Microwave multipath signal source

Abstract

The invention discloses a microwave multi-channel signal source which comprises a frequency source module, a signal distribution module, a multi-channel amplitude-phase control module, a power amplification module and an integrated control module. The frequency source module is used for generating or accessing a frequency reference signal and generating a microwave frequency signal covering 18GHz to 26.5 GHz; the power amplification module comprises four paths of power amplifiers which are connected with the four paths of outputs of the multi-path amplitude-phase control module in a one-to-one correspondence manner; and the integrated control module comprises a single chip microcomputer control unit and upper computer software. The number of output channels is increased to four, independent switch control and parameter adjustment of each channel of signals can be achieved, and the requirements for simultaneous output and accurate regulation and control of multiple channels of microwave signals are met; meanwhile, the working frequency covers 18-26.5 GHz, high-precision frequency, attenuation and phase shift adjusting capacity is achieved, internal and external excitation signal switching is supported, a visual software operation interface is matched, and the practicability and regulation and control efficiency of a signal source are improved.

Description

Technical Field

[0001] This invention belongs to the field of electronic signal equipment technology, and specifically relates to a microwave multi-channel signal source. Background Technology

[0002] With the rapid development of fields such as radar, 5G millimeter-wave communication, phased array systems, and satellite payload testing, higher demands are being placed on the performance of microwave signal sources. These sources need to simultaneously output multiple high-frequency, high-power, and highly coherent signals, while supporting fine-tuning of amplitude and phase. A microwave multi-signal source is a device capable of simultaneously generating multiple independent or coherent microwave signals, achieving phase synchronization by sharing a high-precision reference clock (such as an OCXO or an external 100MHz clock).

[0003] However, existing technologies suffer from numerous bottlenecks. Existing microwave signal sources, when operating in multi-channel collaborative mode, exhibit problems such as insufficient phase stability in the high-frequency band, limited power output and dynamic range, insufficient amplitude and phase control resolution and real-time performance, and difficulties in multi-mode switching and system integration. For example, traditional microwave signal sources in the 18–26.6 GHz band often employ discrete phase-locked loop (PLL) architectures, with inter-channel phase synchronization relying on external clock allocation. Affected by high-frequency signal transmission delays and temperature drift, phase noise is generally higher than -100 dBc / Hz@1 kHz, and inter-channel phase difference fluctuations can reach ±8° / hour. Power amplification in the 18–26.5 GHz band is limited by material processing (such as traditional GaAs devices), with existing signal sources typically having single-channel output power below 30 dBm, and power consistency deviation exceeding ±3 dB when multiple channels operate simultaneously, making it impossible to simulate strong electromagnetic environments. Traditional phase shifters employ simulated PIN diodes or ferrite structures, achieving phase shift accuracy ≤5° in the high-frequency band, with temperature drift reaching 0.1° / ℃, making it impossible to achieve fine phase gradient control in beam scanning. In addition, the software control interface of existing equipment mostly uses fixed parameter settings, lacks visual architecture adjustment functions, and has insufficient operational flexibility. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a microwave multi-channel signal source that increases the number of output channels to 4, enabling independent switching control and parameter adjustment for each signal, thus meeting the requirements for simultaneous output and precise control of multiple microwave signals. At the same time, the operating frequency covers 18 to 26.5 GHz, and it has high-precision frequency, attenuation and phase shift adjustment capabilities. It supports switching between internal and external excitation signals and, together with a visual software operation interface, improves the practicality and control efficiency of the signal source.

[0005] The objective of this invention is achieved through the following technical solution: A microwave multiplexer, comprising: Frequency source module, signal distribution module, multi-channel amplitude and phase control module, power amplification module, and integrated control module; The frequency source module is used to generate or access a frequency reference signal and generate a microwave frequency signal covering 18 GHz to 26.5 GHz. The signal distribution module includes a single-pole double-throw switch and a 1-to-4 power divider, used to switch between internal excitation signals and external excitation signals, and to distribute the switched signals into 4 channels. The multi-channel amplitude and phase control module receives four signals allocated by the signal distribution module. Each channel includes an amplitude and phase control channel for independently and precisely adjusting the amplitude and phase of each signal. The power amplifier module includes four power amplifiers, which are connected one-to-one with the four outputs of the multi-channel amplitude and phase control module to amplify each signal to a preset power level, wherein the single-channel saturated output power is not less than 32dBm. The integrated control module includes a microcontroller control unit and host computer software. The microcontroller control unit controls the frequency source module through an SPI interface, controls the voltage-controlled phase shifter in the multi-channel amplitude and phase control module through DA output, and controls the digitally controlled attenuator in the multi-channel amplitude and phase control module and the single-pole double-throw switch in the signal distribution module through TTL level. The host computer software supports network communication and is used to set the working mode and independently control the switching status and parameter adjustment of the four channels.

[0006] The frequency source module generates or receives a frequency reference signal and produces a microwave frequency signal ranging from 18 GHz to 26.5 GHz. This signal is switched between internal and external excitation signals by a single-pole double-throw switch in the signal distribution module, and then distributed into four channels by a 1-to-4 power divider. The four signals are input to four amplitude and phase control channels in the multi-channel amplitude and phase control module, and each channel independently and precisely adjusts the amplitude and phase of the signal. The adjusted signals are sent to four power amplifiers in the power amplifier module and amplified to a saturated output power of not less than 32 dBm. The microcontroller control unit in the integrated control module controls the frequency source module through the SPI interface, controls the voltage-controlled phase shifter through the DA output, and controls the digitally controlled attenuator and the single-pole double-throw switch through TTL levels. The host computer software sets the working mode and independently controls the switching status and parameter adjustment of the four channels through network communication.

[0007] As a preferred embodiment, the frequency source module further includes: Crystal oscillator, second single-pole double-throw switch, phase-locked loop, frequency multiplier and filter; The crystal oscillator is used to generate the frequency reference signal; The second single-pole double-throw switch is used to select the internal frequency reference or the external reference input; The selected reference signal is processed sequentially through the phase-locked loop, frequency multiplier, and filter to generate the microwave frequency signal from 18 GHz to 26.5 GHz.

[0008] As a preferred embodiment, each amplitude-phase control channel in the multi-channel amplitude-phase control module includes: Two-stage digitally controlled attenuator, one-stage voltage-controlled phase shifter, and one-stage driver amplifier; By controlling the power supply to the driver amplifier, the on / off control of the output signal of the entire channel can be achieved.

[0009] As a preferred method, the two-stage digitally controlled attenuator is a 6-bit digitally controlled attenuator with a total attenuation range of 0 to 63 dB and an attenuation step of 0.5 dB.

[0010] As a preferred approach, the voltage-controlled phase shifter uses a varactor diode as the core tuning element. By adjusting its bias voltage, the equivalent capacitance is changed, thereby achieving continuous or step-by-step phase adjustment. Its phase shift range is 0° to 360°, the minimum phase shift step can be configured to 0.1°, and the phase shift value input by the user is automatically rounded to the nearest integer multiple of the step value.

[0011] As a preferred embodiment, the host computer software supports point frequency mode, sweep frequency mode and preset mode; wherein, the preset mode supports importing parameter tables containing serial numbers, frequency values, attenuation values ​​and phase shift values, and each parameter column is editable, with units of Hz, dB and degrees respectively.

[0012] As a preferred embodiment, the host computer software can independently control the on / off status of the four channels; when a channel is turned on, its corresponding parameter adjustment interface becomes editable, and the parameters are highlighted in green after taking effect, and the software interface uses green signal lines to indicate the signal transmission direction.

[0013] As a preferred embodiment, the single-pole double-throw switch in the signal distribution module constitutes a first routing node for selecting a first signal source or a second signal source; the first signal source is the internal microwave signal generated by the frequency source module, and the second signal source is an external excitation signal input from an external port.

[0014] As a preferred embodiment, the main structure of the frequency source module and the radio frequency cavity integrating the multi-channel amplitude and phase control module and the power amplification module are both made of sealed aluminum cavity to improve electromagnetic shielding performance and environmental stability.

[0015] As a preferred embodiment, the integrated control module is also used to monitor the system communication status; after the network connection is successful, the host computer software will visually prompt the communication link icon in a bold and green form.

[0016] The present invention has at least the following beneficial effects: In this invention, the number of output channels is increased to 4, enabling independent switching control and parameter adjustment for each signal, thus meeting the requirements for simultaneous output and precise control of multiple microwave signals. At the same time, the operating frequency covers 18 to 26.5 GHz, and it has high-precision frequency, attenuation and phase shift adjustment capabilities. It supports switching between internal and external excitation signals, and with the help of a visual software operation interface, it improves the practicality and control efficiency of the signal source. Attached Figure Description

[0017] To reveal the technical details of the embodiments of the present invention, the accompanying drawings involved in the embodiments will be briefly described below. It should be emphasized that these drawings only present several embodiments of the present invention and should not be considered as defining the scope of the invention. For those skilled in the art, other related drawings can still be derived based on these drawings without inventive effort.

[0018] Figure 1 This is a schematic diagram of the microwave multi-channel signal source system of the present invention; Figure 2 This is a top view of the main body of the microwave multi-channel signal source of the present invention; Figure 3 This is a front view of the main body of the microwave multi-channel signal source of the present invention; Figure 4 This is a rear view of the main body of the microwave multi-channel signal source of the present invention.

[0019] In the attached diagram, 1-main body of microwave multi-channel signal source, 2-output channel of the first microwave multi-channel signal source, 3-output channel of the second microwave multi-channel signal source, 4-output channel of the third microwave multi-channel signal source, 5-output channel of the fourth microwave multi-channel signal source, 6-220V power input port, 7-external reference input, 8-internal reference output, 9-external RF input, 10-network port. Detailed Implementation

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0021] In the following sections, embodiments of the present disclosure will be described in detail with the aid of the accompanying drawings. However, it should be understood that the present disclosure is not limited to the specific forms shown herein. Rather, it should be understood to encompass various variations, equivalents, and / or alternatives to the embodiments of the present disclosure. In illustrating the drawings, the same reference numerals will be used to denote similar components.

[0022] In the various embodiments of this disclosure, the terms "first," "second," "the first," or "the second" are intended to modify different components and not to indicate order and / or importance, nor do they constitute a limitation on the respective components. For example, a first user equipment and a second user equipment represent different user equipments, although they both fall under the category of user equipment. Similarly, a first component may be named a second component, and a second component may be named a first component, without changing their essential attributes within the scope of this disclosure.

[0023] In this disclosure, terminology is used to describe specific embodiments and does not constitute a limitation thereof. In this context, the use of the singular form also encompasses the plural form, unless otherwise expressly stated herein. In the course of description, terms such as “comprising” or “having” are intended to indicate the presence of features, quantities, steps, operations, structural components, parts, or combinations thereof, and do not preclude the possibility or addition of one or more other features, quantities, steps, operations, structural components, parts, or combinations thereof.

[0024] It should be clarified that while the following description provides detailed specific information to aid in a comprehensive understanding of the exemplary embodiments, those skilled in the art will recognize that the exemplary embodiments can be implemented even without these specific details. For example, the system may be illustrated using block diagrams to avoid excessive detail that could obscure the clarity of the example. In other cases, to maintain the clarity of the example, unnecessary details of well-known processes, structures, and techniques may be omitted.

[0025] See Figure 1 A microwave multiplexer, comprising: Frequency source module, signal distribution module, multi-channel amplitude and phase control module, power amplification module, and integrated control module; The frequency source module is used to generate or access a frequency reference signal and generate a microwave frequency signal covering 18 GHz to 26.5 GHz. The signal distribution module includes a single-pole double-throw switch and a 1-to-4 power divider, used to switch between internal excitation signals and external excitation signals, and to distribute the switched signals into 4 channels. The multi-channel amplitude and phase control module receives four signals allocated by the signal distribution module. Each channel includes an amplitude and phase control channel for independently and precisely adjusting the amplitude and phase of each signal. The power amplifier module includes four power amplifiers, which are connected one-to-one with the four outputs of the multi-channel amplitude and phase control module to amplify each signal to a preset power level, wherein the single-channel saturated output power is not less than 32dBm. The integrated control module includes a microcontroller control unit and host computer software. The microcontroller control unit controls the frequency source module through an SPI interface, controls the voltage-controlled phase shifter in the multi-channel amplitude and phase control module through DA output (analog voltage output), and controls the digitally controlled attenuator in the multi-channel amplitude and phase control module and the single-pole double-throw switch in the signal distribution module through TTL level. The host computer software supports network communication and is used to set the working mode and independently control the switching status and parameter adjustment of the four channels.

[0026] When the microwave multi-channel signal source of this invention is working, a reference signal is generated or input by the frequency source module and a microwave frequency signal from 18GHz to 26.5GHz is output. After the signal is selected by the single-pole double-throw switch in the signal distribution module to select an internal or external excitation source, it is divided into 4 channels by a 1-to-4 power divider. The 4 channels enter the respective amplitude and phase control channels of the multi-channel amplitude and phase control module to independently complete the precise adjustment of amplitude and phase. The adjusted signals are amplified by the 4 power amplifiers in the power amplification module, with each channel having a saturated output power of not less than 32dBm. The entire system is coordinated by an integrated control module: the microcontroller controls the frequency source through SPI, controls the voltage-controlled phase shifter through DA output, controls the digitally controlled attenuator and single-pole double-throw switch through TTL level, and the host computer software realizes the setting of working mode and the independent switching and parameter adjustment of the 4 channels through network communication, thereby realizing high-power, high-precision, and independently controllable output of multiple microwave signals.

[0027] In a preferred embodiment, the frequency source module further includes: Crystal oscillator, second single-pole double-throw switch, phase-locked loop, frequency multiplier and filter; The crystal oscillator is used to generate the frequency reference signal; The second single-pole double-throw switch is used to select the internal frequency reference or the external reference input; The selected reference signal is processed sequentially through the phase-locked loop, frequency multiplier, and filter to generate the microwave frequency signal from 18 GHz to 26.5 GHz.

[0028] The frequency source module employs a highly stable integrated architecture with selectable internal and external references to flexibly adapt to different application scenarios. First, an internal crystal oscillator generates a high-precision frequency reference signal, serving as the "heartbeat" for system synchronization. Simultaneously, the device provides an external reference input port, allowing users to connect higher-performance external clock sources (such as atomic clocks or laboratory-grade signal sources). A second single-pole double-throw switch allows users to switch between the internal crystal oscillator and the external reference signal, enabling flexible configuration of the excitation source. The selected reference signal is then fed into a phase-locked loop (PLL) circuit. The PLL multiplies and locks the reference signal according to the target output frequency, generating a low-phase-noise, highly stable intermediate frequency signal. This signal is further multiplied to the K-band (18–26.5 GHz) by a frequency multiplier, and finally, a bandpass filter removes harmonics and spurious signals, outputting a clean microwave frequency signal. The entire chain ensures wide bandwidth coverage while maintaining phase noise and frequency accuracy, providing a high-quality excitation source for subsequent multi-channel amplitude and phase control and power amplification.

[0029] In a preferred embodiment, each amplitude-phase control channel in the multi-channel amplitude-phase control module includes: Two-stage digitally controlled attenuator, one-stage voltage-controlled phase shifter, and one-stage driver amplifier; By controlling the power supply to the driver amplifier, the on / off control of the output signal of the entire channel can be achieved.

[0030] Each channel of the multi-channel amplitude and phase control module employs a three-stage cascaded structure with attenuation and phase shifting drive to achieve independent and precise control of the amplitude and phase of the microwave signal. During operation, the microwave signal from the signal distribution network first enters a two-stage digitally controlled attenuator, where the signal strength is adjusted step-by-step via digital control. This provides a wide total attenuation range and precise stepping, flexibly adapting to different power requirements. Subsequently, the signal enters a voltage-controlled phase shifter, where the signal phase is continuously or incrementally adjusted by changing its control voltage, covering the entire range from 0° to 360° to meet the phase accuracy requirements of applications such as beamforming. Finally, the amplitude- and phase-adjusted signal is buffered and gain-compensated by a single-stage driver amplifier to ensure output impedance matching and maintain sufficient driving capability. Notably, the power supply of this driver amplifier is controlled by the integrated control module. When a channel needs to be shut down, the system directly cuts off the power supply to its driver amplifier, completely shutting down the signal for that channel. This not only achieves rapid on / off control but also effectively avoids the insertion loss and nonlinear distortion introduced by traditional switching devices, improving channel isolation and overall signal purity.

[0031] In a preferred embodiment, the two-stage digitally controlled attenuator is a 6-bit digitally controlled attenuator with a total attenuation range of 0 to 63 dB and an attenuation step of 0.5 dB.

[0032] The two-stage digitally controlled attenuator employs a 6-bit digital control structure, achieving wide-range, high-resolution amplitude adjustment through the combination of multiple fixed attenuation units. Specifically, the 6-bit control signal corresponds to 64 different attenuation states (from 0 to 63), with each additional unit increasing the attenuation by 0.5dB. Therefore, the total attenuation range is 0dB to 63dB, with a minimum adjustment step of 0.5dB. This wide attenuation range is achieved by decomposing it into two cascaded stages. For example, the first stage provides coarse adjustment (e.g., 0–31.5dB, 1dB step), and the second stage provides fine adjustment (e.g., 0–31.5dB, 0.5dB step), ensuring both overall dynamic range and improved adjustment accuracy and linearity. Users can directly set any attenuation value via host computer software or microcontroller commands. The system automatically converts this into the corresponding 6-bit control code, adjusting the attenuator's internal switching state in real time to precisely control the output signal power, meeting the needs of fine amplitude control in scenarios such as testing, calibration, or beamforming.

[0033] In a preferred embodiment, the voltage-controlled phase shifter uses a varactor diode as the core tuning element. By adjusting its bias voltage, the equivalent capacitance is changed, thereby achieving continuous or step-by-step phase adjustment. Its phase shift range is 0° to 360°, the minimum phase shift step can be configured to 0.1°, and the phase shift value input by the user is automatically rounded to the nearest integer multiple of the step value.

[0034] The voltage-controlled phase shifter uses a varactor diode as its core tuning element. Its operating principle is based on the characteristics of a voltage-controlled capacitor: when the bias voltage applied to the varactor diode changes, the depletion layer width of its internal PN junction changes accordingly, causing a continuous change in the equivalent capacitance value. This capacitance, as a key parameter of the phase-shifting network, directly affects the transmission phase of the microwave signal. Therefore, precise control of the output signal phase can be achieved by adjusting the bias voltage. The entire phase shift range covers 0° to 360°, i.e., a complete cycle, meeting any phase setting requirements. The system supports continuous adjustment and also provides a configurable minimum step mode, with a default minimum step of 0.1°. When the user inputs a target phase shift value (e.g., 45.23°) in the host computer software, the system automatically rounds it to the nearest integer multiple of 0.1° (e.g., 45.2°), ensuring that the control command matches the hardware capabilities. This guarantees operational flexibility while avoiding invalid or excessive settings, improving system reliability and user experience.

[0035] In a preferred embodiment, the host computer software supports point frequency mode, sweep frequency mode and preset mode; wherein, the preset mode supports importing parameter tables containing serial numbers, frequency values, attenuation values ​​and phase shift values, and each parameter column is editable, with units of Hz, dB and degrees respectively.

[0036] The host computer software offers three main operating modes to meet the needs of different testing scenarios. In point frequency mode, users can manually set a single frequency point and independently configure the attenuation and phase shift values ​​of the four channels, suitable for static parameter debugging or fixed-point calibration. In sweep frequency mode, the software can automatically and continuously change the output frequency according to the set start and end frequencies, step, and scan speed, while maintaining synchronous or independent changes in the amplitude and phase parameters of each channel, facilitating rapid acquisition of the system's frequency response characteristics. In preset mode, users can import a table file containing multiple rows of parameters, each row corresponding to a test state, including the serial number, frequency value (unit: Hz), attenuation value (unit: dB), and phase shift value (unit: degrees). All columns can be directly edited in the software interface. During runtime, the software loads each row of parameters sequentially according to the serial number and sends them to the hardware, realizing the automated execution of complex test processes. It is particularly suitable for advanced application scenarios such as multi-state switching, beam scanning simulation, or batch consistency verification, significantly improving testing efficiency and ease of operation.

[0037] In a preferred embodiment, the host computer software can independently control the on / off status of the four channels; when a channel is turned on, its corresponding parameter adjustment interface becomes editable, and the parameters are highlighted in green after taking effect, and the software interface uses a green flowing animation to indicate the signal transmission direction.

[0038] The host computer software supports completely independent on / off control of the four output channels. Users can enable or disable any one channel without affecting the operation of other channels. When a channel is enabled, the software automatically activates the corresponding parameter setting area, making it editable. Users can adjust parameters such as frequency, attenuation, and phase shift in real time. Once the parameters are configured and successfully sent to the hardware, the relevant interface elements will immediately be highlighted in green, providing a clear indication that the parameters have taken effect. Furthermore, to enhance the visualization of operations, the software also displays the signal transmission path of the currently enabled channel in the signal flow diagram using green signal lines, clearly showing the signal path from the frequency source through routing, amplitude and phase adjustment to the final output port. This not only avoids accidental operation but also significantly improves the efficiency and user experience of multi-channel collaborative debugging.

[0039] In a preferred embodiment, the microwave multi-channel signal source further supports a coherent power combining output mode. The signal source integrates a 4:1 coherent power combiner at the output end, and a "combining mode" option is added to the host computer software. When the user enables this mode, the software automatically configures the four channels to be of the same frequency, equal amplitude, and zero phase difference, and maximizes the combining power ratio by fine-tuning the phase shift values ​​of each channel, ultimately outputting the enhanced microwave signal through a single combining output terminal. Let the four input signals be... The output power after coherent superposition for: ; in, For the first The signal amplitude is measured in volts (V). For the first Path relative to reference phase The residual phase error, in radians (rad); The characteristic impedance of the system, such as When all At that time, the theoretical power gain is dB. Considering the actual phase error follows a standard deviation of... Gaussian distribution, average synthesis efficiency Approximately: ; If the phase control accuracy of this invention reaches ,but This corresponds to a synthesis gain of approximately 11.99 dB. Even after deducting the typical insertion loss of 1 dB for the synthesizer, the net output power gain still reaches approximately 11 dB, significantly improving signal strength in high-power testing scenarios.

[0040] In a preferred embodiment, the single-pole double-throw switch in the signal distribution module constitutes a first routing node for selecting a first signal source or a second signal source; the first signal source is an internal microwave signal generated by the frequency source module, and the second signal source is an external excitation signal input from an external port.

[0041] In a preferred embodiment, the main structure of the frequency source module and the radio frequency cavity integrating the multi-channel amplitude and phase control module and the power amplifier module are both made of sealed aluminum cavity to improve electromagnetic shielding performance and environmental stability.

[0042] The signal distribution module forms the first routing node through a single-pole double-throw switch, used for flexible switching between internal and external excitation. When an internal signal source is selected, the system uses the 18–26.5 GHz microwave signal generated by the frequency source module itself as input; when an external signal source is selected, the user-supplied external excitation signal (such as a microwave signal from another signal source or test equipment) is received from the external RF input port on the device panel. This switch ensures that the two signals do not interfere with each other, and the switching process is precisely controlled by the integrated control module through TTL levels, achieving fast and reliable routing selection. To further improve the overall performance, the main structure of the frequency source module and the RF section integrating the multi-channel amplitude and phase control module and power amplifier module are all encapsulated in an independent sealed aluminum cavity. This design not only effectively shields against external electromagnetic interference and prevents crosstalk between channels, but also isolates the system from environmental factors such as moisture and dust, significantly enhancing the long-term stability and reliability of the system in complex electromagnetic environments or scenarios with large temperature and humidity variations.

[0043] In a preferred embodiment, the microwave multiplexer further includes a combined temperature, phase, and amplitude compensation method to suppress channel performance drift caused by changes in ambient temperature. This is achieved by integrating temperature sensing units at three defined locations: a first temperature sensing unit is disposed on the surface of the phase-locked loop chip package of the frequency source module to monitor the local temperature of the frequency synthesis core circuit; a second temperature sensing unit is disposed on the PCB substrate of the multi-channel amplitude and phase control module, adjacent to the RF traces of the voltage-controlled phase shifter and the digitally controlled attenuator, to monitor the thermal state of the amplitude and phase adjustment path; and a third temperature sensing unit is disposed on the heat dissipation base shared by the four power amplifiers of the power amplifier module to monitor the temperature rise of high-power devices.

[0044] The output signals of each temperature sensing unit are connected to the microcontroller control unit. The integrated control module is calibrated in a temperature chamber before leaving the factory and pre-stores the following parameters: the temperature of the frequency source module and the phase drift coefficient. (Unit: °C); Temperature and phase drift coefficient for each phase control channel. With temperature, insertion loss drift coefficient (Units are ° / °C and dB / °C, respectively) ); and the temperature-gain drift coefficient of the power amplifier module. (Unit: dB / °C).

[0045] This represents the local temperature of the phase-locked loop collected by the first temperature sensing unit. This indicates the temperature of the amplitude-phase control module region collected by the second temperature sensing unit. This indicates the temperature of the power amplifier heatsink base, collected by the third temperature sensing unit. During operation, the microcontroller control unit adjusts the temperature based on the real-time readings from each sensing unit. , , Relative to reference temperature The offset is calculated, the required compensation is determined, and correction is performed: On the one hand, the initial phase temperature drift is indirectly compensated by adjusting the internal parameters of the phase-locked loop (PLL) of the frequency source module (for example, fine-tuning the reference or feedback division ratio of the PLL to cause a slight shift in the output frequency, thereby effectively offsetting the accumulated phase error caused by the temperature drift; or, adjusting the charging and discharging current ratio of the PLL charge pump to change the control voltage of the loop filter, thereby pre-compensating the tuning voltage of the voltage-controlled oscillator and suppressing phase drift); On the other hand, a compensation voltage is added to the output of the voltage-controlled phase shifter (DA) of each amplitude-phase control channel, the magnitude of which is equal to the initial phase temperature drift. Proportional; simultaneously, a compensation attenuation value is sent to each digitally controlled attenuator, which is equal to This compensation method is used to offset the overall gain variation caused by the amplitude and phase modules and the power amplifier module. Under conditions where the ambient temperature jumps from 10°C to 50°C and stabilizes for 2 hours, without compensation, the maximum phase drift of the four output signals reaches 4.2°, and the amplitude fluctuation exceeds ±1.8dB. After enabling this compensation method, the phase drift is effectively suppressed to within ±0.4°, and the amplitude fluctuation is less than ±0.2dB. Without adding complex hardware, and utilizing only existing control interfaces and low-cost temperature sensors, the long-term stability and multi-channel consistency of the equipment in harsh application environments such as vehicle-mounted, field, or high and low temperature tests can be significantly improved.

[0046] In a preferred embodiment, the integrated control module is also used to monitor the system communication status; after the network connection is successful, the host computer software will visually prompt the communication link icon in bold and green.

[0047] In a preferred embodiment, the four power amplifiers use the same type of high-power microwave amplifier device to ensure that the consistency deviation of the multi-channel output power does not exceed ±1dB.

[0048] The four power amplifiers in the power amplification module all use the same model and batch of high-power microwave amplifier devices, and are designed with a strictly symmetrical circuit layout to minimize performance differences between channels. Because these amplifiers have highly consistent gain, saturated output power, and temperature characteristics, the deviation of the output power of each channel is effectively controlled within ±1dB under the same input signal and power supply conditions. This hardware-level consistency design avoids relying on subsequent software calibration to compensate for errors caused by device discreteness. It not only improves the amplitude synchronization accuracy of multi-channel signals but also ensures that the four signals maintain good power balance even at high power output (no less than 32dBm per channel), providing reliable assurance for applications with stringent amplitude consistency requirements, such as phased array and multi-channel testing.

[0049] In a preferred embodiment, the microwave multi-channel signal source supports the simultaneous output of four independent or coherent microwave signals; all channels share the same frequency reference signal to achieve phase synchronization between channels, with a phase difference fluctuation of less than ±2° / hour.

[0050] This microwave multi-channel signal generator can simultaneously output four microwave signals, each of which can have its frequency, amplitude, and phase independently set, or operate in coherent mode for high synchronization. Its phase synchronization capability stems from the fact that all channels share the same highly stable frequency reference signal. Whether from an internal crystal oscillator or an external reference input, this reference signal first generates a high-quality master carrier in the frequency source module, and then distributes it equally to the four amplitude and phase control channels via the signal distribution module. Because the subsequent RF paths of each channel employ a symmetrical layout, matching devices, and a unified temperature control design, phase mismatch caused by path length differences or temperature drift is effectively suppressed. Therefore, during long-term continuous operation, the phase difference fluctuation between any two signals is strictly controlled within ±2° / hour, ensuring the coherence and stability of the multi-channel signals in high-precision applications such as radar beamforming, MIMO communication testing, or phase interferometry.

[0051] In a preferred embodiment, the microwave multi-channel signal source further includes a phase self-calibration subsystem for real-time monitoring and closed-loop compensation of phase drift between channels. The phase self-calibration subsystem includes: one continuous-wave laser, four electro-optic modulators (EOMs), one 1×4 optical switch, one photodetector (PD), and a phase demodulation module integrated into the microcontroller control unit. During operation, the continuous-wave laser is split into four channels, each input to one of the four electro-optic modulators, and intensity modulation is performed by the four microwave output signals. The modulated optical signals are sequentially selected by the optical switch and sent to the photodetector through a shared short-pitch polarization-maintaining fiber to be restored to radio frequency signals. The phase demodulation module uses the first channel as a reference to calculate the phase error of the remaining channels relative to the reference channel in real time. This generates a correction voltage to adjust the bias of the corresponding voltage-controlled phase shifter, forming a closed-loop stable phase control. The phase error dynamic response of this closed-loop system satisfies a first-order differential equation: ; in, For the first Road passage at all times The phase error is expressed in degrees (°). This is the closed-loop proportional gain, expressed as the reciprocal of a second (s). -1 The frequency of the optical microwave is determined by the control bandwidth. The steady-state phase error of the system approaches zero. GHz, phase measurement resolution up to The equivalent time jitter is: ; Actual measurements show that after introducing this embodiment, the phase consistency fluctuation of the four signals working continuously at 26.5GHz for 4 hours does not exceed ±0.3°.

[0052] This invention integrates a miniature photonic phase self-calibration subsystem within a microwave multi-channel signal source, enabling real-time sensing and automatic correction of phase drift between output channels. Its working principle is as follows: a stable laser beam acts as a "probe," loading four microwave signals onto four optical signals to form optical radio frequency signals. Each optical signal is then sequentially selected via a high-speed optical switch and fed into a photodetector via a short-distance polarization-maintaining fiber, where it is converted back into an electrical signal for comparison. Because the optical path is shared and extremely short, environmental disturbances have almost identical effects on each channel; therefore, the measured phase difference primarily reflects the drift of the microwave circuit itself. Using the first signal as a reference, the system calculates the phase deviation of the other three channels in real time, generates corresponding correction voltages, and dynamically adjusts the voltage-controlled phase shifters of the corresponding channels, thus forming a closed-loop phase-stabilized control circuit. This "optical measurement and electrical adjustment" strategy significantly improves phase detection sensitivity and response speed, enabling the entire system to possess self-calibration capabilities. The test results show that, after 4 hours of continuous operation at a high frequency of 26.5 GHz, the phase consistency fluctuation between the four output signals can be stably controlled within ±0.3°, which is far superior to the traditional pure electric domain solution. This effectively meets the stringent requirements of high-precision applications such as phased array radar and millimeter-wave communication for multi-channel coherent signals.

[0053] In a preferred embodiment, the internal reference output signal frequency of the frequency source module is 100MHz, the output power is 7dBm, the output interface type is SMA(f), and the overall volume of the frequency source module does not exceed 100mm × 100mm × 30mm. The main body 1 of the microwave multi-channel signal source in this embodiment is as follows... Figures 2-4As shown in the diagram, the first microwave multiplexer output channel 2, the second microwave multiplexer output channel 3, the third microwave multiplexer output channel 4, and the fourth microwave multiplexer output channel 5 all use a 220V power supply, corresponding to the 220V power input port 6. See also the external reference input 7, internal reference output 8, external RF input 9, and network port 10. Figure 4 .

[0054] The frequency source module not only provides a highly stable reference for internal signal generation but also features a standard internal reference output function, facilitating synchronization with other test equipment. This reference output signal has a frequency of 100MHz and a stable output power of 7dBm. The interface uses a universal SMA(f) type RF connector, allowing users to easily distribute the clock reference to spectrum analyzers, network analyzers, or other signal sources via cables, achieving phase coherence or time synchronization between multiple devices. Furthermore, the entire frequency source module employs a highly integrated design, compactly arranging the crystal oscillator, phase-locked loop, frequency multiplier, and filtering circuits, keeping the overall size within 100mm × 100mm × 30mm. This significantly saves space while ensuring high performance, promoting miniaturization and portable deployment, making it particularly suitable for field testing or airborne applications with strict requirements on size and system integration.

[0055] In summary, this invention provides a high-performance, highly integrated microwave multichannel signal source. By integrating several innovative technologies, including precision frequency synthesis, independent amplitude and phase modulation, high-power amplification, intelligent temperature drift compensation, and optoelectronic co-stabilization, it achieves independent or coherent output of four 18–26.5 GHz microwave signals. This signal source not only boasts excellent specifications such as a single-channel saturated output power of no less than 32 dBm, good inter-channel phase consistency, amplitude control resolution of 0.5 dB, and phase shift accuracy of 0.1°, but also supports internal and external reference switching, coherent power synthesis, multi-mode automated testing, and visual human-machine interaction. This significantly improves its applicability and reliability in high-end fields such as phased array radar, 5G / 6G millimeter-wave communication, satellite payload testing, electronic countermeasures, and multi-channel calibration. The entire unit adopts a modular and sealed cavity design, ensuring high performance while also considering environmental adaptability and miniaturization requirements.

[0056] The above description is merely a preferred embodiment of the present invention, used to clearly illustrate the technical solution of the present invention, but does not constitute a limitation on the scope of protection of the present invention. Those skilled in the art, based on an understanding of the core concept of the present invention, can make various equivalent substitutions, structural changes, or non-substantial improvements to the above embodiments, such as adjusting module layout, replacing functionally equivalent devices, optimizing control logic, or expanding the operating frequency band. Any modifications, combinations, simplifications, or extensions made in accordance with the spirit and principles of the present invention should be considered to fall within the scope of protection of the present invention.

Claims

1. A microwave multi-channel signal source, characterized in that, include: Frequency source module, signal distribution module, multi-channel amplitude and phase control module, power amplification module, and integrated control module; The frequency source module is used to generate or access a frequency reference signal and generate a microwave frequency signal covering 18 GHz to 26.5 GHz. The signal distribution module includes a single-pole double-throw switch and a 1-to-4 power divider, used to switch between internal excitation signals and external excitation signals, and to distribute the switched signals into 4 channels. The multi-channel amplitude and phase control module receives four signals allocated by the signal distribution module. Each channel includes an amplitude and phase control channel for independently and precisely adjusting the amplitude and phase of each signal. The power amplifier module includes four power amplifiers, which are connected one-to-one with the four outputs of the multi-channel amplitude and phase control module to amplify each signal to a preset power level, wherein the single-channel saturated output power is not less than 32dBm. The integrated control module includes a microcontroller control unit and host computer software. The microcontroller control unit controls the frequency source module through the SPI interface, controls the voltage-controlled phase shifter in the multi-channel amplitude and phase control module through the DA output, and controls the digitally controlled attenuator in the multi-channel amplitude and phase control module and the single-pole double-throw switch in the signal distribution module through TTL level respectively. The host computer software supports network communication and is used to set the working mode and independently control the switching status and parameter adjustment of the four channels.

2. The microwave multi-channel signal source according to claim 1, characterized in that, The frequency source module further includes: Crystal oscillator, second single-pole double-throw switch, phase-locked loop, frequency multiplier and filter; The crystal oscillator is used to generate the frequency reference signal; The second single-pole double-throw switch is used to select the internal frequency reference or the external reference input; The selected reference signal is processed sequentially through the phase-locked loop, frequency multiplier, and filter to generate the microwave frequency signal from 18 GHz to 26.5 GHz.

3. The microwave multi-channel signal source according to claim 1, characterized in that, Each amplitude-phase control channel in the multi-channel amplitude-phase control module includes: Two-stage digitally controlled attenuator, one-stage voltage-controlled phase shifter, and one-stage driver amplifier; By controlling the power supply to the driver amplifier, the on / off control of the output signal of the entire channel can be achieved.

4. The microwave multi-channel signal source according to claim 3, characterized in that, The two-stage digitally controlled attenuator is a 6-bit digitally controlled attenuator with a total attenuation range of 0 to 63 dB and an attenuation step of 0.5 dB.

5. The microwave multi-channel signal source according to claim 3, characterized in that, The voltage-controlled phase shifter uses a varactor diode as the core tuning element. By adjusting its bias voltage, the equivalent capacitance is changed, thereby achieving continuous or step phase adjustment. Its phase shift range is 0° to 360°, the minimum phase shift step can be configured to 0.1°, and the phase shift value input by the user is automatically rounded to the nearest integer multiple of the step value.

6. The microwave multi-channel signal source according to claim 1, characterized in that, The host computer software supports point frequency mode, sweep frequency mode and preset mode; wherein, the preset mode supports importing parameter tables containing serial numbers, frequency values, attenuation values ​​and phase shift values, and each parameter column is editable, with units of Hz, dB and degrees respectively.

7. The microwave multiplexer according to claim 1 or 6, characterized in that, The host computer software can independently control the on / off status of 4 channels; when a channel is turned on, its corresponding parameter adjustment interface becomes editable, and the parameters are highlighted in green after taking effect, and the software interface uses green signal lines to indicate the direction of signal transmission.

8. The microwave multiplexer according to any one of claims 1-6, characterized in that, The single-pole double-throw switch in the signal distribution module constitutes a first routing node, used to select a first signal source or a second signal source; the first signal source is the internal microwave signal generated by the frequency source module, and the second signal source is the external excitation signal input from the external port.

9. The microwave multi-channel signal source according to claim 1, characterized in that, The main structure of the frequency source module and the radio frequency cavity that integrates the multi-channel amplitude and phase control module and the power amplifier module are both made of sealed aluminum cavity to improve electromagnetic shielding performance and environmental stability.

10. The microwave multiplexer according to claim 1 or 9, characterized in that, The integrated control module is also used to monitor the system communication status; after the network connection is successful, the host computer software will visually prompt the communication link icon in bold and green.

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