Novel 110GHz cold source noise coefficient measurement system and measurement method
By using the cold source method and a zero-intermediate frequency receiver combined with a 110GHz electronic calibration part, the problems of insufficient measurement accuracy and cumbersome steps in the prior art are solved, and high-precision and fast noise factor measurement are achieved.
Patent Information
- Application Number
- CN202510579928.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-07
- Publication Date
- 2025-08-05
AI Technical Summary
The existing 110GHz noise figure analyzer uses the Y-factor method to have problems with insufficient measurement accuracy and waveguide conversion interface, and the vector network analyzer has problems with cumbersome measurement steps and mismatch errors that cannot be fully calibrated.
The cold source method and the zero-intermediate frequency receiver are used, combined with the 110GHz electronic calibration part and the 1.0mm coaxial interface, and the noise figure is directly calculated through a one-time calibration process, and the noise spread spectrum receiver is used to measure the noise figure of 67-110GHz.
Improve measurement accuracy and speed, simplify measurement steps, reduce errors caused by waveguide transfer interface, and achieve more efficient noise factor measurement.
Smart Images
Figure CN120427993A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of measurement technology, and in particular relates to a novel 110GHz cold source noise figure measurement system and measurement method. Background Art
[0002] Currently, instruments capable of measuring noise figure in the frequency range up to 110 GHz include dedicated noise figure analyzers and vector network analyzers. 110 GHz noise figure analyzers use the Y-factor method. Currently, all 110 GHz noise figure analyzers on the market utilize a waveguide interface and a split-body structure. They employ the Y-factor method, using a 110 GHz noise source for calibration. While these 110 GHz noise figure analyzers can address 110 GHz noise figure measurement challenges, they also have limitations. The use of a waveguide interface complicates the transitions required by the increasing number of 1.0 mm coaxial interface devices, introducing additional errors. Noise figure analyzers utilize the Y-factor method, also known as the hot and cold source method. This method utilizes the difference in noise power between the hot and cold states to determine the receiver's local noise figure, and thus the noise figure of the device under test. The Y-factor method does not consider the matching errors of multiple interfaces such as the noise source and receiver, the noise source and the device under test, and the device under test and the receiver. It does not consider the precise solution of the gain of the device under test, and does not consider the influence of noise parameters. Therefore, it is actually impossible to accurately obtain the noise figure of the device under test.
[0003] The cold source method uses only a cold source, not a hot source, during measurement. This method relies on accurate measurement of the DUT's gain. A vector network analyzer (VNA) utilizes two-port vector error correction technology to determine the DUT's S-parameters, making it an ideal instrument for implementing the cold source method. By using electronic calibration components to modify the source match, combined with unique source-end error correction and vector error calibration techniques, the cold source method can determine the DUT's noise parameters, comprehensively characterizing the device's noise characteristics and accurately calculating the noise figure at a 50Ω source impedance.
[0004] In fact, measurement instruments using the cold source method are already available on the market, and related patents have been reported. These instruments can include noise spread spectrum receivers with frequencies up to 110 GHz. Combined with multiple spread spectrum devices, cables, and spread spectrum switches, they connect to a vector network analyzer (requires a noise option) to measure noise parameters and noise figure. However, this approach has certain drawbacks. First, the instruments reported so far all use waveguide interfaces, which is not suitable for measuring coaxial interface devices. Furthermore, this method employs a double-frequency conversion method, requiring the noise figures of the vector network analyzer's mainframe noise receiver and the noise spread spectrum receiver before calculating the noise figure of the device under test. The noise figure cascade formula used in this calculation ignores the matching errors between the noise spread spectrum receiver and the mainframe noise receiver. Furthermore, the measurement process is cumbersome and slow, making it difficult for users to use. The reported measurement method uses a mechanical mixer. While this method can better measure noise parameters and obtain more accurate noise figures, it is slow and unsuitable for rapid noise figure measurements.
[0005] A noise figure analyzer is an important professional test instrument for characterizing the noise performance of devices and systems. Noise figure measurement is a key step in R&D and process verification in the manufacturing industry, and the development of noise figure analysis products is highly valued both domestically and internationally. Currently, noise figure measurement and analysis primarily utilize the Y-factor method and the cold source method, corresponding to two distinct instrument types. Noise figure analyzers often use the Y-factor method, while vector network analyzers equipped with a noise figure option often utilize the cold source method. Furthermore, if a vector network analyzer incorporates the Y-factor method, both methods can be used for measurement, resulting in a specialized noise figure or noise parameter tester.
[0006] There are some dedicated noise figure analyzers on the market that can reach 110GHz, and the method used to achieve this is the Y-factor method.
[0007] The Y-factor method is a traditional method for testing noise figures. It uses a noise source that can be set to cold and hot states to characterize the noise figure of the receiver itself, and then uses the cascade formula of the noise figure to solve the device under test (DUT). Among them, the ratio of the cold and hot states of the noise source is a pre-calibrated standard value, called the excess noise ratio (ENR). The noise source is generally marked with an ENR table at a specific frequency point, and the values outside the table are obtained using a fitting method. Let the power of the noise source be N on , the power of the noise source is N off , the Y factor is defined as the ratio of the two.
[0008] Y=Non / Noff (1)
[0009] The calculation formula for noise figure NF is:
[0010]
[0011] The cold source method for measuring noise figure based on a vector network analyzer is also called the direct noise measurement method, such as Figure 1 As shown. Assume that the gain of the device under test (DUT) is G a1 , the noise figure is F1, and the gain of the noise receiver is G a2 , the noise factor is F2 and the input noise power is N i . N out2 is the power output by the receiver. N0 is the ambient noise power at 290K. i is the input ambient temperature.
[0012] The cold source method no longer requires the noise source to be connected to the input of the device under test to provide hot and cold noise states. Instead, a source impedance is connected to the input of the device under test at room temperature (cold state) to provide N i If the gain G of the DUT can be measured a1 By calculating the device's added noise power and its cold output power, we can determine the device's noise figure. Vector network analyzers are well-suited for this technique because they can use vector error correction to achieve very accurate gain measurements. The cold source method offers the advantage of a single-connection, fast, and efficient solution for multi-parameter measurements.
[0013] The following formula (3) can be obtained from the basic formula of noise coefficient, and the noise coefficient and noise parameters can be solved according to this formula.
[0014]
[0015] Figure 2 This is a schematic diagram of the 110 GHz cold source method. The noise down-conversion module can independently generate a local oscillator. This approach has both advantages and disadvantages. The advantage is that it does not affect the host's S-parameter local oscillator. The disadvantages are the increased complexity within the module and the cumbersome measurement process. Figure 2 In the figure, box 1 is the host, the two boxes 5 are the spectrum spreader modules, box 2 is the device under test, and boxes 3 and 4 and the local oscillator circuit constitute the noise downconverter module.
[0016] The measurement is a three-step process. The first step is to measure the inverter's noise figure (F2), the second step is to measure the amplifier's gain, and the third step is to measure the noise figure (FT) of the cascaded amplifier and inverter. Finally, the DUT's noise figure (F1) is calculated using the noise figure cascade formula. This measurement process is very cumbersome and does not consider the matching between the inverter module and the host computer under noise conditions, which can lead to certain errors.
[0017] The Y-factor method used in existing noise figure analyzers has problems with insufficient measurement accuracy and waveguide-to-interface issues.
[0018] The existing 110GHz cold source solution for vector network analyzers has problems with complex measurement steps and slow speed, as well as problems with mismatch errors that cannot be fully calibrated and waveguide-to-interface issues. Summary of the Invention
[0019] In response to the above technical problems existing in the prior art, the present invention proposes a novel 110 GHz cold source noise figure measurement system and measurement method, which has a reasonable design, overcomes the shortcomings of the prior art, and has good results.
[0020] In order to achieve the above object, the present invention adopts the following technical solutions:
[0021] A new 110GHz cold-source noise figure measurement system, including:
[0022] The vector network analyzer host is equipped with a noise source power supply interface and a noise intermediate frequency interface; it is configured to power the noise source and input the intermediate frequency of the noise spread spectrum receiver module;
[0023] A spectrum spread controller configured to extend the frequency of the vector network analyzer host to 67-110 GHz;
[0024] The S-parameter measurement module of the first port and the S-parameter measurement module of the second port are configured to perform gain measurement of the device under test;
[0025] The noise spread spectrum receiver module is configured to directly down-convert the RF signal into a baseband IF signal and input the signal into its internal noise receiver via the noise IF interface of the vector network analyzer;
[0026] A 110 GHz electronic calibration module configured to correct the noise parameters of the device under test;
[0027] The noise figure measurement system completes the S-parameter and noise power measurement of the device under test through a single calibration process. Combined with the multi-state matching data of the electronic calibration component, it directly calculates the noise figure and noise parameters of the device under test.
[0028] Preferably, the S parameter measurement module of the first port and the S parameter measurement module of the second port cover a frequency band of 10 MHz to 110 GHz.
[0029] Preferably, the noise spread spectrum receiver module adopts a 1.0mm coaxial interface and supports 67-110GHz spread spectrum.
[0030] Preferably, the 110 GHz electronic calibration component is external to the system and supports 4-8 matching state switches.
[0031] In addition, the present invention also provides a novel 110 GHz cold source noise figure measurement method, which uses the novel 110 GHz cold source noise figure measurement system described above and specifically includes the following steps:
[0032] Step 1: Build a test system;
[0033] Step 2: Connect the test system and preheat the test system;
[0034] Step 3: Enter the noise figure cold source measurement mode of the vector network analyzer;
[0035] Step 4: Set parameters including frequency, power, IF bandwidth, and averaging times;
[0036] Step 5: Select the noise figure calibration method and the noise source calibration type;
[0037] Step 6: Perform noise source calibration;
[0038] Step 7: Calibrate using electronic calibration kit;
[0039] Step 8: Calibrate the noise spread spectrum receiver module;
[0040] Step 9: Through calibration;
[0041] Step 10: Connect the DUT, place the electronic calibration module in the through state, and measure the noise figure of the DUT.
[0042] Step 11: If noise parameter calibration is selected, use the 4-8 matching states of the electronic calibration component in step 9 and measure the S parameters and noise power in each state to measure the noise figure and noise parameters of the device under test.
[0043] Preferably, the noise source calibration in step 6 includes: connecting the noise source to the noise spread spectrum receiver module, and turning on the internal mixer input of the noise spread spectrum receiver module.
[0044] Preferably, the electronic calibration component calibration in step 7 includes performing open circuit, short circuit and load calibration at the output port of the electronic calibration component, and at the same time, placing the electronic calibration component in a through state.
[0045] Preferably, the noise spread spectrum receiver module calibration in step 8 includes performing open circuit, short circuit and load calibration on the noise spread spectrum receiver module, and turning the switch of the noise spread spectrum receiver module to the S parameter measurement module direction of the second port.
[0046] Preferably, the through calibration in step 9 includes calibrating the through S parameters and noise power parameters through the output of the electronic calibration component and the input of the noise spread spectrum receiver module.
[0047] Preferably, the output of the noise spread spectrum receiver module is a zero intermediate frequency signal, and the zero intermediate frequency signal is input into the noise receiver inside the vector network analyzer through the rear panel of the vector network analyzer.
[0048] The beneficial technical effects brought about by the present invention are:
[0049] The present invention uses a noise spread spectrum receiver to measure the noise figure in the 67-110 GHz range. It adopts a cold source method and a zero intermediate frequency receiver. Compared with the Y-factor method, it can better correct the influence of matching on the noise figure measurement. The use of a zero intermediate frequency receiver can make the measurement steps simpler and the measurement accuracy higher.
[0050] The noise spread spectrum receiver of the present invention uses a 1.0 mm interface, which is more convenient for measuring a device under test with a 1.0 mm interface than the waveguide interface commonly used in the prior art, thereby correspondingly improving the noise figure measurement accuracy.
[0051] The present invention uses an electronic calibration component to measure noise parameters, thereby correcting the noise parameters of the device under test and more accurately calculating the noise figure of the device under test. Compared with a solution without an electronic calibration component, the noise figure measurement accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS
[0052] Figure 1 Schematic diagram of the cold source method;
[0053] Figure 2 This is the block diagram of the 110GHz cold source method;
[0054] Figure 3 This is the block diagram of the 110GHz cold source method noise figure measurement. DETAILED DESCRIPTION
[0055] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:
[0056] The present invention adopts a cold source measurement scheme and designs a low-noise receiver with zero intermediate frequency. The measurement steps are simple and the speed is fast. A 1.0mm coaxial adapter scheme is adopted and a 110GHz electronic calibration component is used as a adapter. Good results can be achieved in both measurement speed and measurement accuracy.
[0057] The 110GHz cold source noise figure measurement based on the vector network analyzer host and spread spectrum controller can play an important role in the research and development and production of microwave and millimeter wave device components and other system development fields.
[0058] like Figure 3As shown, the novel 110 GHz cold source noise figure measurement system described in the present invention includes a vector network analyzer, a spread spectrum controller, an S-parameter measurement module for port 1, an S-parameter measurement module for port 2, a noise spread spectrum receiver module, an electronic calibration component, a noise source, and a device under test. The vector network analyzer needs to have a noise source power supply interface and a noise intermediate frequency interface.
[0059] This system follows Figure 2 There are three main differences between the schemes: First, the noise spread spectrum receiver module is a zero intermediate frequency output, and the intermediate frequency is input into the noise receiver inside the vector network analyzer through the rear panel of the vector network analyzer, while Figure 2 The first solution requires secondary frequency conversion, so the signal after frequency conversion is input to the 2-port of the vector network analyzer; the second is that the noise spread spectrum receiver module is a 1.0mm coaxial interface, Figure 2 The first solution is the waveguide interface; the third is the external electronic calibration component, which can measure noise parameters. Figure 2 The scheme cannot measure noise parameters.
[0060] When measuring the DUT's S-parameters, the noise spread spectrum receiver module transmits the signal to the S-parameter measurement module on port 2. When measuring the DUT's noise power, the noise signal is input into the module's mixer, and the resulting IF signal is sent through the vector network analyzer's rear panel to the internal noise receiver. The S-parameter measurement modules on ports 1 and 2 provide spread spectrum transmission and reception for signals from 10 MHz to 110 GHz. The main unit frequency ranges up to 67 GHz. When combined with the noise spread spectrum receiver module, noise figure measurements from 10 MHz to 110 GHz can be made.
[0061] The calibration and testing steps are given below.
[0062] 1. Such as Figure 3 Connect the entire test system, power on the vector network analyzer, spread spectrum controller, S-parameter measurement module for port 1, S-parameter measurement module for port 2, noise spread spectrum receiver module, electronic calibration module, noise source, and device under test and preheat for more than 1 hour.
[0063] 2. Enter the noise figure cold source measurement category.
[0064] 3. Set parameters such as frequency, power, IF bandwidth, and averaging times.
[0065] 4. Click Calibrate, select Noise Figure Calibration, and select Noise Source as the calibration method.
[0066] 5. Set the calibration kit type and connector type to be used.
[0067] 6. Enter the noise source calibration and connect the noise source to the noise spread spectrum receiver module. At this time, the noise spread spectrum receiver should turn the switch to the internal mixer input.
[0068] 7. Click Next and perform open circuit, short circuit, and load calibration at the output port of the electronic calibration component. At this time, the electronic calibration component should be in the through state.
[0069] 8. Click Next to perform open circuit, short circuit, and load calibration on the noise spread spectrum receiver module. At this time, the noise spread spectrum receiver should turn the switch to the S parameter measurement module direction of port 2.
[0070] 9. Click Next to connect the electronic calibration module output to the noise spread spectrum receiver module input and calibrate the S-parameters and noise power parameters.
[0071] 10. Connect the DUT. The electronic calibration unit should be switched to the through state to measure the noise figure of the DUT.
[0072] 11. If noise parameter calibration is selected in step 4, then 4-8 matching states of the electronic calibration component should be applied in step 9. The S-parameter noise power should be measured in each state. In this way, the noise figure and noise parameters of the device under test can be measured in the final step.
[0073] The key points of the present invention are as follows:
[0074] (1) In the cold source noise figure measurement frequency band of 67-110 GHz, the intermediate frequency signal is input into the rear panel of the vector network analyzer using the zero intermediate frequency method and then enters the noise receiver inside the instrument for processing.
[0075] (2) The noise spread spectrum receiver uses a 1.0mm coaxial interface, which is conducive to the measurement of the noise figure of the device under test with a coaxial interface.
[0076] (3) The electronic calibration method is used to facilitate the measurement of the noise parameters of the device under test, thereby better obtaining the noise coefficient of the device under test.
[0077] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.
Claims
1. A new 110GHz cold source noise figure measurement system, characterized by: include: Vector network analyzer host, equipped with noise source power supply interface and noise intermediate frequency interface; configured to be used for powering a noise source and providing an intermediate frequency input to a noise spread spectrum receiver module; A spectrum spreading controller configured to extend the frequency of the vector network analyzer host to 67-110 GHz; The S-parameter measurement module of the first port and the S-parameter measurement module of the second port are configured to perform gain measurement of the device under test; The noise spread spectrum receiver module is configured to directly down-convert the RF signal into a baseband IF signal and input the signal into its internal noise receiver via the noise IF interface of the vector network analyzer; A 110 GHz electronic calibration module configured to correct the noise parameters of the device under test; The noise figure measurement system completes the S-parameter and noise power measurement of the device under test through a single calibration process. Combined with the multi-state matching data of the electronic calibration component, it directly calculates the noise figure and noise parameters of the device under test.
2. The novel 110 GHz cold source noise figure measurement system according to claim 1 is characterized in that: The S-parameter measurement module of the first port and the S-parameter measurement module of the second port cover the frequency band of 10MHz-110GHz.
3. The novel 110 GHz cold source noise figure measurement system according to claim 1 is characterized in that: Noise spread spectrum receiver module, using a 1.0mm coaxial interface, supports 67-110GHz spread spectrum.
4. The novel 110 GHz cold source noise figure measurement system according to claim 1, characterized in that: 110GHz electronic calibration module, external to the system, supports 4-8 matching state switching.
5. A new 110GHz cold source noise figure measurement method, characterized in that: The novel 110 GHz cold source noise figure measurement system according to claim 1 specifically comprises the following steps: Step 1: Build a test system; Step 2: Connect the test system and preheat the test system; Step 3: Enter the noise figure cold source measurement mode of the vector network analyzer; Step 4: Set parameters including frequency, power, IF bandwidth, and averaging times; Step 5: Select the noise figure calibration method and the noise source calibration type; Step 6: Perform noise source calibration; Step 7: Calibrate using electronic calibration kit; Step 8: Calibrate the noise spread spectrum receiver module; Step 9: Through calibration; Step 10: Connect the DUT, place the electronic calibration module in the through state, and measure the noise figure of the DUT. Step 11: If noise parameter calibration is selected, use the 4-8 matching states of the electronic calibration component in step 9 and measure the S parameters and noise power in each state to measure the noise figure and noise parameters of the device under test.
6. The novel 110 GHz cold source noise figure measurement method according to claim 5, characterized in that: The noise source calibration in step 6 includes: connecting the noise source to the noise spread spectrum receiver module, and turning on the internal mixer input of the noise spread spectrum receiver module.
7. The novel 110 GHz cold source noise figure measurement method according to claim 5, characterized in that: The electronic calibration component calibration in step 7 includes performing open circuit, short circuit, and load calibration on the output port of the electronic calibration component, and at the same time, placing the electronic calibration component in a through state.
8. The novel 110 GHz cold source noise figure measurement method according to claim 5, characterized in that: The noise spread spectrum receiver module calibration in step 8 includes performing open circuit, short circuit, and load calibration on the noise spread spectrum receiver module, and turning the switch of the noise spread spectrum receiver module to the S parameter measurement module direction of the second port.
9. The novel 110 GHz cold source noise figure measurement method according to claim 5, characterized in that: The through calibration in step 9 includes calibrating the through S parameters and noise power parameters by passing the output of the electronic calibration module and the input of the noise spread spectrum receiver module.
10. The novel 110 GHz cold source noise figure measurement method according to claim 5, characterized in that: The output of the noise spread spectrum receiver module is a zero intermediate frequency signal, and the zero intermediate frequency signal is input into the noise receiver inside the vector network analyzer through the rear panel of the vector network analyzer.