High-linearity frequency modulation continuous wave height measurement assembly

Abstract

The invention discloses a high-linearity frequency modulation continuous wave height measurement assembly, which comprises a frequency sweep source circuit, a radio frequency transceiver circuit and a digital processing unit, and is characterized in that the frequency sweep circuit is used for generating a linear frequency modulation signal and transmitting the generated linear frequency modulation signal to the radio frequency transceiver unit; the radio frequency transceiving unit is connected with the transmitting antenna and the receiving antenna, and is used for processing the linear frequency modulation signal, transmitting the processed linear frequency modulation signal through the transmitting antenna, receiving an echo signal through the receiving antenna, processing the echo signal to generate an intermediate frequency signal, and transmitting the intermediate frequency signal to the digital processing unit; and the digital processing unit is used for performing frequency spectrum detection on the received intermediate frequency signal and resolving height information. According to the high-linearity frequency modulation continuous wave height measurement assembly provided by the invention, a high-precision height measurement task can be completed under the condition that the size of the assembly is small.

Description

Technical Field

[0001] The present application relates to the technical field of remote measurement and remote sensing, and more specifically, to a high linear frequency modulation continuous wave height measurement component. Background Art

[0002] With the development of modern aerospace systems, linear frequency modulation continuous wave altimeter components are one of the indispensable navigation devices in modern aircraft and are crucial to the safety of aircraft. Therefore, it is necessary to be able to reliably, accurately and quickly measure the true height of the aircraft from the ground or water surface under various climatic conditions.

[0003] High-frequency modulation continuous height measurement components are active remote sensing devices. Because they work in the microwave band, they are also called radar height measurement T / R components and are widely used in various scenarios. However, due to technical limitations, existing high-frequency modulation continuous height measurement components are usually large in size, while small-volume high-frequency modulation continuous height measurement components cannot effectively meet the needs of practical applications. Summary of the invention

[0004] In view of at least one defect or improvement demand in the prior art, the present invention provides a high linear frequency modulation continuous wave height measurement component, which can solve at least one of the problems existing in the above-mentioned background technology.

[0005] To achieve the above object, according to the present invention, a high linear frequency modulation continuous wave height measurement component is provided, which includes a frequency sweep source circuit, a radio frequency transceiver circuit and a digital processing unit, wherein:

[0006] The frequency sweep circuit is used to generate a linear frequency modulation signal, and transmit the generated linear frequency modulation signal to the radio frequency transceiver unit;

[0007] The RF transceiver unit is connected to the transmitting antenna and the receiving antenna, and is used to process the linear frequency modulation signal and transmit it through the transmitting antenna, receive the echo signal through the receiving antenna and process it to generate an intermediate frequency signal, and transmit the intermediate frequency signal to the digital processing unit;

[0008] The digital processing unit is used to perform spectrum detection on the received intermediate frequency signal and calculate the height information.

[0009] Further, in the above-mentioned high linear frequency modulation continuous wave height measurement component, the frequency sweep circuit includes a reference clock source, a fractional-N frequency synthesizer, a loop low-pass filter, a voltage-controlled oscillator and a frequency divider;

[0010] The reference clock source is used to generate a stable clock signal, and the clock signal is input into a fractional-N frequency synthesizer for configuration so that the center frequency meets the carrier design requirements. The output signal is optimized through a loop low-pass filter, and is transmitted to a voltage-controlled oscillator after processing by an adder. The voltage-controlled oscillator processes the signal and obtains a linear frequency modulation signal output. A part of the output linear frequency modulation signal is input into a radio frequency transceiver unit, and the other part is divided by a frequency divider and input into the fractional-N frequency synthesizer.

[0011] Furthermore, in the above-mentioned high-linear frequency-modulated continuous wave height measurement component, the RF transceiver unit includes one transmitting channel and one receiving channel, wherein the transmitting channel includes a filter, a 2-folder, a power divider, a two-stage RF power amplifier chip and a final-stage wave-to-wave conversion node in sequence, and the receiving channel includes a wave-to-wave conversion node, a limiter, a low-noise power amplifier, a mixer, a two-stage intermediate wave filter and a two-stage intermediate frequency amplifier in sequence.

[0012] Furthermore, in the above-mentioned high linear frequency modulation continuous wave height measurement component, the power divider of the transmitting channel is connected to the mixer of the receiving channel through a radio frequency amplifier and a bandpass filter in sequence.

[0013] Furthermore, in the above-mentioned high linear frequency modulation continuous wave height measurement component, the digital processing unit includes an automatic gain control circuit, a digital-analog acquisition circuit, a processor FPGA, a phase-locked loop configuration chip, a frequency sweep control circuit, a power management unit and a 422 communication interface circuit;

[0014] The automatic gain control circuit is used to receive the signal of the radio frequency transceiver unit, and transmit the signal to the analog-to-digital acquisition circuit after processing. The digital-to-analog acquisition circuit is used to convert the analog signal into a digital signal and input it into the processor FPGA. The processor FPGA is respectively connected to the automatic gain control circuit, the digital-to-analog acquisition circuit, the sweep frequency control circuit and the 422 communication interface circuit to control the corresponding process. The sweep frequency control circuit is connected to the adder to output a triangular wave modulated pulse;

[0015] The 422 communication interface circuit is used for connecting to the outside, the phase-locked loop configuration chip is used for controlling the fractional-N frequency synthesizer, and the power management unit is used for managing the power supply of the digital processing unit.

[0016] Furthermore, in the above-mentioned high linear frequency modulation continuous wave height measurement component, the automatic gain control circuit includes a digitally controlled attenuator and a variable gain amplifier.

[0017] Furthermore, in the above-mentioned high linear frequency modulation continuous wave height measurement component, the digital processing unit is connected to a computer.

[0018] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0019] The present invention provides a high-linear frequency modulation continuous wave height measurement component, which uses phase-locked frequency modulation technology to generate a frequency modulation signal with high frequency stability, good linearity and high test accuracy. At the same time, the integrated circuit used in the component is small in size and high in integration, and can complete high-precision height measurement tasks in a smaller component volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the structure of a high linear frequency modulation continuous wave height measurement component provided in an embodiment of the present application;

[0022] Figure 2 A schematic diagram of a frequency sweeping circuit structure of a high linear frequency modulation continuous wave height measurement component provided in an embodiment of the present application;

[0023] Figure 3 A schematic diagram of the structure of a radio frequency transceiver unit of a high linear frequency modulation continuous wave height measurement component provided in an embodiment of the present application;

[0024] Figure 4 A schematic diagram of the structure of a digital processing unit of a high linear frequency modulation continuous wave height measurement component provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] The terms "first", "second", "third", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0027] Figure 1is a structural schematic diagram of a high linear frequency modulation continuous wave height measurement component provided in an embodiment of the present application, such as Figure 1 As shown, a high linear frequency modulation continuous wave height measurement component provided in an embodiment of the present application includes a frequency sweep source circuit, a radio frequency transceiver circuit and a digital processing unit, wherein:

[0028] The frequency sweeping circuit is used to generate a linear frequency modulation signal, and transmit the generated linear frequency modulation signal to the radio frequency transceiver unit;

[0029] The RF transceiver unit is connected to the transmitting antenna and the receiving antenna, and is used to process the linear frequency modulation signal and transmit it through the transmitting antenna, receive the echo signal through the receiving antenna and process it to generate an intermediate frequency signal, and transmit the intermediate frequency signal to the digital processing unit;

[0030] The digital processing unit is used to perform spectrum detection on the received intermediate frequency signal and calculate the height information.

[0031] Specifically, the frequency sweeping circuit is essentially a phase-locked loop frequency modulation circuit with frequency modulation function, which is used to generate a stable carrier, i.e., a linear frequency modulation signal, and transmit the generated linear frequency modulation signal to the RF transceiver unit. The continuous frequency modulation signal generated by the frequency sweeping circuit of the present application has high stability, high linearity, and good test accuracy.

[0032] The RF transceiver unit processes the received linear frequency modulation signal, generates a signal with a radiation power that meets the design requirements, and transmits it through the transmitting antenna. The transmitted signal will be reflected when it encounters the ground or water surface. The reflected echo signal is received by the receiving antenna, and the echo signal is processed and mixed to obtain the intermediate frequency signal, also called the difference frequency signal. The frequency of the intermediate frequency signal contains the distance information of the ranging. After the intermediate frequency signal is processed, it is fed to the digital processing unit for further processing.

[0033] The digital processing unit processes the received signal and converts it into a digital signal. The distance information contained in the original intermediate frequency signal is solved by the processor, and then the distance information can be uploaded to the computer for subsequent processing.

[0034] A high-linear frequency modulation continuous wave height measurement component provided in an embodiment of the present application uses phase-locked frequency modulation technology to generate a frequency modulation signal with high frequency stability, good linearity, and high test accuracy. At the same time, the integrated circuit used in the component is small in size and highly integrated, and can complete high-precision height measurement tasks in a smaller component volume.

[0035] Optionally, the high-linear frequency modulation continuous wave height measurement component provided in the embodiment of the present application, the frequency sweep circuit includes a reference clock source, a fractional-N frequency synthesizer, a loop low-pass filter, a voltage-controlled oscillator and a frequency divider;

[0036] The reference clock source is used to generate a stable clock signal. The clock signal is input into the fractional-N frequency synthesizer for configuration so that the center frequency meets the carrier design requirements. The output signal is optimized through a loop low-pass filter and transmitted to the voltage-controlled oscillator after processing by the adder. The voltage-controlled oscillator processes the signal and obtains a linear frequency modulation signal output. Part of the output linear frequency modulation signal is input into the RF transceiver unit, and the other part is divided by the divider and input into the fractional-N frequency synthesizer.

[0037] Specifically, Figure 2 : is a schematic diagram of the structure of the high linear frequency modulation continuous wave height measurement component sweeping circuit provided in the embodiment of the present application, such as Figure 2 As shown, the frequency sweeping circuit provided in the embodiment of the present application is essentially a phase-locked loop frequency modulation circuit with a frequency adjustment function, which is mainly composed of a reference clock source, a fractional-N frequency synthesizer, a loop low-pass filter, a voltage-controlled oscillator and a frequency divider. The reference clock source usually uses a 100MHz reference clock source. Compared with the traditional open-loop direct-regulation voltage-controlled oscillator solution, the frequency modulation circuit in the embodiment of the present application can overcome temperature drift and nonlinear interference, and the generated carrier stability is very high, which can reach the frequency stability of a crystal oscillator.

[0038] Based on the frequency sweep circuit structure provided in the embodiment of the present application, according to the linear phase model of the loop, the modulation signal μ F (t), the output phase of the loop is

[0039]

[0040] The frequency deviation of the oscillator output frequency relative to the free oscillation frequency ω0 is sθ2(s). Combining the above formula, we can get

[0041] sθ2(s)=H e (s)*K0*U F (s)

[0042] Since K0 is a constant, H e (s) has the characteristics of high-pass filtering, as long as the modulation frequency ω m In H e (s) Within the passband, the output frequency deviation is proportional to the amplitude of the modulated frequency signal, so a frequency modulated continuous wave signal can be generated, which can be used for continuous height measurement.

[0043] After the reference clock source generates the clock signal, the fractional-N frequency synthesizer is first configured through the MCU controller of the digital board to make the center frequency meet the design requirements, and then the bandwidth of the loop filter is optimized so that the bandwidth of the system function covers the FM frequency to obtain the required linear FM signal.

[0044] Optionally, the high-linear frequency-modulated continuous-wave height measurement component provided in the embodiment of the present application, the RF transceiver unit includes one transmitting channel and one receiving channel, wherein the transmitting channel includes a filter, a 2-folder, a power divider, a two-stage RF power amplifier chip and a final-stage wave-to-wave conversion node in sequence, and the receiving channel includes a wave-to-wave conversion node, a limiter, a low-noise power amplifier, a mixer, a two-stage intermediate wave filter and a two-stage intermediate frequency amplifier in sequence.

[0045] Optionally, in the high linear frequency modulation continuous wave height measurement component provided in the embodiment of the present application, the power divider of the transmitting channel is connected to the mixer of the receiving channel through the radio frequency amplifier and the bandpass filter in sequence.

[0046] Specifically, Figure 3 A schematic diagram of the structure of a radio frequency transceiver unit of a high linear frequency modulation continuous wave height measurement component provided in an embodiment of the present application, such as Figure 3 As shown, the RF transceiver unit provided in the embodiment of the present application includes 1 transmission channel and 1 receiving channel. The main function of the transmission channel is to filter the small signal output by the frequency sweeping circuit, filter out the high-order harmonics and stray signals, and then double the frequency to reach the carrier band, and finally amplify it through a two-stage RF power amplifier chip so that the radiation power reaching the antenna end meets the design requirements. At the same time, the power divider divides the signal to the echo signal of the receiving channel for mixing processing.

[0047] The receiving channel amplifies and mixes the echo signal. The intermediate frequency signal after mixing is also called the difference frequency signal. The intermediate frequency signal contains the distance information of the ranging. The receiving channel performs certain amplification and filtering on it and then feeds it to the digital processing unit for further processing.

[0048] Optionally, the high linear frequency modulation continuous wave height measurement component provided in the embodiment of the present application, the digital processing unit includes an automatic gain control circuit, a digital-analog acquisition circuit, a processor FPGA, a phase-locked loop configuration chip, a sweep frequency control circuit, a power management unit and a 422 communication interface circuit;

[0049] The automatic gain control circuit is used to receive the signal of the radio frequency transceiver unit, and transmit the processed signal to the analog-to-digital acquisition circuit. The digital-to-analog acquisition circuit is used to convert the analog signal into a digital signal and input it into the processor FPGA. The processor FPGA is respectively connected to the automatic gain control circuit, the digital-to-analog acquisition circuit, the sweep frequency control circuit and the 422 communication interface circuit to control the corresponding process. The sweep frequency control circuit is connected to the adder to output a triangular wave modulated pulse.

[0050] The 422 communication interface circuit is used for connecting with the outside, the phase-locked loop configuration chip is used for controlling the fractional-N frequency synthesizer, and the power management unit is used for managing the power supply of the digital processing unit.

[0051] Specifically, the digital processing unit mainly includes automatic gain control circuit, analog-to-digital acquisition circuit, processor FPGA, phase-locked loop configuration chip MCU, frequency sweep control circuit, power management unit, 422 communication interface circuit, etc. The digital processing unit is mainly used for system working status configuration, working monitoring, analog-to-digital acquisition, data processing, spectrum detection of intermediate frequency signals, and calculation of effective height information.

[0052] Optionally, in the high linear frequency modulation continuous wave height measurement component provided in the embodiment of the present application, the automatic gain control circuit includes a digitally controlled attenuator and a variable gain amplifier.

[0053] Optionally, in the high linear frequency modulation continuous wave height measurement component provided in the embodiment of the present application, the digital processing unit is connected to a computer.

[0054] The high linear frequency modulation continuous wave height measurement component provided in the embodiment of the present application adopts phase-locked loop frequency modulation technology, with high frequency stability, high linearity and high test accuracy. At the same time, it adopts large-scale integrated circuits and small-volume, highly integrated phase-locked loop circuits to achieve miniaturization and integration, simplify the complexity of hardware design, and has the characteristics of simple structure, easy use, reliable operation and strong applicability.

[0055] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0056] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0057] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0058] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0059] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0060] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] It will be easily understood by those skilled in the art that 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high linear frequency modulation continuous wave height measurement component, characterized in that: It includes a frequency sweep source circuit, a radio frequency transceiver circuit and a digital processing unit, wherein: The frequency sweep circuit is used to generate a linear frequency modulation signal, and transmit the generated linear frequency modulation signal to the radio frequency transceiver unit; The RF transceiver unit is connected to the transmitting antenna and the receiving antenna, and is used to process the linear frequency modulation signal and transmit it through the transmitting antenna, receive the echo signal through the receiving antenna and process it to generate an intermediate frequency signal, and transmit the intermediate frequency signal to the digital processing unit; The digital processing unit is used to perform spectrum detection on the received intermediate frequency signal and calculate the height information.

2. The high linear frequency modulation continuous wave height measurement component according to claim 1, characterized in that: The frequency sweep circuit includes a reference clock source, a fractional-N frequency synthesizer, a loop low-pass filter, a voltage-controlled oscillator and a frequency divider; The reference clock source is used to generate a stable clock signal, and the clock signal is input into a fractional-N frequency synthesizer for configuration so that the center frequency meets the carrier design requirements. The output signal is optimized through a loop low-pass filter, and is transmitted to a voltage-controlled oscillator after processing by an adder. The voltage-controlled oscillator processes the signal and obtains a linear frequency modulation signal output. A part of the output linear frequency modulation signal is input into a radio frequency transceiver unit, and the other part is divided by a frequency divider and input into the fractional-N frequency synthesizer.

3. The high linear frequency modulation continuous wave height measurement component according to claim 1, characterized in that: The radio frequency transceiver unit includes one transmitting channel and one receiving channel, wherein the transmitting channel includes a filter, a double frequency multiplier, a power divider, a two-stage radio frequency power amplifier chip and a final wave conversion node in sequence, and the receiving channel includes a wave conversion node, a limiter, a low-noise power amplifier, a mixer, a two-stage intermediate wave filter and a two-stage intermediate frequency amplifier in sequence.

4. The high linear frequency modulation continuous wave height measurement component according to claim 3, characterized in that: The power divider of the transmitting channel is connected to the mixer of the receiving channel through a radio frequency amplifier and a bandpass filter in sequence.

5. The high linear frequency modulation continuous wave height measurement component according to claim 2, characterized in that: The digital processing unit includes an automatic gain control circuit, a digital-analog acquisition circuit, a processor FPGA, a phase-locked loop configuration chip, a frequency sweep control circuit, a power management unit and a 422 communication interface circuit; The automatic gain control circuit is used to receive the signal of the radio frequency transceiver unit, and transmit the signal to the analog-to-digital acquisition circuit after processing. The digital-to-analog acquisition circuit is used to convert the analog signal into a digital signal and input it into the processor FPGA. The processor FPGA is respectively connected to the automatic gain control circuit, the digital-to-analog acquisition circuit, the sweep frequency control circuit and the 422 communication interface circuit to control the corresponding process. The sweep frequency control circuit is connected to the adder to output a triangular wave modulated pulse; The 422 communication interface circuit is used for connecting to the outside, the phase-locked loop configuration chip is used for controlling the fractional-N frequency synthesizer, and the power management unit is used for managing the power supply of the digital processing unit.

6. The high-linear frequency modulation continuous wave height measurement component according to claim 5, characterized in that: The automatic gain control circuit includes a digitally controlled attenuator and a variable gain amplifier.

7. The high-linear frequency modulation continuous wave height measurement component according to claim 1, characterized in that: The digital processing unit is connected to a computer.

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