E-band large-bandwidth radar signal test system

Abstract

The utility model belongs to the technical field of radar signal testing, and discloses an E-band large-bandwidth radar signal testing system which comprises an E-band external mixer, an FSV spectrum analyzer, an RTO oscilloscope, a one-to-three-end power divider and a radio frequency cable used for being connected with a testing link, a tested E-band radar signal is connected with the input end of the E-band external mixer, and the input end of the E-band external mixer is connected with the output end of the FSV spectrum analyzer. A local oscillator output port of the FSV spectrum analyzer is connected with a local oscillator input port of the E-band external mixer, and an output port of the E-band external mixer is connected with an input port of the power divider. According to the invention, a spectrum analyzer with common performance and an oscilloscope are combined, a high-performance instrument is replaced by using the down-conversion principle of an external mixer and the large bandwidth of the oscilloscope, the frequency domain and time domain related performance index test of an E-band large-bandwidth radar signal is completed, the feasibility of the test and the accuracy of a test result are ensured, and the test efficiency is improved. And the test difficulty and the use cost are greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar signal testing, and more particularly to an E-band large-bandwidth radar signal testing system. BACKGROUND

[0002] Conventional blind spot detection radars usually use multi-frequency shift keying radar signals, most of which work in the 24GHz range. With the development of industrial technology and the requirements of emerging industries, the frequency range is shifted to the E-band (60GHz-90GHz) with the performance advantages of larger bandwidth. Radar signals working in the E-band 77GHz or 79GHz frequency band are mainly used for adaptive cruise control, usually using linear frequency modulation continuous wave signals (LFMCW) or Chirp sequence signals, which belong to a special form of FMCW signals. Linear frequency modulation continuous wave radar signals are applied in many radar systems. Compared with pulsed radar systems, FMCW radars have low transmission power, which makes the radar smaller in size and lower in cost. Other advantages, such as direct Doppler frequency shift measurement, make these radar signals very suitable for use in the automotive and industrial fields. The resolution of the key performance indicators of the radar, distance and direction of view, depends on the signal bandwidth and Chirp length, so the time domain feature measurement of the radar signal is particularly important.

[0003] The performance indicator testing of linear frequency modulation continuous wave radar signals requires testing their frequency domain characteristics and time domain characteristics. In the frequency domain, the occupied bandwidth, peak EIRP, average EIRP, etc. need to be tested, and in the time domain, the Chirp sequence start time, Chirp length, frequency modulation bandwidth and Chirp rate, etc. need to be tested.

[0004] In China, the performance indicator testing of conventional low-frequency and small-bandwidth radar signals uses ordinary spectrum analyzers, and the measurement frequency range of the spectrum analyzers is basically within 50GHz, and the analysis bandwidth is generally several tens of MHz to about 160MHz. Such performance parameters cannot meet the testing of E-band large-bandwidth radar signals. Testing the signal characteristic parameters of such radar signals with high frequency (E-band 60GHz-90GHz) and large bandwidth (bandwidth greater than 1.2GHz) is extremely difficult, which means that the requirements for instruments become very high. High-analysis-bandwidth signal analyzers or high-bandwidth oscilloscopes are difficult to buy in China due to restrictions and are expensive, and ordinary single instruments cannot directly test such signals. Therefore, it is urgent to design an E-band large-bandwidth radar testing system to match multiple ordinary performance instruments to make it easier to test E-band large-bandwidth radar signals. CONTENT OF THE INVENTION

[0005] To solve the above problems, the present application provides an E-band large-bandwidth radar signal testing system.

[0006] The application provides an E-band large-bandwidth radar signal test system which adopts the following technical scheme:

[0007] An E-band large-bandwidth radar signal test system, comprising an E-band external frequency mixer, an FSV spectrum analyzer, an RTO oscilloscope, a 1:3 power divider and a radio frequency cable for connecting a test link, wherein the measured E-band radar signal is connected with an input end of the E-band external frequency mixer, an oscillator output port of the FSV spectrum analyzer is connected with an oscillator input port of the E-band external frequency mixer, an output port of the E-band external frequency mixer is connected with an input port of the power divider, one output port of the power divider is connected with an intermediate frequency input port of the FSV spectrum analyzer, and the remaining two output ports of the power divider are respectively connected with two measurement input ports of the RTO oscilloscope.

[0008] Through the above technical scheme, the measured E-band radar signal is input into the E-band external frequency mixer, the FSV spectrum analyzer outputs the oscillator signal into the E-band external frequency mixer through the external frequency mixing function, the oscillator signal is mixed with the radar signal to down-convert the E-band radar signal to a fixed intermediate frequency signal with a relatively low frequency; the intermediate frequency signal output by the E-band external frequency mixer enters the power divider to divide the signal from one input into three outputs; one of the intermediate frequency signals is output from the power divider to the FSV spectrum analyzer to complete the frequency domain index measurement of the radar signal, such as the occupied bandwidth, the frequency accuracy, the peak EIRP, the average EIRP and the like, through the spectrum scanning function of the spectrum analyzer; the other two intermediate frequency signals are output from the power divider to two measurement channels of the RTO oscilloscope. One of the intermediate frequency signals is input as a trigger signal for synchronous triggering and capturing the radar signal by setting the trigger mode of the oscilloscope as the pulse width trigger and setting the pulse width as the reference radar signal period, and the other one is input as the test signal of the oscilloscope, and the captured radar signal is measured and analyzed in the time domain by using the high bandwidth of the oscilloscope and the analysis software, such as the period, the Chirp sequence, the Chirp length, the bandwidth and the like of the radar signal.

[0009] Further, the FSV frequency range of the FSV spectrum analyzer is 10Hz-44GHz, and the analysis bandwidth is 40MHz.

[0010] Further, the E-band external frequency mixer is a harmonic frequency mixer with 6 times the oscillator frequency mixing.

[0011] Further, the maximum bandwidth supported by the RTO oscilloscope is 6GHz.

[0012] In summary, the application has at least one of the following beneficial technical effects:

[0013] (1) This application combines the general performance spectrum analyzer and oscilloscope, uses the down-conversion principle of external mixer and the large bandwidth of oscilloscope to replace high-performance instruments, completes the frequency domain and time domain related performance index test of E-band large bandwidth radar signal, and ensures the feasibility of the test and the accuracy of the test results;

[0014] (2) This application greatly reduces the test difficulty and use cost, and the test method is universal. Combined with the corresponding automation integration, the related parameter configuration can be programmed to complete all test items, greatly improving the test efficiency and having high industrial value. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The figure is a schematic diagram of the system composition of the application.

[0016] Explanation of figure numbers:

[0017] 1, E-band external mixer; 2, FSV spectrum analyzer; 3, RTO oscilloscope; 4, power divider. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0019] In the description of the application, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom end" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0020] In the description of the application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "sleeved / connected", "connected" and the like should be understood broadly, for example, "connected" can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0021] Example 1:

[0022] The application is further described in detail below with reference to the accompanying drawings.

[0023] The application discloses an E-band large-bandwidth radar signal test system. The basic idea of the E-band large-bandwidth radar signal test method is to input the local oscillator signal of a spectrum analyzer into an external mixer module, and then perform frequency down conversion on the radar signal input into the external mixer to a fixed intermediate frequency, and then input the fixed intermediate frequency signal output by the external mixer into the spectrum analyzer or an oscilloscope for signal measurement and analysis.

[0024] The test system mainly comprises one E-band external mixer 1, one FSV spectrum analyzer 2, one RTO oscilloscope 3, one 1-to-3 power divider 4 and radio frequency cables for connecting test links. The composition schematic diagram is shown in the accompanying drawings. Figure 1 .

[0025] The E-band radar signal to be measured is connected to the input end of the E-band external mixer 1, and the local oscillator output port of the FSV spectrum analyzer 2 is connected to the local oscillator input port of the E-band external mixer 1. The main function is that the E-band radar signal to be measured is input into the E-band external mixer 1, the FSV spectrum analyzer 2 outputs the local oscillator signal into the E-band external mixer 1 through the external mixing function, the local oscillator signal is mixed with the radar signal, and the E-band radar signal is frequency down converted to a fixed intermediate frequency signal with a relatively low frequency.

[0026] The output port of the E-band external mixer is connected to the input port of the power divider 4. The main function is that the intermediate frequency signal output by the E-band external mixer 1 enters the power divider 4, and the signal is divided into three paths from one input path.

[0027] The intermediate frequency input port of the FSV spectrum analyzer 2 is connected to the one output port of the power divider 4. The main function is that one of the intermediate frequency signals is output from the power divider 4 to the FSV spectrum analyzer 2, and the frequency domain index measurement of the radar signal is completed through the spectrum scanning function of the spectrum analyzer, such as the occupied bandwidth, the frequency accuracy, the peak EIRP, the average EIRP and the like.

[0028] The two measurement input ports of the RTO oscilloscope 3 are connected to the two output ports of the power divider 4. The main function is that the two intermediate frequency signals output from the power divider 4 are input into the two measurement channels of the RTO oscilloscope 3. One of the two intermediate frequency signals is input as a trigger signal for synchronous triggering and capturing the radar signal by setting the trigger mode of the oscilloscope as the pulse width trigger and setting the pulse width as the period of the radar signal. The other one is input as the test signal of the oscilloscope, and the captured radar signal is measured and analyzed in the time domain by using the high bandwidth of the oscilloscope and the analysis software, such as the period of the radar signal, the Chirp sequence, the Chirp length, the bandwidth and the like.

[0029] When using RTO oscilloscope 3 to analyze the time domain characteristics of radar signals, the following configurations need to be made:

[0030] 1. The FSV needs to be set to the IQA analysis mode. Its main function is to ensure that the local oscillator signal output by the FSV is fixed and will not be scanned, so that the signal output by the E-band mixer is a real-time wideband signal consistent with the input radar signal bandwidth, to ensure the integrity of the signal when the oscilloscope performs time domain analysis.

[0031] 2. E-band external mixer intermediate frequency output compensation. Its main function is that when the output intermediate frequency signal frequency does not meet the bandwidth of the radar signal to be measured, the center frequency of the spectrum analyzer needs to be reduced to reduce the local oscillator output frequency to increase the intermediate frequency frequency output by the external mixer to meet the large bandwidth radar signal test. For example, the output intermediate frequency signal is 800MHz, and the measured radar signal bandwidth is 2GHz, which is more than 2 times the intermediate frequency frequency, so the current intermediate frequency signal cannot meet the time domain analysis condition, resulting in incorrect test results. According to the mixing principle, the center frequency of the spectrum analyzer is reduced by 500MHz, and the intermediate frequency signal output by the external mixer is 1300MHz, which meets the conditions for time domain analysis of a 2GHz bandwidth radar signal.

[0032] By designing the above test method, the ordinary performance spectrum analyzer and oscilloscope are combined, the down-conversion principle of the external mixer and the large bandwidth of the oscilloscope are used to replace high-performance instruments, and the frequency domain and time domain related performance index tests of E-band large bandwidth radar signals are completed, and the feasibility of the test and the accuracy of the test results are guaranteed.

[0033] This embodiment gives an application implementation case for testing a car radar signal working in E-band and having a frequency range of 77GHz-81GHz. The spectrum analyzer FSV has a frequency range of 10Hz-44GHz and an analysis bandwidth of 40MHz. The external mixer uses harmonic mixing with 6 times local oscillator mixing. The RTO oscilloscope 3 supports a maximum bandwidth of 6GHz. The system composition meets the requirements for testing a car radar signal in the frequency range of 77GHz-81GHz, and can measure a radar signal with a maximum frequency of 90GHz and a maximum bandwidth of 6GHz.

[0034] The utility model discloses E band big bandwidth radar test method of patent, in scientific research field and industry manufacturing has important role, is the foundation of E band big bandwidth radar signal performance index measurement. It not only can be applied to the manual test in scientific research, also can carry out the automation integration for production test process, has the wide application function. In the actual use process, this test method perfect adoption ordinary instrument replaces high -performance instrument, need not high -priced purchase high -end spectrum analyzer and oscilloscope (at present many high -end spectrum analyzer and oscilloscope are the limit state to the domestic, cannot purchase), greatly reduce the test difficulty and use cost. The test method has the universality, and then cooperates corresponding automation integration and can programmatic to complete all test items of relevant parameter configuration, greatly improves the test efficiency, has higher industrial value. Thus this mode as solves the instrument of no high -end performance and cannot carry out E band big bandwidth radar signal of a kind of technical thought and way, has greater application space and application value.

[0035] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, equivalent changes made on the basis of the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. An E-band wideband radar signal test system, characterized by, It includes 1 E-band external mixer (1), 1 FSV spectrum analyzer (2), 1 RTO oscilloscope (3), 1 1 / 3 power divider (4) and RF cable for connecting test link, the measured E-band radar signal is connected with the input end of the E-band external mixer (1), the local oscillator output port of the FSV spectrum analyzer (2) is connected with the local oscillator input port of the E-band external mixer (1), the output port of the E-band external mixer (1) is connected with the input port of the power divider (4), one of the output ports of the power divider (4) is connected with the intermediate frequency input port of the FSV spectrum analyzer (2), the remaining two output ports of the power divider (4) are respectively connected with the two measurement input ports of the RTO oscilloscope (3).

2. The E-band large bandwidth radar signal test system of claim 1, wherein: The FSV frequency range of the FSV spectrum analyzer (2) is 10Hz-44GHz, and the analysis bandwidth is 40MHz.

3. The E-band large bandwidth radar signal test system of claim 1, wherein: The E-band external mixer (1) is harmonic mixing, 6 times local oscillator mixing.

4. The E-band large bandwidth radar signal test system of claim 1, wherein: The maximum bandwidth supported by the RTO oscilloscope (3) is 6GHz.

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