High-efficiency test method and test system for millimeter wave terahertz mixer

Abstract

The invention belongs to the technical field of terahertz mixer testing, and relates to an efficient testing method and system for a millimeter wave terahertz mixer. The test system comprises a vector network analyzer and a terahertz S parameter test module. According to the difference of radio frequency and local oscillation frequency caused by the frequency mixing times of a to-be-tested frequency mixer, test platforms of two structures are arranged; the first test platform comprises a vector network analyzer, a first terahertz S parameter test module and a second terahertz S parameter test module, wherein the first terahertz S parameter test module and the second terahertz S parameter test module are connected with the vector network analyzer. The second test platform comprises a vector network analyzer and a terahertz S parameter test module connected with the vector network analyzer. According to the test method provided by the invention, a vector network analyzer host based on a microwave frequency band is combined with a terahertz S parameter test module to realize efficient test of a terahertz frequency band mixer; the problems that an existing terahertz frequency mixer is low in testing efficiency, complex in testing and high in cost are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of terahertz mixer testing, and in particular relates to an efficient testing method and a testing system for a millimeter wave terahertz mixer. Background Art

[0002] At present, terahertz technology has been widely used in biomedicine, security detection, space exploration and communication. The terahertz mixer is a three-port device that can realize up and down conversion. It is an important part of the front end of the terahertz transceiver. Its performance characteristics have a great impact 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 issues faced by designers during the R&D and production process.

[0003] The main performance indicators of terahertz mixers include frequency range, frequency conversion loss, noise figure, isolation, frequency conversion compression, third-order intermodulation, port standing wave and other indicators. The traditional test methods for the above indicators of terahertz mixers require three main system platforms. The first one can test indicators such as frequency range, frequency conversion loss, and compression point: that is, two microwave signal generators and terahertz frequency multiplication source modules are used to provide RF and local oscillator signals for the terahertz mixer, and the amplitude of the intermediate frequency signal is measured by a microwave spectrum analyzer. By calculating the amplitude of the RF input signal and the amplitude of the intermediate frequency output signal, the frequency range, frequency conversion loss, compression point and other indicators of the terahertz mixer can be obtained. Down-conversion test system, when the test interface of the RF and IF ports is exchanged, the up-conversion test platform can be changed. The second platform is the port standing wave platform for testing the mixer, which mainly uses a signal generator and a terahertz frequency multiplication source to provide the mixer with a local oscillator signal, and then uses a vector network analyzer host to perform intermediate frequency port standing wave test. The RF port can be tested when the spectrum expansion device is connected. The matching load is terminated at the RF and IF ports according to the test requirements. The third type is mainly isolation testing. Considering that the RF and LO operating frequency bands of the millimeter-wave terahertz mixer are generally quite different from the IF operating frequency bands, and the interface forms are quite different, the leakage from the local oscillator to the RF port is mainly tested. The test platform mainly requires a signal source and a frequency extension device to provide local oscillator port excitation for the mixer, and then a power meter or a spectrum analyzer with a spectrum expansion module is used to test the power leakage of the LO 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 at this time.

[0004] As a three-port device, the mixer has a complex test system due to the numerous test parameters and requires more equipment and instruments. On the one hand, this leads to low test efficiency and on the other hand, the test cost is relatively high.

[0005] Millimeter-wave terahertz mixer testing generally includes chip bare die testing and package testing. Compared with microwave frequency band mixer testing, millimeter-wave terahertz mixer testing often requires the combination of a microwave frequency band test host and an external frequency expansion device. The test is more complicated. In addition to the host, a frequency expansion device is also required. It is necessary to build a suitable test environment according to different frequency bands and test requirements. Taking the frequency conversion loss test of the mixer 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 required. On the one hand, many test instruments are required, and on the other hand, the test efficiency is low, and manual calculations and instrument operation are required. Summary of the invention

[0006] In view of the above technical problems, the present invention provides an efficient testing method and testing system for millimeter-wave terahertz mixers. The testing method is based on a vector network analyzer host in the microwave frequency band combined with a terahertz S-parameter testing module (frequency extension device) to achieve efficient testing of terahertz frequency band mixers, and solves the problems of low testing efficiency, complex testing and high cost of existing terahertz mixers.

[0007] The present invention is achieved through the following technical solutions:

[0008] An efficient test system for a millimeter wave terahertz mixer, the test system comprising a vector network analyzer and a terahertz S-parameter test module; two test platforms with different structures are set according to the differences in radio frequency and local oscillator frequency caused by the mixing times of the mixer to be tested;

[0009] 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 respectively connected to the first terahertz S parameter test module and the second terahertz S parameter test module, and the IF port of the mixer to be tested is connected to the vector network analyzer;

[0010] 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 both connected to the vector network analyzer.

[0011] Further, when the number of mixing times of the mixer to be tested is more than two times 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 number of mixing times of the mixer to be tested is one time, the first test platform is used;

[0012] When the mixing times of the mixer to be tested are more than two times and the local oscillator operating frequency of the mixer to be tested is lower than the host frequency of the vector network analyzer, the second test platform is used.

[0013] Furthermore, 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 mixer to be tested;

[0014] 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 mixer to be tested; the operating frequency of the second terahertz S parameter test module is equal to the operating frequency band of the LO port of the mixer to be tested;

[0015] 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 mixer to be tested.

[0016] An efficient testing method for a millimeter wave terahertz mixer, the method comprising:

[0017] Confirm the test frequency band and build the test platform: Confirm the working frequency bands of the RF, LO, and IF ports of the mixer to be tested, and build the first test platform or the second test platform according to the working frequency band information of the mixer to be tested;

[0018] 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 mixer to be tested at different port output powers are tested, including frequency conversion loss test, compression point test, port standing wave test and isolation test.

[0019] Furthermore, when the first test platform is used to perform the conversion loss test:

[0020] The host of the vector network analyzer is set to a sweep frequency working mode; the working frequency adopted by 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 is reasonably set; when the mixer to be tested works in a normal state, the transmission from the first port to the second port of the vector network analyzer is The parameter is the down-conversion loss of the mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is 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 and adjusting the local oscillator input power of the mixer, the change of the conversion loss of the mixer to be tested under different local oscillator driving powers is obtained; by setting the operating frequency of the first terahertz S parameter test module or the second terahertz S parameter test module to set different intermediate frequency working bands, the change of the conversion loss of the mixer under different intermediate frequency working bands is obtained;

[0021] When using the second test platform for conversion loss testing:

[0022] The host of the vector network analyzer is set to a sweep frequency working mode; the terahertz S parameter test module adopts a test module whose working frequency is equal to the working frequency band of the RF port of the mixer to be tested; the output power of the terahertz S parameter test module RF output port is set so that the mixer to be tested works in an uncompressed 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 mixer to be tested; the intermediate frequency is reasonably set; when the mixer to be tested 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 mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be tested; setting different local oscillator port powers PLO can obtain the change of the conversion loss of the mixer under different local oscillator driving powers, and setting different intermediate frequency working bands can obtain the change of the down-conversion loss of the mixer under different intermediate frequency working bands.

[0023] Furthermore, the method for performing compression point testing using the first test platform is as follows:

[0024] The host of the vector network analyzer is set to a frequency sweep mode; the first terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested;

[0025] The first terahertz S parameter test module is set to meet the power scanning range of the compression test of the mixer to be tested; 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 for normal operation of the mixer to be tested;

[0026] Set the intermediate frequency of the mixer to be tested: intermediate frequency = radio frequency - N * local oscillator frequency, N is the number of mixing times; adjust the intermediate frequency of the mixer by setting the working frequencies of the first S parameter test module and the second port of the vector network analyzer host to obtain the required intermediate frequency, which is not higher than the working frequency of the vector network analyzer host;

[0027] The transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the mixer to be measured, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be measured;

[0028] After the power scan of the first terahertz S parameter test module is completed, the RF power scan and frequency conversion loss change curve of the mixer to be tested 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 mixer compression point parameters under different conditions is obtained;

[0029] The method for compression point testing using the second test platform is:

[0030] The host of the vector network analyzer is set to a frequency sweep mode; the terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested;

[0031] Set the terahertz S-parameter test module to meet the power sweep range of the compression test of the mixer to be tested; set the output power of the third port of the vector network analyzer to meet the local oscillator driving power for normal operation of the mixer to be tested;

[0032] Setting the intermediate frequency operating frequency of the mixer to be tested; the transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be tested;

[0033] After the power scan of the terahertz S-parameter test module is completed, the RF power scan and frequency conversion loss change curve of the mixer to be tested 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 mixer compression point parameters under different conditions is obtained.

[0034] Furthermore, the method for performing the port standing wave test using the first test platform is as follows:

[0035] The host of the vector network analyzer is set to a frequency sweep mode; the first terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested;

[0036] The output power of the RF output port of the first terahertz S parameter test module and the second terahertz S parameter test module and the frequency range of the intermediate frequency output port are set so that the mixer to be tested works in a normal state. At this time, the reflection parameters tested by the first terahertz S parameter test module, the second terahertz S parameter test module and the second port of the vector network analyzer host are respectively the standing waves of the RF port, LO port and IF port of the mixer to be tested;

[0037] The method of using the second test platform to perform pressure port standing wave test is:

[0038] The host of the vector network analyzer is set to a frequency sweep mode; the terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested;

[0039] 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 terahertz S parameter test module and the third port and the second port of the vector network analyzer are the standing waves of the RF port, LO port and IF port of the mixer to be tested, respectively.

[0040] Furthermore, the method for performing isolation test on the fundamental harmonic mixer using the first test platform is as follows:

[0041] The host of the vector network analyzer is set to a frequency 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 mixer to be tested is matched and connected to the 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 mixer to be tested;

[0042] The method for testing the isolation of second-harmonic mixers and above using the first test platform is as follows:

[0043] The host of the vector network analyzer is set to a frequency sweep mode; the first terahertz S parameter test module is replaced with a test module using an operating frequency equal to the operating frequency band of the LO port of the mixer to be tested;

[0044] Connecting the IF port of the mixer to be tested to 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 mixer to be tested;

[0045] The method of using the second test platform to test the isolation of the Nth harmonic mixer is as follows:

[0046] The host of the vector network analyzer is set to a 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 using a waveguide-coaxial converter and connected to a port of the vector network analyzer; the IF port of the mixer to be tested is matched with a load connection; the transmission characteristic between the second port to the first port of the vector network analyzer is the isolation parameter from the LO port to the RF port of the mixer to be tested.

[0047] Beneficial technical effects of the present invention:

[0048] The present invention proposes an efficient testing method for the frequency range, frequency conversion loss, frequency conversion compression, port standing wave index, and isolation that are frequently tested in daily mixer tests; the purpose of the present invention is to solve the problems of low efficiency, complex testing, and high cost of existing terahertz mixer tests. The present invention is based on a vector network analyzer host in the microwave frequency band combined with a terahertz S parameter test module of a frequency extension device to achieve efficient testing of terahertz frequency band mixers. Among them, the vector network analyzer can set and program-control the output power of the terahertz S parameter test module port, and can set the relevant test parameters of the mixer, such as the operating frequency, power demand, and scanning step of the three ports. At the same time, the vector network analyzer host can simultaneously control the operation of two S parameter test modules in different frequency bands.

[0049] Based on the test platform provided by the present invention, many common and key parameters (conversion loss, compression point, port standing wave and isolation) of millimeter wave terahertz mixers can be obtained efficiently and accurately. At the same time, the test platform has high versatility and compatibility, fully considering the technical characteristics of the mixer and the port frequency changes caused by different mixing harmonic orders, and has high practical value. It can be widely used in the test of mixers with multiple harmonic orders and different port forms, greatly reducing the time cost and equipment cost caused by the test. The test platform is mainly aimed at the test of millimeter wave terahertz mixers packaged with waveguides, and it also has a high reference value for the on-chip test of similar millimeter wave terahertz mixer chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the first test platform architecture in the embodiment of the present invention (the local oscillator operating frequency is higher than the vector network analyzer host frequency);

[0051] Figure 2 This is the second test platform architecture in the embodiment of the present invention (the local oscillator operating frequency is lower than the vector network analyzer host frequency);

[0052] Figure 3It is a 110GHz-170GHz sub-harmonic mixing frequency conversion loss test platform in an embodiment of the present invention;

[0053] Figure 4 It is a 110GHz-170GHz subharmonic mixing isolation test platform in an embodiment of the present invention;

[0054] Figure 5 It is a 110GHz-170GHz fundamental frequency mixing test platform in an embodiment of the present invention;

[0055] Figure 6 It is a 110GHz-170GHz tenth harmonic mixing test platform in an embodiment of the present invention;

[0056] Figure 7 It is a 220GHz-330GHz second harmonic mixer conversion loss test platform in an embodiment of the present invention;

[0057] Figure 8 It is a 220GHz-330GHz second harmonic mixer isolation test platform in an embodiment of the present invention. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0059] On the contrary, the present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention as defined by the claims. Further, in order to make the public have a better understanding of the present invention, some specific details are described in detail in the detailed description of the present invention below. Those skilled in the art can fully understand the present invention without the description of these details.

[0060] Embodiment 1: An efficient test system for a millimeter wave terahertz mixer, the test system comprising a vector network analyzer and a terahertz S-parameter test module; two test platforms are provided according to the differences in radio frequency and local oscillator frequency caused by the mixing times of the mixer to be tested;

[0061] 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 respectively connected to the first terahertz S parameter test module and the second terahertz S parameter test module, and the IF port of the mixer to be tested is connected to the vector network analyzer;

[0062] 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 both connected to the vector network analyzer.

[0063] In this embodiment, when the number of mixing times of the mixer to be tested is more than two times 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 number of mixing times of the mixer to be tested is one time, the first test platform is used;

[0064] When the mixing times of the mixer to be tested are more than two times and the local oscillator operating frequency of the mixer to be tested is lower than the host frequency of the vector network analyzer, the second test platform is used.

[0065] In this embodiment, 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 mixer to be tested;

[0066] 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 mixer to be tested; the operating frequency of the second terahertz S parameter test module is equal to the operating frequency band of the LO port of the mixer to be tested;

[0067] 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 mixer to be tested.

[0068] Specifically, Figure 1 As shown, in the first test platform, the first port and the third port of the vector network analyzer are respectively connected to the RF input ports of the first terahertz S parameter test module and the second terahertz S parameter test module, and provide RF signals for the two terahertz S parameter test modules respectively; the local oscillator output signal of the vector network analyzer is split into two paths, which are respectively input to the local oscillator input ports 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 RF output port of the first terahertz S parameter test module is connected to the RF port of the mixer to be tested, the RF output port of the second terahertz S parameter test module is connected to the LO port of the mixer to be tested, and the IF port of the mixer to be tested is connected to the second port of the vector network analyzer;

[0069] The second test platform includes a vector network analyzer and a terahertz S parameter test module; the first port of the vector network analyzer is connected to the radio frequency input port of the terahertz S parameter test module to provide a radio frequency signal for the terahertz S parameter test module; the local oscillator output signal of the vector network analyzer is input to 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 to the RF port of the mixer to be tested; the IF and LO ports of the mixer to be tested are respectively connected to the second port and the third port of the vector network analyzer.

[0070] Specifically, the S parameter test module described in the present invention adopts the terahertz spectrum spreading module in the patent application number 202310424859.4, which is a conventional test module, and the vector network analyzer used in the present invention is a conventional device.

[0071] Embodiment 2 A high-efficiency testing method for a millimeter-wave terahertz mixer is provided, using the high-efficiency testing system described in Embodiment 1, and the method comprises:

[0072] Confirm the test frequency band and build the test platform: Confirm the working frequency bands of the RF, LO, and IF ports of the mixer to be tested, and build the first test platform or the second test platform according to the working frequency band information of the mixer to be tested;

[0073] 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 mixer to be tested at different port output powers are tested, including frequency conversion loss test, compression point test, port standing wave test and isolation test.

[0074] In this embodiment, when the first test platform is used to perform the frequency conversion loss test, the method is:

[0075] The host of the vector network analyzer is set to the sweep frequency working mode; the working frequency adopted by 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 is reasonably set (specifically, the intermediate frequency = RF frequency - N * local oscillator frequency, N is the number of mixing times; the required intermediate frequency can be obtained by setting the module working frequencies of the two S parameters; the intermediate frequency needs to meet the conditions that it cannot be higher than the main frequency of the vector network analyzer The working frequency of the machine. ) When the mixer to be tested 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 mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is 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 and adjusting the local oscillator input power of the mixer, the change of the conversion loss of the mixer to be tested under different local oscillator driving powers is obtained; by setting the working frequency of the first terahertz S parameter test module or the second terahertz S parameter test module to set different intermediate frequency working bands, the change of the conversion loss of the mixer under different intermediate frequency working bands is obtained.

[0076] When using the second test platform for conversion loss testing:

[0077] The host of the vector network analyzer is set to the sweep frequency working mode; the terahertz S parameter test module adopts a test module whose working frequency 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 terahertz S parameter test module is set so that the mixer to be tested works in an uncompressed 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 mixer to be tested; the intermediate frequency (intermediate frequency = RF frequency - N * local oscillator frequency, N is the number of mixing times) is reasonably set; the required intermediate frequency can be obtained by setting the module working frequencies of the two S parameters frequency; the intermediate frequency needs to meet the condition that it cannot be higher than the operating frequency of the vector network analyzer host. ); when the mixer to be tested 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 mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be tested; setting different local oscillator port powers PLO can obtain the frequency conversion loss change of the mixer under different local oscillator driving powers, setting different intermediate frequency working bands, and obtaining the frequency conversion loss change of the mixer under different intermediate frequency working bands.

[0078] In this embodiment, when the first test platform is used to perform compression point testing:

[0079] The host of the vector network analyzer is set to a frequency sweep mode; the first terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested;

[0080] The first terahertz S parameter test module is set to meet the power scanning range of the compression test of the mixer to be tested; 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 for normal operation of the mixer to be tested;

[0081] Set the intermediate frequency of the mixer to be tested: intermediate frequency = radio frequency - N * local oscillator frequency, N is the number of mixing times; adjust the intermediate frequency of the mixer 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; the intermediate frequency shall not be higher than the working frequency of the vector network analyzer host;

[0082] The transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the mixer to be measured, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be measured;

[0083] After the power scan of the first terahertz S parameter test module is completed, the RF power scan and frequency conversion loss change curve of the mixer to be tested 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 mixer compression point parameters under different conditions is obtained.

[0084] When using the second test platform for compression point testing:

[0085] The host of the vector network analyzer is set to a frequency sweep mode; the terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested;

[0086] Set the terahertz S-parameter test module to meet the power sweep range of the compression test of the mixer to be tested; set the output power of the third port of the vector network analyzer to meet the local oscillator driving power for normal operation of the mixer to be tested;

[0087] Setting the intermediate frequency operating frequency of the mixer to be tested; the transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be tested;

[0088] After the power scan of the terahertz S-parameter test module is completed, the RF power scan and frequency conversion loss change curve of the mixer to be tested 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 mixer compression point parameters under different conditions is obtained.

[0089] In this embodiment, when the first test platform is used to perform the pressure port standing wave test:

[0090] The host of the vector network analyzer is set to a frequency sweep mode; the first terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested;

[0091] The output power of the RF output port of the first terahertz S parameter test module and the second terahertz S parameter test module and the frequency range of the intermediate frequency output port are set so that the mixer to be tested 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 standing waves of the RF port, LO port and IF port of the mixer to be tested.

[0092] In this embodiment, when the second test platform is used to perform the pressure port standing wave test:

[0093] The host of the vector network analyzer is set to a frequency sweep mode; the terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested;

[0094] 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 terahertz S parameter test module and the third port and the second port of the vector network analyzer are the standing waves of the RF port, LO port and IF port of the mixer to be tested, respectively.

[0095] In this embodiment, the method of using the first test platform to perform isolation test on a fundamental mixer (i.e., a mixer to be tested with one mixing number, where the mixer RF frequency is equal to the local oscillator frequency) is as follows:

[0096] The host of the vector network analyzer is set to a frequency sweep mode; the first S parameter test module and the second S parameter test module should operate in the same frequency band, that is, the RF or local oscillator operating frequency band of the mixer, and the IF port of the mixer to be tested is matched with a load connection (the connection between the IF port of the mixer to be tested 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 parameter from the LO port to the RF port of the mixer to be tested;

[0097] The method for testing the isolation of second-harmonic mixers and above using the first test platform is as follows:

[0098] The host of the vector network analyzer is set to a frequency sweep mode; the first terahertz S parameter test module is replaced with a test module using an operating frequency equal to the operating frequency band of the LO port of the mixer to be tested;

[0099] Connect the IF port of the mixer to be tested to a matching load (disconnect the IF port of the mixer to be tested and the vector network analyzer); 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 mixer to be tested;

[0100] Without loss of generality, when the harmonic order N of the mixer is large enough, and the RF and local oscillator ports of the mixer are both waveguide ports, the waveguide has a high-pass characteristic and will have good suppression on the signal in the local oscillator frequency band. It can be determined that the isolation from the local oscillator to the RF port of the mixer is good at this time.

[0101] The method of using the second test platform to test the isolation of the Nth harmonic mixer is as follows:

[0102] The host of the vector network analyzer is set to a 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 using a waveguide-coaxial converter and connected to a port of the vector network analyzer; the IF port of the mixer to be tested is matched with a load connection (the connection between the IF port of the mixer to be tested and the vector network analyzer is disconnected); the transmission characteristic between the second port to the first port of the vector network analyzer is the isolation parameter from the LO port to the RF port of the mixer to be tested.

[0103] Without loss of generality, when the harmonic order N of the mixer is large enough and the RF port of the mixer is a waveguide port, since the waveguide has a high-pass characteristic, it will have good suppression on the signal in the local oscillator frequency band. It can be determined that the isolation from the local oscillator of the mixer to the RF port is good at this time.

[0104] In the present invention, different test schemes are set according to the mixing times of the mixer, from fundamental (first) mixing, second harmonic mixing, third harmonic mixing, etc., and according to the differences in radio frequency and local oscillator frequency brought about by the mixing times of the mixer:

[0105] For fundamental mixing: At this time, the RF frequency of the mixer is the same as the local oscillator frequency. The configuration scheme is as follows: Figure 1 As shown, the two S parameter test modules have the same frequency. After the connection is completed as shown in the figure, the mixer's conversion loss, port standing wave, compression point, isolation and other indicators can be tested at one time.

[0106] For second harmonic mixing: At this time, the RF frequency of the mixer is twice the local oscillator frequency, and the configuration scheme is also as follows Figure 1 As shown in the figure, the operating frequency of the S parameter test module connected to the mixer RF port should be twice the operating frequency of the S parameter test module connected to the local oscillator port, and should be consistent with the mixer RF and local oscillator operating frequencies. If the mixer's local oscillator operating frequency has fallen into the vector network analyzer operating frequency, the configuration scheme is as follows Figure 2 As shown, port 3 or 4 of the vector network analyzer directly provides a driving signal for the local oscillator operating frequency of the mixer.

[0107] For other harmonic mixing orders (harmonic order is N, N>2), the RF frequency of the mixer is N times the local oscillator frequency. Figure 1 or Figure 2 In the configuration scheme, the operating frequency of the S parameter test module connected to the RF port is consistent with the RF operating frequency of the mixer, and the operating frequency of the S parameter test module connected to the RF or from the host (3 / 4) port is consistent with the local oscillator operating frequency of the mixer.

[0108] The following is an enumeration of actual test cases:

[0109] Example 1: Testing method of 110-170 GHz mixer second harmonic mixer:

[0110] The following takes the test of 110-170GHz second harmonic mixer as an example to specifically explain the test process of the test platform.

[0111] (1) Confirm the test frequency band and build the test platform: First, confirm the operating frequencies of the three ports (RF, LO, IF) of the mixer to be tested, and build the test platform according to the operating frequency band information. The RF operating frequency band is 110GHz-170GHz, the LO operating frequency band is 55GHz-85GHz, and the IF operating frequency band is 0-20GHz. According to the frequency band information, a vector network analyzer host operating at more than 20GHz, an S parameter test module operating at 110-170GHz, two S parameter test modules operating at 55-85GHz, and some test accessories (cables, loads, etc.) are required. 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. By default, the S parameter test modules used in the system have completed power calibration.

[0112] b. System calibration: Set up as Figure 3 The test system shown completes the system calibration work: single-port S parameter calibration of S parameter test modules 1 and 2, and single-port S parameter calibration of the intermediate frequency port (the calibration method is conventional technology).

[0113] c. Frequency conversion loss test: Set the vector network analyzer host to sweep frequency working mode. Reasonably set the port output power P of the first terahertz parameter test module. RF , so that the mixer works in an uncompressed state; reasonably set the port working power P of the second terahertz S parameter test module LO , meet the mixer's local oscillator drive power requirements; reasonably set the intermediate frequency (fixed frequency). At this time, the mixer is working in a normal state. At this time, the transmission parameter from port 1 (i.e., the first port) to port 2 (i.e., the second port) of the vector network analyzer is the mixer's down-conversion loss, and the transmission parameter from port 2 to port 1 is the mixer's up-conversion loss. Set different local oscillator port powers P LO The change of the conversion loss of the mixer under different local oscillator driving powers can be obtained, and the change of the conversion loss of the mixer under different intermediate frequency working bands can be obtained by setting different intermediate frequency working bands.

[0114] d. Compression point test: Set the vector network analyzer host to the point frequency working 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 second terahertz S parameter test module to meet the local oscillator driving power for normal operation of the mixer, and set the intermediate frequency working frequency of the mixer. After the power scan of the first terahertz S parameter test module is completed, the change curve of the RF power scan and frequency conversion loss of the mixer in this frequency band can be obtained, and the 1dB compression point parameter can be obtained. By setting different local oscillator powers and intermediate frequency working frequencies, the change information of the mixer compression point parameters under different conditions can be obtained.

[0115] e. Port standing wave test: Set the vector network analyzer host to the sweep frequency working 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 standing waves of the RF port, LO port and IF port of the mixer.

[0116] f. Isolation test: Figure 4 As shown in FIG. 1 , the vector network analyzer host is set to the sweep frequency working mode, the original first terahertz S parameter test module is replaced with the first terahertz S parameter test module working in the LO frequency band 55-85 GHz, and the transmission S parameter calibration is performed on the first terahertz S parameter test module and the second terahertz S parameter test module, and then the mixer is set to Figure 4 The intermediate frequency port is connected well, and the intermediate frequency port is terminated with a matching load. At this time, 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 mixer.

[0117] Example 2: Testing method of 110-170 GHz fundamental harmonic mixer:

[0118] The following takes the test of 110-170GHz fundamental harmonic mixer as an example to specifically explain the test process of the test platform.

[0119] a. Confirm the test frequency band and build the test platform: First, confirm the operating frequencies of the three ports (RF, LO, IF) of the mixer to be tested, and build the test platform according to the operating frequency band information. The RF operating frequency band is 110GHz-170GHz, the LO operating frequency band is 110GHz-170GHz, and the IF operating frequency band is 0-20GHz. According to the frequency band information, a vector network analyzer host operating at more than 20GHz, two S parameter test modules operating at 110-170GHz, and some test accessories (cables, loads, etc.) are mainly required. The vector network analyzer can adjust the port output power of the S parameter test module through software settings. By default, the S parameter test modules used in the system have completed power calibration.

[0120] b. System calibration: Set up as Figure 5 The test system shown completes 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, and single-port S parameter calibration of the intermediate frequency port.

[0121] c. Frequency conversion loss test: Set the vector network analyzer host to sweep frequency working mode. Reasonably set the port output power P of the first terahertz S parameter test module. RF , so that the mixer works in an uncompressed state; reasonably set the port working power P of the second terahertz S parameter test module LO , meet the mixer's local oscillator drive power requirements; reasonably set the intermediate frequency (fixed frequency). At this time, the mixer is working in a normal state. At this time, the transmission parameter from port 1 to port 2 of the vector network analyzer is the mixer's down-conversion loss, and the transmission parameter from port 2 to port 1 is the mixer's up-conversion loss. Set different local oscillator port powers P LO The change of the conversion loss of the mixer under different local oscillator driving powers can be obtained, and the change of the conversion loss of the mixer under different intermediate frequency working bands can be obtained by setting different intermediate frequency working bands.

[0122] d. Compression point test: Set the vector network analyzer host to the point frequency working 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 for normal operation of the mixer, and set the intermediate frequency working frequency of the mixer. After the power scan of the first terahertz S parameter test module is completed, the change curve of the RF power scan and frequency conversion loss of the mixer in this frequency band can be obtained, and the 1dB compression point parameter can be obtained. By setting different local oscillator powers and intermediate frequency working frequencies, the change information of the mixer compression point parameters under different conditions can be obtained.

[0123] e. Port standing wave test: Set the vector network analyzer host to the sweep frequency working 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 standing waves of the RF port, LO port and IF port of the mixer.

[0124] f. Isolation test: Figure 5 As shown, the vector network analyzer host is set to the sweep frequency working mode, and 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 mixer.

[0125] Example 3: Testing method of 110-170 GHz tenth harmonic mixer:

[0126] The following takes the test of a 110-170GHz tenth harmonic mixer as an example to specifically explain the test process of the test platform when the local oscillator driving frequency of the mixer is lower than the host operating frequency.

[0127] a. Confirm the test frequency band and build the test platform: First, confirm the operating frequencies of the three ports (RF, LO, IF) of the mixer to be tested, and build the test platform according to the operating frequency band information. The RF operating frequency band is 110GHz-170GHz, the LO operating frequency band is 11GHz-17GHz, and the IF operating frequency band is 0-20GHz. According to the frequency band information, a vector network analyzer host operating at more than 20GHz, an S parameter test module operating at 110-170GHz, and some test accessories (cables, loads, etc.) are mainly required. The vector network analyzer can adjust the port output power of the S parameter test module through software settings. By default, the S parameter test modules used in the system have completed power calibration.

[0128] b. System calibration: Set up as Figure 6The test system shown completes the system calibration work: single-port S parameter calibration of the first terahertz S parameter test module and the three ports of the vector network analyzer host, and single-port S parameter calibration of the intermediate frequency port.

[0129] c. Frequency conversion loss test: Set the vector network analyzer host to sweep frequency working mode. Reasonably set the port output power P of the first terahertz S parameter test module. RF , so that the mixer works in an uncompressed state; reasonably set the 3-port working power P of the vector network analyzer LO , meet the mixer's local oscillator drive power requirements; reasonably set the intermediate frequency (fixed frequency). At this time, the mixer is working in a normal state. At this time, the transmission parameter from port 1 to port 2 of the vector network analyzer is the mixer's down-conversion loss, and the transmission parameter from port 2 to port 1 is the mixer's up-conversion loss. Set different local oscillator port powers P LO The change of the conversion loss of the mixer under different local oscillator driving powers can be obtained, and the change of the conversion loss of the mixer under different intermediate frequency working bands can be obtained by setting different intermediate frequency working bands.

[0130] d. Compression point test: Set the vector network analyzer host to the point frequency working 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 3-port of the vector network analyzer host to meet the local oscillator driving power for normal operation of the mixer, and set the intermediate frequency working frequency of the mixer. After the power scan of the first terahertz S parameter test module is completed, the change curve of the RF power scan and frequency conversion loss of the mixer in this frequency band can be obtained, and the 1dB compression point parameter can be obtained. By setting different local oscillator powers and intermediate frequency working frequencies, the change information of the mixer compression point parameters under different conditions can be obtained.

[0131] e. Port standing wave test: Set the vector network analyzer host to the sweep frequency working 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 a normal state. At this time, the reflection S parameters of S parameter module 1 and port 3 and port 2 of the vector network analyzer host are the standing waves of the RF port, LO port and IF port of the mixer.

[0132] f. Isolation test: At this time, due to the large frequency difference between the RF port and the LO port, and the difficulty in making the frequency conversion interface from 110-170GHz (RF) to 11-17GHz (LO), the isolation cannot be tested. At this time, the natural high-pass characteristics of the waveguide can be used to infer that the isolation is high.

[0133] Example 4: 220-330 GHz mixer second harmonic mixer test method:

[0134] The following takes the test of 220-330GHz second harmonic mixer as an example to explain in detail the main steps of the test process of the test platform when testing mixers in different frequency bands.

[0135] a. Confirm the test frequency band and build the test platform: First, confirm the operating frequencies of the three ports (RF, LO, IF) of the mixer to be tested, and build the test platform according to the operating frequency band information. The RF operating frequency band is 220GHz-330GHz, the LO operating frequency band is 110GHz-165GHz, and the IF operating frequency band is 0-20GHz. According to the frequency band information, a vector network analyzer host operating at more than 20GHz, an S parameter test module operating at 220-330GHz, two S parameter test modules operating at 110-170GHz, and some test accessories (cables, loads, etc.) are required. 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. By default, the S parameter test modules used in the system have completed power calibration.

[0136] b. System calibration: Set up as Figure 7 The test system shown completes 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, and single-port S parameter calibration of the intermediate frequency port.

[0137] c. Frequency conversion loss test: Set the vector network analyzer host to sweep frequency working mode. Reasonably set the port output power P of the first terahertz S parameter test module. RF , so that the mixer works in a non-compressed state; set the port working power P of S parameter test module 2 LO , meet the mixer's local oscillator drive power requirements; reasonably set the intermediate frequency (fixed frequency). At this time, the mixer is working in a normal state. At this time, the transmission parameter from port 1 to port 2 of the vector network analyzer is the mixer's down-conversion loss, and the transmission parameter from port 2 to port 1 is the mixer's up-conversion loss. Set different local oscillator port powers P LO The change of the conversion loss of the mixer under different local oscillator driving powers can be obtained, and the change of the conversion loss of the mixer under different intermediate frequency working bands can be obtained by setting different intermediate frequency working bands.

[0138] d. Compression point test: Set the vector network analyzer host to the point frequency working 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 second terahertz S parameter test module to meet the local oscillator driving power for normal operation of the mixer, and set the intermediate frequency working frequency of the mixer. After the power scan of the first terahertz S parameter test module is completed, the change curve of the RF power scan and frequency conversion loss of the mixer in this frequency band can be obtained, and the 1dB compression point parameter can be obtained. By setting different local oscillator powers and intermediate frequency working frequencies, the change information of the mixer compression point parameters under different conditions can be obtained.

[0139] e. Port standing wave test: Set the vector network analyzer host to the sweep frequency working 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 standing waves of the RF port, LO port and IF port of the mixer.

[0140] f. Isolation test: Figure 8 As shown in FIG. 1 , the vector network analyzer host is set to the sweep frequency working mode, the original first terahertz S parameter test module is replaced with the first terahertz S parameter test module working in the LO frequency band 110-170 GHz, and the transmission S parameter calibration is performed on the first terahertz S parameter test module and the second terahertz S parameter test module, and then the mixer is set to Figure 8 The intermediate frequency port is connected well, and the intermediate frequency port is terminated with 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 from the LO port to the RF port of the mixer.

[0141] The test platform provided by the present invention can be used to test parameters such as frequency range, frequency conversion loss, compression point, port standing wave, isolation, etc. The test platform provided by the present invention has the following characteristics:

[0142] (1) Simple test platform: The test platform mainly consists of a vector network analyzer, two S-parameter test modules and test accessories. The system architecture is clear and easy to build.

[0143] (2) Convenient and efficient testing: By controlling the port power tuning of the S-parameter test module, the characteristics of the mixer at different port output powers can be quickly obtained, such as the changes in relevant parameters of the mixer at different local oscillator drive powers, the compression of the mixer at different RF powers, etc., which enriches the test parameters and greatly saves the test time.

[0144] The test platform architecture provided by the present invention proposes a terahertz mixer test architecture based on a terahertz vector network analyzer for the first time. The architecture combines the commonly used terahertz mixer parameter test requirements, utilizes the frequency sweep and power sweep modes of the vector network analyzer, and the S parameter test module based on the external spread spectrum, which can simply and efficiently implement the test of many conventional parameters, requiring fewer instruments, simple interconnection, and less test time. The corresponding software function development is integrated into the system, which is convenient for users to operate.

[0145] The S parameter test module with programmable tuning of port power in the present invention: the power-tunable S parameter test module used 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 platform's demand for continuous port output power;

[0146] Compared with the traditional mixer testing method, the testing method provided by the present invention can test more complete parameters, requires less testing equipment and has higher measurement efficiency.

[0147] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An efficient testing system for millimeter wave terahertz mixer, characterized in that: The test system includes a vector network analyzer and a terahertz S-parameter test module; two test platforms are set according to the differences in radio frequency and local oscillator frequency caused by the mixing times of the mixer to be tested; 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 respectively connected to the first terahertz S parameter test module and the second terahertz S parameter test module, and the IF port of the mixer to be tested is connected to the vector network analyzer; 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 both connected to the vector network analyzer.

2. The efficient testing system for millimeter wave terahertz mixer according to claim 1, characterized in that: When the number of mixing times of the mixer to be tested is more than two times 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 number of mixing times of the mixer to be tested is one time, the first test platform is used; When the mixing times of the mixer to be tested are more than two times and the local oscillator operating frequency of the mixer to be tested is lower than the host frequency of the vector network analyzer, the second test platform is used.

3. The efficient testing system for millimeter wave terahertz mixer according to claim 1, characterized in that: 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 mixer to be tested; 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 mixer to be tested; the operating frequency of the second terahertz S parameter test module is equal to the operating frequency band of the LO port of the mixer to be tested; 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 mixer to be tested.

4. An efficient testing method for a millimeter wave terahertz mixer, using the efficient testing system according to any one of claims 1 to 3, characterized in that: The method comprises: Confirm the test frequency band and build the test platform: Confirm the working frequency bands of the RF, LO, and IF ports of the mixer to be tested, and build the first test platform or the second test platform according to the working frequency band information of the mixer to be tested; 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 mixer to be tested at different port output powers are tested, including frequency conversion loss test, compression point test, port standing wave test and isolation test.

5. The efficient testing method for millimeter wave terahertz mixer according to claim 4, characterized in that: When using the first test platform to perform conversion loss test: The host of the vector network analyzer is set to a sweep frequency working mode; the working frequency adopted by 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; Reasonably set the intermediate frequency; when the mixer to be tested 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 mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is 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 and adjusting the local oscillator input power of the mixer, the change of the conversion loss of the mixer to be tested under different local oscillator driving powers is obtained; by setting the operating frequency of the first terahertz S parameter test module or the second terahertz S parameter test module to set different intermediate frequency working bands, the change of the conversion loss of the mixer under different intermediate frequency working bands is obtained; When using the second test platform for conversion loss testing: Set the host of the vector network analyzer to sweep frequency working mode; The terahertz S parameter test module uses a test module with an operating frequency equal to the operating frequency band of the RF port of the mixer to be tested; the output power of the RF output port of the terahertz S parameter test module is set so that the mixer to be tested works in an uncompressed 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 mixer to be tested; Reasonably set the intermediate frequency; when the mixer to be tested 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 mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be tested; by setting different local oscillator port powers PLO, the change of the conversion loss of the mixer under different local oscillator driving powers can be obtained, and by setting different intermediate frequency working bands, the change of the conversion loss of the mixer under different intermediate frequency working bands can be obtained.

6. The efficient testing method for millimeter wave terahertz mixer according to claim 4, characterized in that: The method for compression point testing using the first test platform is: The host of the vector network analyzer is set to a frequency sweep mode; the first terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested; The first terahertz S parameter test module is set to meet the power scanning range of the compression test of the mixer to be tested; 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 for normal operation of the mixer to be tested; Set the intermediate frequency of the mixer to be tested: intermediate frequency = radio frequency - N*local oscillator frequency, where N is the number of mixing times; The intermediate frequency of the mixer is adjusted by setting the operating frequencies of the first S parameter test module and the second port of the vector network analyzer host to obtain the required intermediate frequency, wherein the intermediate frequency is not higher than the operating frequency of the vector network analyzer host; The transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the mixer to be measured, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be measured; After the power scan of the first terahertz S parameter test module is completed, the RF power scan and frequency conversion loss change curve of the mixer to be tested 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 mixer compression point parameters under different conditions is obtained; The method for compression point testing using the second test platform is: The host of the vector network analyzer is set to a frequency sweep mode; the terahertz S parameter test module uses a test module whose operating frequency is equal to the operating frequency band of the RF port of the mixer to be tested; Set the terahertz S-parameter test module to meet the power sweep range of the compression test of the mixer to be tested; set the output power of the third port of the vector network analyzer to meet the local oscillator driving power for normal operation of the mixer to be tested; Setting the intermediate frequency operating frequency of the mixer to be tested; the transmission parameter from the first port to the second port of the vector network analyzer is the down-conversion loss of the mixer to be tested, and the transmission parameter from the second port to the first port of the vector network analyzer is the up-conversion loss of the mixer to be tested; After the power scan of the terahertz S-parameter test module is completed, the RF power scan and frequency conversion loss change curve of the mixer to be tested 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 mixer compression point parameters under different conditions is obtained.

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

8. The efficient testing method for millimeter wave terahertz mixer according to claim 4, characterized in that: The method for testing the isolation of the fundamental harmonic mixer using the first test platform is as follows: The host of the vector network analyzer is set to a frequency 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 mixer to be tested is matched and connected to the 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 mixer to be tested; The method for testing the isolation of second-harmonic mixers and above using the first test platform is as follows: The host of the vector network analyzer is set to a frequency sweep mode; the first terahertz S parameter test module is replaced with a test module using an operating frequency equal to the operating frequency band of the LO port of the mixer to be tested; Connecting the IF port of the mixer to be tested to 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 mixer to be tested; The method of using the second test platform to test the isolation of the Nth harmonic mixer is as follows: The host of the vector network analyzer is set to a 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 using a waveguide-coaxial converter and connected to a port of the vector network analyzer; the IF port of the mixer to be tested is matched with a load connection; the transmission characteristic between the second port to the first port of the vector network analyzer is the isolation parameter from the LO port to the RF port of the mixer to be tested.

Images