency band is 55GHz-85GHz, and the IF working frequency band is 0-20GHz. According to the frequency band information, a vector network analyzer host working at more than 20GHz, a S parameter test module working at 110-170GHz, a S parameter test module working at 55-85GHz, and some test accessories (cables, loads, etc.) are mainly needed. The vector network analyzer can control two S parameter test modules of different frequency bands at the same time and can adjust the port output power of the S parameter test module through software settings. The S parameter test modules used in the default system have been calibrated.

[0113] b, system calibration: build the test system as shown in Figure 3, complete the system calibration work: single-port S parameter calibration of S parameter test modules 1 and 2, single-port S parameter calibration of intermediate frequency port (calibration method is conventional technology).

[0114] c, variable frequency loss test: set the vector network analyzer host to sweep mode. Reasonably set the port output power P RF of the first terahertz parameter test module so that the mixer works in an uncompressed state; reasonably set the port working power P LO of the second terahertz S parameter test module to meet the local oscillator driving power requirement of the mixer; reasonably set the intermediate frequency frequency (fixed frequency). At this time, the mixer has worked in a normal state, and the transmission parameters from port 1 (i.e. the first port) to port 2 (i.e. the second port) of the vector network analyzer are the down-conversion loss of the mixer, and the transmission parameters from port 2 to port 1 are the up-conversion loss of the mixer. By setting different local oscillator port powers P LO , the variable frequency loss of the mixer under different local oscillator driving powers can be obtained, and by setting different intermediate frequency working frequency bands, the variable frequency loss of the mixer under different intermediate frequency working frequency bands can be obtained.

[0115] d. Compression point test: set the vector network analyzer host to operate in the point frequency mode, set the first terahertz S parameter test module to meet the power scanning range of the mixer compression test, set the second terahertz S parameter test module to meet the LO drive power of the mixer normal working power, and set the mixer intermediate frequency operating frequency point. The RF power scanning and conversion loss curve of the mixer in this frequency band can be obtained after the first terahertz S parameter test module power scanning is completed, that is, the 1dB compression point parameter can be obtained. By setting different LO power and intermediate frequency operating frequency points, the change information of the mixer compression point parameter under different conditions can be obtained.

[0116] e. Port standing wave test: set the vector network analyzer host to operate in the sweep frequency mode, and reasonably set the port output power of the first terahertz S parameter test module and the second terahertz S parameter test module and the frequency range of the intermediate frequency port, so that the mixer works in the normal state. At this time, the reflection S parameters tested by the first terahertz S parameter test module and the second terahertz S parameter test module are the RF port, LO port and IF port standing waves of the mixer.

[0117] f. Isolation test: as shown in FIG. 4, set the vector network analyzer host to operate in the sweep frequency mode, replace the original first terahertz S parameter test module with a first terahertz S parameter test module working in the LO frequency band 55-85GHz, and calibrate the transmission S parameters of the first terahertz S parameter test module and the second terahertz S parameter test module. After that, connect the mixer according to FIG. 4, and terminate the intermediate frequency port with a matching load. At this time, the transmission characteristics between the second terahertz S parameter test module and the first terahertz S parameter test module are the LO port to RF port isolation parameters of the mixer.

[0118] Example 2: Test method of 110-170GHz fundamental harmonic mixer:

[0119] The following takes the test of 110-170GHz fundamental harmonic mixer as an example to specifically explain the test process of the test platform.

[0120] a. Confirm the test frequency band and build the test platform: first, confirm the working frequency of the three ports (RF, LO, IF) of the mixer to be tested, and build the test platform according to the working frequency band information. The RF working frequency band is 110GHz-170GHz, the LO working frequency band is 110GHz-170GHz, and the IF working frequency band is 0-20GHz. According to the frequency band information, one vector network analyzer host working at more than 20GHz, two S parameter test modules working at 110-170GHz, and some test accessories (cables, loads, etc.) are mainly needed. The vector network analyzer can adjust the port output power of the S parameter test module through software setting. The S parameter test modules used in the default system have been completed power calibration.

[0121] b. System calibration: build a test system as shown in Figure 5, complete the system calibration work: single-port S parameter calibration of the first and second terahertz S parameter test modules, single-port S parameter calibration of the intermediate frequency port.

[0122] c. Frequency conversion loss test: set the vector network analyzer host to sweep frequency mode. Reasonably set the port output power P RF of the first terahertz S parameter test module so that the mixer works in an uncompressed state; reasonably set the port working power P LO of the second terahertz S parameter test module to meet the local oscillator driving power requirement of the mixer; reasonably set the intermediate frequency frequency (fixed frequency). At this time, the mixer has worked in a normal state, and the transmission parameters of the vector network analyzer 1 port to 2 port are the down-conversion loss of the mixer, and the transmission parameters of the 2 port to 1 port are the up-conversion loss of the mixer. By setting different local oscillator port powers P LO , the conversion loss variation of the mixer under different local oscillator driving powers can be obtained, and by setting different intermediate frequency working frequency bands, the conversion loss variation of the mixer under different intermediate frequency working frequency bands can be obtained.

[0123] d. Compression point test: set the vector network analyzer host to point frequency mode, set the first terahertz S parameter test module to meet the power scanning range of the mixer compression test, set the output power of the S parameter test module 2 to meet the local oscillator driving power of the mixer normal working, and set the intermediate frequency working frequency point of the mixer. After the power scanning of the first terahertz S parameter test module is completed, the radio frequency power scanning and conversion loss variation curve of the mixer at this frequency band can be obtained, that is, the 1 dB compression point parameter can be obtained. By setting different local oscillator powers and intermediate frequency working frequency points, the compression point parameter variation information of the mixer under different conditions can be obtained.

[0124] e. Port standing wave test: set the vector network analyzer host to sweep frequency mode, reasonably set the port output power of the first and second terahertz S parameter test modules and the frequency range of the intermediate frequency port, so that the mixer works in a normal state, at this time, the reflection S parameters tested by the first and second terahertz S parameter test modules are the RF port, LO port and IF port standing waves of the mixer.

[0125] f. Isolation test: as shown in Figure 5, set the vector network analyzer host to sweep frequency mode, and the transmission characteristics between the second terahertz S test parameter module and the first terahertz S parameter test module are the LO port to RF port isolation parameters of the mixer.

[0126] Example 3: Test method of 110-170GHz tenth harmonic mixer

[0127] The following is an example of testing a 110-170GHz tenth harmonic mixer to illustrate the test process of the test platform when the local oscillator driving frequency of the mixer is lower than the host frequency.

[0128] a. Confirm the test frequency band and build the test platform: First, confirm the working frequency of the three ports (RF, LO, IF) of the mixer to be tested, and build the test platform according to the working frequency band information. The RF working frequency band is 110-170GHz, the LO working frequency band is 11-17GHz, and the IF working frequency band is 0-20GHz. According to the frequency band information, a vector network analyzer host working at more than 20GHz, a S-parameter test module working at 110-170GHz, and some test accessories (cables, loads, etc.) are mainly needed. The vector network analyzer can adjust the port output power of the S-parameter test module through software settings. The S-parameter test module used in the default system has been calibrated for power.

[0129] b. System calibration: Build the test system as shown in Figure 6 and complete the system calibration work: single-port S-parameter calibration of the first terahertz S-parameter test module and the 3-port vector network analyzer host, and single-port S-parameter calibration of the intermediate frequency port.

[0130] c. Conversion loss test: Set the vector network analyzer host to sweep mode. Reasonably set the port output power P RF of the first terahertz S-parameter test module so that the mixer works in an uncompressed state; reasonably set the 3-port working power P LO of the vector network analyzer to meet the local oscillator driving power requirement of the mixer; and reasonably set the intermediate frequency frequency (fixed frequency). At this time, the mixer is working in a normal state, and the transmission parameters from port 1 to port 2 of the vector network analyzer are the down-conversion loss of the mixer, and the transmission parameters from port 2 to port 1 are the up-conversion loss of the mixer. Setting different local oscillator port powers P LO can obtain the conversion loss variation of the mixer under different local oscillator driving powers, and setting different intermediate frequency working frequency bands can obtain the conversion loss variation of the mixer under different intermediate frequency working frequency bands.

[0131] d. Compression point test: Set the vector network analyzer host to the point frequency mode, set the first terahertz S parameter test module to meet the power scan range of the mixer compression test, set the vector network analyzer host 3 port output power to meet the local oscillator driving power of the mixer normal working, set the mixer intermediate frequency working frequency point. The first terahertz S parameter test module power scan is completed, the radio frequency power scan and conversion loss change curve of the mixer in this frequency band can be obtained, that is, the 1dB compression point parameter can be obtained. By setting different local oscillator power and intermediate frequency working frequency point, the change information of the mixer compression point parameter under different conditions can be obtained.

[0132] e. Port standing wave test: Set the vector network analyzer host to the sweep frequency mode, reasonably set the port output power of the first terahertz S parameter test module and the vector network analyzer host port and the frequency range of the intermediate frequency port, so that the mixer works in the normal state. At this time, the S parameter module 1 and the vector network analyzer host 3 port, 2 port reflection S parameter is the RF port, LO port and IF port standing wave of the mixer.

[0133] f. Isolation test: At this time, due to the large difference between the radio frequency port and the local oscillator port, and the difficulty in manufacturing the frequency conversion interface of 110-170GHz (radio frequency) to 11-17GHz (local oscillator), the isolation cannot be tested. At this time, the high isolation can be inferred relying on the high pass characteristic of the waveguide.

[0134] Example 4: 220-330GHz mixer second harmonic mixer test method:

[0135] The following takes the test of 220-330GHz second harmonic mixer as an example to specifically explain the main steps of the test process of the test platform in different frequency band mixer test.

[0136] a. Confirm the test frequency band and build the test platform: First, confirm the working frequency of the three ports (RF, LO, IF) of the mixer to be tested, and build the test platform according to the working frequency band information. The RF working frequency band is 220GHz-330GHz, the LO working frequency band is 110GHz-165GHz, and the IF working frequency band is 0-20GHz. According to the frequency band information, one vector network analyzer host working at more than 20GHz, one S parameter test module working at 220-330GHz, two S parameter test modules working at 110-170GHz and some test accessories (cables, loads, etc.) are mainly needed. The vector network analyzer can control two S parameter test modules of different frequency bands at the same time and can set and adjust the port output power of the S parameter test module through software. The S parameter test modules used in the system by default have been calibrated.

[0137] b. System calibration: build a test system as shown in Figure 7, complete the system calibration work: single-port S parameter calibration of the first terahertz S parameter test module and the second terahertz S parameter test module, single-port S parameter calibration of the intermediate frequency port.

[0138] c. Frequency conversion loss test: set the vector network analyzer host to sweep mode. Reasonably set the port output power P RF of the first terahertz S parameter test module, so that the mixer works in an uncompressed state; set the port working power P LO of the S parameter test module 2 to meet the local oscillator driving power requirement of the mixer; reasonably set the intermediate frequency frequency (fixed frequency). At this time, the mixer has worked in a normal state, and the transmission parameters from port 1 to port 2 of the vector network analyzer 1 are the down-conversion loss of the mixer, and the transmission parameters from port 2 to port 1 are the up-conversion loss of the mixer. Set different local oscillator port powers P LO to obtain the conversion loss changes of the mixer under different local oscillator driving powers, and set different intermediate frequency working frequency bands to obtain the conversion loss changes of the mixer under different intermediate frequency working frequency bands.

[0139] d. Compression point test: set the vector network analyzer host to point frequency mode, set the first terahertz S parameter test module to meet the power scanning range of the mixer compression test, set the second terahertz S parameter test module to meet the local oscillator driving power of the mixer normal working, and set the intermediate frequency working frequency point of the mixer. After the power scanning of the first terahertz S parameter test module is completed, the RF power scanning and conversion loss change curve of the mixer in this frequency band can be obtained, that is, the 1dB compression point parameter can be obtained. By setting different local oscillator powers and intermediate frequency working frequency points, the compression point parameter change information of the mixer under different conditions can be obtained.

[0140] e. Port standing wave test: set the vector network analyzer host to sweep mode, reasonably set the port output power of the first terahertz S parameter test module and the second terahertz S parameter test module and the frequency range of the intermediate frequency port, so that the mixer works in a normal state, at this time, the reflection S parameters tested by the first terahertz S parameter test module and the second terahertz S parameter test module are the RF port, LO port and IF port standing wave of the mixer.

[0141] f, isolation test: as shown in Figure 8, the vector network analyzer host is set to the sweep mode, the original first terahertz S parameter test module is replaced by the first terahertz S parameter test module working at the LO frequency band 110-170GHz, and the transmission S parameter calibration of the first terahertz S parameter test module and the second terahertz S parameter test module is carried out, then the mixer is connected as shown in Figure 8, and the intermediate frequency port is terminated by a matching load. At this time, the transmission characteristic between the first terahertz S parameter test module and the second terahertz S parameter test module is the isolation parameter of the LO port to the RF port of the mixer.

[0142] The test platform provided by the application can complete the test of frequency range, frequency conversion loss, compression point, port standing wave, isolation and other parameters. The test platform provided by the application has the following characteristics:

[0143] (1) The test platform is simple: the test platform mainly includes a vector network analyzer, two S parameter test modules and test accessories. The system architecture is clear and simple to build.

[0144] (2) Convenient and efficient test: by controlling the S parameter test module port power tuning, the characteristics of the mixer under different port output powers can be quickly obtained, such as the change of the mixer related parameters under different local oscillator driving powers, the compression of the mixer under different radio frequency powers, etc. The test parameters are rich, and the test time is greatly saved.

[0145] The test platform architecture provided by the application first proposes a terahertz mixer test architecture based on a terahertz vector network analyzer. The architecture combines the common terahertz mixer parameter test requirements, uses the sweep and power scanning mode of the vector network analyzer, and based on the externally expanded S parameter test module, can simply and efficiently realize the test of many conventional parameters, requires less instrument, simple interconnection, and less test time. The corresponding software function development is integrated into the system, which is convenient for user operation.

[0146] The S parameter test module with port power program control tuning in the application: the power tunable S parameter test module is a key part of the system. Based on the communication between the vector network analyzer host software and the S parameter test module, the output power of the S parameter test module is controlled to meet the needs of the platform for constant port output power;

[0147] Compared with the traditional mixer test method, the test method provided by the application can test more complete parameters, requires less test equipment, and has higher measurement efficiency.

[0148] The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high efficiency test system for a millimeter wave terahertz mixer characterized by, The test system comprises a vector network analyzer and a terahertz S-parameter test module; two kinds of test platforms are set up according to the difference between the radio frequency and the local oscillator frequency caused by the mixing frequency of the mixer to be tested; The first kind of test platform comprises a vector network analyzer and a first terahertz S-parameter test module and a second terahertz S-parameter test module connected with the vector network analyzer; the RF and LO ports of the mixer to be tested are connected with the first and second terahertz S-parameter test modules respectively, and the IF port of the mixer to be tested is connected with the vector network analyzer; The second kind of test platform comprises a vector network analyzer and a terahertz S-parameter test module connected with the vector network analyzer; the RF port of the mixer to be tested is connected with the terahertz S-parameter test module; the IF and LO ports of the mixer to be tested are connected with the vector network analyzer.

2. The high efficiency test system for a millimeter wave terahertz frequency mixer according to claim 1, wherein, When the mixing frequency of the mixer to be tested is more than twice and the local oscillator working frequency of the mixer to be tested is higher than the host frequency of the vector network analyzer, and when the mixing frequency of the mixer to be tested is once, the first kind of test platform is adopted; When the mixing frequency of the mixer to be tested is more than twice and the local oscillator working frequency of the mixer to be tested is lower than the host frequency of the vector network analyzer, the second kind of test platform is adopted.

3. The high efficiency test system for a millimeter wave terahertz frequency mixer according to claim 1, wherein, The working frequency of the vector network analyzer is greater than or equal to the highest value of the working frequency band of the IF port of the mixer to be tested; In the first kind of test platform, the working frequency of the first terahertz S-parameter test module is equal to the working frequency band of the RF port of the mixer to be tested; the working frequency of the second terahertz S-parameter test module is equal to the working frequency band of the LO port of the mixer to be tested; In the second kind of test platform, the working frequency of the first terahertz S-parameter test module is equal to the working frequency band of the RF port of the mixer to be tested.

4. A method for efficient testing of a millimeter wave terahertz mixer, using the efficient testing system of any one of claims 1-3, wherein, The method comprises: Confirming the test frequency band and building the test platform: confirming the working frequency band of the RF, LO and IF ports of the mixer to be tested, and building the first kind of test platform or the second kind of test platform according to the working frequency band information of the mixer to be tested; Based on the communication between the host of the vector network analyzer and the terahertz S-parameter test module, the output power of the terahertz S-parameter test module is controlled, and the characteristics of the mixer to be tested under different port output powers are tested, including the frequency conversion loss test, the compression point test, the port standing wave test and the isolation test.

5. The method of claim 4, wherein the method further comprises: When the first kind of test platform is adopted for the frequency conversion loss test: The host of the vector network analyzer is set to the sweep frequency working mode; the working frequency of the first terahertz S-parameter test module is equal to the working frequency band of the RF port of the mixer to be tested; the output power of the RF output port of the first terahertz S-parameter test module is set so that the mixer to be tested works in the non-compressed state; the output power of the RF output port of the second terahertz S-parameter test module is set to meet the local oscillator driving power requirement of the mixer to be tested; Reasonable set intermediate frequency frequency; the measured mixer works in the normal state, the transmission parameter of the first port to the second port of the vector network analyzer is the down conversion loss of the measured mixer, the transmission parameter of the second port to the first port of the vector network analyzer is the up conversion loss of the measured mixer; by adjusting the output power of the second terahertz S parameter test module radio frequency output port, the local oscillator input power of the mixer is adjusted, the conversion loss change of the measured mixer under different local oscillator driving power is obtained; by setting the working frequency of the first terahertz S parameter test module or the second terahertz S parameter test module Set different intermediate frequency frequency bands to obtain the conversion loss change of the mixer under different intermediate frequency frequency bands When the second test platform is used for conversion loss test: Set the host computer of the vector network analyzer to sweep frequency mode; The terahertz S parameter test module adopts a test module with a working frequency equal to the working frequency band of the RF port of the measured mixer; the output power of the terahertz S parameter test module radio frequency output port is set so that the measured mixer works in a non-compressed state; the output power of the third port of the vector network analyzer is set to meet the local oscillator driving power requirement of the measured mixer; Reasonable set intermediate frequency frequency; the measured mixer works in the normal state, the transmission parameter of the first port to the second port of the vector network analyzer is the down conversion loss of the measured mixer, the transmission parameter of the second port to the first port of the vector network analyzer is the up conversion loss of the measured mixer; set different local oscillator port power PLO to obtain the conversion loss change of the mixer under different local oscillator driving power, set different intermediate frequency frequency bands to obtain the conversion loss change of the mixer under different intermediate frequency frequency bands.

6. The efficient test method of the millimeter wave terahertz mixer according to claim 4, characterized in that The method for performing compression point test by using the first test platform is: Set the host computer of the vector network analyzer to sweep frequency mode; the first terahertz S parameter test module adopts a test module with a working frequency equal to the working frequency band of the RF port of the measured mixer; Set the first terahertz S parameter test module to meet the power scanning range of the compression test of the measured mixer; set the output power of the radio frequency output port of the second terahertz S parameter test module to meet the local oscillator driving power of the normal operation of the measured mixer; Set the intermediate frequency frequency of the measured mixer: intermediate frequency frequency = radio frequency frequency - N*local oscillator frequency, N is the frequency conversion times; Adjust the intermediate frequency frequency of the mixer by setting the working frequency of the first S parameter test module and the two-port host computer of the vector network analyzer, and obtain the required intermediate frequency frequency, which is not higher than the working frequency of the host computer of the vector network analyzer; The transmission parameter of the first port to the second port of the vector network analyzer is the down conversion loss of the measured mixer, and the transmission parameter of the second port to the first port of the vector network analyzer is the up conversion loss of the measured mixer; After the power scanning of the first terahertz S-parameter test module is completed, the change curves of the radio frequency power scanning and the frequency conversion loss of the to-be-tested frequency mixer in the corresponding frequency band are obtained, and then the 1dB compression point parameters are obtained; different local oscillator powers and intermediate frequency working frequencies are set, and then the change information of the compression point parameters of the frequency mixer under different conditions is obtained; The method for testing the compression point by using the second test platform is: The host of the vector network analyzer is set as a sweep point frequency mode; the terahertz S-parameter test module uses a test module with a working frequency equal to the working frequency band of the RF port of the to-be-tested frequency mixer; The power scanning range of the terahertz S-parameter test module is set to meet the compression test of the to-be-tested frequency mixer; the output power of the third port of the vector network analyzer is set to meet the local oscillator driving power for the normal working of the to-be-tested frequency mixer; The intermediate frequency working frequency of the to-be-tested frequency mixer is set; the transmission parameters from the first port to the second port of the vector network analyzer are the down-conversion loss of the to-be-tested frequency mixer, and the transmission parameters from the second port to the first port of the vector network analyzer are the up-conversion loss of the to-be-tested frequency mixer; After the power scanning of the first terahertz S-parameter test module is completed, the change curves of the radio frequency power scanning and the frequency conversion loss of the to-be-tested frequency mixer in the corresponding frequency band are obtained, and then the 1dB compression point parameters are obtained; different local oscillator powers and intermediate frequency working frequencies are set, and then the change information of the compression point parameters of the frequency mixer under different conditions is obtained.

7. The efficient test method of the millimeter wave terahertz frequency mixer according to claim 4, characterized in that, The method for testing the port standing wave by using the first test platform is: The host of the vector network analyzer is set as a sweep mode; the first terahertz S-parameter test module uses a test module with a working frequency equal to the working frequency band of the RF port of the to-be-tested frequency mixer; The output powers of the radio frequency output ports of the first terahertz S-parameter test module and the second terahertz S-parameter test module and the frequency range of the test intermediate frequency output port are set so that the to-be-tested frequency mixer works in a normal state; at this time, the reflection parameters of the first terahertz S-parameter test module, the second terahertz S-parameter test module and the second port of the vector network analyzer host tested are the RF port, the LO port and the IF port standing waves of the to-be-tested frequency mixer respectively; The method for testing the port standing wave by using the second test platform is: The host of the vector network analyzer is set as a sweep mode; the terahertz S-parameter test module uses a test module with a working frequency equal to the working frequency band of the RF port of the to-be-tested frequency mixer; The output powers of the terahertz S-parameter test module and the third port of the vector network analyzer and the frequency range of the test intermediate frequency output port are set so that the to-be-tested frequency mixer works in a normal state; at this time, the reflection parameters of the terahertz S-parameter test module and the third port and the second port of the vector network analyzer are the RF port, the LO port and the IF port standing waves of the to-be-tested frequency mixer respectively.

8. The efficient test method of the millimeter wave terahertz frequency mixer according to claim 4, characterized in that, The method for testing the isolation of the fundamental wave harmonic frequency mixer by using the first test platform is: The host of the vector network analyzer is set to sweep mode; the first S parameter test module and the second S parameter test module should work in the same frequency band, and the IF port of the to-be-tested frequency mixer is connected with a matching load; the transmission characteristic between the second terahertz S parameter test module and the first terahertz S parameter test module is the isolation parameter from the LO port to the RF port of the to-be-tested frequency mixer; The method for testing the isolation of the second and higher harmonic frequency mixer by using the first test platform is: The host of the vector network analyzer is set to sweep mode; the first terahertz S parameter test module is replaced by a test module with a working frequency equal to the working frequency band of the LO port of the to-be-tested frequency mixer; The IF port of the to-be-tested frequency mixer is connected with a matching load; the transmission characteristic between the second terahertz S parameter test module and the first terahertz S parameter test module is the isolation parameter from the LO port to the RF port of the to-be-tested frequency mixer; The method for testing the isolation of the Nth harmonic frequency mixer by using the second test platform is: The host of the vector network analyzer is set to sweep mode; the first terahertz S parameter test module is removed, and the waveguide output port of the frequency mixer is converted into a coaxial output port by using a waveguide-coaxial converter and is connected to a port of the vector network analyzer; the IF port of the to-be-tested frequency mixer is connected with a matching load; the transmission characteristic between the second port and the first port of the vector network analyzer is the isolation parameter from the LO port to the RF port of the to-be-tested frequency mixer.

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