Artificial Surface Plasmon Pattern Reconfigurable Antenna

Abstract

This invention relates to a pattern-reconfigurable antenna based on artificial surface plasmon polaritons (SSPPs), belonging to the field of antenna technology. The antenna includes a coplanar waveguide feed line, a transition structure, a reconfigurable SSPP waveguide, and periodic radiating elements. The reconfigurable SSPP waveguide modifies the dispersion characteristics by adding a varactor diode to a traditional SSPP element and adjusting the capacitance value using a bias circuit. The periodic radiating elements are elliptical patches with rectangular slots, coupled to the reconfigurable SSPP waveguide to radiate electromagnetic waves. This invention solves the problems of single radiation direction in traditional antennas and low gain in existing reconfigurable antennas. It achieves fixed-frequency beam scanning (maximum 23°) and frequency beam scanning (maximum 90°) in the 11.5GHz-15GHz frequency band, with gains greater than 9dBi (maximum 11.1dBi), expanding the detection range and increasing the detection distance, making it suitable for fields such as UAV detection.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically relating to a pattern-reconfigurable antenna based on artificial surface plasmon polaritons (SSPP), which is mainly used in wireless communication, radar systems and UAV detection scenarios. Background Technology

[0002] In modern wireless communication and intelligent sensing systems, reconfigurable antennas have become a key technology due to their ability to flexibly adjust their operating modes. Among them, pattern reconfigurable antennas can switch beam direction as needed, which is particularly important in fields such as UAV detection and defense systems. They not only need to meet the integration requirements of miniaturized devices, but also need to achieve wide-area coverage and high-precision tracking in complex environments.

[0003] Surface plasmon polaritons (SPPs) are surface waves that propagate at the interface between a metal and a dielectric, exhibiting slow wave characteristics and finding wide application in optics. To extend their reach to the microwave and terahertz bands, researchers have created artificial surface plasmon polaritons (SSPPs) by periodically etching grooves on metal surfaces. These SSPPs possess characteristics such as low loss and tunable dispersion, and have been used to design high-gain, low-profile microwave devices and antennas.

[0004] However, traditional antennas suffer from a single radiation direction, which limits the detection coverage. While existing pattern-reconfigurable antennas can extend the radiation range, they generally suffer from low gain, resulting in insufficient signal transmission and reception power, which limits the detection distance, makes it difficult to capture weak signals, and reduces system reliability and efficiency.

[0005] Therefore, developing a pattern-reconfigurable antenna that combines a wide beam scanning range with high gain has become an important direction to meet the needs of modern communication and detection. Summary of the Invention

[0006] The purpose of this invention is to address the limitations in coverage caused by the single radiation direction of traditional antennas and the detection range limitations of existing pattern reconfigurable antennas due to low gain. This invention provides a pattern reconfigurable antenna based on artificial surface plasmon polaritons. By adding a varactor diode to a traditional SSPP waveguide to form a reconfigurable SSPP waveguide, and combining it with a periodic elliptical patch radiating element with a rectangular slot, the capacitance value of the varactor diode is adjusted to change the dispersion characteristics of the SSPP, achieving fixed-frequency beam scanning (maximum 23°) and frequency beam scanning (maximum 90°) within the 11.5GHz-15GHz range, while maintaining a gain greater than 9dBi in this frequency band.

[0007] To achieve the above-mentioned objectives, the present invention employs the following technical solution: a pattern-reconfigurable antenna based on artificial surface plasmon polaritons, comprising:

[0008] Coplanar waveguide feed lines are used to achieve impedance matching and transmit radio frequency signals;

[0009] The transition structure connects the coplanar waveguide feed line and the reconfigurable artificial surface plasmon waveguide; the transition structure is a flared structure.

[0010] The reconfigurable artificial surface plasmon waveguide is composed of artificial surface plasmon units and varactor diodes. The varactor diodes are connected to a bias circuit on the bottom of the dielectric substrate through metallized vias. The bias circuit includes an inductor for isolating radio frequency signals. The dispersion characteristics of the reconfigurable artificial surface plasmon waveguide can be changed by adjusting the capacitance value of the varactor diode.

[0011] The periodic radiating element consists of an elliptical patch with rectangular slots. The elliptical patch is coupled to a reconfigurable artificial surface plasmon waveguide to radiate electromagnetic waves into free space. The periodic radiating element is arranged periodically along the reconfigurable artificial surface plasmon waveguide.

[0012] The antenna operates in the 11.5GHz-15GHz frequency band. Fixed-frequency beam scanning is achieved by adjusting the capacitance value of the varactor diode, and frequency beam scanning within this frequency band is achieved by the leakage characteristics of the periodic radiating element.

[0013] Furthermore, the microstrip line width of the coplanar waveguide feeder is 2-3 mm, and the gap between the microstrip line and ground is 0.1-0.15 mm to achieve 50 ohm impedance matching.

[0014] Furthermore, the flared shape of the transition structure is determined by the function y=C1*e αx +C2 determines, where α = 0.1 - 0.15.

[0015] Furthermore, the capacitance value of the varactor diode can be adjusted from 0.44pF to 4.7pF, corresponding to a bias voltage adjustment range of 0V to 20V.

[0016] Furthermore, the groove depth of the artificial surface plasmon resonance unit is 2.6-2.8 mm, and the spacing of the periodic radiation units is 8-10 mm.

[0017] Furthermore, the parameters of the elliptical patch with rectangular slots are as follows: the major axis and minor axis of the elliptical patch are 7-9mm and 4-5mm respectively, and the length and width of the rectangular slots are 4-6mm and 0.4-0.6mm respectively.

[0018] Furthermore, the maximum scanning range of the fixed-frequency beam scanning function is 23°, and the maximum scanning range of the frequency beam scanning function is 90°.

[0019] Furthermore, the antenna gain is not less than 9dBi in the 11.5GHz-15GHz frequency band, and the maximum gain is 11.1dBi.

[0020] Furthermore, the modulation period of the reconfigurable artificial surface plasmon waveguide is 2.3-2.5 mm.

[0021] Furthermore, the bias circuit at the bottom of the dielectric substrate is electrically connected to the varactor diode through a metallized via, and the inductor is connected in series in the bias circuit to block the radio frequency signal from entering the bias circuit.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. It solves the problem of the single radiation direction of traditional antennas: the beam direction can be quickly switched by fixed frequency beam scanning (maximum 23°) to achieve UAV tracking and avoid interference signals; the detection range can be expanded by frequency beam scanning (maximum 90°) to detect multiple frequency UAVs at the same time, reducing equipment costs.

[0024] 2. Overcomes the low gain of existing reconfigurable antennas: Based on the slow wave characteristics of SSPP, the gain is greater than 9dBi (maximum 11.1dBi) in the 11.5GHz-15GHz frequency band, which improves the signal reception capability and detection range, and enhances the communication and information acquisition capabilities in complex environments.

[0025] 3. High integration and stable performance: The dispersion characteristics and beam pointing can be flexibly adjusted by regulating the capacitance value of the varactor diode. The structural design is adapted to miniaturized equipment and is suitable for practical scenarios such as UAV detection. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an antenna structure according to an embodiment of the present invention, wherein (a) is the front side and (b) is the back side;

[0027] Figure 2 This is a diagram of a traditional SSPP waveguide structure;

[0028] Figure 3 This is the dispersion relation diagram of a traditional SSPP waveguide structure;

[0029] Figure 4 This is a diagram of a reconfigurable SSPP waveguide structure according to an embodiment of the present invention;

[0030] Figure 5 This is an equivalent circuit diagram of a reconfigurable SSPP waveguide according to an embodiment of the present invention;

[0031] Figure 6 This is a dispersion relation diagram according to an embodiment of the present invention;

[0032] Figure 7 This is an antenna return loss diagram according to an embodiment of the present invention;

[0033] Figure 8 The antenna pattern (a) according to an embodiment of the present invention represents the 11.5 GHz band;

[0034] Figure 9 The antenna pattern (b) according to an embodiment of the present invention represents the 13.25 GHz band;

[0035] Figure 10 The antenna pattern (c) according to an embodiment of the present invention represents the 15GHz frequency band;

[0036] Figure 11 This is an antenna gain diagram according to an embodiment of the present invention.

[0037] In the figure, 1 is the dielectric substrate; 2 is the ground; 3 is the microstrip line; 4 is the reconfigurable SSPP waveguide; 5 is the patch; and 6 is the bias circuit. Detailed Implementation

[0038] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0039] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0040] like Figure 2 As shown, the top layer of a traditional SSPP element is an H-shaped groove, and the bottom is a dielectric substrate. The specific values ​​of the elements are: p = 2.5 mm, a = 1.5 mm, h1 = 4 mm. We investigated the dispersion relation using the eigenmode solver in CST Microwave Studio. Figure 3 As shown (x-axis is...), (Normalized propagation constant, (where H is the propagation constant of the fundamental mode in the SSPP waveguide, and p is the period of the SSPP element). The traditional SSPP dispersion curve deviates significantly from the light beam, exhibiting slow wave characteristics. As the slot depth H increases, the cutoff frequency of the SSPP element decreases. Clearly, to change the dispersion characteristics of a traditional SSPP element, the slot depth must first be changed. However, once the SSPP antenna is fabricated, the slot depth is fixed, making it impossible to control the dispersion characteristics of the SSPP, thus resulting in imperfect performance of the SSPP antenna.

[0041] In response to the above issues, such as Figure 1 ((a) is the front, (b) is the back) and Figure 4 As shown, this invention provides a pattern-reconfigurable antenna based on artificial surface plasmon polaritons (SSPPs). It aims to achieve beam scanning by manipulating the dispersion characteristics of SSPPs and, combined with a periodic radiating element design, achieve high gain and wide bandwidth performance. The overall antenna structure, from top to bottom (or overall layout), includes a coplanar waveguide (CPW) feed line, a transition structure, a reconfigurable SSPP waveguide 4, and periodic radiating elements. These components work together to achieve both fixed-frequency beam scanning and frequency beam scanning functions within the 11.5 GHz-15 GHz frequency band.

[0042] like Figure 1 As shown, this pattern-reconfigurable antenna based on artificial surface plasmon polaritons includes:

[0043] I. Overall Structure Description

[0044] 1. Coplanar waveguide (CPW) feeder line

[0045] The coplanar waveguide feed line is used to achieve RF signal transmission and impedance matching. Its structure includes a microstrip line 3 and ground planes 2 on both sides. To meet the 50-ohm impedance matching requirement, after parameter optimization, the width of the microstrip line 3 is set to 2-3 mm (preferably 3 mm), and the gap (gs) between the microstrip line 3 and ground planes 2 is set to 0.1-0.15 mm (preferably 0.13 mm). This design ensures that the feed line can efficiently transmit the input signal to the subsequent transition structure, reducing signal reflection loss.

[0046] 2. Transition Structure

[0047] A transition structure connects the coplanar waveguide feed line to the reconfigurable SSPP waveguide 4, enabling a smooth transition between the two waveguide modes and reducing mode conversion loss. Its flared shape is determined by an exponential function. The exponential flare design is determined by the following parameters: α is set to 0.1, and C1 and C2 are constant coefficients. C1 controls the magnitude of the exponential term, determining the rate of change of the transition shape. Adjusting C1 controls the degree of change in the waveguide flare, making the transition smoother or more abrupt. C2 controls the offset of the transition, determining the starting position or offset of the flare, which typically affects the initial size and impedance matching of the waveguide. This exponential flare design effectively matches the impedance characteristics of CPW and SSPP waveguides, ensuring a stable conversion of electromagnetic waves from CPW mode to SSPP mode and improving signal transmission efficiency.

[0048] 3. Reconfigurable SSPP waveguide

[0049] The reconfigurable SSPP waveguide 4 is the core component for beam control and is an improvement on the traditional SSPP unit.

[0050] Traditional SSPP unit basics: such as Figure 2 As shown, the traditional SSPP cell has an H-shaped groove on the top layer and a dielectric substrate on the bottom. Its period length p = 2.5 mm, groove-related parameters a = 1.5 mm, and original groove depth h1 = 4 mm. This structure has slow wave characteristics, but its groove depth is fixed, making it impossible to control the dispersion characteristics.

[0051] Reconfigurable design: such as Figure 4 As shown, a varactor diode is added to the top of the dielectric substrate 1 of a conventional SSPP cell. The varactor diode is connected to the bias line at the bottom of the substrate through a metallized via, and an inductor is used to isolate the radio frequency signal (to prevent the radio frequency signal from entering the bias circuit 6 and affecting performance), thus forming the bias circuit 6. By adjusting the bias voltage (0V to 20V), the capacitance value (C) of the varactor diode can be continuously adjusted within the range of 4.7pF to 0.44pF.

[0052] Dispersion characteristic modulation: The change in the capacitance value of the varactor diode directly alters the dispersion relation of the SSPP waveguide—as the capacitance value increases, the cutoff frequency decreases (e.g., the cutoff frequency is 16.71 GHz when C=4.71 pF, and 17.15 GHz when C=0.44 pF). This modulation mechanism allows the equivalent wavenumber of the SSPP waveguide to be dynamically adjusted, providing a basis for beam direction control.

[0053] The reconfigurable SSPP cell structure can be equivalent to a circuit such as Figure 5 In this circuit structure, the entire SSPP unit can be viewed as a combination of two symmetrical series branches and a parallel admittance. Based on this, the dispersion relation can be described by a simple equation:

[0054] (1)

[0055] in, and The equivalent wavenumber and impedance of the series branch (describe the propagation characteristics of electromagnetic waves in the series branch). is the equivalent wavenumber of the entire structure (reflecting the rate of phase change of electromagnetic waves propagating in the structure); l is the equivalent length of the series branch; p is the period length of the SSPP element (the length of the repeating element in a periodic structure); j is the imaginary unit (j 2 =-1), reflecting the "phase / complex characteristics" of electromagnetic quantities; Y is the admittance of the shunt (parallel) branch (reflecting the shunt effect of the parallel branch on the overall circuit, controlled by the adjustable capacitor C), which can be obtained from formula (2):

[0056] (2)

[0057] in, Angular frequency; , , These are the wavenumber, impedance, and equivalent length of the parallel branch (determined by the physical structure of the parallel branch, and are fixed parameters); C is the adjustable capacitance of the varactor diode (a core control parameter, changed by the bias voltage).

[0058] Clearly, the value of C directly affects the dispersion relation of the SSPP waveguide. For example... Figure 6 As shown, with the same groove depth H as a traditional SSPP element, the reconfigurable SSPP element has a higher cutoff frequency and exhibits slow wave characteristics. Furthermore, the cutoff frequency of the reconfigurable SSPP waveguide decreases as capacitance C increases. When the capacitance C decreases sequentially from 4.7 pF to 0.44 pF, the cutoff frequencies of the reconfigurable SSPP waveguide are 16.71 GHz, 16.79 GHz, 16.88 GHz, and 17.15 GHz, respectively. This means that with a given capacitance C, when the electromagnetic wave frequency is higher than these corresponding cutoff frequencies, the electromagnetic wave will no longer be transmitted by the reconfigurable SSPP waveguide. (Antenna radiation angle) (i.e., beam pointing, measured in radians or degrees) can be described as:

[0059] (3)

[0060] Where p is the modulation period of the SSPP waveguide (the length of the repeating unit of the periodic structure, a fixed parameter); d is the radiating unit spacing. For free space beams ( =2π / λ, where λ is the wavelength of the electromagnetic wave in free space, which is positively correlated with the operating frequency. Based on the above theoretical analysis, it can be clearly seen that the wavenumber of the SSPP waveguide structure can be controlled by the bias voltage. This allows for control of the antenna's radiation angle. This is crucial for achieving reconfigurable SSPP and beam scanning.

[0061] Key parameter optimization: Through simulation optimization, the groove depth (H) of the reconfigurable SSPP waveguide is set to 2.8mm, and other parameters are l1=10mm, l2=24mm, l3=152mm, and wf=15mm, to ensure stable slow wave characteristics and adjustability in the 11.5GHz-15GHz frequency band.

[0062] 4. Periodic radiation unit

[0063] The periodic radiating element is used to couple electromagnetic waves from the reconfigurable SSPP waveguide into free space. It consists of elliptical patches 5 with rectangular slots, arranged periodically along the reconfigurable SSPP waveguide (spacing d = 10 mm).

[0064] Elliptical patch 5 parameters: The major axis parameter dl=8.5mm and the minor axis parameter ds=5mm for elliptical patch 5; the length of the rectangular slit etched inside it is ls=5mm and the width is ws=0.5mm.

[0065] Coupling and radiation principle: The elliptical patch 5 obtains energy from the reconfigurable SSPP waveguide through electromagnetic coupling, and the rectangular slot design enhances the energy radiation efficiency; the periodic arrangement gives the antenna the characteristics of a leaky antenna, and with the dispersion modulation of the SSPP waveguide, frequency beam scanning in a wide bandwidth can be achieved.

[0066] II. Function Implementation Principle

[0067] 1. Fixed-frequency beam scanning function

[0068] like Figures 8-10 As shown, at a fixed frequency, the dispersion characteristics of the reconfigurable SSPP waveguide are changed by adjusting the capacitance value of the varactor diode, thereby adjusting the waveguide's equivalent wavenumber. According to the radiation angle formula, the change in the equivalent wavenumber directly leads to a change in the antenna radiation angle: at 11.5 GHz, as... Figure 8 As shown, the capacitance decreased from 4.71 pF to 0.44 pF, and the radiation angle changed from 314° to 307°; at 13.25 GHz, as Figure 9 As shown, the angle changes from 353° to 341°; at 15GHz, as... Figure 10 As shown, the angle changes from 44° to 21°. Ultimately, a maximum range of 23° is achieved for fixed-frequency beam scanning, enabling rapid target tracking and interference avoidance.

[0069] 2. Frequency beam scanning function

[0070] Based on the leakage characteristics of the periodic radiating elements and combined with Floquet's theorem, the propagation constant of the spatial harmonics excited by the antenna satisfies ( (where d = 10 mm is the fundamental mode propagation constant of the SSPP waveguide, d = 10 mm is the period, and n is the harmonic order). Let n be the wave number of the nth spatial harmonic.

[0071] It is necessary to shift the slow wave to the fast wave region, which can be achieved under the condition that n ≤ -1. When n = -1, spatial harmonics enter... The fast wave region, the main radiation direction is from ( The free-space wavenumber (which is a fixed value) is determined. Furthermore, since d is already determined and will not change, ... p is the modulation period of the reconfigurable SSPP waveguide, such as Figure 2 As shown, it is also a fixed value.

[0072] because With frequency variation, within the 11.5GHz-15GHz frequency band, the radiation direction changes continuously with frequency: Figures 8-10 In the case of capacitance = 4.71pF, the angle changes from 314° at 11.5GHz to 44° at 15GHz; when capacitance = 0.44pF, the angle changes from 307° to 21°, with a maximum scanning range of 90°, which can detect multiple frequency targets simultaneously.

[0073] III. Performance Testing and Result Analysis

[0074] The antenna performance was simulated and verified using the commercial software CST. The results are as follows:

[0075] Return loss: such as Figure 7 As shown, within the 11.5GHz-15GHz frequency band, regardless of the capacitance value, the return loss is less than -10dB, indicating that the antenna can effectively radiate electromagnetic waves within this frequency band.

[0076] Gain characteristics: such as Figure 11 As shown, within the operating frequency range of 11.5GHz-15GHz, the gain is greater than 9dBi under four different C values. The gain is the highest at 11.1dBi when C=0.44pF and 14.6GHz, which meets the requirements for high-gain detection.

[0077] Radiation pattern: such as Figures 8-10 As shown, under different combinations of frequency and capacitance, the radiation pattern exhibits stable beam scanning characteristics. The fixed-frequency scanning and frequency scanning ranges are 23° and 90°, respectively, verifying the effectiveness of the beam control function.

[0078] IV. Summary

[0079] The reconfigurable antenna based on artificial surface plasmon polaritons designed in this embodiment achieves high gain (≥9dBi) and wide-range beam scanning (fixed frequency 23°, frequency 90°) in the 11.5GHz-15GHz frequency band through the coordinated design of reconfigurable SSPP waveguides and periodic radiating elements. It solves the problems of single directionality of traditional antennas and low gain of existing reconfigurable antennas, and is suitable for scenarios with high requirements for flexibility and detection capabilities, such as UAV detection.

[0080] The parts of this invention not described in detail are prior art, therefore they are not described in detail here.

[0081] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0082] Although this document uses a considerable amount of technical terminology, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

[0083] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes made to their shape or structure, any technical solution that is the same as or similar to this invention falls within the protection scope of this invention.

Claims

1. A pattern-reconfigurable antenna based on artificial surface plasmon polaritons, characterized in that, include: Coplanar waveguide feed lines are used to achieve impedance matching and transmit radio frequency signals; A transition structure connects the coplanar waveguide feed line to the reconfigurable artificial surface plasmon waveguide, and the transition structure is a flared structure. A reconfigurable artificial surface plasmon waveguide is composed of artificial surface plasmon units and varactor diodes. The varactor diodes are connected to a bias circuit at the bottom of a dielectric substrate through metallized vias. The bias circuit includes an inductor for isolating radio frequency signals. The dispersion characteristics of the reconfigurable artificial surface plasmon waveguide can be changed by adjusting the capacitance value of the varactor diodes. A periodic radiating element is composed of an elliptical patch with a rectangular slot, the elliptical patch being coupled to a reconfigurable artificial surface plasmon waveguide to radiate electromagnetic waves into free space, the periodic radiating element being arranged periodically along the reconfigurable artificial surface plasmon waveguide; The antenna operates in the 11.5GHz-15GHz frequency band. It achieves fixed-frequency beam scanning by adjusting the capacitance value of the varactor diode and frequency beam scanning within this frequency band by utilizing the leakage characteristics of the periodic radiating element.

2. The pattern-reconfigurable antenna according to claim 1, characterized in that, The microstrip line width of the coplanar waveguide feeder is 2-3 mm, and the gap between the microstrip line and ground is 0.1-0.15 mm to achieve 50 ohm impedance matching.

3. The pattern-reconfigurable antenna according to claim 1, characterized in that, The flared shape of the transition structure is determined by the function y=C1*e αx +C2 determines, where α = 0.1 - 0.

15.

4. The pattern-reconfigurable antenna according to claim 1, characterized in that, The capacitance value of the varactor diode is adjustable from 0.44pF to 4.7pF, corresponding to a bias voltage adjustment range of 0V to 20V.

5. The pattern-reconfigurable antenna according to claim 1, characterized in that, The groove depth of the artificial surface plasmon resonance unit is 2.6-2.8 mm, and the spacing of the periodic radiation units is 8-10 mm.

6. The pattern-reconfigurable antenna according to claim 1, characterized in that, The parameters of the elliptical patch with rectangular slots are as follows: the major axis and minor axis of the elliptical patch are 7-9mm and 4-5mm respectively, and the length and width of the rectangular slots are 4-6mm and 0.4-0.6mm respectively.

7. The pattern-reconfigurable antenna according to claim 1, characterized in that, The maximum scanning range of the fixed-frequency beam scanning function is 23°, and the maximum scanning range of the frequency beam scanning function is 90°.

8. The pattern-reconfigurable antenna according to any one of claims 1-7, characterized in that, The antenna has a gain of not less than 9 dBi in the 11.5 GHz-15 GHz frequency band and a maximum gain of 11.1 dBi.

9. The pattern-reconfigurable antenna according to any one of claims 1-7, characterized in that, The modulation period of the reconfigurable artificial surface plasmon waveguide is 2.3-2.5 mm.

10. The pattern-reconfigurable antenna according to any one of claims 1-7, characterized in that, The bias circuit at the bottom of the dielectric substrate is electrically connected to the varactor diode through a metallized via, and the inductor is connected in series in the bias circuit to block radio frequency signals from entering the bias circuit.

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