A terahertz broadband up-down conversion device and an implementation method thereof

Abstract

The application belongs to the technical field of spectrum analysis, and discloses a terahertz broadband up-conversion and down-conversion device and an implementation method thereof, which comprises: a local oscillator intermediate frequency multiplex port connected with an analyzer unit, used for receiving a local oscillator signal output by the analyzer unit; a diplexer; a local oscillator signal processor, used for filtering harmonic components of the local oscillator signal, and combining a local oscillator excitation frequency required for frequency conversion of the local oscillator signal to a target position; a mixing processor, used for receiving the local oscillator signal according to a radio frequency result of the local oscillator excitation frequency, and combining a waveguide interface to obtain an intermediate frequency signal output by a measured waveband terahertz signal; and an intermediate frequency signal processor. The application is based on flexible local oscillator and intermediate frequency port jumper design, so that it can not only be used for spectrum analysis of terahertz frequency band down-conversion, but also be used for signal output of terahertz frequency band broadband vector signal up-conversion.

Description

Technical Field

[0001] This invention relates to the field of spectrum analysis technology, and in particular to a terahertz broadband up-conversion device and its implementation method. Background Technology

[0002] Spectrum analysis in the terahertz band is usually performed by connecting a spectrum analyzer to a dedicated terahertz downconversion device, which downconverts the terahertz signal to the intermediate frequency of the spectrum analyzer for spectrum measurement. The generation of terahertz signals is usually performed by connecting a signal source to a dedicated terahertz upconversion device, which upconverts the millimeter-wave signal generated by the signal source to the terahertz band output through a mixer or frequency multiplier.

[0003] In terahertz frequency spectrum analysis, the local oscillator signal is output from the spectrum analyzer to provide the local oscillator signal for the downconverter. Existing spectrum analyzers also incorporate a duplexer, a dual-channel filter containing a high-pass filter (HPF) and a low-pass filter (LPF), to combine the local oscillator output and intermediate frequency input into a single port, simplifying the test connection. Figure 7 As shown, in order to improve performance and simplify the internal structure, the local oscillator output and intermediate frequency input of the spectrum analyzer are two different RF ports, such as... Figure 8 As shown.

[0004] However, existing up and down frequency converters have the following drawbacks:

[0005] (1) Although the internal components of the spectrum analyzer downconverter and the signal source upconverter using the mixed frequency working mode are the same and the structure is similar, they are usually designed as independent downconverter modules or upconverter modules. If it is necessary to measure the spectrum of terahertz signals and generate terahertz frequency band signals, it is necessary to purchase downconverter modules and upconverter modules respectively.

[0006] (2) A downconversion module that shares a port for local oscillator input and intermediate frequency output can only be adapted to a spectrum analyzer that shares a RF port for local oscillator output and intermediate frequency input. A downconversion module that has two ports for local oscillator input and intermediate frequency output can also only be adapted to a spectrum analyzer with two ports for local oscillator output and intermediate frequency input, which significantly reduces the compatibility of the downconversion module.

[0007] Therefore, how to provide a terahertz broadband up-conversion device and its implementation method is an urgent problem to be solved. Summary of the Invention

[0008] This invention provides a terahertz broadband up-conversion device and its implementation method to solve the problem of poor compatibility of up-conversion devices in the prior art.

[0009] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or to describe the scope of protection of these embodiments. Its sole purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0010] According to a first aspect of the present invention, a terahertz broadband up-conversion / down-conversion device is provided.

[0011] In one embodiment, a terahertz broadband up / down converter includes:

[0012] The local oscillator intermediate frequency multiplexing port connected to the analyzer unit is used to receive the local oscillator signal output by the analyzer unit;

[0013] A duplexer is used to connect to the local oscillator intermediate frequency multiplexing port to obtain the local oscillator signal, output to the local oscillator link, and perform low-pass filtering on the input signal during spectrum analysis.

[0014] The local oscillator signal processor is used to filter out the harmonic components of the local oscillator signal and, in conjunction with the local oscillator link, convert the local oscillator signal to the local oscillator excitation frequency required for the target position.

[0015] A mixer processor is used to receive the local oscillator signal based on the RF result of the local oscillator excitation frequency, and to obtain the intermediate frequency signal of the terahertz signal of the measured band by combining the waveguide interface.

[0016] The intermediate frequency signal processor is used to isolate the DC component of the intermediate frequency signal and input the intermediate frequency signal to the analyzer unit after up-conversion and down-conversion modulation to complete the spectrum analysis of the terahertz signal in the measured band.

[0017] The output of the analyzer unit is connected to the input of the local oscillator intermediate frequency multiplexing port. The output of the local oscillator intermediate frequency multiplexing port is connected to the input of the duplexer. The output of the duplexer is connected to the input of the local oscillator signal processor. The output of the local oscillator signal processor is connected to the input of the mixer processor. The output of the mixer processor is connected to the input of the intermediate frequency signal processor. The output of the intermediate frequency signal processor is connected to the input of the analyzer unit.

[0018] In one embodiment, the duplexer includes a high-pass filter and a low-pass filter;

[0019] A high-pass filter is used to connect to the local oscillator intermediate frequency multiplexing port to obtain the local oscillator signal, and the output is connected to the local oscillator link.

[0020] A low-pass filter is used to filter out stray components in the intermediate frequency signal during the application of a mixer processor, thereby improving the purity of the spectrum analysis.

[0021] In one embodiment, the local oscillator signal processor includes:

[0022] The first bandpass filter is used to filter out the harmonic components of the local oscillator signal;

[0023] A frequency doubler is used for the first-stage local oscillator frequency multiplication.

[0024] First jumper port;

[0025] The high-frequency local oscillator input jumper port is used to process the local oscillator signal and output a clean local oscillator excitation.

[0026] A power amplifier is used to provide drive power for the second-stage frequency multiplier.

[0027] The second bandpass filter is used to filter the frequency multiplier output of the first-stage local oscillator.

[0028] A six-fold frequency multiplier is used to multiply the local oscillator signal to the local oscillator excitation frequency required by the mixer processor;

[0029] An isolator is used to improve the local oscillator port matching of the mixer and prevent reflected signals from the local oscillator port from entering the mixer and participating in mixing, thus generating spurious components.

[0030] The input of the first bandpass filter is connected to the output of the high-pass filter. The output of the first bandpass filter is connected to the input of the first jumper port. The output of the first jumper port is connected to the input of the high-frequency local oscillator input jumper port. The output of the high-frequency local oscillator input jumper port is connected to the input of the power amplifier. The output of the power amplifier is connected to the input of the second bandpass filter. The output of the second bandpass filter is connected to the input of the sixth frequency multiplier. The output of the sixth frequency multiplier is connected to the input of the isolator. The output of the isolator is connected to the input of the mixer processor.

[0031] In one embodiment, the intermediate frequency signal processor includes:

[0032] An isolator is used to isolate DC components and prevent damage to the mixer from external DC input at the intermediate frequency port;

[0033] Intermediate frequency input / output jumper port;

[0034] The second jumper port is used to connect to the corresponding modulation signal analyzer according to the frequency conversion working mode to perform up and down frequency conversion processing.

[0035] A low-noise amplifier is used to reduce the noise figure of the subsequent analyzer unit. Its output is connected to the low-pass filter, which filters out the spurious components generated by the mixer processor.

[0036] The input of the isolator is connected to the output of the mixer, the output of the isolator is connected to the input of the intermediate frequency (IF) input / output jumper port, the output of the IF input / output jumper port is connected to the input of the second jumper port, the output of the second jumper port is connected to the input of the low-noise amplifier, and the output of the low-noise amplifier is connected to the input of the low-pass filter.

[0037] In one embodiment, connecting a corresponding modulation signal analyzer according to the frequency conversion operating mode and performing up-conversion / down-conversion processing includes:

[0038] When in broadband downconversion mode, the second jumper port is used to connect the broadband intermediate frequency output to a broadband modulation signal analysis instrument.

[0039] When in broadband upconversion mode, the second jumper port is used to connect to a broadband vector signal source and upconvert the broadband modulated signal to the terahertz band via a mixer.

[0040] In one embodiment, the analyzer unit is one of the following: a first spectrum analyzer with a local oscillator and intermediate frequency multiplexing port; a second spectrum analyzer with two working modes, local oscillator output and intermediate frequency input port; a signal source as local oscillator output and signal analyzer as intermediate frequency input; a signal source as local oscillator signal data; and a vector signal source that generates microwave broadband modulation signals.

[0041] According to a second aspect of the present invention, a method for implementing a terahertz broadband up-conversion device is provided.

[0042] In one embodiment, the method for implementing a terahertz broadband up-conversion device includes:

[0043] The local oscillator signal is output by the analyzer unit and multiplied to the local oscillator excitation frequency required by the mixer based on the six-fold frequency multiplier. After the frequency multiplication is completed, the local oscillator signal is input to the mixer.

[0044] The terahertz signal of the measured band is input through the waveguide interface and combined with the local oscillator signal to output the intermediate frequency signal using a mixer processor.

[0045] The intermediate frequency signal is converted between up and down frequencies using the frequency conversion mode. Based on the processing result, a low-pass filter is applied to filter out spurious components from the intermediate frequency signal, and the processing result is input to the analyzer unit.

[0046] In one embodiment, the local oscillator signal is output from the analyzer unit, and the local oscillator signal is multiplied to the local oscillator excitation frequency required by the mixer processor based on a six-fold frequency multiplier. After the frequency multiplication is completed, the local oscillator signal is input to the mixer processor, which includes:

[0047] Connect the local oscillator intermediate frequency multiplexing port to the analyzer unit output port and output it to the input of the duplexer. Use the high-pass filter output of the duplexer to connect the local oscillator link to the first bandpass filter.

[0048] The harmonic components of the local oscillator signal are filtered out using the first bandpass filter, and the first stage local oscillator output is generated in the local oscillator link and sent to the sixth frequency multiplier to generate the local oscillator signal at the target frequency.

[0049] An isolator is used to improve the local oscillator port matching state of the mixer, preventing the reflected signal from the local oscillator port from entering the mixer and participating in mixing, and the local oscillator signal is input to the mixer based on the improvement result.

[0050] In one embodiment, the intermediate frequency (IF) signal is subjected to up-down-down frequency conversion processing using a frequency conversion mode, and a low-pass filter is applied to the IF signal to remove spurious components based on the processing result. The processing result is then input to the analyzer unit, including:

[0051] The output process of the intermediate frequency signal based on the mixer processor uses an isolator to isolate the DC component to avoid damage to the mixer processor. When in broadband downconversion mode, the intermediate frequency signal output is connected to the broadband modulation signal analysis instrument through the second jumper port.

[0052] When in broadband upconversion mode, the broadband vector signal source is connected via the second jumper port, and the intermediate frequency signal is upconverted to the terahertz band by the mixer.

[0053] After the up-and-down frequency processing is completed, the second jumper port is connected to the noise amplifier to reduce the noise figure of the analyzer unit. Once the noise figure and noise floor value meet the requirements, the process stops, and the intermediate frequency signal is input to the low-pass filter to filter out the spurious components generated by the mixer. The processed intermediate frequency signal is then input to the analyzer unit.

[0054] In one embodiment, the noise figure of the analyzer unit ranges from 15 to 20 dB, and the noise floor is -155 dBm / Hz.

[0055] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0056] This invention is based on a flexible local oscillator and intermediate frequency (IF) port jumper design, which enables it to be used not only for spectrum analysis of terahertz downconversion but also for signal output of terahertz broadband vector signals upconversion. At the same time, through the built-in duplexer and flexible port jumper design, it supports local oscillator / IF sharing a single port input / output, or local oscillator / IF using their own independent port input / output. When used for downconversion measurements in a spectrum analyzer, it can be flexibly adapted to the frequency expansion of spectrum analyzers from different manufacturers.

[0057] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0058] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0059] Figure 1 This is a schematic block diagram of a terahertz broadband up-conversion device according to an exemplary embodiment;

[0060] Figure 2 This is a flowchart illustrating an implementation method of a terahertz broadband up-conversion device according to an exemplary embodiment;

[0061] Figure 3 This is a test connection diagram of a terahertz broadband up-conversion device for a spectrum analyzer intermediate frequency / local oscillator multiplexing interface, according to an exemplary embodiment.

[0062] Figure 4 This is an exemplary embodiment illustrating a terahertz broadband up-conversion device for testing the independent interface of intermediate frequency and local oscillator in a spectrum analyzer.

[0063] Figure 5 This is a schematic diagram illustrating an application scenario of a terahertz broadband up-conversion device for broadband down-conversion, according to an exemplary embodiment.

[0064] Figure 6 This is a schematic diagram illustrating an application scenario of a terahertz broadband up-conversion device for broadband up-conversion, according to an exemplary embodiment.

[0065] Figure 7 This is a schematic diagram of a terahertz spectrum analysis spread spectrum device with a local oscillator / intermediate frequency multiplexed RF port;

[0066] Figure 8 This is a schematic diagram of a terahertz spectrum analysis spread spectrum device that uses different radio frequency ports for local oscillator output and intermediate frequency input.

[0067] Figure label:

[0068] 1. Analyzer unit; 2. Local oscillator and intermediate frequency multiplexing port; 3. Duplexer; 4. Local oscillator signal processor; 5. Mixer processor; 6. Intermediate frequency signal processor. Detailed Implementation

[0069] The following description and accompanying drawings fully illustrate specific embodiments described herein to enable those skilled in the art to practice them. Some embodiments may include or substitute parts and features of other embodiments. The scope of the embodiments herein encompasses the entire scope of the claims and all available equivalents thereof. Throughout this document, the terms “first,” “second,” etc., are used only to distinguish one element from another without requiring or implying any actual relationship or order between the elements. Indeed, a first element can also be referred to as a second element, and vice versa. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure, apparatus, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a structure, apparatus, or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the structure, apparatus, or device that includes said element. The various embodiments described herein are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.

[0070] The terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this document to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are used solely for the convenience of describing the document 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. In the description herein, unless otherwise specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two elements; they can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0071] In this document, unless otherwise stated, the term "multiple" means two or more.

[0072] In this article, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0073] In this article, the term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0074] It should be understood that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order constraint on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the diagram may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0075] The modules in the apparatus or system of this application can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0076] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0077] Figure 1 An embodiment of the terahertz broadband up-conversion device of the present invention is shown.

[0078] In this optional embodiment, the terahertz broadband up / down converter includes:

[0079] The local oscillator intermediate frequency multiplexing port 2, which is connected to the analyzer unit 1, is used to receive the local oscillator signal output by the analyzer unit;

[0080] The duplexer 3 is used to connect to the local oscillator intermediate frequency multiplexing port 2 to obtain the local oscillator signal, output to the local oscillator link, and perform low-pass filtering on the input signal during spectrum analysis.

[0081] Local oscillator signal processor 4 is used to filter out the harmonic components of the local oscillator signal and, in conjunction with the local oscillator link, convert the local oscillator signal to the local oscillator excitation frequency required for the target position.

[0082] Mixer processor 5 is used to receive the local oscillator signal based on the RF result of the local oscillator excitation frequency, and to obtain the intermediate frequency signal of the terahertz signal of the measured band by combining the waveguide interface, i.e., fundamental frequency mixer 111.

[0083] The intermediate frequency signal processor 6 is used to isolate the DC component of the intermediate frequency signal and input the intermediate frequency signal to the analyzer unit 1 after up-conversion and down-conversion modulation to complete the spectrum analysis of the terahertz signal in the measured band.

[0084] The output of analyzer unit 1 is connected to the input of local oscillator intermediate frequency multiplexing port 2. The output of local oscillator intermediate frequency multiplexing port 2 is connected to the input of duplexer 3. The output of duplexer 3 is connected to the input of local oscillator signal processor 4. The output of local oscillator signal processor 4 is connected to the input of mixer processor 5. The output of mixer processor 5 is connected to the input of intermediate frequency signal processor 6. The output of intermediate frequency signal processor 6 is connected to the input of analyzer unit 1.

[0085] In this optional embodiment, the duplexer 3 includes a high-pass filter and a low-pass filter;

[0086] The high-pass filter is used to connect to the local oscillator intermediate frequency multiplexing port to obtain the local oscillator signal, and the output is connected to the local oscillator link; the low-pass filter is used to filter out the spurious components in the intermediate frequency signal during the application of the mixer processor, thereby improving the purity of the spectrum analysis.

[0087] In this optional embodiment, the local oscillator signal processor 4 includes:

[0088] The first bandpass filter 103 is used to filter out the harmonic components of the local oscillator signal;

[0089] Frequency doubler 104 is used for the first-stage local oscillator frequency doubling;

[0090] First jumper port 105;

[0091] The high-frequency local oscillator input jumper port 106 is used to process the local oscillator signal and output a clean local oscillator excitation.

[0092] Power amplifier 107 is used to provide drive power for the second-stage frequency multiplier;

[0093] The second bandpass filter 108 is used to filter the output of the first-stage local oscillator frequency multiplication.

[0094] A six-fold frequency multiplier 109 is used to multiply the local oscillator signal to the local oscillator excitation frequency required by the mixer processor.

[0095] Isolator 110 is used to improve the local oscillator port matching of the mixer and prevent the reflected signal from the local oscillator port from entering the mixer and participating in mixing, thus generating spurious components.

[0096] The input terminal of the first bandpass filter 103 is connected to the output terminal of the high-pass filter. The output terminal of the first bandpass filter 103 is connected to the input terminal of the frequency doubler 104. The output terminal of the frequency doubler 104 is connected to the input terminal of the first jumper port 105. The output terminal of the first jumper port 105 is connected to the input terminal of the high-frequency local oscillator input jumper port 106. The output terminal of the high-frequency local oscillator input jumper port 106 is connected to the input terminal of the power amplifier 107. The output terminal of the power amplifier 107 is connected to the input terminal of the second bandpass filter 108. The output terminal of the second bandpass filter 108 is connected to the input terminal of the frequency doubler 109. The output terminal of the frequency doubler 109 is connected to the input terminal of the isolator 110. The output terminal of the isolator 110 is connected to the input terminal of the mixer processor 5.

[0097] In this optional embodiment, the intermediate frequency signal processor 6 includes:

[0098] Isolator 113 is used to isolate DC components and prevent damage to the mixer from external DC input at the intermediate frequency port;

[0099] Intermediate frequency input / output jumper port 114;

[0100] The second jumper port 115 is used to connect to the corresponding modulation signal analyzer according to the frequency conversion working mode to perform up and down frequency conversion processing.

[0101] The low-noise amplifier 116 is used to reduce the noise figure of the subsequent analyzer unit. Its output is connected to the low-pass filter, which filters out the spurious components generated by the mixer processor.

[0102] The input terminal of isolator 113 is connected to the output terminal of mixer processor 5. The output terminal of isolator 113 is connected to the input terminal of intermediate frequency input / output jumper port 114. The output terminal of intermediate frequency input / output jumper port 114 is connected to the input terminal of second jumper port 115. The output terminal of second jumper port 115 is connected to the input terminal of low noise amplifier 116. The output terminal of low noise amplifier 116 is connected to the input terminal of low pass filter.

[0103] In this optional embodiment, connecting the corresponding modulation signal analyzer according to the frequency conversion working mode and performing up-conversion and down-conversion processing includes: when in the broadband down-conversion working mode, the jumper port is used to connect the broadband intermediate frequency output to the broadband modulation signal analyzer; when in the broadband up-conversion working mode, the jumper port is used to connect the broadband vector signal source and up-convert the broadband modulation signal to the terahertz band through the mixer processor.

[0104] In this optional embodiment, the analyzer unit 1 is one of the following: a first spectrum analyzer 100 with a local oscillator and intermediate frequency multiplexing port; a second spectrum analyzer 200 with two working modes: local oscillator output and intermediate frequency input port; a signal source 300 as local oscillator output and signal analyzer 400 as intermediate frequency input; a signal source 300 as local oscillator signal data and a vector signal source 500 for generating microwave broadband modulation signals.

[0105] It should be explained that the terahertz band has a frequency range of 0.1-10 THz, falling between the microwave and infrared bands. From a communication perspective, the terahertz band has an extremely wide bandwidth, approximately 1000 times the combined bandwidth of longwave, medium wave, shortwave, and microwave. This high bandwidth characteristic can meet the ever-increasing demands for communication speeds in the future, solving current problems such as spectrum scarcity and capacity limitations in wireless systems, thus laying a solid foundation for future communication development. In the scientific research field, terahertz waves can penetrate most non-polar materials and are sensitive to the vibrational and rotational frequencies of biological macromolecules. Using them for spectral analysis can assist in drug quality supervision, food safety testing, and can also be used for soil and water pollution analysis. Terahertz radar is used for environmental monitoring, such as air pollutant detection. From a military perspective, it offers high resolution and strong anti-stealth capabilities. Terahertz communication provides excellent security and has significant advantages in complex electromagnetic environments. Furthermore, breakthroughs in terahertz radiation source technology can drive the interdisciplinary development of materials science, optics, and other fields. Developing the terahertz frequency band has enormous strategic significance for enhancing national communication capabilities, scientific research levels, and consolidating national defense security. Therefore, equipment using the terahertz frequency band is widely used in communication, security inspection, imaging, and sensing. The spectrum analysis of terahertz signals and the generation of terahertz test signals also place extensive demands on measuring instruments.

[0106] A spectrum analyzer is an instrument used to measure and analyze signals. Its main measurements include signal frequency, power, and purity (phase noise and spurious signals). Correspondingly, the main performance indicators of a spectrum analyzer include frequency and power accuracy, noise level (the level of the smallest measurable signal), gain compression, harmonic and intermodulation distortion (the level of the largest measurable signal), phase noise, and spurious signals. In addition to basic spectrum analysis functions, many spectrum analyzers also have a broadband analysis mode, which can receive broadband modulated signals and demodulate and analyze them to obtain performance parameters such as the amplitude of vector error (EVM), adjacent channel power ratio (ACPR), and complementary cumulative distribution function (CCDF) statistical characteristics of the modulated signal. Therefore, spectrum analyzers are also often called signal analyzers.

[0107] A spectrum analyzer essentially processes the measured signal by performing power adjustment (attenuation or amplification), pre-selection filtering, down-conversion, intermediate frequency filtering, and amplification, and then obtains the characteristics of the measured signal through analog-to-digital conversion (ADC) and digital signal processing. Spectrum analyzers typically have a built-in local oscillator frequency synthesizer that can be tuned. Due to cost constraints and application requirements, the frequency range of the main unit of a spectrum analyzer usually covers up to 50 GHz. For spectrum analysis in the terahertz band, such as the W-band (75 GHz to 110 GHz), a terahertz spread spectrum device is needed to spread the frequency of the spectrum analyzer, down-converting the measured signal in the terahertz band to a low-frequency signal that the spectrum analyzer can receive and process. The spectrum analyzer and the terahertz spread spectrum device work together to complete the spectrum analysis in the terahertz band. Spectrum analyzers that support terahertz spread spectrum usually provide a local oscillator output port and an intermediate frequency input port, allowing the built-in local oscillator frequency synthesizer to be used to provide local oscillator excitation for the mixer inside the terahertz spread spectrum device and to receive the intermediate frequency output signal generated by the terahertz spread spectrum device.

[0108] A signal generator is an instrument used to generate and output various electrical signals. Its core function is to provide stable and adjustable signal excitation for scenarios such as electronic measurement, communication systems, and scientific research experiments. The output signal types are rich and diverse, including basic waveforms such as sine waves, square waves, and triangular waves, as well as complex modulation signals such as frequency modulation, amplitude modulation, phase modulation, and pulse modulation. Correspondingly, the main performance indicators of a signal generator cover frequency range, frequency accuracy, output power range, power flatness, phase noise, and modulation accuracy. The frequency range determines its applicable application scenarios, while frequency accuracy and phase noise affect the stability and purity of the signal. Output power range and power flatness ensure effective transmission of the signal under different transmission distances and loads. Modulation accuracy ensures the quality and reliability of the modulated signal. In addition, many high-performance signal generators also have extended capabilities such as multi-channel synchronous output, arbitrary waveform editing, and frequency hopping functions. They can simulate complex electromagnetic environments and communication scenarios, realize flexible control and precise output of signal time domain, frequency domain, and modulation domain parameters, and provide accurate signal input for wireless communication testing, radar system development, and satellite navigation verification.

[0109] The core of a radio frequency (RF) modulation signal source is to load information onto a high-frequency carrier wave to achieve wireless signal transmission. First, the carrier generation stage generates a stable high-frequency sinusoidal carrier wave using an oscillator (such as an LC oscillator or crystal oscillator), covering the very low frequency to millimeter-wave bands. The modulation process, depending on the modulation method (AM, FM, PM, or digital modulation such as QAM or PSK), loads the baseband signal (voice, data, etc.) onto the carrier wave. For example, AM modulation reflects changes in the baseband signal by changing the carrier amplitude; FM modulation embeds information by changing the carrier frequency. In digital modulation, the baseband signal is encoded and converted into digital symbols, and then the phase, amplitude, and other parameters of the carrier wave are discretized and modulated. The signal processing and amplification stage filters the modulated signal to remove spurious components and enhances the signal strength through a power amplifier to ensure transmission distance and anti-interference capability. The modulated RF signal is then radiated into space via an antenna, completing the conversion from electrical signal to electromagnetic wave. This process requires ensuring carrier stability, modulation linearity, and controllable output power to meet the performance requirements of the communication process.

[0110] Due to the technical difficulties and cost issues associated with directly generating terahertz signals, a lower-frequency radio frequency or millimeter-wave modulated signal is typically generated first by a signal source. Then, an external upconverter (mixer) is used to output the terahertz signal. The core component of a terahertz broadband modulated signal upconversion device based on a mixer is the mixer itself. It mixes the input low-frequency modulated signal with the local oscillator signal, generating a terahertz upconverted signal through frequency combination. The local oscillator section typically includes a local oscillator generator and a frequency multiplier, used to generate the required frequency local oscillator signal and multiply it to meet the terahertz band requirements. Its working principle utilizes the nonlinear characteristics of the mixer to add the frequencies of the low-frequency modulated signal and the local oscillator signal to obtain the terahertz output signal while maintaining the modulation information unchanged. To ensure signal quality, a power amplifier is needed to compensate for signal attenuation, and phase noise suppression technology is employed to ensure the stability and purity of the terahertz signal, meeting the needs of communication, imaging, and other applications. Example 1

[0111] The terahertz up-conversion and down-conversion device proposed in this embodiment can achieve down-conversion and up-conversion functions respectively by changing the external jumper, and is compatible with all spectrum analyzers that can provide local oscillator output and intermediate frequency input, such as... Figure 3 As shown, it offers a flexible local oscillator and intermediate frequency (IF) port jumper design, allowing the upconverter / downconverter to not only downconvert for terahertz spectrum analysis but also upconvert for terahertz signal generation via mixing. Furthermore, the built-in duplexer 102 and flexible port jumper design of the upconverter / downconverter support either a shared input / output port for the local oscillator and IF, or separate input / output ports for each. This allows for flexible frequency expansion adaptability to spectrum analyzers from different manufacturers, as detailed below:

[0112] Figure 3 The spectrum analyzer 100 shown is a spectrum analyzer with a built-in duplexer and a local oscillator / intermediate frequency multiplexing port. The local oscillator / intermediate frequency multiplexing port of the spectrum analyzer is connected to the local oscillator / intermediate frequency multiplexing port 101 in this embodiment via an SMA cable.

[0113] Inside the up and down converter, the local oscillator / intermediate frequency multiplexing port is connected to the common terminal of the duplexer 102 via an SMA cable. The high-pass filter (HPF) output of the duplexer 102 is connected to the local oscillator link, which multiplies the local oscillator signal provided by the spectrum analyzer 100 to the local oscillator frequency band (W band) required by the fundamental frequency mixer 111 through two stages of frequency multiplication. Each stage of frequency multiplication includes independent amplification and filtering circuits. The output of the high-pass filter (HPF) of the duplexer 102 is connected to a first band-pass filter 103 (BPF) to further filter out the harmonic components of the local oscillator output signal of the spectrum analyzer 100. The output of the first band-pass filter 103 is connected to a frequency doubler 104 for the first stage of local oscillator frequency multiplication. The output of the frequency doubler 104 is connected to the first jumper port 105 via an SMA cable. The first jumper port 105 is connected to the high-frequency local oscillator input jumper port 106 via an SMA jumper.

[0114] When using the up-converter for broadband modulation signal up-conversion, the local oscillator signal source can be connected to the local oscillator / intermediate frequency multiplexing port 101 of the up-converter. If a higher frequency local oscillator signal source is available, it can also be connected to the high-frequency local oscillator input jumper port 106 of the up-converter. Connecting to the high-frequency local oscillator input jumper port 106 results in a cleaner output from the high-frequency signal source, providing a cleaner local oscillator excitation. The local oscillator input jumper port is then connected to the power amplifier 107 via an SMA cable. This power amplifier provides sufficiently high drive power for the second-stage frequency multiplier. The power amplifier 107 is connected to... The signal is fed to a second bandpass filter 108 (BPF), which filters the output of the first-stage frequency multiplier to make the local oscillator excitation purer. The second bandpass filter 108 is connected to a sixth frequency multiplier 109, which multiplies the local oscillator signal to the local oscillator excitation frequency (W band) required by the fundamental frequency mixer 111. The output of the sixth frequency multiplier 109 is connected to an isolator 110, which improves the local oscillator port matching of the fundamental frequency mixer 111 and prevents the reflected signal from the local oscillator port from re-entering the fundamental frequency mixer 111 to participate in mixing and generate unnecessary spurious components. The output of the isolator 110 is connected to the local oscillator port of the mixer 111.

[0115] The RF input port 112 of mixer 111 is a standard waveguide interface, used to connect the terahertz signal input of the measured band. The intermediate frequency (IF) output of mixer 111 is connected to DC blocker 113, which is used to isolate DC components and prevent damage to mixer 111 from external DC input at the IF port. The output of DC blocker 113 is connected to IF input / output jumper port 114. When the upconversion / downconversion device operates in broadband downconversion mode, jumper port 114 can be used to connect the broadband IF output to a dedicated broadband modulation signal analysis instrument, such as a signal analyzer or oscilloscope. In broadband upconversion mode, jumper port 114 is used to connect a broadband vector signal source to upconvert the broadband modulation signal to the terahertz band via the fundamental frequency mixer 111. In both broadband upconversion and downconversion modes, it is necessary to... An independent signal source provides local oscillator excitation to the mixer via port 101 or jumper port 106; the intermediate frequency input / output jumper port 114 is connected to the second jumper port 115 via an SMA jumper; the second jumper port 115 is connected to the low-noise amplifier 116 via an SMA cable. This low-noise amplifier is used to reduce the noise figure of the subsequent spectrum analyzer (according to the noise figure cascade formula), so that the noise figure of the entire system (including up and down converters and spectrum analyzer) is controlled at 15~20dB, and the noise floor reaches -155dBm / Hz or even lower; the output of the low-noise amplifier 116 is connected to the low-pass filter (LPF) port of the duplexer 102. The intermediate frequency signal is filtered by the low-pass filter to remove the spurious components generated by the fundamental frequency mixer, further ensuring the purity of the spectrum analysis.

[0116] In this embodiment, the up-conversion and down-conversion devices and the spectrum analyzer are used together to complete terahertz spectrum analysis. In actual use, the local oscillator frequency multiplication factor is set in the spectrum analyzer firmware. The spectrum analyzer will automatically set the frequency of its local oscillator frequency synthesizer during the measurement process, so that the difference between the harmonic frequency of this local oscillator and the target frequency of the terahertz spectrum analysis is exactly the intermediate frequency required by the spectrum analyzer, thereby completing the spectrum analysis of the target terahertz frequency. Through a factory calibration process, the conversion loss of the up-conversion and down-conversion devices at different frequencies is measured in advance and compensated in the spectrum analyzer firmware, so that the power of the measured signal can be accurately displayed in the terahertz spectrum analysis.

[0117] It should be explained that when using up-converters and spectrum analyzers together to complete terahertz spectrum analysis, the user first needs to set the local oscillator (LO) multiplication factor in the spectrum analyzer's firmware. For example, setting it to N times means that the local oscillator signal will be amplified N times before participating in the mixing. This determines which harmonic order will participate in the mixing, which helps improve the mixer's response to specific frequency bands (such as terahertz), allowing for flexible selection of the target frequency band and improving measurement compatibility and equipment adaptability.

[0118] After setting the frequency multiplication factor, the local oscillator synthesizer of the spectrum analyzer will automatically generate a suitable frequency so that the difference between its harmonic (Nth harmonic) and the terahertz signal frequency is equal to the intermediate frequency (IF) of the analyzer. Assuming the target terahertz frequency is 0.45THz, the IF is set to 1.5GHz, and the frequency multiplication factor N is 30, the spectrum analyzer will automatically generate a suitable frequency (450GHz±1.5GHz) / 30, which is approximately 15GHz. The terahertz signal and the Nth harmonic of the local oscillator are input to the mixer to generate difference frequency and sum frequency components. The difference frequency signal is selected by a filter (because it is within the IF range that the analyzer can process) and unwanted high-frequency components are filtered out. After the IF signal passes through the amplifier (IFA mplifier) ​​and the bandpass filter (IFFilter), it enters the digital signal processing module of the spectrum analyzer for further analysis.

[0119] In this embodiment, after the intermediate frequency signal passes through an IF amplifier and an IF filter, it enters the digital signal processing module of the spectrum analyzer for further analysis. During this process, an adaptive IF gain control mechanism is activated. This mechanism dynamically adjusts the amplifier gain based on the real-time detected signal amplitude to avoid signal overload leading to nonlinear distortion, while also improving the ability to identify weak signals. Next, the signal enters a variable-bandwidth digital bandpass filter (VBPF). Unlike fixed-bandwidth designs, this filter can quickly reconstruct the passband range through digital configuration to adapt to different types of terahertz signals, accurately filtering from narrowband continuous waves to broadband modulated signals, reducing noise floor and sidelobe interference. Finally, a multi-window spectrometer is used for time-frequency conversion. The Engine automatically selects the optimal window function (such as Blackman-Harris, Kaiser, FlatTop, etc.) based on signal characteristics to optimize the trade-off between resolution and sidelobe suppression, thereby significantly improving the clarity and accuracy of the spectrum display. It uses internal dual-sampling path fusion technology to dynamically reconstruct the range of strong and weak signals, ensuring that weak frequency points are not masked by strong signals. It also uses a spectral equalization algorithm to visually enhance the spectrum curve. All processed intermediate frequency signals enter the Intelligent Frequency Calibration & Rendering technology. Combining the local oscillator frequency and harmonic factor recorded in the up-conversion and down-conversion links, it recovers the true terahertz frequency coordinates through reverse demodulation calculation and presents the results in the user interface as a vector resolution map, supporting real-time scaling, dynamic marking, and modulation feature extraction.

[0120] Specifically, in the process of calculating and recovering the true terahertz frequency coordinates, the core objective is to accurately map the analysis results in the intermediate frequency domain back to the true terahertz frequency coordinate system. This is achieved through four steps: "link recording, reverse demodulation, dynamic matching, and coordinate reconstruction." This establishes a highly self-consistent and traceable frequency conversion closed loop from the intermediate frequency to the true frequency. First, the local oscillator fundamental frequency and harmonic factors are recorded in real time through up-conversion and down-conversion links, serving as the sole source of frequency mapping parameters for spectrum analysis, ensuring the synchronous consistency and dynamic availability of frequency information. Then, based on the reverse demodulation calculation, a dual-path demodulation logic is used. By judging the frequency relationship between the intermediate frequency signal and the local oscillator harmonics, the up-conversion and down-conversion paths are actively identified (i.e., determining whether the target frequency is higher or lower than the local oscillator harmonics) to determine the accurate frequency reconstruction direction. Thus, the accurate reverse reconstruction is completed according to the formula: target terahertz frequency = harmonic factor * suitable frequency ± intermediate frequency setting. Next, a dynamic matching algorithm is introduced to compare the demodulated frequency with the preset range of the target frequency band. If boundary drift or harmonic drift exists... The system automatically adjusts the local oscillator frequency backtracking calculation logic and corrects frequency deviations during the inversion process, making the frequency calibration results robust and fault-tolerant. Finally, it enters the coordinate reconstruction stage, constructing a multi-dimensional coordinate mapping matrix in the spectrum plotting engine. This re-renders the horizontal axis coordinate of the spectrum plot from the "intermediate frequency domain" to the "terahertz original frequency domain," and provides repositioning functions for frequency scales, reference lines, and marker points based on the actual frequency conversion path. This allows users to obtain a spectrum plot on the graphical interface that is the frequency distribution view of the original terahertz signal without manual conversion. This upgrades the frequency calibration process from passive back-calculation to an active mapping logic network driven by the link. This not only improves the accuracy and traceability of spectrum calibration but also gives the spectrum results the triple capabilities of "source frequency visualization, adjustable link parameters, and feedback of plotting logic." Unlike existing technologies that use intermediate frequency as a reference and static parameters to calculate frequency points, this system demonstrates stronger intra-system linkage and forward scalability, making it a highly intelligent frequency space reconstruction solution in terahertz measurement systems. Example 2

[0121] In addition to the typical spectrum analyzer 100 shown in Example 1 having a local oscillator / intermediate frequency multiplexed port, for spectrum analyzers with independent local oscillator / intermediate frequency ports, the following can be used: Figure 4 The connection method shown is in Figure 4 The second spectrum analyzer 200 has independent local oscillator output and intermediate frequency input ports. The local oscillator output port of the second spectrum analyzer 200 is connected to the local oscillator / intermediate frequency multiplexing port 101 of the up and down frequency converter via an SMA cable, and the intermediate frequency input / output jumper port 114 of the up and down frequency converter is connected to the intermediate frequency input port of the second spectrum analyzer 200 via an SMA cable. Example 3

[0122] In addition to the application methods of the terahertz band up-conversion and down-conversion devices proposed in Embodiments 1 and 2, they can also be used in broadband down-conversion application scenarios, such as... Figure 5 The diagram shown illustrates a terahertz broadband downconversion application scenario where the intermediate frequency and local oscillator use different interfaces. Figure 5 A separate signal source 300 provides a fixed-frequency local oscillator excitation signal to the up and down frequency converters. The terahertz broadband modulation signal is input to the up and down frequency converters through the waveguide port 112, down-converted to the intermediate frequency by the fundamental frequency mixer 111, and then connected to the signal analyzer / oscilloscope 400 through the DC blocker 113 and the intermediate frequency input / output jumper port 114, and the latter performs the demodulation and analysis of the broadband signal. Example 4

[0123] In addition to the application scenarios of terahertz broadband upconversion devices in Examples 1 to 3, it can also be used in broadband upconversion application scenarios, such as... Figure 6 As shown, in Figure 6 An independent signal source 300 is used to provide a fixed frequency local oscillator excitation signal for the up and down frequency converters. In order to improve the output signal quality, the signal source here needs to have high phase noise performance and harmonic noise suppression performance. The radio frequency / microwave broadband modulation signal generated by the vector signal source 500 is input to the intermediate frequency input / output jumper port 114 of the up and down frequency converters through the SMA cable, and after passing through the DC blocker 113 inside the up and down frequency converters, it is up-converted to the terahertz band by the fundamental frequency mixer 111 and output from the waveguide interface 112.

[0124] Figure 2 An embodiment of the implementation method of the terahertz broadband up-conversion device of the present invention is shown.

[0125] In this optional embodiment, the method for implementing the terahertz broadband up-conversion device includes:

[0126] Step S201: The local oscillator signal is output by the analyzer unit 1 and multiplied to the local oscillator excitation frequency required by the mixer processor 111 based on the six-fold frequency multiplier 109. After the frequency multiplication is completed, the local oscillator signal is input to the mixer processor 111.

[0127] Step S202: Based on the waveguide interface 112, the terahertz signal of the measured band is input, and combined with the local oscillator signal, the intermediate frequency signal is output by the mixer processor 111.

[0128] Step S203: The intermediate frequency signal is subjected to frequency conversion processing using the frequency conversion working mode. Based on the processing result, a low-pass filter is applied to filter out spurious components from the intermediate frequency signal, and the processing result is input to the analyzer unit 1.

[0129] In this optional embodiment, when the local oscillator signal is output by the analyzer unit 1 and multiplied to the required local oscillator excitation frequency of the mixer processor 111 based on the six-fold frequency multiplier 109, and the local oscillator signal is input to the mixer processor 111 after the frequency multiplication is completed, the local oscillator intermediate frequency multiplexing port 101 can be connected to the output port of the analyzer unit 1 and output to the input terminal of the duplexer 2. The high-pass filter output of the duplexer 2 is used to connect the local oscillator link to the first band-pass filter 103. The first band-pass filter 103 is used to filter out the harmonic components of the local oscillator signal and generate the first stage local oscillator output in the local oscillator link, which is sent to the six-fold frequency multiplier 109 to generate the local oscillator signal of the target frequency. The isolator 110 is used to improve the local oscillator port matching state of the mixer processor 111, preventing the reflected signal of the local oscillator port from entering the mixer processor 111 to participate in mixing, and the local oscillator signal is input to the mixer processor 111 according to the improvement result.

[0130] In one embodiment, when using the frequency conversion mode to perform up-conversion and down-conversion processing on the intermediate frequency signal, applying a low-pass filter to filter out spurious components from the intermediate frequency signal based on the processing result, and inputting the processing result to the analyzer unit 1, the DC component can be isolated using the isolator 113 based on the output process of the intermediate frequency signal from the mixer processor 111 to prevent damage to the mixer processor 111. When in the broadband down-conversion mode, the intermediate frequency signal output is connected to the broadband modulation signal analyzer using the second jumper port 115. When in the broadband up-conversion mode, the broadband vector signal source is connected using the second jumper port 115, and the intermediate frequency signal is up-converted to the terahertz band by the mixer processor. After the up-conversion and down-conversion processing is completed, the second jumper port 115 is connected to the noise amplifier 1116 to reduce the noise figure of the analyzer unit 1. The process stops when the noise figure and noise floor value meet the requirements, and the intermediate frequency signal is input to the low-pass filter to filter out the spurious components generated by the mixer processor. The processed intermediate frequency signal is then input to the analyzer unit 1.

[0131] This invention is not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this invention is limited only by the appended claims.

Claims

1. A terahertz broadband up / down converter, characterized in that, It includes a local oscillator intermediate frequency multiplexing port connected to the analyzer unit, used to receive the local oscillator signal output by the analyzer unit; A duplexer is used to connect to the local oscillator intermediate frequency multiplexing port to obtain the local oscillator signal, output to connect to the local oscillator link, and perform low-pass filtering on the input signal during spectrum analysis. The local oscillator signal processor is used to filter out the harmonic components of the local oscillator signal and, in conjunction with the local oscillator link, convert the local oscillator signal to the local oscillator excitation frequency required for the target position. A mixer processor is used to receive the local oscillator signal based on the RF result of the local oscillator excitation frequency, and to obtain the intermediate frequency signal of the terahertz signal of the measured band by combining the waveguide interface. An intermediate frequency signal processor is used to isolate the DC component of the intermediate frequency signal and input the intermediate frequency signal to the analyzer unit after up-conversion and down-conversion modulation to complete the spectrum analysis of the terahertz signal in the measured band. The output terminal of the analyzer unit is connected to the input terminal of the local oscillator intermediate frequency multiplexing port. The output terminal of the local oscillator intermediate frequency multiplexing port is connected to the input terminal of the duplexer. The output terminal of the duplexer is connected to the input terminal of the local oscillator signal processor. The output terminal of the local oscillator signal processor is connected to the input terminal of the mixer processor. The output terminal of the mixer processor is connected to the input terminal of the intermediate frequency signal processor. The output terminal of the intermediate frequency signal processor is connected to the input terminal of the analyzer unit.

2. The terahertz broadband up / down converter according to claim 1, characterized in that, The duplexer includes a high-pass filter and a low-pass filter; The high-pass filter is used to connect to the local oscillator intermediate frequency multiplexing port to obtain the local oscillator signal and output it to connect to the local oscillator link; the low-pass filter is used to filter out spurious components in the intermediate frequency signal during the application of the mixer processor, thereby improving the purity of the spectrum analysis.

3. The terahertz broadband up / down converter according to claim 2, characterized in that, The local oscillator signal processor includes: The first bandpass filter is used to filter out the harmonic components of the local oscillator signal; A frequency doubler is used for the first-stage local oscillator frequency multiplication. First jumper port; The high-frequency local oscillator input jumper port is used to process the local oscillator signal and output a clean local oscillator excitation. A power amplifier is used to provide drive power for the second-stage frequency multiplier. The second bandpass filter is used to filter the frequency multiplier output of the first-stage local oscillator. A six-fold frequency multiplier is used to multiply the local oscillator signal to the local oscillator excitation frequency required by the mixer processor; An isolator is used to improve the local oscillator port matching of the mixer and prevent reflected signals from the local oscillator port from entering the mixer and participating in mixing, thus generating spurious components. The input terminal of the first bandpass filter is connected to the output terminal of the high-pass filter. The output terminal of the first bandpass filter is connected to the input terminal of the frequency doubler. The output terminal of the frequency doubler is connected to the input terminal of the first jumper port. The output terminal of the first jumper port is connected to the input terminal of the high-frequency local oscillator input jumper port. The output terminal of the high-frequency local oscillator input jumper port is connected to the input terminal of the power amplifier. The output terminal of the power amplifier is connected to the input terminal of the second bandpass filter. The output terminal of the second bandpass filter is connected to the input terminal of the frequency doubler. The output terminal of the frequency doubler is connected to the input terminal of the isolator. The output terminal of the isolator is connected to the input terminal of the mixer processor.

4. The terahertz broadband up / down converter according to claim 3, characterized in that, The intermediate frequency signal processor includes: An isolator is used to isolate the DC component and prevent damage to the mixer from external DC input at the intermediate frequency port; Intermediate frequency input / output jumper port; The second jumper port is used to connect to the corresponding modulation signal analyzer according to the frequency conversion working mode to perform up and down frequency conversion processing. A low-noise amplifier is used to reduce the noise figure of the subsequent analyzer unit. Its output is connected to the low-pass filter, which filters out the spurious components generated by the mixer processor. The input terminal of the isolator is connected to the output terminal of the mixer, the output terminal of the isolator is connected to the input terminal of the intermediate frequency input / output jumper port, the output terminal of the intermediate frequency input / output jumper port is connected to the input terminal of the second jumper port, the output terminal of the second jumper port is connected to the input terminal of the low noise amplifier, and the output terminal of the low noise amplifier is connected to the input terminal of the low-pass filter.

5. The terahertz broadband up / down converter according to claim 4, characterized in that, The step of connecting the corresponding modulation signal analyzer according to the frequency conversion working mode and performing up and down frequency conversion processing includes: When in broadband downconversion mode, the second jumper port is used to connect the broadband intermediate frequency output to a broadband modulation signal analysis instrument. When in broadband upconversion mode, the second jumper port is used to connect to a broadband vector signal source and upconvert the broadband modulated signal to the terahertz band via the mixer.

6. The terahertz broadband up / down converter according to claim 5, characterized in that, The analyzer unit is one of the following: a first spectrum analyzer with a local oscillator and intermediate frequency multiplexing port; a second spectrum analyzer with two working modes: local oscillator output and intermediate frequency input port; a signal source as local oscillator output and signal analyzer as intermediate frequency input; and a signal source as either local oscillator signal data or a vector signal source that generates microwave broadband modulation signals.

7. A method for implementing a terahertz broadband up-converter / down-converter, used to implement the frequency conversion of the terahertz broadband up-converter / down-converter as described in any one of claims 1-6, characterized in that, include: The local oscillator signal is output by the analyzer unit and multiplied to the local oscillator excitation frequency required by the mixer based on the six-fold frequency multiplier. After the frequency multiplication is completed, the local oscillator signal is input to the mixer. The terahertz signal of the measured band is input through the waveguide interface and combined with the local oscillator signal to output the intermediate frequency signal using a mixer processor. The intermediate frequency signal is converted between up and down frequencies using the frequency conversion mode. Based on the processing result, a low-pass filter is applied to filter out spurious components from the intermediate frequency signal, and the processing result is input to the analyzer unit.

8. The method for implementing the terahertz broadband up-conversion / down-conversion device according to claim 7, characterized in that, The process of using the analyzer unit to output the local oscillator signal, multiplying the local oscillator signal to the required local oscillator excitation frequency of the mixer based on a six-fold frequency multiplier, and then inputting the local oscillator signal to the mixer after frequency multiplication includes: Connect the local oscillator intermediate frequency multiplexing port to the analyzer unit output port and output it to the input of the duplexer. Use the high-pass filter output of the duplexer to connect the local oscillator link to the first bandpass filter. The harmonic components of the local oscillator signal are filtered out using the first bandpass filter, and the first stage local oscillator output is generated in the local oscillator link and sent to the sixth frequency multiplier to generate the local oscillator signal at the target frequency. An isolator is used to improve the local oscillator port matching state of the mixer, preventing the reflected signal from the local oscillator port from entering the mixer and participating in mixing, and the local oscillator signal is input to the mixer based on the improvement result.

9. The method for implementing the terahertz broadband up-conversion / down-conversion device according to claim 7, characterized in that, The process of using a frequency conversion mode to perform up-and-down frequency conversion on the intermediate frequency signal, applying a low-pass filter to remove spurious components from the intermediate frequency signal based on the processing result, and inputting the processing result to the analyzer unit includes: The output process of the intermediate frequency signal based on the mixer processor uses an isolator to isolate the DC component to avoid damage to the mixer processor. When in broadband downconversion mode, the intermediate frequency signal output is connected to the broadband modulation signal analysis instrument through the second jumper port. When in broadband upconversion mode, the broadband vector signal source is connected via the second jumper port, and the intermediate frequency signal is upconverted to the terahertz band by the mixer. After the up-and-down frequency processing is completed, the second jumper port is connected to the noise amplifier to reduce the noise figure of the analyzer unit. Once the noise figure and noise floor value meet the requirements, the process stops, and the intermediate frequency signal is input to the low-pass filter to filter out the spurious components generated by the mixer. The processed intermediate frequency signal is then input to the analyzer unit.

10. The method for implementing the terahertz broadband up-conversion / down-conversion device according to claim 9, characterized in that, The noise figure of the analyzer unit ranges from 15 to 20 dB, and the noise floor is -155 dBm / Hz.

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