Metasurface antennas and programmable array antenna systems with dual modulation characteristics

Abstract

This application relates to a metasurface antenna with dual modulation characteristics and a programmable array antenna system. The metasurface antenna with dual modulation characteristics includes: a dielectric substrate and an antenna structure disposed on the dielectric substrate; the antenna structure includes: a central patch disposed at the center of the antenna structure and two phase-shifting patches symmetrically disposed about the central patch; grounded transmission channels are symmetrically disposed on the two phase-shifting patches, and diodes are symmetrically disposed between the central patch and the phase-shifting patches; it also includes: an RF circuit; the RF circuit is connected to the antenna structure through a feed probe, the feed probe being disposed at the center of the central patch; it also includes: a DC bias circuit; the DC bias circuit includes a DC bias line and a decoupling stub; one end of the DC bias line is connected to a DC power supply, and the other end is connected to the feed probe, and the decoupling stub is connected to the DC bias line. This application can simultaneously possess dual modulation characteristics of reflection phase and radiation phase.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a metasurface antenna with dual modulation characteristics and a programmable array antenna system. Background Technology

[0002] Existing programmable metasurface array antennas mainly involve two operating modes: reflection and transmission. The presence of a spatial feed results in a large system size and profile. Integrating the feed with the phase modulation structure can effectively reduce the antenna's profile height, thus achieving a low-profile design, which is an ideal way to realize novel low-profile radiating programmable metasurface antennas. In integrated antenna design, combining holographic theory with coded metasurface theory can achieve flexible and programmable beamforming. In this regard, Professor DRSmith's team at Duke University has conducted extensive research. In 2013, the team designed a metasurface holographic antenna based on a microstrip transmission line feed. Its structure mainly consists of complementary capacitor-inductor metasurface resonator units (cELCs) with PIN diodes placed on a microstrip line. This antenna uses the switching of PIN diodes to control the radiation state of the antenna elements to achieve spatial scanning of the radiated beam. Subsequently, the team conducted more in-depth research on this type of antenna, designed a large-aperture dynamically programmable metasurface antenna, and verified its applications in radar computational imaging, synthetic aperture imaging, and other fields.

[0003] However, this type of programmable antenna has problems such as low energy coupling efficiency at the end of the transmission line and energy leakage, which will degrade the antenna's radiation efficiency and gain. Summary of the Invention

[0004] Therefore, it is necessary to provide a metasurface antenna and programmable array antenna system with dual modulation characteristics to address the above-mentioned technical problems. This system has both reflection phase and radiation phase modulation characteristics, and features a low profile and high feeding efficiency.

[0005] A metasurface antenna with dual modulation characteristics includes: a dielectric substrate and an antenna structure disposed on the dielectric substrate;

[0006] The antenna structure includes: a central patch located at the center of the antenna structure and two phase-shifting patches symmetrical about the central patch; grounded transmission channels are symmetrically provided on the two phase-shifting patches, and diodes are symmetrically provided between the central patch and the phase-shifting patches.

[0007] In one embodiment, it further includes: a radio frequency circuit;

[0008] The radio frequency circuit is connected to the antenna structure via a feed probe, which is located at the center of the central patch.

[0009] In one embodiment, it further includes: a DC bias circuit;

[0010] The DC bias circuit includes a DC bias line and a decoupling stub; one end of the DC bias line is connected to a DC power supply, and the other end is connected to the power supply probe; the decoupling stub is connected to the DC bias line.

[0011] In one embodiment, the dielectric substrate includes: a first dielectric layer, a second dielectric layer, and a third dielectric layer stacked sequentially from top to bottom; the first dielectric layer and the third dielectric layer are bonded together through the second dielectric layer;

[0012] The antenna structure is located on top of the first dielectric layer, the radio frequency circuit and the DC bias circuit are both located at the bottom of the third dielectric layer, and a ground plane is provided at the bottom of the first dielectric layer.

[0013] A programmable array antenna system, comprising: a feed network and multiple metasurface antennas with dual modulation characteristics;

[0014] Multiple metasurface antennas are arranged in a rectangular array, and the feeding network is connected to the radio frequency circuit of each metasurface antenna.

[0015] In one embodiment, the distance between two adjacent metasurface antennas is equal to the wavelength of the radiated wave.

[0016] In one embodiment, the number of metasurface antennas located in the length or width direction of the rectangular array is an integer multiple of 8.

[0017] In one embodiment, the plurality of metasurface antennas share a first dielectric layer, a ground plane, a second dielectric layer, and a third dielectric layer.

[0018] In one embodiment, an isolation groove is provided on the floor corresponding to the position between two adjacent metasurface antennas;

[0019] The isolation slot includes multiple array-spaced strip slots.

[0020] In one embodiment, each DC bias line is connected to the first dielectric layer via a metal tube that penetrates the dielectric substrate perpendicularly.

[0021] The medium plate is provided with a through hole corresponding to the metal tube, and the through hole is provided with an annular groove on the hole wall corresponding to the floor to serve as an isolation ring;

[0022] The metasurface antennas located along the length of the rectangular array are divided into two symmetrical groups, with each group of metasurface antennas sharing an isolation ring.

[0023] The aforementioned metasurface antenna and programmable array antenna system with dual modulation characteristics is a radiating coded metasurface element antenna that can operate in the X-band. It integrates the feeding structure and phase modulation structure into a single unit, resulting in a compact antenna structure that solves the problem of high antenna profile in existing technologies. It incorporates PIN diodes, using their switching on and off to control the radiation state of the antenna structure, enabling spatial scanning of the radiated beam and exhibiting dual modulation characteristics for both the reflected and radiated phases of the reflected wave. Furthermore, the antenna element does not contain a grounded coplanar waveguide feed structure (GCPW), thus possessing perfect symmetry and enabling 1-bit modulation of the reflected electromagnetic wave phase. Additionally, the antenna element is directly fed by microstrip lines, eliminating the need for redundant grounded coplanar waveguide structures, allowing its application in two-dimensional array antenna designs. Each element in the array antenna is independently fed by a microstrip line, resulting in high feeding efficiency, avoiding energy leakage, and thus improving energy coupling efficiency. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a metasurface antenna with dual modulation characteristics in one embodiment;

[0025] Figure 2 This is a schematic diagram of the first dielectric layer and antenna structure in one embodiment;

[0026] Figure 3 This is a schematic diagram of the floor in one embodiment;

[0027] Figure 4 This is a schematic diagram of the third dielectric layer, radio frequency circuit, and DC bias circuit in one embodiment;

[0028] Figure 5 This is a schematic diagram showing the dimensions of the first dielectric layer in one embodiment;

[0029] Figure 6 This is a schematic diagram showing the dimensions of the third dielectric layer in one embodiment;

[0030] Figure 7 (a) is a schematic diagram of the current distribution when the diode states of the two antenna elements are different in one embodiment; (b) is a schematic diagram of the electric field distribution when the diode states of the two antenna elements are different in one embodiment.

[0031] Figure 8 This is a schematic diagram of the S-parameter simulation results of antenna elements in different states in one embodiment;

[0032] Figure 9 This is a schematic diagram showing the simulation results of the radiation direction of antenna elements in different states in one embodiment;

[0033] Figure 10This is a simulation diagram of the reflection amplitude of an antenna element at different frequencies in one embodiment.

[0034] Figure 11 This is a simulation diagram of the reflection phase of an antenna element at different frequencies in one embodiment.

[0035] Figure 12 This is a schematic diagram of the first dielectric layer of a programmable array antenna system in one embodiment;

[0036] Figure 13 This is a schematic diagram of the floor of a programmable array antenna system in one embodiment;

[0037] Figure 14 This is a schematic diagram of the third dielectric layer of a programmable array antenna system in one embodiment;

[0038] Figure 15 This is an enlarged schematic diagram of part A of a programmable array antenna system in one embodiment;

[0039] Figure 16 This is an enlarged schematic diagram of part B of a programmable array antenna system in one embodiment;

[0040] Figure 17 This is an enlarged schematic diagram of section C of a programmable array antenna system in one embodiment;

[0041] Figure 18 (a) is a simulation result of the radiation pattern with a radiation beam deflection angle of (60°, 0°) in one embodiment; (b) is a simulation result of the radiation pattern with a radiation beam deflection angle of (30°, 20°) in one embodiment.

[0042] Figure 19 This is a schematic diagram of a reflective programmable array antenna with 16×16 antenna elements in one embodiment;

[0043] Figure 20 (a) is a simulation result of a three-dimensional radiation pattern with a reflected beam deflection angle of (30°, 0) in one embodiment; (b) is a simulation result of a three-dimensional radiation pattern with a reflected beam deflection angle of (40°, 40°) in one embodiment.

[0044] Figure 21 This is a test diagram of the antenna azimuth radiation pattern in one embodiment;

[0045] Figure 22 This is a graph showing the S-parameter test results obtained at different deflection angles in one embodiment;

[0046] Figure 23 This is a schematic diagram of the gain curves tested at different deflection angles in one embodiment;

[0047] Figure 24 This is a test and simulation pattern for a deflection angle of (30°, 0°) in one embodiment;

[0048] Figure 25 This is a test and simulation pattern for a deflection angle of (60°, 0°) in one embodiment;

[0049] Figure 26 This is a test diagram of the antenna reflection pattern in one embodiment;

[0050] Figure 27 This is a test result diagram of the azimuth reflection pattern of a programmable array antenna in one embodiment;

[0051] Figure 28 This is a graph showing the test results of the reflection pattern gain of a programmable array antenna in one embodiment.

[0052] Attachment Number:

[0053] Center patch 1, phase-shifting patch 2, transmission channel 3, diode 4, RF circuit 5, feed probe 6, DC bias line 71, decoupling stub 72, first dielectric layer 8, second dielectric layer 9, third dielectric layer 10, feed network 11, isolation groove 12, metal tube 13, isolation ring 14, DC socket solder joint 15, ground plane 16. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0055] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0056] Furthermore, the use of terms such as "first," "second," etc., in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0058] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0059] like Figures 1 to 4 As shown, the metasurface antenna with dual modulation characteristics provided in this application, in one embodiment, includes: a dielectric substrate and an antenna structure disposed on the dielectric substrate;

[0060] The antenna structure includes: a central patch 1 located at the center of the antenna structure and two phase-shifting patches 2 symmetrical about the central patch 1; grounded transmission channels 3 are symmetrically provided on the two phase-shifting patches 2, and diodes 4 are symmetrically provided between the central patch 1 and the phase-shifting patches 2.

[0061] Preferably, it further includes: a radio frequency circuit 5 for radiating electromagnetic waves;

[0062] The radio frequency circuit 5 is connected to the antenna structure via a feed probe 6, which is located at the center of the central patch 1.

[0063] Preferably, it further includes: a DC bias circuit for controlling the on / off state of diode 4 and switching the state of diode 4;

[0064] The DC bias circuit includes a DC bias line 71 and decoupling stubs 72. One end of the DC bias line 71 is connected to a DC power supply, and the other end is connected to the feed probe 6, which is then connected to a diode. The decoupling stubs 72 are connected to the DC bias line 71. More preferably, two fan-shaped decoupling stubs 72 are symmetrically arranged on a single DC bias line 71. The tips of the decoupling stubs 72 are connected to the DC bias line 71, and the radius of the decoupling stubs 72 is one-quarter of the radiation wavelength, used to isolate the influence of radio frequency signals on the DC circuit.

[0065] In this embodiment, the center patch 1, the phase-shifting patch 2, the radio frequency circuit 5, and the DC bias circuit are all made of metal.

[0066] This application does not limit the shape of the dielectric substrate, the center patch 1, and the phase-shifting patch 2, and the specific design can be made according to the actual situation. Preferably, the dielectric substrate and the center patch 1 are square, and the phase-shifting patch 2 is rectangular.

[0067] The transmission channel 3 is a hollow metal pipe disposed on the dielectric substrate, preferably placed vertically. This application does not limit the number or size of the transmission channels 3; specific designs can be made according to actual conditions. Preferably, each phase-shifting patch 2 has eight transmission channels 3. Grounding the eight transmission channels 3 allows the current to flow uniformly to the ground along the X-axis, suppressing the antenna's cross-polarization level and thus improving antenna performance.

[0068] Diode 4 can be a PIN diode. By loading two PIN diodes onto the antenna structure and changing the state of the integrated diodes, the direction of current flow and the distribution area of ​​the electric field can be adjusted, allowing the far-field radiation phase difference of the antenna to have two modulated states of 0° and 180°, with 1-bit digital adjustable characteristics. For convenience, "0" represents the diode being off, "1" represents the diode being on, and "01" represents the left diode PIN1 being off and the right diode PIN2 being on, and so on.

[0069] The operation of this embodiment is as follows: In radiation mode, an excitation signal is applied to the feed line of the RF circuit, and the antenna structure is excited through the feed probe. The DC bias line is connected to the diode through the feed probe. When a DC voltage of -1.3V and +1.3V is applied to the DC bias line, the two PIN diodes can be turned on respectively. The radiated signal reaches the center patch of the antenna structure through the RF circuit, and after passing through the diode, it reaches the phase-shifting patch and then radiates out. The phase-shifting patch is grounded through the transmission channel, thus forming a closed loop. In reflection mode, when the electromagnetic wave irradiates the antenna structure, adjusting the on / off state of the diodes on the antenna structure can make the phase difference of the reflected wave 180°. Specifically, at 9.76GHz, when one of the diodes on the antenna structure is turned on, the phase of the reflected wave reflected by the antenna structure is 135°. When both diodes on the antenna are turned off, the phase of the reflected wave is -45°. The phase difference of the reflected wave in the two antenna states is 180°, thereby achieving a 1-bit modulation capability of the reflected wave phase.

[0070] In this embodiment, the center patch, the feed probe, and the microstrip line of the RF circuit together constitute the feed structure, and the phase-shifting patch constitutes the phase modulation structure.

[0071] The aforementioned metasurface antenna with dual modulation characteristics is a radiating coded metasurface element antenna that can operate in the X-band. It integrates the feeding structure and phase modulation structure, allowing the antenna structure to modify the phase and amplitude of electromagnetic wave radiation and reflection, thus achieving electromagnetic wave modulation. The antenna structure is compact, solving the problem of high antenna profile in existing technologies. It also incorporates PIN diodes, using their switching to control the antenna structure's radiation state, enabling spatial scanning of the radiated beam and exhibiting dual modulation characteristics for both the reflected and radiated phases. Furthermore, the antenna element does not contain a grounded coplanar waveguide feed structure (GCPW), thus possessing perfect symmetry, which endows it with 1-bit modulation capability for the reflected electromagnetic wave phase. Additionally, the antenna element uses direct microstrip line feeding, eliminating the need for a redundant grounded coplanar waveguide structure, allowing its application in two-dimensional array antenna designs. Each element in the array antenna is independently fed using a microstrip line, resulting in high feeding efficiency, avoiding energy leakage, and improving energy coupling efficiency.

[0072] In one embodiment, the dielectric substrate includes a first dielectric layer 8, a second dielectric layer 9, and a third dielectric layer 10 stacked sequentially from top to bottom; the first dielectric layer 8 and the third dielectric layer 10 are pressed together by the second dielectric layer 9.

[0073] The antenna structure is located on top of the first dielectric layer 8, and the radio frequency circuit 5 and the DC bias circuit are both located at the bottom of the third dielectric layer 10. A ground plane 16 is provided at the bottom of the first dielectric layer 8. The transmission channel 3 is connected to the ground plane 16.

[0074] In this embodiment, a metasurface antenna containing a three-layer dielectric structure is an antenna element.

[0075] like Figures 5 to 6As shown, preferably, the first dielectric layer 8 uses a Rogers 4350B dielectric substrate with a thickness h1 of 1.524 mm, and the ground plane is made of metal. The second dielectric layer 9 uses a Rogers 4450F prepreg with a thickness of 0.1 mm for bonding. The third dielectric layer 10 uses a Rogers 4350B dielectric substrate with a thickness h2 of 0.508 mm. The dielectric substrate is a square with a side length p of 12 mm, the side length a of the center patch 1 is 1 mm, and the phase-shifting patch 2... The length l is 8mm, the width w of the phase-shifting patch 2 is 2.7mm, the distance between the center patch 1 and the phase-shifting patch 2 is 0.33mm, the diameter r1 of the transmission channel 3 is 0.36mm, the spacing v1 of the transmission channel 3 is 0.81mm, the diameter r2 of the feed probe 6 is 0.15mm; the width dw of the DC deflection line 71 is 0.2mm, the width sw of the RF circuit microstrip line 5 is 1.24mm, and the radius R of the decoupling stub 72 is one-quarter of the radiation wavelength.

[0076] like Figures 7 to 11 As shown, a simulation analysis is performed on a metasurface antenna with dual modulation characteristics.

[0077] Figure 7 (a) and (b) show the current and voltage distributions when different DC voltages are applied to the two antenna elements, respectively. When different DC voltages are applied, the surface current flows in opposite directions on the elements, and the electric field distribution regions also exhibit opposite characteristics, which will make the radiation phase difference between the two elements close to 180°.

[0078] Figure 8 and Figure 9 Simulation results of S-parameters and radiation patterns are presented for two elements with different voltage values ​​applied. Port1 and Port3 are the RF feed ports of the two elements, and Port2 and Port4 are the DC bias line ports of the two elements. The simulation results show that the antenna element operates in the bandwidth of 9.6-10.4 GHz. When the DC voltages applied to the two elements are +1.3V (-1.3V) and -1.3V (+1.3V), respectively, there is a dip at 0° in the synthesized radiation pattern, which verifies that there is a phase difference of nearly 180° between the elements. It can be deduced that when the voltages applied to the two elements are the same, the radiation patterns synthesized by the elements are superimposed, and the radiation phase difference is 0°. The above analysis verifies that the switching state of the diode can change the far-field radiation phase of the element, so that the radiation phase difference between the elements has a 1-bit adjustable characteristic.

[0079] Figure 10 and Figure 11The simulation results demonstrate the changes in reflection amplitude and phase at different frequencies. For x-polarized electromagnetic waves, when the two diodes on the unit are in states "01" and "00", the corresponding reflection phase difference at 9.76 GHz is 180°, and the reflection loss is less than 2 dB. Due to the left-right symmetry of the unit, the reflection characteristics are identical in both diode states "01" and "10". By defining the state when one diode is conducting as state1 and both diodes are off as state0, the reflection characteristics of the unit can be encoded using digital information.

[0080] like Figures 12 to 17 As shown, this application also provides a programmable array antenna system, which in one embodiment includes: a feed network 11 and a plurality of metasurface antennas with dual modulation characteristics;

[0081] Multiple metasurface antennas are arranged in a rectangular array, and the feeding network 11 is connected to the radio frequency circuit of each metasurface antenna.

[0082] Preferably, the distance between two adjacent metasurface antennas is equal to the wavelength of the radiated wave.

[0083] Preferably, the number of metasurface antennas located in the length or width direction of the rectangular array is an integer multiple of 8.

[0084] In this embodiment, a series-parallel feeding network is used to feed each antenna element to form a radiating programmable array antenna. The DC bias line passes through the third dielectric layer, the second dielectric layer, the ground plane and the first dielectric layer and is connected to the DC socket solder joint 15.

[0085] Multiple antenna elements are spliced ​​together to form an array, creating a radial programmable beam scanning array antenna system with flexible modulation capabilities for reflected waves. The antenna array integrates PIN diodes, providing programmability. Each antenna element contributes to the final beam modulation, and each element is independently fed using a microstrip line, resulting in high feeding efficiency, avoiding energy leakage, and improving energy coupling efficiency. The elements in the array are encoded according to digital holography theory, enabling programmable and flexible control of the radiated waves.

[0086] Preferably, the plurality of metasurface antennas share a first dielectric layer, a ground plane, a second dielectric layer, and a third dielectric layer.

[0087] The above design facilitates processing, simplifies assembly, and is more practical.

[0088] In one embodiment, an isolation groove 12 is provided on the floor corresponding to the position between two adjacent metasurface antennas to improve the isolation.

[0089] The isolation slot 12 includes multiple array-spaced strip slots.

[0090] In one embodiment, each DC bias line is connected to the first dielectric layer via a metal tube 13, which penetrates the dielectric substrate perpendicularly.

[0091] The medium plate is provided with a through hole corresponding to the metal tube 13, and the through hole is provided with an annular groove on the hole wall corresponding to the floor to serve as an isolation ring 14;

[0092] The metasurface antennas located along the length of the rectangular array are divided into two symmetrical groups, with each group of metasurface antennas sharing an isolation ring 14.

[0093] The isolation ring isolates the power supply line of the DC bias line from ground.

[0094] Preferably, multiple antenna elements are arrayed together. The designed two-dimensional programmable array antenna contains 8×16 coded antenna elements. The spacing between two adjacent antenna elements is one waveguide wavelength sp = 18 mm, the distance between metal tubes is dp = 2.54 mm, and the diameter of the metal tubes is r3 = 1.1 mm.

[0095] Programmable array antennas with dual modulation capabilities for both radiated and reflected beams can serve as 5G relay base station antennas. These antennas can reflect and modulate electromagnetic signals transmitted by the previous base station, and reflect received signals into signal dead zones or weak signal areas of the previous base station, thereby enhancing signal strength in those areas. Simultaneously, the antenna's active radiation characteristics can amplify and modulate the received signal, further enhancing signal transmission stability. This dual functionality is not found in existing single-mode base station antennas.

[0096] In one specific embodiment, a low-profile programmable radiating beam-scanning array antenna comprising 8 encoding units in the width direction and 16 in the length direction was designed. Each antenna unit was fed using an 8×16 series-parallel feeding network. Each unit was encoded using digital holographic antenna theory, achieving beam scanning of -60° to 60° in the azimuth plane and -40° to 40° in the elevation plane. This achieved flexible phased beamforming without relying on phase shifter components. Furthermore, based on the principle of reflective programmable antennas, the modulation characteristics of the reflected waves of the designed encoding units were analyzed. The constructed reflective programmable antenna can achieve beam scanning of -40° to 40°. The relevant simulation analysis results are as follows: Figures 18 to 28 As shown.

[0097] Figure 18Simulation results of radiation patterns for the array antenna with deflection angles of (60°, 0°) and (30°, 20°) are presented. The main lobes of the radiation patterns are accurately deflected, verifying the flexible control of the radiation beam by the programmable array antenna.

[0098] like Figure 19 As shown, to verify the modulation effect of the programmable array antenna on the reflected wave, two 8×16 programmable arrays were combined to form a 16×16 element reflection array, and a horn antenna was used as a spatial excitation source to illuminate the reflection array. The simulation results of the three-dimensional radiation patterns with reflected beam deflection angles of (30°, 0) and (40°, 40°) are shown below. Figure 20 As shown.

[0099] An 8×16 two-dimensional array antenna was fabricated, and a digital circuit driver board based on an STM32 microcontroller was designed to realize programmable control of the array antenna.

[0100] like Figure 21 As shown, the array antenna was fixed on a turntable in a microwave anechoic chamber to test its active radiation characteristics. The S11 and gain curves measured at different deflection angles are shown below. Figure 22 and Figure 23 As shown, the operating bandwidth is basically the same at each deflection angle, and S11 < -10dB is basically satisfied in the 9-10.4GHz frequency band.

[0101] Figure 24 and Figure 25 Test and simulation radiation patterns with deflection angles of (30°, 0°) and (60°, 0°) are shown. Ignoring the error in the antenna placement angle during the test, the test radiation pattern beams can accurately point to the preset angle and have high gain and good directivity.

[0102] like Figure 26 As shown, when testing the modulation effect of the array antenna on the reflected wave, a fabricated 8×16 array antenna was used as a programmable reflector array, and a standard gain horn operating in the X-band was used as the excitation source, placed 270mm in front of the array. The measured azimuth beam pattern and gain are shown below. Figure 27 and Figure 28 As shown, the measured main lobe of the radiation pattern has high pointing accuracy, and the test gain is above 16.4 dBi.

[0103] This application employs an integrated feeding structure and phase modulation structure to design a radial coding unit loaded with PIN diodes. By switching the state of the diodes, the far-field radiation phase and reflection phase of the antenna element can be adjusted, exhibiting a 1-bit adjustable digital characteristic. Based on this, a radial programmable beam scanning array antenna containing 8×16 elements is designed, possessing flexible modulation capability for reflected waves. The elements in the array are encoded according to digital holography theory, and simulation and experimental tests verify the programmable and flexible beamforming control of the array antenna for both radiated and reflected beams. The novel antenna proposed in this application possesses the advantages of traditional reflective array antennas. As a novel low-profile radial programmable antenna, the new programmable array exhibits flexible beamforming capability for both reflected and radiated beams within the same aperture, showing broad application prospects in radar detection, mobile communication, electronic countermeasures, and microwave imaging.

[0104] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A metasurface antenna with dual modulation characteristics, characterized in that, include: The dielectric substrate and the antenna structure disposed on the dielectric substrate; The antenna structure includes: a central patch located at the center of the antenna structure and two phase-shifting patches symmetrical about the central patch; grounded transmission channels are symmetrically provided on the two phase-shifting patches, and diodes are symmetrically provided between the central patch and the phase-shifting patches; It also includes: radio frequency circuits; The radio frequency circuit is connected to the antenna structure via a feed probe, which is located at the center of the central patch. It also includes: a DC bias circuit; the DC bias circuit includes a DC bias line, one end of which is connected to a DC power supply and the other end of which is connected to the feed probe; In radiation mode, an excitation signal is applied to the feed line of the RF circuit and the antenna structure is excited through the feed probe; the DC bias line is connected to the diode through the feed probe, so that the two diodes are turned on respectively; the radiated signal reaches the center patch of the antenna structure through the RF circuit, and after passing through the diode, it reaches the phase-shifting patch and then radiates out. In reflection mode, when electromagnetic waves irradiate the antenna structure, the on / off state of the diodes on the antenna structure is adjusted so that the phase difference of the reflected wave is 180°, thereby achieving 1-bit modulation of the phase of the reflected wave.

2. The metasurface antenna with dual modulation characteristics according to claim 1, characterized in that, The DC bias circuit also includes a decoupling stub; the decoupling stub is connected to the DC bias line.

3. The metasurface antenna with dual modulation characteristics according to claim 2, characterized in that, The dielectric substrate includes a first dielectric layer, a second dielectric layer, and a third dielectric layer stacked sequentially from top to bottom; the first dielectric layer and the third dielectric layer are pressed together by the second dielectric layer. The antenna structure is located on top of the first dielectric layer, the radio frequency circuit and the DC bias circuit are both located at the bottom of the third dielectric layer, and a ground plane is provided at the bottom of the first dielectric layer.

4. A programmable array antenna system, characterized in that, include: The feeding network and the metasurface antenna with dual modulation characteristics as described in claims 3; Multiple metasurface antennas are arranged in a rectangular array, and the feeding network is connected to the radio frequency circuit of each metasurface antenna.

5. The programmable array antenna system according to claim 4, characterized in that, The distance between two adjacent metasurface antennas is equal to the wavelength of the radiated wave.

6. The programmable array antenna system according to claim 5, characterized in that, The number of metasurface antennas located in the length or width direction of the rectangular array is an integer multiple of 8.

7. The programmable array antenna system according to claim 6, characterized in that, Multiple metasurface antennas share a first dielectric layer, a ground plane, a second dielectric layer, and a third dielectric layer.

8. The programmable array antenna system according to claim 7, characterized in that, An isolation groove is provided on the floor corresponding to the position between two adjacent metasurface antennas; The isolation slot includes multiple array-spaced strip slots.

9. The programmable array antenna system according to claim 8, characterized in that, Each DC bias line is connected to the first dielectric layer via a metal tube that penetrates the dielectric substrate perpendicularly. The medium plate is provided with a through hole corresponding to the metal tube, and the through hole is provided with an annular groove on the hole wall corresponding to the floor to serve as an isolation ring; The metasurface antennas located along the length of the rectangular array are divided into two symmetrical groups, with each group of metasurface antennas sharing an isolation ring.

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