Device and method for calibrating time delay of components in microwave photon phased array area array

Abstract

The invention discloses a microwave photon phased array area array component time delay self-calibration device and method. The microwave photon phased array comprises a plurality of photoelectric hybrid components, a receiving channel of each component has an independent switching function, and the working wavelengths of lasers are different from one another, so that radio frequency signals of different receiving antenna units can be borne by utilizing a wavelength division multiplexing technology. Meanwhile, an optical delayer module is designed in each photoelectric hybrid receiving assembly, and the delay amount of the optical delayer module can be controlled through a delayer control word. During component channel time delay calibration, a far-field signal source is used for respectively controlling switches of a detected component channel laser, so that a wavelength division multiplexer only outputs radio frequency optical carrier signals of a current calibration component channel and a reference channel, and a control circuit board calculates the time delay inequality of the detected channel according to radio frequency signals demodulated by a photoelectric detector; and a delayer control word is generated, so that the time delay calibration of the component is completed. The method has the characteristics of rapidness and high efficiency.

Description

Technical Field

[0001] The invention belongs to the technical fields of microwave photon technology and radar phased array technology. Background Art

[0002] In traditional phased array systems, antenna beam scanning is achieved by adjusting the phase relationship between radiating units. However, there are still many problems in using microwave components to implement a fully electronic control system for phased array antenna units. First, the phase shifter implemented using microwave technology is highly complex, and the loss (especially in the millimeter wave band) and weight of the microwave phase shifter itself are also important factors that restrict the performance of phased array radars. Secondly, the phased array controls the phase of the signal to delay the signal, which results in different frequency signals having different time delays even if they have the same phase delay. As a result, traditional phased array antennas have the problem of beam pointing deviation in broadband signal conditions, which results in the inability of traditional phased array radar technology to obtain a large instantaneous signal bandwidth, which directly affects the radar's ability to distinguish, identify and image targets.

[0003] In recent years, microwave photonic technology has been applied to radar, communication and electronic warfare systems. By compensating the aperture transit time by real-time delay in the optical domain, wide-bandwidth angular scanning of phased array radar can be achieved; at the same time, optical true delay transmission has inherent advantages such as low loss, wide bandwidth, and anti-electromagnetic interference. Therefore, it can meet the development requirements of modern warfare for all-round and high-performance radar, and become an important direction for the development of phased array radar. In the field of electronic countermeasures, the direction-finding positioning accuracy and sensitivity of the radiation source and the extraction and identification of the target signal mainly depend on the array signal processing technology, among which accurate beamforming and signal wave arrival direction estimation are the key to achieve target detection and tracking, and the accurate delay assignment of each component in the corresponding array is the key factor for accurate beamforming. However, in the array technology of microwave photonics, the calibration of the optical delay between each component requires a relatively complicated process, especially after long-term operation or replacement of spare parts, recalibration is required, which seriously restricts the advantages of its miniaturization. Summary of the invention

[0004] In order to solve the problem of complex calibration process in the prior art, the present invention proposes a time delay self-calibration device and method for a microwave photon phased array receiving component.

[0005] The invention provides a microwave photon phased array receiving component delay self-calibration device, which comprises a signal source, a transmitting antenna, a photoelectric detector, a control circuit board and a microwave photon phased array containing a photoelectric hybrid component to be tested;

[0006] The microwave photon phased array comprises a first optoelectronic hybrid component to an nth optoelectronic hybrid component, a wavelength division multiplexer, and an optical coupler;

[0007] Each optoelectronic hybrid component includes the first antenna unit to the mth antenna unit, a microwave module, a laser, an optical modulator, and an optical delay device; the output of the antenna unit in the optoelectronic hybrid component is sent to the limiting amplifier filter circuit, and its output is output through a column synthesis module, and after passing through a digitally controlled attenuator, it is loaded onto the optical modulator, and at the same time, the laser output is connected to the optical modulator, and the optical modulator is connected to the optical delay device; the laser of each channel has independent switch control, and the delay value of the optical delay device can be controlled by the program delay device control word;

[0008] The outputs of the first to nth optoelectronic hybrid components are all connected to a wavelength division multiplexer. After the output of the wavelength division multiplexer passes through an optical coupler, 9 / 10 of the light is output to the back end of the main branch according to a ratio of 1:9, and 1 / 10 of the light is sent to the photodetector in the calibration branch. The output of the photodetector generates a delay control word after passing through a control circuit board.

[0009] Furthermore, the transmitting antenna is placed in the normal far field of the microwave photonic phased array, and the transmitting horn antenna is connected to the signal source; the control circuit board includes amplification filtering, amplitude comparator, and delay control word generation module; the radio frequency signal is sent to the amplitude comparator after amplification and filtering, the delay control word generation module is connected to the amplitude comparator, and outputs the delay control word.

[0010] The present invention also provides a microwave photon phased array array delay calibration method, comprising the following steps:

[0011] Step 1: Set the signal source to output a single-frequency RF signal, and the signal frequency is consistent with the operating frequency of the microwave photonic phased array;

[0012] Step 2: Turn on the laser of the first optoelectronic hybrid component and turn off the lasers of all other components, read the amplitude value of the demodulated RF optical carrier of the first optoelectronic hybrid component by controlling the delay control word generation module in the circuit board, and control the delay control word generation module to output the delay device control word to the delay device in the first optoelectronic hybrid component, so that it works at half of the maximum delay value, and record the control word;

[0013] Step 3: Turn on the laser of the second optoelectronic hybrid component;

[0014] Step 4: Read the current amplitude value by controlling the delay control word generation module in the circuit board; change the delay control word in accordance with the minimum delay step so that the delay works from 0 delay to the maximum delay value, record the amplitude values ​​collected by the delay control word generation module in turn and fit them, and simultaneously record the delay control words corresponding to the multiple maximum points of the amplitude extreme value in the fitting curve;

[0015] Step 5: Using 1 / 10 of the operating frequency range of the microwave photonic phased array array component as the step value, change the output frequency of the signal source in sequence, and repeat step 4;

[0016] Step 6: The delay control word generation module in the control circuit board converts the corresponding delay value according to the delay control word recorded at 10 step frequency points, and takes the delay value with an error within ±5ps that is available at all frequency points; calculates the square root mean of the delay value within the 10 frequency points, and uses the delay control word corresponding to the delay value as the final delay control word; turns off the laser of the second optoelectronic hybrid component;

[0017] Step 7: Turn on the lasers of the third optoelectronic hybrid component to the nth optoelectronic hybrid component in turn, and repeat steps 4 to 6 until all components of the array are traversed.

[0018] In microwave photonic array technology, the calibration of optical delays between each component requires a relatively complicated process. In particular, recalibration is required after replacing spare parts, which seriously restricts the advantages of miniaturization.

[0019] The beneficial effects of the present invention are:

[0020] (1) The problem of long-term working delay consistency between microwave photonic phased array components and calibration after replacement of spare parts is solved through online calibration;

[0021] (2) The components of this solution can be easily implemented in the back end of the existing microwave photonic phased array by adding an optical coupler and a matching control circuit board. The timing control based on the internal integrated control circuit board can realize the rapid self-calibration of the time delay of all channels of the full phased array without major modifications to the existing array. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the delay calibration device of the microwave photon phased array area array component in the present invention.

[0023] Figure 2 This is a schematic diagram of the control circuit board in the present invention.

[0024] Figure 3 It is a specific embodiment diagram of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and examples. The examples are implemented based on the technical solution of the present invention, and detailed implementation methods and processes are given, but the protection scope of the present invention is not limited to the following examples.

[0026] The preferred embodiment of the present invention adopts the following technical solutions:

[0027] Figure 1The schematic diagram of the structure of the preferred embodiment of the microwave photon phased array delay calibration device in the present invention. It includes a signal source, a transmitting antenna, a photodetector, a control circuit board, and a microwave photon phased array array containing optoelectronic hybrid components to be measured; wherein the microwave photon phased array array includes the first optoelectronic hybrid component to the nth optoelectronic hybrid component, a wavelength division multiplexer, and an optical coupler; wherein each optoelectronic hybrid component includes the first antenna unit to the mth antenna unit, a microwave module, a laser, an optical modulator, and an optical delay device; the output of the antenna unit in the optoelectronic hybrid component is sent to the limiting amplifier filter circuit, and its output is output through a column synthesis module, and after passing through a digitally controlled attenuator, it is loaded into the optical modulator. The laser output is connected to the optical modulator, and the optical modulator is connected to the optical delay device; the laser of each channel has independent switch control, and the delay value of the optical delay device can be controlled by the program delay device control word; wherein the outputs of the first optoelectronic hybrid component to the nth optoelectronic hybrid component are all connected to the wavelength division multiplexer, and the output of the wavelength division multiplexer is output to the rear end of the main branch according to the ratio of 1:9 after passing through the optical coupler, and 9 / 10 of the light is sent to the photodetector in the calibration branch, and the output of the photodetector generates the delay device control word after passing through the control circuit board.

[0028] The present invention also proposes a method for calibrating a delay calibration device for a microwave photon phased array. In a preferred embodiment, the array size of the microwave photon phased array is 16 times 16, corresponding to a total of 16 components; in each component, a radio frequency signal output by 16 columns is modulated to an optical modulator; the input light of the optical modulator comes from the laser in the component, and 16 different components are equipped with different lasers, whose output wavelengths meet the 200GHz interval specified by WDM, totaling 16 wavelengths; the optical signals of different components are output through an optical wavelength division multiplexer to form a 16-wavelength optical signal; the operating frequency of the array is 6-18GHz. The total length of the optical delay device is 200ps, with a step of 1ps.

[0029] After the control circuit board amplifies and filters the input radio frequency signal, its delay control word generation module generates the corresponding delay device control word after processing the output of the amplitude comparator.

[0030] Step 1: Set the signal source to output a single-frequency RF signal of 6 GHz. The signal frequency is consistent with the operating frequency of the microwave photonic phased array.

[0031] Step 2: Turn on the laser of the first optoelectronic hybrid component and turn off the lasers of all other components, read the amplitude value of the demodulated RF optical carrier of the first optoelectronic hybrid component by controlling the delay control word generation module in the circuit board, and control the delay control word generation module to output the delay device control word to the delay device in the first optoelectronic hybrid component, so that it works at half of the maximum delay value, and record the control word;

[0032] Step 3: Turn on the laser of the second optoelectronic hybrid component;

[0033] Step 4: Read the current amplitude value by controlling the delay control word generation module in the circuit board; change the delay control word in accordance with the minimum delay step so that the delay works from 0 delay to the maximum delay value, record the amplitude values ​​collected by the delay control word generation module in turn and fit them, and simultaneously record the delay control words corresponding to the multiple maximum points of the amplitude extreme value in the fitting curve;

[0034] Step 5: Use 600MHz as the step value to change the output frequency of the signal source in sequence, and repeat step 4;

[0035] Step 6: The delay control word generation module in the control circuit board converts the corresponding delay value according to the delay control word recorded at 10 step frequency points, and takes the delay value with an error within ±5ps that is available at all frequency points; calculates the square root mean of the delay value within the 10 frequency points, and uses the delay control word corresponding to the delay value as the final delay control word; turns off the laser of the second optoelectronic hybrid component;

[0036] Step 7: Turn on the lasers of the third optoelectronic hybrid component to the sixteenth optoelectronic hybrid component in sequence, and repeat steps 4 to 6 until all components of the array are traversed.

Claims

1. A microwave photon phased array array component delay self-calibration device, characterized by: It includes a signal source, a transmitting antenna, a photoelectric detector, a control circuit board and a microwave photon phased array containing a photoelectric hybrid component to be tested; The microwave photon phased array comprises a first optoelectronic hybrid component to an nth optoelectronic hybrid component, a wavelength division multiplexer, and an optical coupler; Each optoelectronic hybrid component includes the first antenna unit to the mth antenna unit, a microwave module, a laser, an optical modulator, and an optical delay device; the output of the antenna unit in the optoelectronic hybrid component is sent to the limiting amplifier filter circuit, and its output is output through a column synthesis module, and after passing through a digitally controlled attenuator, it is loaded onto the optical modulator, and at the same time, the laser output is connected to the optical modulator, and the optical modulator is connected to the optical delay device; the laser of each channel has independent switch control, and the delay value of the optical delay device can be controlled by the delay device control word in the software program of the control circuit board; The outputs of the first to nth optoelectronic hybrid components are all connected to a wavelength division multiplexer. After the output of the wavelength division multiplexer passes through an optical coupler, 9 / 10 of the light is output to the back end of the main branch according to a ratio of 1:9, and 1 / 10 of the light is sent to the photodetector in the calibration branch. The output of the photodetector generates a delay control word after passing through a control circuit board.

2. The microwave photon phased array array component delay calibration device according to claim 1, characterized in that: The transmitting antenna is placed in the normal far field of the microwave photon phased array, and is connected to a signal source; the control circuit board includes an amplification filter, an amplitude comparator, and a delay control word generation module; the radio frequency signal is sent to the amplitude comparator after amplification and filtering, the delay control word generation module is connected to the amplitude comparator, and outputs a delay control word.

3. A method for calibrating using the delay calibration device of any one of claim 1 and claim 2, characterized in that: Step 1: Set the signal source to output a single-frequency RF signal, and the signal frequency is consistent with the operating frequency of the microwave photonic phased array; Step 2: Turn on the laser of the first optoelectronic hybrid component and turn off the lasers of all other components, read the amplitude value of the demodulated RF optical carrier of the first optoelectronic hybrid component by controlling the delay control word generation module in the circuit board, and control the delay control word generation module to output the delay device control word to the delay device in the first optoelectronic hybrid component, so that it works at half of the maximum delay value, and record the control word; Step 3: Turn on the laser of the second optoelectronic hybrid component; Step 4: Read the current amplitude value by controlling the delay control word generation module in the circuit board; change the delay control word in accordance with the minimum delay step so that the delay works from 0 delay to the maximum delay value, record the amplitude values ​​collected by the delay control word generation module in turn and fit them, and simultaneously record the delay control words corresponding to the multiple maximum points of the amplitude extreme value in the fitting curve; Step 5: Using 1 / 10 of the operating frequency range of the microwave photonic phased array array component as the step value, change the output frequency of the signal source in sequence, and repeat step 4; Step 6: The delay control word generation module in the control circuit board converts the corresponding delay value according to the delay control word recorded at 10 step frequency points, and takes the delay value with an error within ±5ps for all frequency points; calculates the square root mean of the delay value within the 10 frequency points, and takes the delay control word corresponding to the delay value as the final delay control word; turns off the laser of the second optoelectronic hybrid component; Step 7: Turn on the lasers of the third optoelectronic hybrid component to the nth optoelectronic hybrid component in turn, and repeat steps 4 to 6 until all components of the array are traversed.

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