Multi-channel microwave reflectometer assembly and signal processing method and design method thereof

Abstract

The invention relates to a multi-channel microwave reflectometer assembly and a signal processing method and a design method thereof, the multi-channel microwave reflectometer assembly comprises a transmitting module, a receiving module and an equipment shell, the transmitting module is provided with a plurality of independent transmitting channels, signals of the transmitting channels can be combined into one path to be output, each transmitting channel comprises an oscillator and a frequency multiplier, and the frequency multiplier is connected with the receiving module. The power divider, the multiplexer, the antenna and the receiving module are provided with a plurality of independent receiving channels, signals of the multiple receiving channels can be amplified and output, the oscillator generates dot frequency source signals, the power divider can generate local oscillation signals of the receiving channels, and the design method comprises four steps. Each transmitting channel can generate 50-75GHz dot frequency signals, and the 50-75GHz dot frequency signals are synthesized into one path through a multiplexer to be efficiently transmitted; and a receiving channel performs down-mixing by using the same local oscillator signal, and amplifies an intermediate frequency signal through a high-performance video amplifier to ensure the definition and sensitivity of the signal.

Description

Technical Field

[0001] The invention relates to the field of radio frequency microwaves, and in particular to a multi-channel microwave reflectometer component and a signal processing method and a design method thereof. Background Art

[0002] Microwave reflectometer originated from radar system. It is a plasma diagnostic derived from radar technology. It was first used in the Earth's ionosphere height measurement experiment. Later, it was widely used in various magnetic confinement fusion devices. Microwave reflectometer can be divided into three main types, including frequency modulated continuous wave reflectometer, amplitude modulation reflectometer, and pulse compression radar reflectometer.

[0003] The frequency modulation reflectometer is the most widely used reflectometer at present. It transmits a series of microwaves with continuously changing frequencies to the plasma. The microwaves enter the plasma through the transmitting antenna, and then are cut off and reflected in the plasma and received by the receiving antenna. They are mixed with the local oscillator signal in the receiving channel. Since the flight time of the microwave signal in the transmitting and receiving channels is different, and the frequency of the microwave signal is swept linearly with time, the intermediate frequency signal obtained after mixing has sideband spurious, resulting in insufficient signal clarity. Summary of the invention

[0004] To solve the above problems, the present invention provides a multi-channel microwave reflectometer component and its signal processing method and design method, which can realize 16 independent transmitting channels transmitting signals through a multiplexer and 16 independent receiving channels receiving signals through the multiplexer, and the mixed signals are amplified by a video amplifier.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a multi-channel microwave reflectometer component and a signal processing method and a design method thereof. A multi-channel microwave reflectometer component comprises: Transmitting module, receiving module, device housing 1, the transmitting module has multiple independent transmitting channels, which can synthesize the signals of multiple transmitting channels into one output, and the transmitting channel includes an oscillator, a doubler, a power divider, a multiplexer, and an antenna.

[0006] The receiving module has multiple independent receiving channels, which can amplify and output the signals of multiple receiving channels. The oscillator generates a point frequency source signal, and the power divider can generate the local oscillator signal of the receiving channel.

[0007] The oscillator is used to generate a point frequency signal, the frequency multiplier is used to multiply the frequency of the point frequency signal, and the power divider divides the power of the point frequency signal into two signals which are respectively connected to the multiplexer and the receiving channel; The multiplexer is used to receive the signals from multiple power splitters and combine them into one output through the antenna; The receiving channel includes an antenna, a multiplexer, a mixer and a video amplifier. The mixer is used to receive a signal from the multiplexer and mix it with the local oscillator signal of the receiving channel, and then amplify and output it through the video amplifier. The video amplifier has an ultra-wideband operational amplifier chip.

[0008] Preferably, the oscillator is a phase-locked dielectric oscillator, and the frequency multiplier is a frequency doubler; It also includes an attenuator, which is arranged at the end of the phase-locked dielectric oscillator and is used to attenuate the point frequency source generated by the phase-locked dielectric oscillator.

[0009] Preferably, the video amplifier has an ultra-wideband operational amplifier chip.

[0010] Preferably, the transmitting module further comprises a clock source module, the clock source module internally integrates an external reference input module, and the external reference input module is connected to the oscillator for making the point frequency source signal common reference.

[0011] Preferably, the external reference input module locks the frequency of the phase-locked dielectric oscillator through dual-loop sampling phase locking and low phase noise step diodes to provide a stable clock signal.

[0012] Preferably, the multiplexer is also connected to an antenna.

[0013] The signal processing method is that the transmitting module has multiple independent transmitting channels, which can synthesize the signals of multiple transmitting channels into one output. The mixer of the receiving channel of the receiving module is used to receive one signal of the multiplexer, and after mixing with the local oscillator signal of the receiving channel, it is amplified and output through the video amplifier.

[0014] A multi-channel microwave reflectometer component design method comprises the following steps: S1: Design the specific circuits of each transmitting channel and receiving channel, including the selection and connection of oscillators, frequency multipliers, power dividers, mixers and video amplifiers, to ensure that each channel can independently and efficiently generate and receive microwave signals of a specific frequency band; S2: Design the frequency band allocation and signal splitting logic of the multiplexer so that the multiplexer can accurately combine the transmit signal into one channel and radiate it out, and at the same time allocate the signal received from the antenna to the corresponding receiving channel according to the frequency band; S3: Setting the initial reference frequency of the clock source module and the external reference input module to provide a basis for frequency stabilization and phase synchronization of the multi-channel microwave reflectometer assembly; S4: Optimize the structural position layout between components, reduce the loss and signal leakage risk between channels through reasonable layout design, and improve the overall performance of the multi-channel microwave reflectometer assembly.

[0015] Preferably, step S1 also includes performing performance testing and matching verification on the selected oscillator, frequency multiplier, power divider, mixer and video amplifier to ensure that the components can work together in the system and achieve the expected performance indicators.

[0016] Preferably, in step S2, advanced frequency synthesis technology and frequency band division algorithm are used to improve the frequency band allocation accuracy and signal splitting efficiency of the multiplexer.

[0017] Preferably, in step S3, the clock source module uses a low phase noise, high stability crystal oscillator as a reference source, and the external reference input module cooperates with the phase-locked medium oscillators of 16 independent transmission channels through an adaptive circuit to achieve precise synchronization and phase locking of the signal.

[0018] The beneficial effects of the present invention are: 1. The present invention has 16 independent transmitting channels and receiving channels. Each transmitting channel can generate a 50-75GHz point frequency signal and synthesize it into a high-efficiency transmission through a multiplexer; the receiving channel uses the same local oscillator signal for down-mixing and amplifies the intermediate frequency signal through a high-performance video amplifier, ensuring the clarity and sensitivity of the signal.

[0019] 2. Direct interconnection of internal components of the system reduces channel loss and leakage risk.

[0020] 3. The sixteen-channel point frequency sources adopt a common reference scheme to increase system stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a principle block diagram of a multi-channel microwave reflectometer assembly of the present invention; Figure 2 It is a structural schematic diagram of a transmission channel of a multi-channel microwave reflectometer assembly of the present invention; Figure 3 It is a schematic diagram of the layout structure of a multi-channel microwave reflectometer assembly of the present invention; Figure 4 This is a first partial structural diagram of the principle of a clock source module of a multi-channel microwave reflectometer assembly of the present invention; Figure 5 This is a second partial structural diagram of the principle of a clock source module of a multi-channel microwave reflectometer component of the present invention.

[0022] Description of the drawings: 1. Equipment housing; 2. Phase-locked dielectric oscillator; 3. Attenuator; 4. Doubler; 5. Power divider; 6. Multiplexer; 7. Antenna; 8. Down-mixer; 9. Video amplifier; 10. Clock source module. DETAILED DESCRIPTION

[0023] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0024] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, a multi-channel microwave reflectometer assembly comprises: Transmitting module, receiving module, the transmitting module has multiple independent transmitting channels, and can synthesize the signals of multiple transmitting channels into one output. The receiving module has multiple independent receiving channels, and can amplify and output the signals of multiple receiving channels. The power divider can generate the local oscillator signal of the receiving channel.

[0025] The transmitting channel has a phase-locked dielectric oscillator 2, an attenuator 3, a frequency doubler 4, a power divider 5, a multiplexer 6, and an antenna 7 which are connected in sequence.

[0026] The phase-locked dielectric oscillator 2 is used to generate a point frequency signal, which is called a point frequency source signal. The attenuator 3 is set at the end of the phase-locked dielectric oscillator, and is used to attenuate the point frequency source generated by the phase-locked dielectric oscillator 2. The doubler 4 is used to multiply the frequency of the point frequency signal. The power divider 5 divides the point frequency signal into two signals, which are respectively connected to the multiplexer 6 and the receiving channel; the multiplexer 6 is used to receive signals from multiple power dividers 5, and synthesize them into one signal and output it through the antenna 7.

[0027] The receiving channel includes an antenna 7, a multiplexer 6, a down-mixer 8 and a video amplifier 9. The down-mixer 8 is used to receive a signal from the multiplexer 6, and after mixing with the local oscillator signal of the receiving channel, it is amplified and output through the video amplifier 9. The video amplifier 9 has an ultra-wideband operational amplifier chip. The video amplifier 9 uses an ultra-wideband operational amplifier chip to perform impedance matching, realize DC-500MHz bandwidth operation, and the gain is adjustable from 0 to 30db.

[0028] The transmitting module also includes a clock source module 10, which has an external reference input module integrated therein. The external reference input module is connected to the phase-locked medium oscillator 2 and is used to make the point frequency source signal co-referenced. The external reference input module locks the oscillation frequency generated by the phase-locked medium oscillator 2 by means of dual-loop sampling phase locking and low phase noise step diode sampling phase detection to obtain very excellent phase noise characteristics and provide a stable clock signal. The external reference input module is used in conjunction with the phase-locked medium oscillators in 16 independent transmitting channels to realize 16-channel transmitting channel signal sources.

[0029] A specific working process and signal processing method of a multi-channel microwave reflectometer component is that the transmitting module includes 16 transmitting channels, each transmitting channel is generated by a phase-locked dielectric oscillator 2, a point frequency source signal of 25GHz to 37GHz and an output power of 13dBm, and then passes through an attenuator 3 with a frequency of DC-40GHz and an attenuation of 6dB to obtain signals with frequencies of 25GHz to 37GHz and an output power of 7dBm. This signal is used as an input signal and passes through a doubler 4 to obtain a 50GHz to 74GHz signal; this output signal is further passed through a 50-75GHz power divider to obtain two 50GHz to 74GHz signals, one of which is directly transmitted through a multiplexer 6 and then transmitted through an antenna 7; the other is used as a local oscillator signal in the receiving channel and as a local oscillator driving signal of a down-mixer 8.

[0030] The signal received by the antenna 7 of the receiving module passes through the 16-channel multiplexer 6, and the multiplexer 6 realizes frequency division according to the corresponding frequency band to generate 50-75GHz corresponding signals. After division, the corresponding signals enter the down-mixer 8 respectively and are mixed with the local oscillator driving signal of the down-mixer 8. The mixed intermediate frequency signal is filtered out by a low-pass filter to remove spurious signals, and finally displayed in the video amplifier 9.

[0031] A multi-channel microwave reflectometer component design method comprises the following steps: S1: Design the specific circuits of each transmitting channel and receiving channel, including the selection and connection of phase-locked dielectric oscillator, frequency multiplier, power divider, down-mixer and video amplifier, to ensure that each channel can independently and efficiently generate and receive microwave signals of a specific frequency band; S2: Design the frequency band allocation and signal splitting logic of the multiplexer so that the multiplexer can accurately combine the transmit signal into one channel and radiate it out, and at the same time allocate the signal received from the antenna to the corresponding receiving channel according to the frequency band; S3: Setting the initial reference frequency of the clock source module and the external reference input module to provide a basis for frequency stabilization and phase synchronization of the multi-channel microwave reflectometer assembly; S4: Optimize the structural position layout between components, reduce the loss and signal leakage risk between channels through reasonable layout design, and improve the overall performance of the multi-channel microwave reflectometer assembly.

[0032] In the embodiment, step S1 also includes performance testing and matching verification of the selected phase-locked dielectric oscillator, frequency multiplier, power divider, down-mixer and video amplifier to ensure that the components can work together in the system and achieve the expected performance indicators.

[0033] In the embodiment, in step S2, advanced frequency synthesis technology and frequency band division algorithm are used to improve the frequency band allocation accuracy and signal separation efficiency of the multiplexer.

[0034] In the embodiment, in step S3, the clock source module uses a low phase noise, high stability crystal oscillator as a reference source, and the external reference input module cooperates with the phase-locked medium oscillators of 16 independent transmission channels through an adaptive circuit to achieve precise synchronization and phase locking of the signal.

[0035] Specifically, the multi-channel microwave reflectometer component achieves efficient transmission and reception of microwave signals in multiple independent frequency bands through carefully designed circuit structure and signal processing flow. First, at the transmitting end, the phase-locked dielectric oscillator in each transmitting channel generates a stable point frequency source, which is multiplied to the required 50-75GHz frequency band by a frequency multiplier and divided into two paths by a power divider. One signal is synthesized by a multiplexer and radiated by the antenna; the other is used as the local oscillator signal of the down-mixer in the receiving channel for subsequent signal processing.

[0036] During reception, the microwave signal received by the antenna passes through the multiplexer and is allocated to the corresponding receiving channel according to the frequency band. In the receiving channel, the received signal is mixed with the point frequency source as the local oscillator signal to generate an intermediate frequency signal. The intermediate frequency signal is then filtered out of stray signals and amplified by the video amplifier to finally output a clear and stable signal for use by subsequent circuits or equipment.

[0037] The multi-channel microwave reflectometer component uses a clock source module and an external reference input module to provide a stable reference frequency and phase synchronization signal for the entire component system, ensuring the high accuracy and stability of the system. At the same time, by using electromagnetic simulation technology to optimize the structural position and layout between components, the loss between channels and the risk of signal leakage are effectively reduced, and the overall performance of the multi-channel microwave reflectometer component is improved.

[0038] In summary, the multi-channel microwave reflectometer component, through its unique working principle, realizes the efficient, stable and accurate transmission and reception of microwave signals in multiple frequency bands, providing important technical support for radar systems, wireless communication systems, test and measurement equipment and other fields.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-channel microwave reflectometer assembly, characterized in that: include: A transmitting module, a receiving module, and a device housing (1). The transmitting module has a plurality of independent transmitting channels, and can combine the signals of the plurality of transmitting channels and output them in one channel. The transmitting channel includes an oscillator, a frequency multiplier, a power divider (5), a multiplexer (6), and an antenna (7). The receiving module has a plurality of independent receiving channels, and can amplify and output the signals of the plurality of receiving channels. The oscillator generates a point frequency source signal, and the power divider (5) can generate a local oscillator signal of the receiving channel.

2. A multi-channel microwave reflectometer assembly according to claim 1, characterized in that: The oscillator is used to generate a point frequency signal, the frequency multiplier is used to multiply the frequency of the point frequency signal, and the power divider (5) divides the power of the point frequency signal into two signals which are respectively connected to the multiplexer (6) and the receiving channel; The multiplexer (6) is used to receive signals from a plurality of power dividers (5), and synthesize the signals for output via an antenna.

3. A multi-channel microwave reflectometer assembly according to claim 1, characterized in that: The receiving channel comprises the antenna (7), the multiplexer (6), a mixer and a video amplifier (9), wherein the mixer is used to receive a signal from the multiplexer (6), mix it with a local oscillator signal of the receiving channel, and then amplify and output it through the video amplifier (9), wherein the video amplifier (9) has an ultra-wideband operational amplifier chip.

4. A multi-channel microwave reflectometer assembly according to claim 3, characterized in that: The mixer is a down-mixer (8), and the video amplifier (9) uses an ultra-wideband operational amplifier chip to perform impedance matching, achieve DC-500MHz bandwidth operation, and have an adjustable gain of 0 to 30db.

5. A multi-channel microwave reflectometer assembly according to claim 2, characterized in that: The oscillator is a phase-locked dielectric oscillator (2), the frequency multiplier is a doubler (4), and the phase-locked dielectric oscillator (2) further comprises an attenuator (3), wherein the attenuator (3) is arranged at the end of the phase-locked dielectric oscillator (2) and is used to attenuate a point frequency source signal generated by the phase-locked dielectric oscillator (2).

6. A multi-channel microwave reflectometer assembly according to claim 2, characterized in that: The invention also comprises a clock source module (10), wherein the clock source module (10) internally integrates an external reference input module, the external reference input module is connected to the oscillator and is used to make the point frequency source signal common reference, and the external reference input module locks the frequency of the phase-locked medium oscillator through dual-loop sampling phase locking and low phase noise step diode to provide a stable clock signal.

7. A multi-channel microwave reflectometer assembly signal processing method, comprising the multi-channel microwave reflectometer assembly according to any one of claims 1 to 6, characterized in that: The transmitting module device contains multiple transmitting channels, each channel is composed of a phase-locked dielectric oscillator to generate a 25GHz The point frequency source signal is a DC-40GHz attenuator with an attenuation of 6dB, and then passes through an attenuator with a frequency of DC-40GHz and an attenuation of 6dB to obtain a signal with a frequency of 25GHz to 37GHz and an output power of 7dBm. This signal is used as the input signal and passes through a doubler to obtain a 50GHz to 74GHz signal. This output signal passes through a 50-75GHz power divider to obtain two 50GHz to 74GHz signals, one of which passes directly through a multiplexer and is transmitted through an antenna. The other is used as the local oscillator signal in the receiving channel and as the local oscillator driving signal of the down-mixer. The signal received by the antenna of the receiving module passes through a multi-channel multiplexer, and the multiplexer realizes frequency division according to the corresponding frequency band to generate a 50-75GHz corresponding signal. After division, the corresponding signals enter the down-mixer respectively and are mixed with the local oscillator driving signal of the down-mixer. The intermediate frequency signal mixed is filtered out by a low-pass filter to remove spurious signals and finally displayed in the video amplifier.

8. A method for designing a multi-channel microwave reflectometer assembly, comprising the multi-channel microwave reflectometer assembly according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Design the specific circuits of each transmitting channel and receiving channel, including the selection and connection of oscillators, frequency multipliers, power dividers, mixers and video amplifiers, to ensure that each channel can independently and efficiently generate and receive microwave signals of a specific frequency band; S2: Design the frequency band allocation and signal splitting logic of the multiplexer so that the multiplexer can accurately combine the transmit signal into one channel and radiate it out, and at the same time allocate the signal received from the antenna to the corresponding receiving channel according to the frequency band; S3: Setting the initial reference frequency of the clock source module and the external reference input module to provide a basis for frequency stabilization and phase synchronization of the multi-channel microwave reflectometer assembly; S4: Optimize the structural position layout between components, reduce the loss and signal leakage risk between channels through reasonable layout design, and improve the overall performance of the multi-channel microwave reflectometer assembly.

9. The multi-channel microwave reflectometer component design method according to claim 8, characterized in that: In step S1, it also includes performance testing and matching verification of the selected phase-locked dielectric oscillator, frequency multiplier, power divider, down-mixer and video amplifier to ensure that the components can work together in the system and achieve the expected performance indicators.

10. The multi-channel microwave reflectometer component design method according to claim 8, characterized in that: In step S2, advanced frequency synthesis technology and frequency band division algorithm are used to improve the frequency band allocation accuracy and signal branching efficiency of the multiplexer. The clock source module uses a low phase noise, high stability crystal oscillator as a reference source, and the external reference input module cooperates with the phase-locked medium oscillators of multiple independent transmission channels through an adaptive circuit to achieve accurate signal synchronization and phase locking.

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