Millimeter wave dual tone signal generation apparatus, third order intermodulation test system and method

Abstract

The application discloses a millimeter wave double-tone signal generation device, and a millimeter wave device third-order intermodulation test system and a test method using the device. The millimeter wave double-tone signal generation device comprises a first drive amplifier, a second drive amplifier, a first frequency multiplier, a second frequency multiplier and a power combiner. Two low-frequency signals with different frequencies and independent of each other are input into the first drive amplifier and the first frequency multiplier, and the second drive amplifier and the second frequency multiplier respectively, and then two high-frequency signals are obtained, and the two high-frequency signals are combined into a high-frequency double-tone signal by the power combiner. By replacing the drive amplifiers, the frequency multipliers and the power combiner with different parameters, millimeter wave double-tone signal generation devices of different frequency bands are formed. The device has a compact structure, less self-clutter and high linearity, and can meet the high-precision test requirements of the third-order intermodulation indicators of various circuits in the millimeter wave band.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of millimeter wave testing, and particularly relates to a dual-tone signal generation device used in IP3 index testing of a millimeter wave device, and a testing system and a testing method using the device. BACKGROUND

[0002] The linearity of a millimeter wave device is usually measured by using third-order intermodulation IP3, and the most commonly used testing method for IP3 is a dual-tone testing method. A dual-tone signal is input into the millimeter wave device to be tested, and the size of the third-order intermodulation is measured by measuring the ratio of the third-order dual-tone intermodulation product to the main output signal. The dual-tone signal used for testing is usually generated by frequency multiplication or frequency expansion of a signal below 50 GHz, and the linearity of the dual-tone signal itself has a strong influence on the accuracy of the test result. The Chinese patent document with the application number 202011332739.4 discloses a W-band waveguide structure passive intermodulation testing system and method, and the generation process of the intermodulation testing signal, i.e. the dual-tone signal, is as follows: a combiner combines two initial radio frequency signals to generate an initial testing signal; the initial testing signal is frequency-multiplied to the W-band by a frequency multiplier, and the intermodulation testing signal is obtained after the power and level of the initial testing signal are adjusted by a power amplifier. Since the frequency multiplier is a nonlinear device, the initial multiple testing signals will generate mixing spur after passing through the frequency multiplier, and introduce nonlinearity. When the mixing spur falls within the working frequency band and is close to the main signal, the effect of the isolator, filter and other devices for eliminating the mixing spur is limited, resulting in that the generated intermodulation testing signal carries the mixing spur which affects the test accuracy. In addition, the amplifier amplifies the W-band signal after frequency multiplication, which also introduces nonlinearity to the generated intermodulation testing signal, further affecting the test accuracy. SUMMARY

[0003] The application aims to provide a millimeter wave dual-tone signal generation device which can generate a millimeter wave high-frequency dual-tone signal with less mixing spur.

[0004] Technical scheme: The application provides a millimeter wave dual-tone signal generation device, which comprises a first drive amplifier, a second drive amplifier, a first frequency multiplier, a second frequency multiplier and a power combiner.

[0005] The input end of the first drive amplifier is connected with a first signal source, and the output end of the first drive amplifier is connected with the input end of a first frequency multiplier; the output end of the first frequency multiplier is connected with the first input end of a power combiner; the input end of the second drive amplifier is connected with a second signal source, and the output end of the second drive amplifier is connected with the input end of a second frequency multiplier; the output end of the second frequency multiplier is connected with the second input end of the power combiner; the output end of the power combiner outputs a generated millimeter wave double-tone signal; and the first signal source and the second signal source are configured so that the output signal frequency interval and amplitude of the millimeter wave double-tone signal output by the power combiner meet the signal requirements of a third-order intermodulation test condition.

[0006] The first signal source and the second signal source are both low-frequency signals, and two high-frequency signals are obtained after the first signal source and the second signal source pass through the first drive amplifier and the first frequency multiplier and the second drive amplifier and the second frequency multiplier, respectively; the two high-frequency signals are combined into a high-frequency double-tone signal by the power combiner. The signal power of the two frequency points in the double-tone signal is adjusted by adjusting the parameters of the first drive amplifier and the second drive amplifier, and the frequencies of the two frequency points are adjusted by adjusting the multiplication of the first frequency multiplier and the second frequency multiplier.

[0007] Further, the first drive amplifier and the first frequency multiplier constitute a first combination module, the second drive amplifier and the second frequency multiplier constitute a second combination module, the input ends of the first combination module and the second combination module are coaxial connectors, and the output ends of the first combination module and the second combination module are waveguide ports.

[0008] Further, the first signal source and the second signal source are independent signal sources.

[0009] Further, the first input end and the second input end of the power combiner are waveguide ports, and the output end of the first combination module and the first input end of the power combiner and the output end of the second combination module and the second input end of the power combiner are connected by 90-degree bent waveguide tubes.

[0010] Further, the waveguide tubes between the output end of the first combination module and the first input end of the power combiner and between the output end of the second combination module and the second input end of the power combiner are of the same size.

[0011] Further, the first combination module and the second combination module are building block standard modules, the millimeter wave dual-tone signal generation device further comprises a bottom plate, the bottom plate is a bearing plate of the building block standard modules, a plurality of unit squares are arranged on the bearing plate, and mounting holes for fixing the standard modules are arranged at four corners of each unit square; the first combination module, the second combination module and the power combiner are placed on the bottom plate, and relative positions of the first combination module, the second combination module and the power combiner on the bottom plate are fixed.

[0012] Further, when the first signal source and the second signal source are replaced by V-band, E-band or W-band standard devices, the millimeter wave dual-tone signal generation device is configured as a V-band, E-band or W-band dual-tone signal generation device.

[0013] Further, the output signal frequency range of the first signal source and the second signal source is 16.67-25GHz, the working frequency of the first driving amplifier at least includes 16.67-25GHz, the frequency multiplication multiple of the first frequency multiplier and the second frequency multiplier is 3, the output waveguide port of the power combiner is a WR-15 waveguide port, the output waveguide port flange is a UG-385 / U, and the output frequency of the power combiner is 50-75GHz.

[0014] Further, the output signal frequency range of the first signal source and the second signal source is 20-30GHz, the working frequency of the first driving amplifier at least includes 20-30GHz, the frequency multiplication multiple of the first frequency multiplier and the second frequency multiplier is 3, the output waveguide port of the power combiner is a WR-12 waveguide port, the output waveguide port flange is a UG-387 / U, and the output frequency of the power combiner is 60-90GHz.

[0015] Further, the output signal frequency range of the first signal source and the second signal source is 12.5-18.3GHz, the working frequency of the first driving amplifier at least includes 12.5-18.3GHz, the frequency multiplication multiple of the first frequency multiplier and the second frequency multiplier is 6, the output waveguide port of the power combiner is a WR-10 waveguide port, the output waveguide port flange is a UG-387 / U-M, and the output frequency of the power combiner is 75-110GHz.

[0016] In another aspect, the application also provides a millimeter wave device third-order intermodulation test system, comprising the above-mentioned millimeter wave dual-tone signal generation device and a spectrum analyzer; the output end of the power combiner in the millimeter wave dual-tone signal generation device is connected with the input end of a millimeter wave device to be tested; and the input end of the spectrum analyzer is connected with the output end of the millimeter wave device to be tested.

[0017] The application also provides a method for testing by using the above-mentioned third-order intermodulation test system of a millimeter wave device, comprising the following steps:

[0018] A millimeter wave dual-tone signal generating device is used to generate a dual-tone signal with frequencies of f1 and f2, where f1 < f2, and the dual-tone signal is input into a millimeter wave device to be tested;

[0019] A spectrum analyzer is used to analyze the output signal of the millimeter wave device to be tested, and the powers Po1, Po2, Po3 and Po4 of the output signal at frequencies f1, f2, 2f1-f2 and 2f2-f1 are obtained; the powers Po1 and Po2 are equal;

[0020] The third-order intermodulation index IP3 of the millimeter wave device to be tested is calculated by using the formula: IP3 = Po1 + (Po1-Po3) / 2 or IP3 = Po2 + (Po2-Po4) / 2.

[0021] Beneficial effects: Compared with the prior art, the millimeter wave dual-tone signal generating device disclosed by the application has the following advantages:

[0022] 1. The driving amplifier in the application only amplifies low-frequency signals, has good linearity, and will not introduce nonlinearity to the generated dual-tone signal;

[0023] 2. The frequency multiplier in the application only multiplies signals of a single frequency, will only generate harmonics, and will not generate mixed-frequency noise; during testing, these harmonics fall outside the working frequency band and will not affect the test results; 3. The power combiner is a passive linear device and will not introduce additional nonlinearity. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a principle block diagram of the millimeter wave dual-tone signal generating device disclosed in Embodiment 1;

[0025] Figure 2 It is a perspective view of the millimeter wave dual-tone signal generating device disclosed in Embodiment 1;

[0026] Figure 3 It is a three-view drawing of the millimeter wave dual-tone signal generating device disclosed in Embodiment 1;

[0027] Figure 4 It is a waveform diagram of the E-band millimeter wave dual-tone signal generated in Embodiment 1;

[0028] Figure 5 It is a composition schematic diagram of the third-order intermodulation test system of a millimeter wave device disclosed in Embodiment 2;

[0029] Figure 6 It is a principle schematic diagram of the third-order intermodulation test method of a millimeter wave device disclosed in Embodiment 2. Detailed Implementation

[0030] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] like Figure 1 As shown, the millimeter-wave dual-tone signal generation device disclosed in this invention includes: a first driver amplifier 101, a second driver amplifier 102, a first frequency multiplier 103, a second frequency multiplier 104, and a power combiner 105; wherein the input terminal of the first driver amplifier 101 is connected to a first signal source S1, and the output terminal of the first driver amplifier 101 is connected to the input terminal of the first frequency multiplier 103; the output terminal of the first frequency multiplier 103 is connected to the first input terminal of the power combiner 105; the input terminal of the second driver amplifier 102 is connected to a second signal source S2, and the second... The output of the driver amplifier 102 is connected to the input of the second frequency multiplier 104; the output of the second frequency multiplier 102 is connected to the second input of the power combiner 105; the power combiner 105 outputs the generated millimeter-wave dual-tone signal; the first signal source S1 and the second signal source S2 are independent signal sources, and their output signal frequency interval and amplitude are configured such that the millimeter-wave dual-tone signal output by the power combiner meets the requirements of the third-order intermodulation test. Typically, the amplitudes of their output signals are equal, and the frequency interval must be greater than or equal to 1MHz. The output signals of the first signal source S1 and the second signal source S2 can be adjusted by observing the spectral characteristic curve of the output millimeter-wave dual-tone signal. In this embodiment, the inputs of the first driver amplifier 101 and the second driver amplifier 102 are both coaxial connectors; the outputs of the first frequency multiplier 103 and the second frequency multiplier 104 are both waveguide ports; the first and second inputs of the power combiner are waveguide ports. The output signals of the first signal source S1 and the second signal source S2 are input into the millimeter-wave dual-tone signal generation device through a coaxial connector; the high-frequency signals output by the first frequency multiplier and the second frequency multiplier are both input into the power synthesizer through waveguides.

[0033] Furthermore, the first driver amplifier and the first frequency multiplier are arranged adjacent to each other to form the first combined module M1; the second driver amplifier and the second frequency multiplier are arranged adjacent to each other to form the second combined module M2. The first and second combined modules are modular standard modules, that is, circuit modules defined according to certain size standards. The first and second combined modules and the power combiner are respectively placed on the base plate 1, which serves as the support plate for the modular standard modules. The support plate has multiple unit squares, and each unit square has mounting holes at its four corners for fixing standard modules. Each standard module can be easily fixed onto the support plate through the mounting holes at the four corners of a unit square. Multiple standard modules in the same device can be installed in multiple unit squares on the support plate and connected by connecting modules. During replacement, the replacement of a single module or multiple modules can be easily achieved. The relative positions of the first combined module, the second combined module, and the power combiner on the base plate are fixed.

[0034] like Figure 2 The diagram shows a perspective view of the millimeter-wave dual-tone signal generation device disclosed in this embodiment. The first signal source S1 and the second signal source S2 are input to the first combined module M1 and the second combined module M2 respectively via two coaxial connectors In1 and In2. The driver amplifier and the frequency multiplier are arranged adjacent to each other, shortening the transmission path of the amplified low-frequency signal and reducing power loss. The two high-frequency signals after frequency multiplication are input to the power combiner 105 via waveguides L1 and L2 respectively. Both ends of waveguides L1 and L2 are equipped with standard waveguide flanges. The generated dual-tone signal is output from the output terminal Out of the power combiner 105. The power-on ports V1 and V2 of the first and second driver amplifiers are located at the top of the first and second driver amplifiers respectively; the matching load Load of the power combiner is also located at the top of the power combiner.

[0035] Figure 3 Three-view diagram of a millimeter-wave dual-tone signal generation device, wherein Figure 3 (a)-3(d) are the front view, left view, top view and right view, respectively. The power combiner 105 is disposed on one axis of symmetry of the base plate 1, and the first combination module M1 and the second combination module M2 are also symmetrically disposed on both sides of the axis of symmetry, so that the two waveguides 4 are of equal size.

[0036] The device of the following mode is selected to generate the double-tone signal of V-band, E-band or W-band: the first driving amplifier and the second driving amplifier are both MWG106 amplifier chips, the first frequency multiplier and the second frequency multiplier are both MWX004 frequency multiplier chips; the power combiner is a magic T; the first combination module M1 and the second combination module M2 are connected to the in-phase port of the magic T through the 90°-bent connecting waveguide L1 and L2 respectively; the E-plane port of the magic T is connected to a matching load Load; and the H-plane port of the magic T is the output port Out. The signal power of the two frequency points in the double-tone signal is adjusted by adjusting the power of the output signals of the first signal source and the second signal source, and the frequencies of the two frequency points are adjusted by adjusting the frequency multiplication of the first frequency multiplier and the second frequency multiplier. The frequency range of the first signal source S1 and the second signal source S2 and the frequency multiplication of the first frequency multiplier 103 and the second frequency multiplier 104 can be set according to actual needs, and correspondingly, the first combination module, the second combination module, the power combiner, the waveguide port and the waveguide are replaced by standard devices of corresponding frequency bands.

[0037] For the double-tone test of each band of millimeter waves, the following parameters can be selected:

[0038] V-band: the frequency range of the output signals of the first signal source S1 and the second signal source S2 is 16.67-25GHz, the working frequency of the first driving amplifier at least includes 16.67-25GHz, the frequency multiplication of the first frequency multiplier 103 and the second frequency multiplier 104 is 3, the output waveguide port of the power combiner is a WR-15 waveguide port, the output waveguide port flange is a UG-385 / U, and the output frequency of the power combiner is 50-75GHz; thus, a high-frequency double-tone signal of 50-75GHz is generated according to the signal of 16.67-25GHz.

[0039] E-band: the frequency range of the output signals of the first signal source S1 and the second signal source S2 is 20-30GHz, the working frequency of the first driving amplifier at least includes 20-30GHz, the frequency multiplication of the first frequency multiplier 103 and the second frequency multiplier 104 is 3, the output waveguide port of the power combiner is a WR-12 waveguide port, the output waveguide port flange is a UG-387 / U, and the output frequency of the power combiner is 60-90GHz; thus, a high-frequency double-tone signal of 60-90GHz is generated according to the signal of 20-30GHz.

[0040] W-band: The output signal frequency range of the first signal source S1 and the second signal source S2 is 12.5-18.3GHz, the operating frequency of the first driving amplifier includes at least 12.5-18.3GHz, the multiplication factor of the first frequency multiplier 103 and the second frequency multiplier 104 is 6, the output waveguide port of the power combiner is a WR-10 waveguide port, the output waveguide port flange is UG-387 / UM, and the output frequency of the power combiner is 75-110GHz; thereby realizing the generation of a high-frequency dual-tone signal of 75-110GHz based on the 12.5-18.3GHz signal.

[0041] The millimeter-wave dual-tone signal generation device disclosed in this embodiment amplifies only low-frequency signals using both the first and second drive amplifiers, exhibiting good linearity and avoiding the introduction of nonlinearity into the dual-tone signal. The first and second frequency multipliers multiply only single-frequency signals, generating only harmonics. When testing millimeter-wave devices, these harmonics fall outside the operating frequency band and do not affect the test results. The power combiner is a passive linear device, preventing the generation of mixing noise. Therefore, the millimeter-wave dual-tone signal generation device disclosed in this embodiment can generate high-quality dual-tone signals, which provide high accuracy when used for IP3 testing of millimeter-wave devices.

[0042] This embodiment uses the E-band millimeter-wave dual-tone signal generated by this device, such as... Figure 4 As stated, in which Figure 4 (a) is a waveform diagram of a two-tone signal with a 1MHz interval on both sides at 71GHz. Figure 4 (b) is a waveform diagram of a two-tone signal with a 1MHz interval on both sides of 86GHz. Figure 4 (a) and Figure 4 (b) The third-order intermodulation distortion (ΔIM) of the two-tone signal itself is below -60dBc of the spectrum analyzer noise floor.

[0043] Example 2

[0044] like Figure 5 As shown, the third-order intermodulation test system for millimeter-wave devices disclosed in this embodiment includes: the millimeter-wave dual-tone signal generation device and the spectrum analyzer disclosed in Embodiment 1; the output terminal of the power synthesizer in the millimeter-wave dual-tone signal generation device is connected to the input terminal of the millimeter-wave device under test; the input terminal of the spectrum analyzer is connected to the output terminal of the millimeter-wave device under test.

[0045] The steps for performing third-order intermodulation (IP3) testing on millimeter-wave devices using the above testing system are as follows:

[0046] A millimeter-wave dual-tone signal generator is used to generate dual-tone signals with frequencies of f1 and f2. Assuming f1 < f2, the dual-tone signals are input to the millimeter-wave device under test.

[0047] The output signal of the millimeter wave device to be tested is analyzed by a spectrum analyzer to obtain the power Po1, Po2, Po3 and Po4 of the output signal at frequencies f1, f2, 2f1-f2 and 2f2-f1, wherein Po1 and Po2 are equal;

[0048] The third-order intermodulation index IP3 of the millimeter wave device to be tested is calculated by the following formula IP3=Po1+(Po1-Po3) / 2 or IP3=Po2+(Po2-Po4) / 2.

[0049] The IP3 test principle is shown in Figure 6 The millimeter wave dual-tone signal generation device outputs dual-tone signals with frequencies f1 and f2 and powers Pin (dBm), which are input into the millimeter wave device to be tested. The spectrum of the output signal is analyzed by a spectrum analyzer, wherein the output power at f1 and f2 is considered as useful power, and the output power at 2f1-f2 and 2f2-f1 is considered as useless power. Thus, the formula IP3=Po1+(Po2-Po3) / 2 or IP3=Po1+(Po1-Po4) / 2 is obtained to calculate the third-order intermodulation index IP3 of the millimeter wave device to be tested.

Claims

1. A millimeter-wave dual-tone signal generation device, characterized in that, The application relates to a millimeter wave double-tone signal generating device. The first driving amplifier, the second driving amplifier, the first frequency multiplier, the second frequency multiplier and the power combiner are included. The input end of the first driving amplifier is connected with a first signal source, the output end of the first driving amplifier is connected with the input end of the first frequency multiplier, the output end of the first frequency multiplier is connected with the first input end of the power combiner, the input end of the second driving amplifier is connected with a second signal source, the output end of the second driving amplifier is connected with the input end of the second frequency multiplier, the output end of the second frequency multiplier is connected with the second input end of the power combiner, and the output end of the power combiner outputs generated millimeter wave double-tone signals. The first driving amplifier and the first frequency multiplier constitute a first combined module, the second driving amplifier and the second frequency multiplier constitute a second combined module, the input ends of the first combined module and the second combined module are coaxial connectors, and the output ends of the first combined module and the second combined module are waveguide openings.

2. The millimeter-wave dual-tone signal generating apparatus according to claim 1, wherein The first signal source and the second signal source are independent signal sources.

3. The millimeter-wave dual-tone signal generating apparatus according to claim 1, wherein The first input end and the second input end of the power combiner are waveguide openings, the output end of the first combined module and the first input end of the power combiner are connected by a 90-degree bending waveguide, and the output end of the second combined module and the second input end of the power combiner are connected by a 90-degree bending waveguide.

4. The millimeter-wave dual-tone signal generating apparatus according to claim 2, wherein The waveguide between the output end of the first combined module and the first input end of the power combiner and the waveguide between the output end of the second combined module and the second input end of the power combiner are of the same size.

5. The millimeter-wave dual-tone signal generating apparatus according to claim 2, wherein The first combined module and the second combined module are standard modules, the millimeter wave double-tone signal generating device further comprises a bottom plate, the bottom plate is a bearing plate of the standard modules, a plurality of unit squares are arranged on the bearing plate, mounting holes for fixing the standard modules are arranged at the four corners of each unit square, the first combined module, the second combined module and the power combiner are placed on the bottom plate, and the relative positions of the first combined module, the second combined module and the power combiner on the bottom plate are fixed.

6. The millimeter-wave dual-tone signal generating apparatus according to claim 4, wherein When the first combined module, the second combined module, the power combiner, the waveguide opening and the waveguide are replaced by standard devices of V-band, E-band or W-band, the millimeter wave double-tone signal generating device is configured as a double-tone signal generating device of V-band, E-band or W-band.

7. The millimeter-wave dual-tone signal generating apparatus according to claim 6, wherein The frequency range of the output signals of the first signal source and the second signal source is 16.67-25GHz, the working frequency of the first driving amplifier at least includes 16.67-25GHz, the frequency multiplication of the first frequency multiplier and the second frequency multiplier is 3, the output waveguide opening of the power combiner is a WR-15 waveguide opening, the output waveguide opening flange is a UG-385 / U, and the output frequency of the power combiner is 50-75GHz.

8. The millimeter-wave dual-tone signal generating apparatus according to claim 7, wherein ​ Or: the output signal frequency range of the first signal source and the second signal source is 20-30GHz, the working frequency of the first driving amplifier at least includes 20-30GHz, the frequency multiplication multiple of the first frequency multiplier and the second frequency multiplier is 3, the output waveguide port of the power combiner is WR-12 waveguide port, the output waveguide port flange is UG-387 / U, and the output frequency of the power combiner is 60-90GHz. Or: the output signal frequency range of the first signal source and the second signal source is 12.5-18.3GHz, the working frequency of the first driving amplifier at least includes 12.5-18.3GHz, the frequency multiplication multiple of the first frequency multiplier and the second frequency multiplier is 6, the output waveguide port of the power combiner is WR-10 waveguide port, the output waveguide port flange is UG-387 / U-M, and the output frequency of the power combiner is 75-110GHz.

9. A system for third order intermodulation testing of a millimeter wave device, comprising: The millimeter wave dual-tone signal generation device and the spectrum analyzer are connected to the input end and the output end of the millimeter wave device to be tested.

10. A method of testing a millimeter wave device for third order intermodulation, the method comprising: The millimeter wave device third-order intermodulation test method adopts the millimeter wave device third-order intermodulation test system, and comprises the following steps: The millimeter wave dual-tone signal generation device is used to generate a dual-tone signal with frequencies of f1 and f2, and the dual-tone signal is input into the millimeter wave device to be tested; The spectrum analyzer is used to analyze the output signal of the millimeter wave device to be tested, and the powers Po1, Po2, Po3 and Po4 of the output signal at frequencies of f1, f2, 2f1-f2 and 2f2-f1 are obtained, wherein Po1 is equal to Po2; The third-order intermodulation index IP3 of the millimeter wave device to be tested is calculated by using the formula IP3=Po1+(Po1-Po3) / 2 or IP3=Po2+(Po2-Po4) / 2.

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