Small radar target signal source simulation device

Abstract

The invention discloses a small radar target signal source simulation device which comprises a digital phase discriminator, a low-pass filter, a voltage modulation module, a voltage-controlled oscillator, a digital frequency divider, a crystal oscillator, a radio frequency switch, a power amplification regulator, a single chip microcomputer and signal parameter input equipment. The signal parameter input device is connected with the single-chip microcomputer. The single-chip microcomputer is connected with the digital frequency divider, the voltage modulation module and the power amplification adjusting module at the same time. The digital frequency divider and the crystal oscillator are simultaneously connected with the digital phase discriminator; the digital phase discriminator is connected with the voltage modulation module after passing through the low-pass filter; one output of the voltage modulation module is connected with the voltage-controlled oscillator, and the other output of the voltage modulation module is connected with the single-chip microcomputer; one path of output of the voltage-controlled oscillator is connected with the power amplification regulator after passing through the radio frequency switch, and radar analog signal output is carried out after passing through the power amplification regulator; and the other path of output is connected with the digital frequency divider. The device is small in size, light in weight, easy to carry and low in cost.

Description

Technical Field

[0001] The invention relates to the field of radar technology, and in particular to a small radar target signal source simulation device. Background Art

[0002] In radar target search training, radar system testing and maintenance, radar signal processing teaching and scientific research activities, it is often necessary to simulate and generate radar target signals. However, since most existing radar simulators adopt the "intermediate frequency modulation + mixing and filtering" scheme, the time domain and frequency domain modulation output of the signal is realized on the intermediate frequency, and then it is moved to the required output RF signal through the mixer. Due to the limited bandwidth of the filter and mixer, in order to cover a wider RF signal output frequency range, it is usually necessary to use multiple mixers and filters, and connect them to the signal output link in a multi-channel "parallel" manner, which makes the radar simulator structure more complex, and the price is generally high, the volume is also large, and it is not convenient to move. In the actual training, teaching or scientific research process, a small, portable, and low-cost radar target signal simulation device is needed to meet the needs of radar target search, radar system function testing, radar signal processing teaching and scientific research activities. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to solve the problems of large size, poor portability and high cost of existing radar target simulators, and to provide a small radar target signal source simulation device; the device is small in size, light in weight, easy to carry and has low manufacturing cost.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a small radar target signal source simulation device, characterized in that it includes a digital phase detector, a low-pass filter, a voltage modulation module, a voltage-controlled oscillator, a digital frequency divider, a crystal oscillator, a radio frequency switch, a power amplifier regulator, a single-chip microcomputer and a signal parameter input device; The signal parameter input device is connected to the single-chip microcomputer and is used to input the radar signal parameters to be simulated into the single-chip microcomputer, which include the center frequency, signal pattern, signal power, pulse width and repetition period; The single chip microcomputer is simultaneously connected to the digital frequency divider, the voltage modulation module and the power amplification and regulation module; The digital frequency divider and the crystal oscillator are connected to the digital phase detector at the same time, wherein the digital frequency divider outputs the corresponding frequency division signal according to the instruction of the single chip microcomputer, the crystal oscillator is used to output the frequency reference signal, and the digital phase detector performs phase discrimination on the input frequency division signal and the reference signal, and outputs the error voltage signal; The digital phase detector is connected to the voltage modulation module after passing through a low-pass filter; one output of the voltage modulation module is connected to a voltage-controlled oscillator, and the other output is connected to a single-chip microcomputer; One output of the voltage-controlled oscillator is connected to a power amplifier regulator after passing through a radio frequency switch, and a radar analog signal is output after passing through the power amplifier regulator; the other output is connected to a digital frequency divider.

[0005] Furthermore, an output terminal of the single-chip microcomputer is connected to a voltage modulation module via a DAC module, and an output terminal of the voltage modulation module is connected to an input terminal of the single-chip microcomputer via an ADC module.

[0006] Furthermore, the voltage modulation module adopts a single-pole double-throw switch to switch the voltage-controlled oscillator to be connected to the low-pass filter, or to be connected to the single-chip microcomputer.

[0007] Furthermore, the radio frequency switch is a dual-control switch, which is used to control the voltage-controlled oscillator to perform two-phase modulation output or time-domain modulation output.

[0008] Compared with the prior art, the present invention has the following advantages: The RF signal output by the voltage-controlled oscillator (VCO) is directly modulated in the time domain using an RF electronic switch, and the DAC module is used to modulate the RF signal output by the VCO in the frequency domain. This has the characteristics of a wide working bandwidth and does not require multiple mixing and filtering circuits. It can effectively reduce the cost, weight and volume of the entire analog device, making it easier to move and carry. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a circuit principle block diagram of the present invention.

[0010] Figure 2 This is the circuit principle block diagram of the voltage modulation module.

[0011] Figure 3 This is the circuit principle block diagram of the RF switch. DETAILED DESCRIPTION

[0012] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0013] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0015] Example: See Figure 1 , Figure 2 as well as Figure 3 A small radar target signal source simulation device includes a digital phase detector, a low-pass filter, a voltage modulation module, a voltage-controlled oscillator (VCO), a digital frequency divider, a crystal oscillator, a radio frequency switch, a power amplifier regulator, a single-chip microcomputer and a signal parameter input device.

[0016] The signal parameter input device is connected to the single chip microcomputer and is used to input the radar signal parameters to be simulated into the single chip microcomputer, which include the center frequency, signal pattern, signal power, pulse width and repetition period.

[0017] The single chip microcomputer is connected to the digital frequency divider, the voltage modulation module and the power amplification and regulation module at the same time.

[0018] The digital frequency divider and the crystal oscillator are connected to the digital phase detector at the same time, wherein the digital frequency divider outputs a frequency division signal according to the frequency division value output by the single chip microcomputer, and its specific frequency division value is controlled by the single chip microcomputer, thereby changing the output frequency of the radio frequency signal. The crystal oscillator is used to output a frequency reference signal, and the digital phase detector performs phase discrimination on the input frequency division signal and the reference signal, and outputs an error voltage signal.

[0019] The digital phase detector is connected to the voltage modulation module after passing through a low-pass filter; one output of the voltage modulation module is connected to a voltage-controlled oscillator, and another output is connected to a single-chip microcomputer. The voltage modulation module also includes a DAC module and an ADC module; one output end of the single-chip microcomputer is connected to the voltage modulation module after passing through the DAC module, and one output of the voltage modulation module is connected to one input end of the single-chip microcomputer after passing through the ADC module. Since the voltage modulation module is mainly used to generate a regulating voltage for controlling the VCO, the output voltage of the voltage modulation module is controlled by the single-chip microcomputer so that it outputs a specific regulating voltage, thereby enabling the VCO to output radio frequency signals of different frequencies. The voltage modulation module uses a single-pole double-throw switch to switch the voltage-controlled oscillator to be connected to the low-pass filter, or to be connected to the single-chip microcomputer.

[0020] The output signal of the voltage-controlled oscillator is a differential signal (i.e., the phase difference between the two is 180 degrees). One output is connected to the power amplifier regulator after passing through the RF switch, and the radar analog signal is output after passing through the power amplifier regulator; the other output is connected to the digital frequency divider, and is input to the digital phase detector after being divided by the digital frequency divider to meet the input requirements of the phase detector. The RF switch is a dual-control switch, which is used to control the voltage-controlled oscillator to perform two-phase modulation output or time domain modulation output. The ADRF5020 type RF switch is used in the specific implementation; the main purpose of the filter is to filter out the harmonics of the RF signal, and the power amplifier regulator uses existing products, which are mainly used to amplify the signal power.

[0021] Based on the existing phase-locked loop structure, this solution is connected to an external ADC and DAC circuit to realize the acquisition of the VCO adjustment voltage signal and the frequency domain modulation of the VCO output signal. During the working process: the user sets the parameters of the radar signal to be simulated through the signal parameter input device, and the input device extracts the corresponding parameters and transmits them to the single-chip microcomputer as instructions. The single-chip microcomputer sets the frequency division value of the "digital divider" module according to the "center frequency" information in the instruction. The frequency division signal output by the "digital divider" and the reference signal output by the crystal oscillator are phase-detected in the "digital phase detector" and the error voltage signal is output. After the error voltage signal passes through the "low-pass filter", the voltage signal Vtune that controls the voltage-controlled oscillator (VCO) is obtained. In order to realize the frequency domain modulation of the VCO RF signal output, the ADC module is used to convert Vtune into analog-to-digital, and the digital quantity of Vtune is modulated in the single-chip microcomputer. Then, the DAC is used for digital-to-analog conversion to form Vtune with a modulated signal, thereby realizing the frequency domain modulation of the VCO RF output. Then, two working states are switched through a single-pole double-throw switch: one is to connect the "low-pass filter" and "VCO", at which time the Vtune in the phase-locked loop does not add modulation information; the other is to connect the "DAC" and "VCO", at which time the Vtune output by the DAC carries modulation information. The RF signal output by the VCO is a continuous wave signal. In order to achieve the modulation of the RF signal in the time domain, this scheme uses the RF electronic switch to directly modulate the RF signal output by the VCO in the time domain, and then obtains the required radar target signal.

[0022] In this solution, since RF mixing is not used, the RF signal output by the VCO is directly modulated in the frequency domain and time domain using RF switches and DAC modules. This solution has the characteristics of a wide working bandwidth and does not require multiple mixing and filtering circuits, which can effectively reduce system costs and production volume.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A small radar target signal source simulation device, characterized in that: Including digital phase detector, low-pass filter, voltage modulation module, voltage-controlled oscillator, digital frequency divider, crystal oscillator, radio frequency switch, power amplifier regulator, single-chip microcomputer and signal parameter input device; The signal parameter input device is connected to the single-chip microcomputer and is used to input the radar signal parameters to be simulated into the single-chip microcomputer, which include the center frequency, signal pattern, signal power, pulse width and repetition period; The single chip microcomputer is simultaneously connected to the digital frequency divider, the voltage modulation module and the power amplification and regulation module; The digital frequency divider and the crystal oscillator are connected to the digital phase detector at the same time, wherein the digital frequency divider outputs the corresponding frequency division signal according to the instruction of the single chip microcomputer, the crystal oscillator is used to output the frequency reference signal, and the digital phase detector performs phase discrimination on the input frequency division signal and the reference signal, and outputs the error voltage signal; The digital phase detector is connected to the voltage modulation module after passing through a low-pass filter; one output of the voltage modulation module is connected to a voltage-controlled oscillator, and the other output is connected to a single-chip microcomputer; One output of the voltage-controlled oscillator is connected to a power amplifier regulator after passing through a radio frequency switch, and a radar analog signal is output after passing through the power amplifier regulator; the other output is connected to a digital frequency divider.

2. A small radar target signal source simulation device according to claim 1, characterized in that: An output terminal of the single chip microcomputer is connected to a voltage modulation module via a DAC module, and an output of the voltage modulation module is connected to an input terminal of the single chip microcomputer via an ADC module.

3. A small radar target signal source simulation device according to claim 1, characterized in that: The voltage modulation module adopts a single-pole double-throw switch, which is used to switch the voltage-controlled oscillator to be connected with the low-pass filter, or to be connected with the single-chip microcomputer.

4. A small radar target signal source simulation device according to claim 1, characterized in that: The radio frequency switch is a dual-control switch, which is used to control the voltage-controlled oscillator to perform two-phase modulation output or time-domain modulation output.

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