Signal enhancement method and system based on lens antenna

Abstract

The invention relates to the technical field of communication, and discloses a signal enhancement system based on a lens antenna, and the system specifically comprises a central control and light modulation module which is used for generating a modulated transmitted light signal or processing a received light signal; the input end of the passive optical power distribution network module is optically coupled with the central control and optical modulation module, and the passive optical power distribution network module is provided with a plurality of optical output ports and is used for distributing the transmitted optical signals to the optical output ports; the high-frequency lens collimation module is used as a space feed and beam forming component; and the photoelectric conversion and radiation array module is arranged on the focal plane or the focal curved surface of the high-frequency lens collimation module and consists of a plurality of photoelectric radiation units. The ultra-short-distance metal wire bonding or flip-chip bonding technology is adopted in the photoelectric radiation unit to achieve electrical interconnection, and ohmic loss and dielectric loss caused by the skin effect and dielectric loss of a traditional metal feed network in the high frequency band are fundamentally eliminated.

Description

Technical Field

[0001] This invention relates to the field of communication technology, specifically to a signal enhancement method and system based on a lens antenna. Background Technology

[0002] With the rapid development of modern wireless communication technology, global data traffic has exploded, driving communication systems to continuously evolve towards higher speeds, greater bandwidth, and lower latency. To meet the increasing performance demands and alleviate the scarcity of low-frequency spectrum resources, the communications industry has turned its attention to higher frequency bands such as millimeter waves and even terahertz. However, the propagation loss of electromagnetic waves in free space is proportional to the square of their operating frequency, meaning that high-frequency signals experience more severe path attenuation during transmission. To effectively compensate for this attenuation and ensure the quality and coverage of communication links, employing directional antennas with high gain and narrow beam characteristics, and using beamforming technology to spatially focus signal energy, has become a key supporting technology and an inevitable choice for high-frequency wireless communication systems.

[0003] Among existing high-gain antenna technologies, phased array antennas have been widely used and extensively studied because they can achieve fast electronically scanned beams without mechanical parts. This technology has shown significant advantages in solving the beam directivity problem in the mid-to-low frequency band, laying a solid foundation for the construction of modern communication systems.

[0004] Extensive research revealed that, with the continuous development of related technologies and the shift of application scenarios to higher frequency bands, the inherent characteristics of traditional phased array antenna schemes, as described above, are gradually showing insurmountable limitations in addressing new challenges. The core contradiction lies in the antenna array's feed network. Traditional phased array antennas, especially large-scale arrays, typically rely on complex planar microstrip or stripline metal feed networks to achieve signal distribution and phase control for each antenna element. When operating frequencies reach millimeter waves and higher frequency bands, the skin effect in the metal conductor and the loss tangent of the dielectric material surrounding the transmission line increase dramatically, leading to a significant increase in the ohmic and dielectric losses of the feed network itself. This loss not only directly weakens the signal power fed to the antenna elements, severely reducing the antenna's radiation efficiency, but also triggers a series of chain reactions. To compensate for the huge losses from the feed network and maintain the equivalent omnidirectional radiation power required by the system, the power amplifier in the RF front-end must operate at higher output power, which directly results in a sharp increase in the DC power consumption of the entire system. Correspondingly, the huge energy consumption translates into severe heat dissipation, which places extremely demanding requirements on the thermal management design of the system. It often requires a large and complex heat dissipation structure, which runs counter to the design trend of modern communication equipment pursuing miniaturization, lightweighting and high energy efficiency. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a signal enhancement method and system based on a lens antenna, which solves the problem of "low working efficiency" in the aforementioned background technologies.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: a signal enhancement system based on a lens antenna, specifically comprising:

[0009] The central control and optical modulation module is used to generate modulated transmitted optical signals or process received optical signals.

[0010] A passive optical power distribution network module has an input end that is optically coupled to the central control and optical modulation module, and has multiple optical output ports for distributing the emitted optical signal to the multiple optical output ports;

[0011] High-frequency lens collimation module, used as a space feeding and beamforming component;

[0012] A photoelectric conversion and radiation array module, wherein the array is disposed on the focal plane or focal curvature surface of the high-frequency lens collimation module and is composed of multiple photoelectric radiation units, each of which is connected to the optical output port of the passive optical power distribution network module.

[0013] A beam pointing control module, electrically connected to each of the photoelectric radiation units of the photoelectric conversion and radiation array module, is used to selectively activate specific photoelectric radiation units in the photoelectric conversion and radiation array module according to a preset beam pointing command. This causes the activated specific photoelectric radiation unit to convert the transmitted light signal received from the passive optical power distribution network module into a radio frequency signal and radiate it to the high-frequency lens collimation module. The high-frequency lens collimation module then collimates the electromagnetic wave formed by the radio frequency signal radiation into a beam with a specific direction.

[0014] Preferably, the high-frequency lens collimation module is a Luneburg lens, which has a spherical structure and the refractive index n(r) of its internal medium is distributed in a gradient from the center of the sphere to the surface. This refractive index n(r) satisfies n(r) = n0*sqrt(2-(r / R)). 2The relationship between the photoelectric conversion and radiation array module and the spherical surface of the Luneburg lens is given by the function of ...

[0015] Preferably, the Luneburg lens is made of a low-loss dielectric material, such as high-purity single-crystal silicon or polytetrafluoroethylene. The Luneburg lens contains a three-dimensional subwavelength aperture array. By precisely controlling the geometric size or density of the apertures at different radial positions r, the equivalent dielectric constant at that position is adjusted, thereby increasing the macroscopic equivalent refractive index n of the Luneburg lens. e ff(r) fits the distribution n(r) = n0*sqrt(2-(r / R)). 2 The functional relationship of ) is used to achieve the gradient refractive index effect.

[0016] Preferably, each of the photoelectric radiation units is provided with a high-speed photodetector for the transmission path, a signal processing link for the receiving path, a miniature antenna unit shared with both the transmission and receiving paths, and a local bias and switch control circuit. The optical input end of the high-speed photodetector is used to receive the transmitted optical signal, and the radio frequency output end of the high-speed photodetector is directly electrically connected to the feed point of the miniature antenna unit through an electrical interconnection structure with a length of less than a micrometer. The local bias and switch control circuit receives control commands from the beam pointing control module and selectively provides operating bias for the high-speed photodetector or the signal processing link of the receiving path, thereby realizing the switching between the transmission and receiving functions.

[0017] Preferably, the high-speed photodetector is a single-row carrier photodiode, and the single-row carrier photodiode uses a flip-chip bonding process to bond its radio frequency output electrode to the feed pad of the micro antenna unit. The micro antenna unit is a substrate integrated waveguide slot antenna, and the antenna is manufactured on a flexible dielectric substrate that can conform to the curved surface of the high-frequency lens collimation module.

[0018] Preferably, the signal processing link of the receiving path includes a low-noise amplifier and an electro-absorption modulator. The input terminal of the low-noise amplifier is connected to the feed point of the micro-antenna unit and is used to amplify the radio frequency signal received by the micro-antenna unit. The radio frequency input terminal of the electro-absorption modulator is connected to the output terminal of the low-noise amplifier. The optical input terminal of the electro-absorption modulator is used to receive continuous wave probe light from the central control and optical modulation module. The electro-absorption modulator is used to modulate the radio frequency signal amplified by the low-noise amplifier onto the continuous wave probe light to form a received modulated signal and transmit it back to the central control and optical modulation module.

[0019] Preferably, the passive optical power distribution module includes a planar optical waveguide type 1×N optical splitter based on silicon dioxide waveguide technology, where N is the number of the photoelectric radiation units. The input end of the optical splitter, its internal cascaded branch waveguides, its N output ports, and the N optical fibers connecting the N output ports to the N photoelectric radiation units adopt polarization-maintaining optics and polarization-maintaining single-mode fibers to ensure the stability of the polarization state of the transmitted optical signal during transmission and distribution.

[0020] Preferably, the beam pointing control module internally stores a beam pointing-radiation unit address mapping table, which pre-records the unique correspondence between the desired far-field direction of the beam and the physical position coordinates of a specific photoelectric radiation unit in the photoelectric conversion and radiation array module. When the beam pointing control module receives a beam pointing instruction containing target direction information, it queries the mapping table to determine the uniquely corresponding target photoelectric radiation unit.

[0021] Preferably, after determining the target photoelectric radiation unit, the beam pointing control module sends an activation command to the local bias and switching control circuit inside the target photoelectric radiation unit via the control bus. The activation command is used to apply a working bias voltage to the high-speed photodetector used for the transmission path in the target photoelectric radiation unit, while ensuring that all other non-target photoelectric radiation units in the photoelectric conversion and radiation array are inactive.

[0022] Preferably, a signal enhancement method based on a lens antenna includes the following steps:

[0023] S1: Within the central control and optical modulation module, a radio frequency electrical signal is generated and an optical carrier is modulated using the radio frequency electrical signal to generate a modulated transmitted optical signal.

[0024] S2: The emitted optical signal is injected into the passive optical power distribution network module, and the passive optical power distribution network module distributes and transmits the emitted optical signal in parallel to each photoelectric radiation unit of the photoelectric conversion and radiation array module;

[0025] S3: The beam pointing control module determines the unique target photoelectric radiation unit in the photoelectric conversion and radiation array module that corresponds to the target direction based on an externally input beam target direction command;

[0026] S4: The beam pointing control module sends an activation command to the target photoelectric radiation unit to enable its transmission function, while ensuring that the transmission functions of all other photoelectric radiation units in the array remain off.

[0027] S5: Inside the activated target photoelectric radiation unit, the received transmitted light signal is photoelectrically converted to generate a high-frequency current consistent with the radio frequency electrical signal in step S1, and the high-frequency current is used to excite the micro antenna unit to radiate electromagnetic waves to the high-frequency lens collimation module.

[0028] S6: The high-frequency lens collimation module performs spatial phase transformation and collimation on the received electromagnetic wave, forming a high-gain beam that is precisely pointed to the target direction in the far field.

[0029] (III) Beneficial Effects

[0030] This invention provides a signal enhancement method and system based on a lens antenna. It has the following beneficial effects:

[0031] (1) This invention uses a passive optical power distribution network module to replace the traditional metal-fed network. Optical signal distribution is achieved through a planar optical waveguide splitter using silicon dioxide waveguide technology and a polarization-maintaining single-mode fiber. The absorption loss of the transmission medium itself is negligible, and the total loss is determined only by the splitting ratio. At the same time, electrical interconnection is achieved within the optoelectronic radiation unit using extremely short-distance gold wire bonding or flip-chip bonding technology, fundamentally eliminating the ohmic and dielectric losses caused by the skin effect and dielectric loss in the high-frequency band of the traditional metal-fed network. This significantly reduces signal power attenuation, lowers the demand for the output power of the RF front-end power amplifier, thereby reducing the system's DC power consumption and heat dissipation. It eliminates the need for complex heat dissipation structures and is suitable for miniaturized, lightweight, and high-efficiency design requirements.

[0032] (2) This invention uses a high-frequency lens collimation module as its core, combined with a beam pointing control module and a photoelectric conversion and radiation array module to form a collaborative mechanism. The beam pointing control module, through a pre-stored beam pointing radiation unit address mapping table, can selectively activate specific photoelectric radiation units on a nanosecond-level timescale, utilizing the physical properties of the Luneburg lens to convert spherical waves into precisely pointed plane waves. Compared to traditional phased arrays that rely on complex phase adjustment circuits for beam scanning, this invention eliminates the need for cumbersome phase compensation, achieving ultra-high-speed beam direction switching simply by switching radiation units. Furthermore, it avoids mechanical inertia limitations, significantly improving the response speed and control flexibility of beam pointing, and efficiently adapting to the beam tracking requirements of dynamic communication scenarios. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the system framework of the present invention.

[0034] In the diagram: 1. Central control and optical modulation module; 2. Passive optical power distribution network module; 3. Photoelectric conversion and radiation array module; 4. High-frequency lens collimation module; 5. Beam pointing control module; 31. Photoelectric radiation unit; 311. High-speed photodetector; 312. Low-noise amplifier; 313. Electro-absorption modulator; 314. Miniature antenna unit; 315. Switch control circuit. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see Figure 1 This invention provides a signal enhancement system based on a lens antenna, characterized in that the system includes a central control and optical modulation module 1, a passive optical power distribution network module 2, a high-frequency lens collimation module 4, a photoelectric conversion and radiation array module 3, and a beam pointing control module 5, specifically:

[0037] The central control and optical modulation module 1 is located at the signal processing back end of the system. It is used to generate the radio frequency signal to be transmitted and modulate it onto the optical carrier, or to demodulate the radio frequency signal received from the optical carrier. Specifically, the central control and optical modulation module 1 integrates a baseband signal processing module, an up-conversion / down-conversion module, a high-linearity electro-optic modulator, a narrow-linewidth laser source, a coherent optical receiver, and the system master clock. In transmit mode, the baseband signal processing module generates a baseband IQ signal based on the digital information to be transmitted. The up-conversion module mixes the baseband IQ signal with a local oscillator signal to generate an intermediate frequency (IF) or radio frequency (RF) signal at a specific frequency. The narrow-linewidth laser source is specifically a distributed feedback (DFB) laser operating in a 1550nm communication window, which outputs a stable and continuous single-mode light wave. The high-linearity electro-optic modulator is specifically a lithium niobate Mach-Zehnder modulator, whose RF input is electrically connected to the output of the up-conversion module, and whose optical input is optically coupled to the optical output of the narrow-linewidth laser source. This modulates the amplitude and phase information of the RF signal onto the light wave to form a modulated optical signal. In receive mode, the coherent optical receiver receives the return optical signal carrying useful information and recovers the RF signal by coherent demodulation with a local optical oscillator. The down-conversion module and the baseband signal processing module then perform further processing.

[0038] One end of the passive optical power distribution network module 2 is optically coupled to the optical signal output port of the central control and optical modulation module 1, while the other end branches out to multiple optical output ports, which are used to distribute the modulated optical signal generated by the central control and optical modulation module 1 to each unit of the photoelectric conversion and radiation array module 3 with extremely low loss and equal power.

[0039] Furthermore, the passive optical power distribution network module 2 employs a planar optical waveguide type 1×N optical splitter based on silicon dioxide waveguide technology, where N represents the number of radiating units in the photoelectric conversion and radiation array module 3. The PLC splitter and its connecting optical fibers both use polarization-maintaining single-mode fiber to ensure the stability of the optical signal polarization state during transmission, thereby avoiding a decrease in photoelectric conversion efficiency due to polarization mismatch. The insertion loss of the entire optical distribution network is strictly controlled within the operating wavelength band, and its total loss is mainly determined by the splitting ratio; the absorption loss of the transmission medium itself is negligible.

[0040] The high-frequency lens collimation module 4 is the core physical device for realizing spatial beamforming and phase modulation. Its lens body is made of a high-frequency dielectric material with extremely low loss tangent (less than 1e-4), such as high-purity, high-resistivity (>10kΩ·cm) single-crystal silicon or polytetrafluoroethylene (PTFE). Specifically, the lens can be designed as an improved Luneburg lens, a spherical structure with a dielectric constant εr exhibiting a specific non-uniform gradient distribution from the center to the surface, and its refractive index n(r) satisfying n(r)=n0*sqrt(2-(r / R)).2 ), where R is the lens radius, r is the radial distance to the center of the sphere, and n0 is the refractive index of the lens surface, usually set to match the free space impedance, i.e., n0 = 1. The photoelectric conversion and radiation array module 3 is precisely attached to or integrated onto the spherical surface of this Luneburg lens. According to the physical characteristics of the Luneburg lens, when a spherical wave is generated at any point on its surface (e.g., by an activated photoelectric radiation unit) and radiates into the lens, the spherical wave, after being refracted by the lens body with a specific refractive index gradient, will exit on the other side of the lens to form a highly collimated plane wave, the direction of which is completely opposite to the line connecting the feed point and the center of the sphere. Conversely, a plane wave incident from a specific direction will be precisely focused by the lens onto a corresponding point on its surface.

[0041] The photoelectric conversion and radiation array module 3 is a key component for realizing the core function of this invention, namely low-loss signal distribution and spatial power feeding. Its array is set on the focal plane or focal curvature of the high-frequency lens collimation module 4 and is composed of multiple photoelectric radiation units 31. Each photoelectric radiation unit 31 is connected to one optical output port of the passive optical power distribution network module 2.

[0042] Furthermore, each photoelectric radiating unit 31 structurally includes a high-speed photodetector 311 for the transmission path, a low-noise amplifier 312 for the receiving path, an electroabsorption modulator 313, a miniature antenna unit 314 shared with both the transmission and receiving paths, and a local bias and switching control circuit 315. The high-speed photodetector 311 is specifically a single-row carrier photodiode with a photoelectric response bandwidth greater than 200 GHz and a saturated output power exceeding 15 dBm. Its optical input end is precisely aligned and coupled to one output fiber of the passive optical power distribution network module 2 via a miniature fiber optic connector. The RF output pin of the single-row carrier photodiode is directly electrically connected to the feed point of the miniature antenna unit 314 via gold wire bonding or flip-chip bonding technology with a length less than 300 micrometers. This extremely short electrical interconnection path fundamentally eliminates the significant transmission line loss present in traditional feed networks.

[0043] The miniature antenna element 314, designed according to the system's operating frequency (e.g., 140 GHz), can be a patch antenna, dipole antenna, or Vivaldi end-fire antenna. Its material is a thin metal film (such as gold or copper) deposited on a low-loss dielectric substrate (such as quartz or high-resistivity silicon). The low-noise amplifier 312 and the electro-absorption modulator 313 constitute the core of the receiving link. The input of the low-noise amplifier 312 is connected to the feed point of the miniature antenna element 314 to amplify the weak high-frequency signal received by the antenna. The RF input of the electro-absorption modulator 313 is connected to the output of the low-noise amplifier 312, and its optical input receives continuous wave probe light from the central unit through another independent passive optical network. When a signal is amplified by the low-noise amplifier 312 and drives the electro-absorption modulator 313, the absorption coefficient of the electro-absorption modulator 313 changes accordingly, thereby modulating the received high-frequency signal onto the probe light to form a received modulated signal. This signal is returned to the coherent optical receiver of the central control and optical modulation unit through a third optical fiber network.

[0044] The local bias and switching control circuit 315 receives a DC control signal from the beam pointing control module 5 to independently and selectively provide forward or reverse bias voltages to the single-row carrier photodiodes within the unit, or to provide operating power to the low-noise amplifier 312 and the electro-absorption modulator 313. When the photoelectric radiation unit 31 is selected for transmission, its single-row carrier photodiodes are reverse biased, putting them in a high-efficiency photoelectric conversion state; simultaneously, the low-noise amplifier 312 and the electro-absorption modulator 313 of this unit are in a non-operating state. When the photoelectric radiation unit 31 is selected for reception, its low-noise amplifier 312 and the electro-absorption modulator 313 are supplied with operating power, while its single-row carrier photodiodes are in an unbiased or de-energized state. In this way, precise and independent control of the transmission / reception function of each radiation point in the array is achieved.

[0045] The beam pointing control module 5 is the core of digital logic control, typically implemented using a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC). Internally, the beam pointing control module 5 stores a pre-calculated and fixed beam pointing-radiating element address mapping table. This table establishes a unique correspondence between the desired far-field direction of the beam (azimuth θ, elevation φ) and the physical position coordinates (x, y) of a specific photoelectric radiation element 31 in the photoelectric conversion and radiation array module 3. The input of the beam pointing control module 5 communicates with the upper layers of the system (such as the baseband MAC layer) to receive beam pointing commands; its output is connected via multiple DC control lines to the local bias and switching control circuit 315 of each photoelectric radiation element 31 in the photoelectric conversion and radiation array module 3. When a transmit command pointing to (θ1, φ1) is received, the beam pointing control module 5 queries the beam pointing-radiation unit address mapping table to find the corresponding unit address (x1, y1). Then, it sends a high-level activation signal to the photoelectric radiation unit 31 at that address via the control line, applying a working bias to its single-row carrier photodiode, while all other units remain inactive. Thus, only the selected unit converts the optical signal into a radio frequency signal and radiates it, forming a narrow beam pointing to (θ1, φ1) via a Luneburg lens. By switching the activation of different photoelectric radiation units 31 on a nanosecond-level timescale, inertia-free, ultra-high-speed beam scanning can be achieved.

[0046] The present invention also provides a signal enhancement method based on a lens antenna, comprising the following steps:

[0047] S1: In the central control and optical modulation module 1, an radio frequency electrical signal is generated and an optical carrier is modulated using the radio frequency electrical signal to generate a modulated transmitted optical signal.

[0048] S2: The transmitted optical signal is injected into the passive optical power distribution network module 2, and the passive optical power distribution network module 2 distributes and transmits the transmitted optical signal in parallel to each photoelectric radiation unit 31 of the photoelectric conversion and radiation array module 3.

[0049] S3: The beam pointing control module 5 determines the unique target photoelectric radiation unit 31 in the photoelectric conversion and radiation array module 3 that corresponds to the target direction according to the externally input beam target direction command;

[0050] S4: The beam pointing control module 5 sends an activation command to the target photoelectric radiation unit 31 to enable its transmission function, while ensuring that the transmission function of all other photoelectric radiation units 31 in the array remains off.

[0051] S5: Inside the activated target photoelectric radiation unit 31, the received transmitted light signal is photoelectrically converted to generate a high-frequency current consistent with the radio frequency electrical signal in step S1, and the high-frequency current is used to excite the micro antenna unit 314 to radiate electromagnetic waves to the high-frequency lens collimation module 4.

[0052] S6: The high-frequency lens collimation module 4 performs spatial phase transformation and collimation on the received electromagnetic waves, forming a high-gain beam that is precisely pointed to the target direction in the far field.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A signal enhancement system based on a lens antenna, characterized in that, Specifically, it includes: The central control and optical modulation module (1) is used to generate modulated transmitted optical signals or process received optical signals; The passive optical power distribution network module (2) has an input end that is optically coupled to the central control and optical modulation module (1) and has multiple optical output ports for distributing the emitted optical signal to the multiple optical output ports; High-frequency lens collimation module (4) serves as a space feed and beamforming component; The photoelectric conversion and radiation array module (3) is set on the focal plane or focal curvature of the high-frequency lens collimation module (4) and is composed of multiple photoelectric radiation units (31). Each photoelectric radiation unit (31) is connected to the optical output port of the passive optical power distribution network module (2). A beam pointing control module (5) is electrically connected to each of the photoelectric radiation units (31) of the photoelectric conversion and radiation array module (3). It is used to selectively activate a specific photoelectric radiation unit (31) in the photoelectric conversion and radiation array module (3) according to a preset beam pointing command. The activated specific photoelectric radiation unit (31) converts the transmitted light signal received from the passive optical power distribution network module (2) into a radio frequency signal and radiates it to the high-frequency lens collimation module (4). The high-frequency lens collimation module (4) collimates the electromagnetic wave formed by the radio frequency signal radiation into a beam with a specific direction.

2. The signal enhancement system based on a lens antenna according to claim 1, characterized in that: The high-frequency lens collimation module (4) is a Luneburg lens, which is a spherical structure. The refractive index n(r) of the internal medium is distributed in a gradient from the center of the sphere to the surface. This refractive index n(r) satisfies n(r)=n0*sqrt(2-(r / R)). 2 The function relationship is given by R, where R is the radius of the Luneburg lens, r is the radial distance to the center of the sphere, and n0 is the refractive index of the Luneburg lens surface. The photoelectric conversion and radiation array module (3) is conformally disposed on the spherical surface of the Luneburg lens. When the beam pointing control module (5) activates a photoelectric radiation unit (31) located at a specific position on the spherical surface, the spherical electromagnetic wave radiated by the photoelectric radiation unit (31) is refracted by the Luneburg lens and forms a collimated plane wave on the radial exit surface of the Luneburg lens. Its propagation direction is opposite to the direction of the line connecting the photoelectric radiation unit (31) at the specific position and the center of the sphere.

3. The signal enhancement system based on a lens antenna according to claim 2, characterized in that: The Luneburg lens is made of a low-loss dielectric material, such as high-purity single-crystal silicon or polytetrafluoroethylene. The Luneburg lens contains a three-dimensional subwavelength aperture array. By precisely controlling the geometric size or density of the apertures at different radial positions r, the equivalent dielectric constant at that location is adjusted, thereby increasing the macroscopic equivalent refractive index n of the Luneburg lens. e ff(r) fits the distribution n(r) = n0*sqrt(2-(r / R)). 2 The functional relationship of ) is used to achieve the gradient refractive index effect.

4. The signal enhancement system based on a lens antenna according to claim 1, characterized in that: Each of the photoelectric radiation units (31) is provided with a high-speed photodetector (311) for the transmission path, a signal processing link for the receiving path, a miniature antenna unit (314) shared with the transmission and receiving paths, and a local bias and switch control circuit (315). The optical input end of the high-speed photodetector (311) is used to receive the transmitted optical signal. The radio frequency output end of the high-speed photodetector (311) is directly electrically connected to the feed point of the miniature antenna unit (314) through an electrical interconnection structure with a length of less than 300 micrometers. The local bias and switch control circuit (315) receives control commands from the beam pointing control module (5) and selectively provides working bias for the high-speed photodetector (311) or the signal processing link of the receiving path, thereby realizing the switching between the transmission and receiving functions.

5. A signal enhancement system based on a lens antenna according to claim 4, characterized in that: The high-speed photodetector (311) is a single-row carrier photodiode. The single-row carrier photodiode uses a flip-chip bonding process to bond its radio frequency output electrode to the feed pad of the micro antenna unit (314). The micro antenna unit (314) is a substrate integrated waveguide slot antenna. The antenna is manufactured on a flexible dielectric substrate that can fit the curved surface of the high-frequency lens collimation module (4).

6. A signal enhancement system based on a lens antenna according to claim 4, characterized in that: The signal processing link of the receiving path includes a low-noise amplifier (312) and an electro-absorption modulator (313). The input terminal of the low-noise amplifier (312) is connected to the feed point of the miniature antenna unit (314) and is used to amplify the radio frequency signal received by the miniature antenna unit (314). The radio frequency input terminal of the electro-absorption modulator (313) is connected to the output terminal of the low-noise amplifier (312). The optical input terminal of the electro-absorption modulator (313) is used to receive continuous wave probe light from the central control and optical modulation module (1). The electro-absorption modulator (313) is used to modulate the radio frequency signal amplified by the low-noise amplifier (312) onto the continuous wave probe light to form a received modulated signal and transmit it back to the central control and optical modulation module (1).

7. The signal enhancement system based on a lens antenna according to claim 1, characterized in that: The passive optical power distribution module (2) includes a planar optical waveguide type 1×N optical splitter based on silicon dioxide waveguide technology, where N is the number of the photoelectric radiation units (31). The input end of the optical splitter, its internal cascaded branch waveguides, its N output ports, and the N optical fibers connecting the N output ports to the N photoelectric radiation units (31) adopt polarization-maintaining optical devices and polarization-maintaining single-mode fibers to ensure the stability of the polarization state of the transmitted optical signal during transmission and distribution.

8. The signal enhancement system based on a lens antenna according to claim 1, characterized in that: The beam pointing control module (5) stores a beam pointing-radiation unit address mapping table, which pre-records the unique correspondence between the desired far-field direction of the beam and the physical position coordinates of a specific photoelectric radiation unit (31) in the photoelectric conversion and radiation array module (3). When the beam pointing control module (5) receives a beam pointing instruction containing target direction information, it queries the mapping table to determine the unique target photoelectric radiation unit (31).

9. A signal enhancement system based on a lens antenna according to claim 8, characterized in that: After the target photoelectric radiation unit (31) is determined, the beam pointing control module (5) sends an activation command to the local bias and switch control circuit (315) inside the target photoelectric radiation unit (31) through the control bus. The activation command is used to apply a working bias voltage to the high-speed photodetector (311) used for the transmission path inside the target photoelectric radiation unit (31), while ensuring that all other non-target photoelectric radiation units (31) in the photoelectric conversion and radiation array (3) are in an inactive state.

10. A signal enhancement method based on a lens antenna, characterized in that, The method, when applied to the system according to any one of claims 1 to 9, includes the following steps: S1: In the central control and optical modulation module (1), a radio frequency electrical signal is generated and an optical carrier is modulated by the radio frequency electrical signal to generate a modulated transmitted optical signal; S2: The emitted optical signal is injected into the passive optical power distribution network module (2), and the passive optical power distribution network module (2) distributes and transmits the emitted optical signal in parallel to each photoelectric radiation unit (31) of the photoelectric conversion and radiation array module (3); S3: The beam pointing control module (5) determines the unique target photoelectric radiation unit (31) in the photoelectric conversion and radiation array module (3) that corresponds to the target direction according to an externally input beam target direction command; S4: The beam pointing control module (5) sends an activation command to the target photoelectric radiation unit (31) to enable its transmission function, while ensuring that the transmission functions of all other photoelectric radiation units (31) in the array remain off. S5: Inside the activated target photoelectric radiation unit (31), the received transmitted light signal is photoelectrically converted to generate a high-frequency current consistent with the radio frequency electrical signal in step S1, and the high-frequency current is used to excite the micro antenna unit (314) to radiate electromagnetic waves to the high-frequency lens collimation module (4). S6: The high-frequency lens collimation module (4) performs spatial phase transformation and collimation on the received electromagnetic wave, forming a high-gain beam that is precisely pointed to the target direction in the far field.

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