CN-121984578-A - Ultra-wideband weak signal detection method and system based on all-optical oscillation and phase-amplitude conversion

CN121984578ACN 121984578 ACN121984578 ACN 121984578ACN-121984578-A

Abstract

The application discloses an ultra-wideband weak signal detection method and system based on all-optical oscillation and phase-amplitude conversion, wherein the method comprises the following steps of utilizing spontaneous radiation light generated by an erbium-doped fiber amplifier as an optical carrier; modulating a weak radio frequency signal to be detected received by an antenna onto the optical carrier wave through an optical modulator to form a modulated optical signal, injecting the modulated optical signal into an all-optical oscillating circuit formed by double loops, enabling the all-optical oscillating circuit to generate multimode optical oscillation through an adjusting optical attenuator, wherein the all-optical oscillating circuit comprises a double loop interference structure, performing phase-amplitude conversion through adjusting the delay difference of two optical paths in the double loops to form an equivalent microwave photon filter so as to select and amplify the modulated optical signal corresponding to the radio frequency signal of a set frequency band, and converting the selected and amplified modulated optical signal into an electric signal and performing frequency spectrum analysis so as to detect the weak radio frequency signal to be detected.

Inventors

ZHANG XIN
ZHU HUATAO
XU XIANGMING
CHEN SHUWEN
LI FEIYU

Assignees

中国人民解放军信息支援部队工程大学

Dates

Publication Date: 20260505
Application Date: 20260122

Claims (10)

1. An ultra-wideband weak signal detection method based on all-optical oscillation and phase-amplitude conversion is characterized by comprising the following steps: The self-emission light generated by the erbium-doped fiber amplifier is used as an optical carrier; modulating a weak radio frequency signal to be detected received by an antenna onto the optical carrier through an optical modulator to form a modulated optical signal; Injecting the modulated optical signal into an all-optical oscillating circuit formed by double loops, and enabling the all-optical oscillating circuit to generate multi-mode optical oscillation by adjusting an optical attenuator, wherein the all-optical oscillating circuit comprises a double loop interference structure; phase-amplitude conversion is carried out by adjusting the delay difference of two light paths in the double loop, so as to form an equivalent microwave photon filter to select and amplify the modulated light signals corresponding to the radio frequency signals of the set frequency band; And converting the selected and amplified modulated optical signal into an electric signal and performing spectrum analysis to detect the weak radio frequency signal to be detected.
2. The ultra-wideband weak signal detection method based on all-optical oscillation and phase-amplitude conversion according to claim 1, wherein said generating the multi-mode optical oscillation by adjusting the optical attenuator comprises: and controlling loop gain by adjusting the optical attenuator to compensate the insertion loss and the transmission loss of the all-optical oscillation loop, so that the erbium-doped fiber amplifier outputs stable multimode oscillation light.
3. The ultra-wideband weak signal detection method based on all-optical oscillation and phase-amplitude conversion as claimed in claim 1, wherein the method further comprises: Uniformly dividing the optical signals into two paths by using the double-loop interference structure, and combining the two paths of optical signals by using a coupler after the optical signals respectively pass through the corresponding adjustable delay lines; and controlling the interference phase of the dual-loop interference structure by adjusting the delay difference between the two corresponding adjustable delay lines.
4. The ultra-wideband weak signal detection method based on all-optical oscillation and phase-amplitude conversion according to claim 3, wherein after said optical signal is uniformly split into two paths by using said dual-loop interference structure, said method further comprises: And continuously adjusting the center frequency of the pass band of the equivalent microwave photon filter by adjusting the delay difference of the two light paths in the double loop.
5. The ultra-wideband weak signal detection system based on all-optical oscillation and phase-amplitude conversion is characterized by comprising an antenna, an erbium-doped optical fiber amplifier, an optical modulator, a first optical coupler, a photoelectric detector, a spectrum analyzer, a first optical adjustable delay line, an optical attenuator, a second optical coupler, a third optical coupler, a second optical adjustable delay line and a third optical adjustable delay line; The output end of the erbium-doped fiber amplifier is connected to the optical input end of the optical modulator and is used for providing spontaneous radiation light generated as an optical carrier; the antenna is used for receiving a radio frequency signal to be detected and inputting the radio frequency signal to a radio frequency input end of the optical modulator; the output end of the optical modulator is connected to the input end of the first optical coupler and is used for modulating the weak radio frequency signal to be detected onto the optical carrier wave to form a modulated optical signal; the first output end of the first optical coupler is sequentially connected with the photoelectric detector and the spectrum analyzer and is used for converting a part of the modulated optical signals into electric signals and carrying out spectrum analysis; The second output end of the first optical coupler, the first optical adjustable delay line, the second optical coupler, the second optical adjustable delay line, the third optical coupler and the optical attenuator are sequentially connected and finally fed back to the input end of the erbium-doped fiber amplifier to jointly form an all-optical oscillation loop; wherein, the second optical coupler, the second optical adjustable delay line, the third optical adjustable delay line and the third optical coupler form a double-loop interference structure; the optical attenuator is used for adjusting the loop gain of the all-optical oscillation circuit so as to enable the all-optical oscillation circuit to generate stable multimode optical oscillation; And phase amplitude conversion is realized by adjusting the delay difference between the second optical adjustable delay line and the third optical adjustable delay line so as to form an equivalent microwave photon filter in the all-optical oscillating circuit, and the modulated optical signals corresponding to the radio frequency signals with the set frequency band are selected and amplified.
6. The ultra-wideband weak signal detection system based on all-optical oscillation and phase-amplitude conversion of claim 5, wherein the first optically tunable delay line is used for adjusting the total delay of the all-optical oscillation circuit to control the frequency interval of the multimode oscillation mode, and is used for adjusting the filter passband interval of the equivalent microwave photon filter.
7. The ultra-wideband weak signal detection system based on all-optical oscillation and phase-amplitude conversion according to claim 5, wherein the all-optical oscillation loop is characterized in that two optical path branches with the same length are constructed by the second optical coupler and the third optical coupler to form a double-loop structure.
8. The ultra-wideband weak signal detection system based on all-optical oscillation and phase-amplitude conversion according to claim 5, wherein the second optical adjustable delay line and the third optical adjustable delay line are used for controlling the delay difference of two optical paths in the double loop, and adjusting the passband center frequency of the equivalent microwave photon filter.
9. A computer-readable storage medium, characterized in that the computer-readable storage medium comprises a stored program, wherein the program when run performs the method of any one of claims 1 to 4.
10. An electronic device comprising a memory and a processor, characterized in that the memory has stored therein a computer program, the processor being arranged to execute the method according to any of claims 1 to 4 by means of the computer program.

Description

Ultra-wideband weak signal detection method and system based on all-optical oscillation and phase-amplitude conversion Technical Field The application relates to the technical field of microwave photon detection, in particular to an ultra-wideband weak signal detection method and system based on all-optical oscillation and phase-amplitude conversion. Background Conventional rf signal detection is mainly based on electronics. However, the inherent bandwidth limitations and high thermal noise of electronics make them drastically degraded when detecting weak signals at frequencies exceeding tens of GHz. Although the opto-electronic oscillator based solution is capable of generating high frequency microwave signals through an opto-electronic hybrid circuit, its typical structure relies on an opto-electronic-optical conversion process, which must include a plurality of active and passive devices such as lasers, electrical amplifiers, electrical filters, and high Q-factor electrical filters. The complex structure not only increases the cost, volume and power consumption of the system, but also introduces additional noise and limits the detection sensitivity of the system to weak signals. Furthermore, existing photon-assisted rf detection schemes often rely on tunable optical or electrical filters for frequency selective functionality. The bandwidth limitation of the filters becomes the bottleneck of the system working bandwidth, so that the detection frequency range is difficult to break through the hundred GHz limitation, and the requirement of ultra-wideband detection cannot be met. Meanwhile, the multimode photoelectric oscillation system can provide multichannel processing capability, but the loop of the multimode photoelectric oscillation system still needs to comprise photoelectric conversion and electric amplification modules, the structure is still complex, and noise and bandwidth limitation caused by electronic bottlenecks are difficult to thoroughly eliminate. Therefore, a new technology for detecting weak radio frequency signals, which can get rid of electronic bottlenecks, has a simple structure and low cost, has high gain and high sensitivity, and can work in the ultra-wideband range of hundreds of GHz, is needed to be provided. Disclosure of Invention Aiming at least one defect or improvement requirement of the prior art, the invention provides an ultra-wideband weak signal detection method and system based on all-optical oscillation and phase-amplitude conversion, which solve the technical problems of limited bandwidth and insufficient sensitivity of the existing radio frequency detection technology in a high-frequency weak signal detection scene. According to a first aspect of the present invention, there is provided an ultra-wideband weak signal detection method based on all-optical oscillation and phase-amplitude conversion, comprising using spontaneous radiation light generated by an erbium-doped fiber amplifier as an optical carrier, modulating a weak radio frequency signal to be detected received by an antenna onto the optical carrier through an optical modulator to form a modulated optical signal, injecting the modulated optical signal into an all-optical oscillation circuit formed by two loops, and generating multi-mode optical oscillation by the all-optical oscillation circuit through an optical attenuator, wherein the all-optical oscillation circuit comprises a two-loop interference structure, performing phase-amplitude conversion by adjusting delay differences of two optical paths in the two loops to form an equivalent microwave photon filter to select and amplify the modulated optical signal corresponding to a radio frequency signal of a set frequency band, and converting the selected and amplified modulated optical signal into an electrical signal and performing frequency spectrum analysis to detect the weak radio frequency signal to be detected. In one exemplary embodiment, the generating multimode optical oscillation of the all-optical tank by adjusting the optical attenuator includes controlling a loop gain to compensate for insertion loss and transmission loss of the all-optical tank by adjusting the optical attenuator so that the erbium-doped fiber amplifier outputs stable multimode oscillation light. In an exemplary embodiment, the method further comprises the steps of uniformly dividing the optical signals into two paths by the double-loop interference structure, combining the two paths of optical signals by the coupler after the optical signals pass through the corresponding adjustable delay lines respectively, and controlling the interference phase of the double-loop interference structure by adjusting the delay difference between the corresponding two adjustable delay lines. In an exemplary embodiment, after the optical signal is uniformly split into two paths by using the dual-loop interference structure, the method further comprises continuously adjusting the passband cente