Method and system for testing intermediate frequency interface wireless devices

Abstract

This invention provides a testing method and system for intermediate frequency interface wireless devices. In this method, by introducing a signal coupling unit and a frequency conversion unit into the test link, the reference signal coupled from the transmission path is cleverly frequency-converted, so that its frequency is strictly consistent with the frequency of the response signal output by the wireless device. This design enables the reference receiver and the measurement receiver of the test instrument to operate at the exact same frequency, thus successfully transforming the complex frequency conversion test into a conventional same-frequency measurement mode. This not only frees the testing process from dependence on expensive mixer options, significantly reducing equipment usage costs, but also completely avoids the cumbersome frequency switching and circuit stabilization time in the "dual frequency sweep" mode, thereby greatly improving the overall testing efficiency.

Description

Technical Field

[0001] This invention relates to the field of communication testing technology, and in particular to a testing method and testing system for intermediate frequency interface wireless devices. Background Technology

[0002] Currently, in the testing of satellite internet communication terminals and other equipment, many wireless devices only provide intermediate frequency (IF) input / output interfaces and do not directly expose radio frequency (RF) ports. When performing OTA (Over-The-Air) tests on such devices, a vector network analyzer (VNA) in frequency conversion testing mode is typically required. Taking the uplink S21 test as an example, the network analyzer outputs an IF signal to the terminal under test (DUT), which upconverts it to an RF signal and radiates it. After being received by the test antenna, the signal is sent back to the measurement receiver input of the network analyzer. At this time, the reference receiver of the network analyzer operates in the IF band, while the measurement receiver operates in the RF band. Due to the different operating frequencies of the two receivers and limitations imposed by the hardware architecture, the instrument must adopt a "dual-frequency sweep" mode. That is, first, the frequency required by the reference receiver is set for measurement, and then the hardware settings are switched to the frequency required by the measurement receiver for measurement.

[0003] This existing frequency conversion testing method has obvious drawbacks: on the one hand, conventional network analyzers do not directly support this function, requiring the upgrading of additional mixers or frequency conversion test options, which increases equipment costs; on the other hand, the "dual frequency sweep" mode results in longer frequency switching and circuit stabilization time, which significantly reduces testing efficiency compared to traditional same-frequency S21 measurement.

[0004] In summary, traditional testing solutions for intermediate frequency interface wireless devices suffer from technical problems such as high testing costs and low testing efficiency. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a testing method and testing system for intermediate frequency interface wireless devices, so as to alleviate the technical problems of high testing cost and low testing efficiency of traditional intermediate frequency interface wireless device testing schemes.

[0006] In a first aspect, the present invention provides a testing method for intermediate frequency interface wireless devices, comprising: The test instrument provides an excitation signal, which is used to cause the wireless device to generate a response signal; The signal coupling unit couples out a portion of the signal from the transmission path of the excitation signal as a reference signal; The frequency conversion unit performs frequency conversion on the reference signal to obtain a converted reference signal, the frequency of which is the same as the frequency of the response signal; The test instrument receives the response signal and the conversion reference signal, and performs same-frequency transmission characteristic measurement based on both.

[0007] Furthermore, when the wireless device is in transmit mode; The test instrument provides an intermediate frequency excitation signal as the excitation signal and outputs it to the intermediate frequency input interface of the wireless device. The wireless device upconverts the intermediate frequency excitation signal into a radio frequency signal and transmits it over the air interface through the antenna of the wireless device. The test antenna receives the radio frequency signal and sends it as the response signal to the measurement receiving port of the test instrument; The signal coupling unit couples out a portion of the signal from the transmission path of the intermediate frequency excitation signal as the reference signal; The frequency conversion unit up-converts the reference signal into a radio frequency reference signal, which is then output as the converted reference signal to the reference receiving port of the test instrument. The frequency of the radio frequency reference signal is the same as the frequency of the radio frequency signal.

[0008] Furthermore, when the wireless device is in receiving mode; The test instrument provides a radio frequency excitation signal as the excitation signal, outputs it to the test antenna, and transmits it through the test antenna via the air interface. The wireless device receives the radio frequency excitation signal, down-converts it to an intermediate frequency signal, and sends it as the response signal to the measurement receiving port of the test instrument. The signal coupling unit couples out a portion of the signal from the transmission path of the radio frequency excitation signal as the reference signal; The frequency conversion unit down-converts the reference signal into an intermediate frequency reference signal, and outputs it as the converted reference signal to the reference receiving port of the test instrument. The frequency of the intermediate frequency reference signal is the same as the frequency of the intermediate frequency signal.

[0009] Furthermore, the frequency conversion unit includes a mixer; The mixer receives the local oscillator signal provided by the test instrument and performs mixing processing on the reference signal based on the local oscillator signal to achieve the frequency conversion processing.

[0010] Furthermore, the signal coupling unit includes a directional coupler, which is connected in series in the transmission path of the excitation signal and couples out the reference signal.

[0011] Furthermore, the wireless device includes an intermediate frequency (IF) input interface and / or an IF output interface.

[0012] Secondly, the present invention also provides a testing system for intermediate frequency interface wireless devices, comprising: Test the antenna and configure it to establish an air interface transmission link with the wireless device; The test instrument includes a signal output port, a reference receiving port, and a measurement receiving port. The test instrument is configured to provide an excitation signal through the signal output port, receive a response signal generated by the wireless device through the measurement receiving port, and receive a converted reference signal through the reference receiving port. The signal coupling unit is configured to couple a portion of the signal from the transmission path of the excitation signal as a reference signal; A frequency conversion unit, connected to the signal coupling unit, is configured to receive the reference signal, perform frequency conversion on the reference signal to obtain the converted reference signal, and output it to the reference receiving port of the test instrument. The frequency of the converted reference signal is the same as the frequency of the response signal.

[0013] Furthermore, when the wireless device is in transmit mode, the signal coupling unit is connected between the signal output port and the intermediate frequency input interface of the wireless device, and the frequency conversion unit is configured to upconvert the reference signal into a radio frequency reference signal; When the wireless device is in receive mode, the signal coupling unit is connected between the signal output port and the test antenna, and the frequency conversion unit is configured to downconvert the reference signal into an intermediate frequency reference signal.

[0014] Furthermore, the test instrument includes a vector network analyzer, or the test instrument includes a signal source and a spectrum analyzer.

[0015] Furthermore, the signal coupling unit is a directional coupler, and the frequency conversion unit is a mixer.

[0016] This invention provides a testing method for an intermediate frequency (IF) interface wireless device, comprising: a test instrument providing an excitation signal, the excitation signal being used to induce a response signal in the wireless device; a signal coupling unit coupling a portion of the signal from the transmission path of the excitation signal as a reference signal; a frequency conversion unit performing frequency conversion on the reference signal to obtain a converted reference signal, the frequency of which is the same as the frequency of the response signal; and the test instrument receiving the response signal and the converted reference signal, and performing same-frequency transmission characteristic measurement based on both. As described above, the testing method for an IF interface wireless device of this invention cleverly converts the reference signal coupled from the transmission path by introducing a signal coupling unit and a frequency conversion unit into the test link, ensuring that its frequency is strictly consistent with the frequency of the response signal output by the wireless device. This design allows the reference receiver and measurement receiver of the test instrument to operate at the exact same frequency, thus successfully transforming the complex frequency conversion test into a conventional same-frequency measurement mode. This not only eliminates the reliance on expensive mixer options during testing, significantly reducing equipment usage costs, but also completely avoids the cumbersome frequency switching and circuit settling time in the "dual-frequency sweep" mode, thereby greatly improving overall testing efficiency. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a testing method for an intermediate frequency interface wireless device provided in an embodiment of the present invention; Figure 2 A schematic diagram of a test architecture provided in an embodiment of the present invention; Figure 3 A schematic diagram of another test architecture provided in an embodiment of the present invention; Figure 4 A schematic diagram of a test architecture for a wireless device in transmission mode, provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of a test architecture for a wireless device in receiving mode, as provided in an embodiment of the present invention. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Currently, traditional testing solutions for intermediate frequency interface wireless devices are costly and inefficient.

[0021] Based on this, in the testing method of the intermediate frequency interface wireless device of the present invention, by introducing a signal coupling unit and a frequency conversion unit in the test link, the reference signal coupled from the transmission path is cleverly frequency-converted so that its frequency is strictly consistent with the frequency of the response signal output by the wireless device. This design enables the reference receiver and the measurement receiver of the test instrument to work at the exact same frequency, thereby successfully transforming the complex frequency conversion test into a conventional same-frequency measurement mode. This not only frees the testing process from dependence on expensive mixer options and significantly reduces the cost of equipment use, but also completely avoids the cumbersome frequency switching and circuit stabilization time in the "dual frequency sweep" mode, thereby greatly improving the overall testing efficiency.

[0022] To facilitate understanding of this embodiment, a testing method for an intermediate frequency interface wireless device disclosed in this embodiment of the invention will first be described in detail.

[0023] Example 1: like Figure 1 As shown, this embodiment provides a testing method for intermediate frequency interface wireless devices. This method constructs a test architecture including test instruments, a signal coupling unit, a frequency conversion unit, and a test antenna, as follows: Figure 2 and Figure 3 As shown, this embodiment enables efficient testing of wireless devices with intermediate frequency interfaces. This example focuses on the core process of the testing method: by using an external frequency conversion mechanism, the frequency of the reference signal is adjusted to match the frequency of the response signal, thereby solving the problem of low testing efficiency caused by frequency differences in existing technologies.

[0024] Specifically, the method includes the following steps: In step S100, the test instrument provides an excitation signal, which is used to cause the wireless device to generate a response signal.

[0025] In step S200, the signal coupling unit couples out a portion of the signal from the transmission path of the excitation signal as a reference signal.

[0026] This reference signal will be used for subsequent frequency conversion processing to construct the reference channel signal required by the test instrument. Specifically, the signal coupling unit can employ a directional coupler, utilizing its directional coupling characteristics to allow the main signal to pass through with extremely low insertion loss, while the coupling end extracts a weak signal with a fixed coupling degree. Alternatively, a power divider (such as a resistive power divider) or coupling probe can be used; however, a power divider will attenuate the energy of the main signal by half, leading to an increase in the total path loss of the link, thus affecting the dynamic range of the link, and should be selected with caution. Any device that can achieve the function of splitting or coupling a reference signal from the transmission path falls within the protection scope of this embodiment. This embodiment preferably uses a directional coupler because it has high isolation characteristics and can ensure the signal integrity of the test link to the greatest extent.

[0027] In step S300, the frequency conversion unit performs frequency conversion on the reference signal to obtain a converted reference signal, the frequency of which is the same as the frequency of the response signal.

[0028] This step is the core technical feature of this embodiment, and the frequency conversion unit is the key component for achieving "same-frequency measurement" in this embodiment. Its input terminal is connected to the coupling output terminal of the signal coupling unit to receive the aforementioned reference signal; its output terminal is connected to the reference receiving port of the test instrument. Internally, the frequency conversion unit shifts the frequency of the reference signal according to a preset frequency conversion scheme. For example, if the reference signal is an intermediate frequency (IF) signal, the frequency conversion unit can up-convert it to a radio frequency (RF) signal; if the reference signal is an RF signal, the frequency conversion unit can down-convert it to an IF signal. In terms of hardware implementation, the frequency conversion unit can be a frequency conversion circuit composed of a mixer, a local oscillator, and a filter, or it can be an integrated frequency converter module or a spread spectrum module. Those skilled in the art can select a specific frequency conversion unit according to actual testing needs, as long as it can achieve the frequency shifting function.

[0029] In step S400, the test instrument receives the response signal and the conversion reference signal, and performs a same-frequency transmission characteristic measurement based on both.

[0030] In traditional technologies, when wireless devices have an intermediate frequency (IF) interface, the reference receiver and measurement receiver of the test instrument often need to operate at different frequencies. For example, when the wireless device is in receive mode, the RF signal output from the test instrument's signal source is radiated through the test antenna. After being received by the wireless terminal, it is down-converted to the IF frequency by the mixer inside the wireless terminal and sent back to the test instrument's measurement receiver from the IF output interface. In other words, the test instrument's measurement receiver operates in the IF band, while the reference receiver operates in the RF band. In this case, the measured S21 reflects the frequency conversion transmission characteristic of "RF input → IF output". Conventional test instruments do not directly support this frequency conversion S21 test method and require the upgrading of additional mixers / frequency conversion test options to achieve it. Even when using test instruments that support this function, limitations in the instrument's internal hardware architecture prevent its common local oscillator from simultaneously providing local oscillator signals to two receivers at different frequencies. This necessitates a "dual-frequency sweep" mode: first, the instrument's hardware resources are set to the reference signal frequency; after the circuit stabilizes, the reference receiver performs the measurement and stores the data; then, the frequency is switched to the response signal frequency, and after stabilization, the measurement receiver performs the measurement. This "set-stabilize-measure" cycle is executed twice at each test frequency, significantly increasing test time and reducing efficiency.

[0031] This embodiment utilizes a frequency conversion unit to convert the reference signal frequency to match the response signal frequency. At this point, the reference receiver and measurement receiver of the test instrument receive signals at the same frequency, enabling the test instrument to operate in the traditional "same-frequency measurement" mode. In this mode, a single local oscillator source within the test instrument can simultaneously provide local oscillator signals to both receivers, achieving synchronous data acquisition between the reference and measurement channels. This design eliminates the time consumption caused by frequency switching and circuit restabilization in traditional technologies, significantly improving test efficiency. It also allows ordinary test instruments without frequency conversion test options to perform such test tasks, reducing test costs.

[0032] This embodiment provides a detailed description of an application scenario where the wireless device is in transmission mode.

[0033] Specifically, when the wireless device is in transmit mode, the signal output port P1 of the test instrument (such as a vector network analyzer, VNA) outputs an intermediate frequency excitation signal, such as... Figure 4As shown, the signal is transmitted to the intermediate frequency (IF) input interface of the wireless device. The wireless device, acting as the transmitter, uses its integrated up-conversion module (such as a mixer) to up-convert the IF excitation signal, converting it into a radio frequency (RF) signal. This RF signal is then transmitted via its own antenna through the over-the-air (OTA) interface. The receiving antenna (i.e., the test antenna for receiving the signal) receives this RF signal and sends it to the measurement receiving port P4 of the test instrument. The response signal output by the wireless device at this point is the RF signal.

[0034] Meanwhile, to establish conditions for same-frequency measurement, a signal coupling unit is connected to the link between the test instrument and the intermediate frequency (IF) input interface of the wireless device, coupling a portion of the IF excitation signal as a reference signal. Since the reference signal is still an IF signal at this time, while the measurement receiving port P4 receives a radio frequency (RF) signal, the two frequencies are different, making direct same-frequency measurement impossible. Therefore, the frequency conversion unit receives this IF reference signal and up-converts it to the same frequency band as the RF signal transmitted by the wireless device, outputting an RF reference signal. This RF reference signal is then sent to the reference receiving port P2 of the test instrument.

[0035] In this embodiment, the local oscillator signal (i.e., the local oscillator signal) required for up-conversion processing by the frequency conversion unit can be provided by the VNA's built-in source through its auxiliary output port P3, or by an external independent signal source (the external independent signal source needs to be clock-synchronized with the test instrument's built-in source). By appropriately setting the frequency of the local oscillator signal, the frequency of the RF reference signal output by the frequency conversion unit is precisely equal to the frequency of the RF signal transmitted by the wireless device. At this time, the reference receiving port P2 of the test instrument receives the RF reference signal, and the measurement receiving port P4 receives the RF signal, both at completely identical frequencies. The receiver inside the test instrument can operate synchronously at the same local oscillator frequency, thereby achieving synchronous measurement of the wireless device's transmission link characteristics.

[0036] This embodiment solves the problem of inconsistency between the reference signal (IF) and the response signal (RF) frequencies in transmission mode by up-converting the reference signal. Compared to existing technologies that require test instruments to perform two separate frequency sweep measurements for the IF and RF frequencies, the method in this embodiment allows the test instruments to complete data acquisition synchronously, avoiding the time loss caused by frequency switching and significantly improving test efficiency in transmission mode. Furthermore, this solution eliminates the need for expensive frequency conversion measurement options on the test instruments, reducing test costs.

[0037] The following embodiment provides a detailed description of an application scenario where the wireless device is in receive mode.

[0038] Specifically, when the wireless device is in receive mode, the signal output port P1 of the test instrument (e.g., VNA) outputs an RF excitation signal, such as... Figure 5 As shown. The RF excitation signal is transmitted to the transmitting antenna (i.e., the test antenna for transmitting the signal), which radiates it out through the over-the-air (OTA) interface. The wireless device receives this OTA signal through its own antenna and transmits it to its internal RF input interface. The down-conversion module (such as a mixer) integrated inside the wireless device processes the RF excitation signal, down-converting it to an intermediate frequency (IF) signal, and outputs it through the IF output interface to the measurement receiving port P4 of the test instrument. At this time, the response signal output by the wireless device is the IF signal.

[0039] Meanwhile, to establish the same-frequency measurement conditions, a signal coupling unit is connected to the link between the signal output port P1 of the test instrument and the transmitting antenna, coupling out a portion of the transmitted radio frequency excitation signal as a reference signal. Since the reference signal is a radio frequency signal at this time, while the measurement receiving port P4 receives the intermediate frequency (IF) signal output by the wireless device, the two signals have different frequencies and cannot be directly measured at the same frequency. Therefore, the frequency conversion unit receives the radio frequency reference signal and down-converts it to the same frequency band as the IF signal output by the wireless device, outputting an IF reference signal. This IF reference signal is sent to the reference receiving port P2 of the test instrument.

[0040] In this embodiment, the local oscillator signal (i.e., the local oscillator signal) required for down-conversion processing by the frequency conversion unit can also be provided by the VNA's built-in source through its auxiliary output port P3 or by an external signal source. By appropriately setting the frequency of the local oscillator signal, the frequency of the intermediate frequency (IF) reference signal output by the frequency conversion unit is precisely equal to the frequency of the IF signal output by the wireless device. At this time, the reference receiving port P2 of the test instrument receives the IF reference signal, and the measurement receiving port P4 receives the IF signal; their frequencies are completely identical. The receiver inside the test instrument can operate synchronously at the same local oscillator frequency, thereby achieving synchronous measurement of the wireless device's receiving link transmission characteristics.

[0041] This embodiment solves the problem of frequency inconsistency between the reference signal (RF) and the response signal (IF) in the receiving mode by down-converting the reference signal, thus covering downlink testing scenarios. Compared with existing technologies, this embodiment also eliminates the need for test instruments with frequency conversion measurement options and avoids the time loss caused by the "dual frequency sweep" mode, significantly improving testing efficiency in the receiving mode. Combined with uplink testing scenarios, the method provided by this invention can fully cover the entire transmission and reception testing of wireless devices, forming a complete testing solution.

[0042] This embodiment mainly provides a detailed description of the specific hardware structure for implementing frequency conversion, signal coupling, and signal source provision. It should be understood that the specific hardware devices described below are merely preferred examples for implementing the technical solution of this invention and are not intended to limit the scope of protection of this invention. Those skilled in the art can select devices with equivalent functions to replace them according to actual testing needs.

[0043] Specifically, regarding the implementation of the frequency conversion unit, in this embodiment, the frequency conversion unit is preferably a mixer. A mixer is a typical nonlinear device that utilizes its nonlinear characteristics to achieve frequency mixing. The mixer receives two input signals: one is a reference signal from the signal coupling unit, and the other is a local oscillator signal (LoU). The mixer internally mixes these two signals, using its nonlinear characteristics to generate new frequency components, mainly including the sum and difference frequencies of the two input signals. Through subsequent filtering, the desired frequency components can be selected, thereby achieving the shifting of the reference signal frequency. For example, in the transmit mode test, the mixer uses the LoU signal to up-convert the intermediate frequency reference signal to an radio frequency reference signal; in the receive mode test, the mixer down-converts the radio frequency reference signal to an intermediate frequency reference signal. The mixer has the advantages of simple structure, low conversion loss, and low cost, making it very suitable for application in the test system of this invention. Of course, besides a mixer, the frequency conversion unit can also be implemented using an integrated frequency converter module or a spread spectrum module, as long as it can achieve the function of converting the input signal frequency to the desired output frequency. Alternatively, the frequency conversion unit can also use a phase-locked loop-based frequency synthesizer. In this case, there is no need for the test instrument to provide a continuous wave local oscillator signal; frequency conversion can be achieved simply by receiving the reference clock output by the test instrument.

[0044] Regarding the implementation of the signal coupling unit, in this embodiment, the signal coupling unit is preferably a directional coupler. A directional coupler is a four-port microwave device with directional transmission characteristics. It consists of a main line and a secondary line. The main line is connected in series in the transmission path of the excitation signal, while the secondary line is used to couple the output signal. The core advantage of the directional coupler lies in its weak intrusive sampling characteristic: when the main line transmits the excitation signal, the secondary line can proportionally couple out a portion of the energy as a reference signal, with minimal impact on the transmission of the main line signal (low insertion loss). It also has high directivity, effectively distinguishing between forward and reverse signals, thereby reducing the impact of secondary line side reflections on the main path test. This makes the directional coupler very suitable for extracting reference signals from the test link. Those skilled in the art should understand that, in addition to directional couplers, the signal coupling unit can also be implemented using power dividers (such as Wilkinson power dividers), coupling probes, microstrip couplers, or resistive power dividers, as long as they can achieve the function of splitting the reference signal from the transmission path.

[0045] Furthermore, the testing method and system of this embodiment are particularly suitable for wireless devices with intermediate frequency (IF) interfaces. These wireless devices include an IF input interface and / or an IF output interface. Such devices are especially common in satellite internet communication terminals, typically integrating a frequency conversion module internally and exposing only the IF interface externally, without directly providing a radio frequency (RF) port for testing. This invention, by introducing the aforementioned signal coupling unit and frequency conversion unit into the test link, successfully solves the problem of low testing efficiency and high cost caused by interface frequency mismatch in OTA testing of such devices, and has extremely high practical value.

[0046] Example 2: This embodiment provides a testing system for intermediate frequency interface wireless devices. This system and the method embodiment one belong to the same inventive concept and are used to implement the above-described testing method. Figure 2 and Figure 3 As shown, the test system mainly includes test instruments, a signal coupling unit, a frequency conversion unit, and a test antenna. Each module is connected sequentially according to the signal flow direction via transmission media such as RF cables or waveguides, forming a complete test link.

[0047] Specifically, in this embodiment, the test antenna is configured to establish an air interface transmission link with the wireless device; the test instrument includes at least three key ports: a signal output port, a reference receiving port, and a measurement receiving port. The signal output port outputs an excitation signal to the wireless device, which in turn excites the wireless device to generate a response signal. The measurement receiving port receives the response signal output by the wireless device: when the wireless device is in transmit mode, it radiates a radio frequency signal in response to the excitation signal, and the test antenna receives this radio frequency signal and transmits it as a response signal to the measurement receiving port; when the wireless device is in receive mode, the excitation signal is radiated through the test antenna, and the wireless device receives this radiated signal and outputs a response signal to the measurement receiving port, which reflects the processing result of the excitation signal by the wireless device. The reference receiving port receives a converted reference signal, which serves as a measurement reference for calculating transmission characteristics (such as parameters in S21). It should be understood that the model and number of ports of the test instrument do not constitute a limitation on the present invention, as long as the ports have the above-mentioned functions.

[0048] The signal coupling unit is configured to connect to the test link, coupling a portion of the signal from the transmission path of the excitation signal as a reference signal. Physically, the signal coupling unit is connected in series in the transmission path between the signal output port and the wireless device, or in series between the signal output port and the test antenna (which acts as the transmitting antenna in this case), depending on the operating mode of the wireless device. The signal coupling unit has a main input terminal, a main output terminal, and a coupled output terminal. The main input and main output terminals are connected in series in the main transmission path of the excitation signal, allowing most of the signal energy to pass through; the coupled output terminal extracts a small portion of the signal energy as a reference signal and transmits it to the frequency conversion unit. This connection method allows for real-time acquisition of the reference signal without interrupting the main signal transmission, ensuring the continuity of the test.

[0049] The frequency conversion unit is connected to the signal coupling unit. Its input is connected to the coupling output of the signal coupling unit, and its output is connected to the reference receiving port of the test instrument. The core function of the frequency conversion unit is to perform frequency conversion on the reference signal. Since the frequency of the reference signal coupled out by the signal coupling unit may differ from the frequency of the response signal received by the measurement receiving port, directly inputting it to the reference receiving port of the test instrument would prevent the instrument from performing simultaneous frequency measurements. Therefore, the frequency conversion unit shifts the frequency of the reference signal according to a preset frequency conversion rule, ensuring that the frequency of the converted reference signal output to the reference receiving port is the same as the frequency of the response signal. For example, when the reference signal is intermediate frequency (IF) and the response signal is radio frequency (RF), the frequency conversion unit performs an up-conversion operation; conversely, it performs a down-conversion operation.

[0050] As an example, the test instruments include a vector network analyzer, or a signal generator and a spectrum analyzer. It is understood that the latter configuration lacks frequency sweep testing capabilities and can only perform point-by-point testing. While it can achieve the same testing purpose as a vector network analyzer, it is less efficient.

[0051] With the aforementioned hardware architecture, the test system in this embodiment successfully constructs a frequency-adjustable reference channel. The test instrument's signal output port outputs an excitation signal, the signal coupling unit couples a reference signal from the test link, and the frequency conversion unit converts this reference signal into a signal with the same frequency as the response signal and sends it to the reference receiving port. At this time, the test instrument's reference receiver and measurement receiver operate at the same frequency, enabling synchronous data acquisition using the traditional S21 measurement mode. This system architecture eliminates the need for expensive frequency conversion test components in the test instrument, reducing hardware costs; simultaneously, it significantly improves test efficiency by avoiding the "dual frequency sweep" operation required in traditional technologies due to frequency differences.

[0052] This embodiment provides a detailed description of the connection topology between various units within a testing system for wireless devices under different operating modes. It should be understood that this embodiment and the aforementioned method embodiment respectively illustrate the same inventive concept from the perspectives of system architecture and method flow, and their technical features correspond to each other.

[0053] Specifically, when the wireless device is in transmit mode, the connection topology of the test system is as follows: a signal coupling unit is connected between the signal output port of the test instrument and the intermediate frequency (IF) input interface of the wireless device. At this time, the excitation signal output by the test instrument is an IF excitation signal, which is transmitted to the IF input interface of the wireless device via the signal coupling unit. The signal coupling unit couples a portion of this IF excitation signal as a reference signal and transmits it to the frequency conversion unit. Since the wireless device is in transmit mode, its output response signal is a radio frequency (RF) signal. To meet the conditions for same-frequency measurement, the frequency conversion unit is configured to up-convert the received IF reference signal to an RF reference signal and output it to the reference receiving port of the test instrument. Simultaneously, the measurement receiving port of the test instrument receives the RF signal transmitted by the wireless device. Through this connection topology, it is ensured that the signal frequencies received by the reference receiving port and the measurement receiving port are the same, thereby achieving efficient same-frequency measurement in transmit mode.

[0054] When the wireless device is in receive mode, the connection topology of the test system needs to be adjusted accordingly: the signal coupling unit is connected between the signal output port of the test instrument and the transmitting antenna. At this time, the excitation signal output by the test instrument is a radio frequency (RF) excitation signal, which is transmitted to the transmitting antenna via the signal coupling unit and radiated to the wireless device through the air interface. The signal coupling unit couples a portion of this RF excitation signal as a reference signal and transmits it to the frequency conversion unit. Since the wireless device is in receive mode, its output response signal is an intermediate frequency (IF) signal. To meet the conditions for same-frequency measurement, the frequency conversion unit is configured to down-convert the received RF reference signal to an IF reference signal and output it to the reference receiving port of the test instrument. Simultaneously, the measurement receiving port of the test instrument receives the RF signal transmitted by the wireless device (sent in via the receiving antenna). Through this connection topology, it is also ensured that the signal frequencies received by the reference receiving port and the measurement receiving port are the same, thus achieving efficient same-frequency measurement in receive mode.

[0055] This embodiment allows for flexible adjustment of the signal coupling unit's access position and the frequency conversion unit's frequency conversion direction, enabling the same test system to be compatible with both transmit and receive modes in different test scenarios. This configurability of the connection topology greatly enhances the versatility and practicality of the test system, allowing for comprehensive testing of the wireless device's transceiver link without replacing core test equipment. In practice, this connection switching can be achieved by manually replacing RF cables or by integrating a multi-channel switch matrix into the system for automated switching; this embodiment does not impose specific limitations on either approach.

[0056] This embodiment provides a low-cost, easy-to-implement hardware setup solution, which is particularly suitable for laboratory environments or production line testing scenarios.

[0057] Specifically, in this embodiment, the signal coupling unit is preferably a directional coupler. A directional coupler is a standard RF / microwave device, readily available and inexpensive on the market. When selecting one, the following parameters are mainly considered: First, the frequency range. The operating frequency range of the directional coupler must cover the excitation signal frequency output by the test instrument, whether it is an intermediate frequency signal or an RF signal, ensuring it is within the coupler's passband. Second, the coupling degree. Typically, devices with a coupling degree between 10dB and 20dB are selected. A smaller coupling degree results in a stronger coupled reference signal, but also introduces greater insertion loss to the main path, potentially affecting the transmission quality of the main path signal. A larger coupling degree results in less insertion loss to the main path, but the coupled reference signal may be too weak, falling below the sensitivity limit of the test instrument's reference receiver. Therefore, a trade-off must be made based on the actual signal power and receiver sensitivity. Finally, directivity and isolation are important. A highly directional coupler can effectively suppress the influence of reflected signals on the coupling port, improving the purity of the reference signal. In practical connections, the input of the directional coupler is connected to the signal output port of the test instrument, the output is connected to the wireless device or transmitting antenna, and the coupling port is connected to the input of the frequency conversion unit. This connection method is simple and straightforward, allowing testers to quickly set up the test system.

[0058] For the frequency conversion unit, a mixer is preferred in this embodiment. A mixer is also a mature standard device, and its core function is to achieve frequency shifting using nonlinear characteristics. When selecting a mixer, the frequency coverage range should be a key consideration; the frequency ranges of its RF port, IF port, and local oscillator port must all meet the test requirements. For example, during transmit mode testing, the mixer's IF port must support the input IF reference signal, and the RF port must support the output RF reference signal; the opposite is true for receive mode testing. Furthermore, conversion loss should be considered. Lower conversion loss means higher conversion efficiency and less signal power loss, which helps ensure that the signal input to the reference receiving port of the test instrument has a sufficient signal-to-noise ratio. The mixer's local oscillator port is connected to the auxiliary output port of the test instrument to receive the local oscillator signal. It should be understood that a mixer is only one preferred method for frequency conversion. In other embodiments, the frequency conversion unit can also be implemented using integrated up-conversion modules, down-conversion modules, or frequency synthesizers with the same function; this embodiment does not impose any limitations on this.

[0059] By employing the aforementioned standard directional couplers and mixers as core components, the test system in this embodiment is entirely built from general-purpose devices, eliminating the need to purchase expensive dedicated frequency converter test options or customized test equipment. This not only significantly reduces the hardware cost of the test system but also improves its maintainability and interchangeability. When test requirements change, only the coupler or mixer for the corresponding frequency band needs to be replaced, without replacing the core test instruments, greatly enhancing the flexibility and versatility of the test system.

[0060] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0061] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0062] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A testing method for an intermediate frequency interface wireless device, characterized in that, include: The test instrument provides an excitation signal, which is used to cause the wireless device to generate a response signal; The signal coupling unit couples out a portion of the signal from the transmission path of the excitation signal as a reference signal; The frequency conversion unit performs frequency conversion on the reference signal to obtain a converted reference signal, the frequency of which is the same as the frequency of the response signal; The test instrument receives the response signal and the conversion reference signal, and performs same-frequency transmission characteristic measurement based on both.

2. The method according to claim 1, characterized in that, When the wireless device is in transmit mode; The test instrument provides an intermediate frequency excitation signal as the excitation signal and outputs it to the intermediate frequency input interface of the wireless device. The wireless device upconverts the intermediate frequency excitation signal into a radio frequency signal and transmits it over the air interface through the antenna of the wireless device. The test antenna receives the radio frequency signal and sends it as the response signal to the measurement receiving port of the test instrument; The signal coupling unit couples out a portion of the signal from the transmission path of the intermediate frequency excitation signal as the reference signal; The frequency conversion unit up-converts the reference signal into a radio frequency reference signal, which is then output as the converted reference signal to the reference receiving port of the test instrument. The frequency of the radio frequency reference signal is the same as the frequency of the radio frequency signal.

3. The method according to claim 1, characterized in that, When the wireless device is in receive mode; The test instrument provides a radio frequency excitation signal as the excitation signal, outputs it to the test antenna, and transmits it through the test antenna via the air interface. The wireless device receives the radio frequency excitation signal, down-converts it to an intermediate frequency signal, and sends it as the response signal to the measurement receiving port of the test instrument. The signal coupling unit couples out a portion of the signal from the transmission path of the radio frequency excitation signal as the reference signal; The frequency conversion unit down-converts the reference signal into an intermediate frequency reference signal, and outputs it as the converted reference signal to the reference receiving port of the test instrument. The frequency of the intermediate frequency reference signal is the same as the frequency of the intermediate frequency signal.

4. The method according to claim 1, characterized in that, The frequency conversion unit includes a mixer; The mixer receives the local oscillator signal provided by the test instrument and performs mixing processing on the reference signal based on the local oscillator signal to achieve the frequency conversion processing.

5. The method according to claim 1, characterized in that, The signal coupling unit includes a directional coupler, which is connected in series in the transmission path of the excitation signal and couples out the reference signal.

6. The method according to claim 1, characterized in that, The wireless device includes an intermediate frequency (IF) input interface and / or an IF output interface.

7. A test system for intermediate frequency interface wireless devices, characterized in that, include: Test the antenna and configure it to establish an air interface transmission link with the wireless device; The test instrument includes a signal output port, a reference receiving port, and a measurement receiving port. The test instrument is configured to provide an excitation signal through the signal output port, receive a response signal generated by the wireless device through the measurement receiving port, and receive a converted reference signal through the reference receiving port. The signal coupling unit is configured to couple a portion of the signal from the transmission path of the excitation signal as a reference signal; A frequency conversion unit, connected to the signal coupling unit, is configured to receive the reference signal, perform frequency conversion on the reference signal to obtain the converted reference signal, and output it to the reference receiving port of the test instrument. The frequency of the converted reference signal is the same as the frequency of the response signal.

8. The system according to claim 7, characterized in that, When the wireless device is in transmit mode, the signal coupling unit is connected between the signal output port and the intermediate frequency input interface of the wireless device, and the frequency conversion unit is configured to upconvert the reference signal into a radio frequency reference signal; When the wireless device is in receive mode, the signal coupling unit is connected between the signal output port and the test antenna, and the frequency conversion unit is configured to downconvert the reference signal into an intermediate frequency reference signal.

9. The system according to claim 7, characterized in that, The test instrument includes a vector network analyzer, or the test instrument includes a signal source and a spectrum analyzer.

10. The system according to claim 7, characterized in that, The signal coupling unit is a directional coupler, and the frequency conversion unit is a mixer.

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