Flexible leaky-wave antenna for uniform and efficient radio frequency transmission in ultrahigh-field MRI (Magnetic Resonance Imaging) and design method

Abstract

The invention relates to a flexible leaky-wave antenna for uniform and efficient radio frequency transmission in ultrahigh field MRI, which comprises a double-layer dielectric substrate, a transmission line, an isolation pad and an LWA structure layer, the double-layer dielectric substrate comprises a first dielectric substrate and a second dielectric substrate, the transmission line comprises a first copper layer, the first copper layer is laid on the upper surface of the first dielectric substrate, and the isolation pad is laid on the upper surface of the second dielectric substrate. An isolation pad is arranged between the first dielectric substrate and the second dielectric substrate to form spaced arrangement of the double-layer dielectric substrates, the LWA structure layer comprises a second copper layer, six annular grooves with the same size are formed in the LWA structure layer at equal intervals, discs are embedded in the six annular grooves, and the LWA structure layer is arranged below the isolation pad and attached to the second dielectric substrate. And a flexible layer made of a segmented high-dielectric flexible material is arranged below the second dielectric substrate. The invention further comprises an antenna design method. According to the invention, the transmission efficiency of the LWA and the distribution uniformity of the B1 + field are improved, the flexible design fits the human body, and the signal intensity is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical imaging and magnetic resonance imaging (MRI), and specifically relates to a flexible leaky-wave antenna for uniform and efficient radio frequency transmission in ultra-high field MRI and a design method thereof. BACKGROUND

[0002] Leaky-wave antenna (LWA, Leaky-Wave Antenna) is a basic principle of realizing directional radiation by "leaking" electromagnetic waves along a certain direction or path of the antenna structure. Its research focuses include improving imaging quality, low specific absorption rate and improving radiation efficiency, etc.

[0003] The existing LWA is made of hard material as a whole, and the existing LWA has the following problems: (1) B1 + field distribution is uneven: B1 + Uneven B1 + field distribution will significantly affect image quality and imaging results, resulting in differences in magnetic resonance signal intensity at different positions, thereby affecting the contrast of the image. Some areas may have strong signals, while other areas have weak signals, resulting in poor image uniformity, which further affects the clarity and resolution of the lesion. In addition, uneven B1 + field distribution may also cause artifacts or geometric distortion, especially in areas far from the coil, such as limbs, resulting in lower excitation efficiency in these areas. Therefore, the MR (Magnetic Resonance, Magnetic Resonance) signal in these areas is weak, affecting the clarity and accuracy of the overall imaging.

[0004] (2) High specific absorption rate (SAR, Specific Absorption Rate): High SAR in MRI mainly brings effects such as heat effect, potential tissue damage, and decline in imaging quality. Higher SAR will cause excessive absorption of radio frequency energy during MRI, thereby increasing the temperature of the tissue. Long-term or high-intensity radio frequency exposure may cause thermal effects, resulting in patient discomfort or even tissue damage. This causes different tissues to have different excitation conditions during magnetic resonance imaging, which may cause uneven excitation in different regions, affecting the contrast of the image. Tissues may show different brightness and clarity due to absorbing more radio frequency energy.

[0005] (3) Low transmission efficiency: Lower transmission efficiency means weaker signal transmission from the RF coil to the receiving system. This results in insufficient received signal strength, thus affecting image quality. Low signal strength leads to decreased image contrast. When signal transmission efficiency is low, it is usually necessary to increase the scanning time or increase signal amplification to compensate for insufficient signal. This may introduce more noise, especially in the low-frequency band, thus increasing the noise level of the image and affecting the clarity and recognizability of the final image. In the case of poor signal transmission, artifacts may occur during the imaging process.

[0006] (4) Air gap exists between the coil and the human body: An air gap between the coil and the human body reduces signal transmission efficiency, affects image quality, increases imaging instability, and may lead to a decrease in image resolution and contrast. The conductivity of air is much lower than that of human tissue, and an air gap will cause a decrease in the coupling efficiency between the coil and the human body. In MRI, the transmission and reception of radio frequency signals usually depend on close contact between the coil and the tissue. An air gap makes the transmission of radio frequency signals less effective than when in direct contact, resulting in signal attenuation. Signal attenuation will directly affect the intensity of the received MR signal, which will lead to a decrease in the signal-to-noise ratio (SNR) in imaging. Due to incomplete signal reception, an air gap may cause uneven signal intensity in different tissues, affecting image resolution.

[0007] (5) Longer LWA size: A longer LWA may have some impact on image quality, equipment design, and operating procedures. A longer LWA usually needs to cover a larger area of ​​the patient, especially during whole-body scans, which may cause patient discomfort. It increases the overall size and space occupied by the MRI equipment. Although a longer antenna can cover a larger area, it may lead to uneven distribution of the radio frequency field, which will affect the image quality and signal strength, resulting in reduced image contrast or local signal loss.

[0008] Therefore, a new type of leaky antenna is urgently needed to address the aforementioned problems. Summary of the Invention

[0009] To address the imaging problems of existing leaky wave antennas, a flexible leaky wave antenna (LWA) and its design method for uniform and efficient radio frequency transmission in ultra-high field MRI are presented. The LWA utilizes a double-layer dielectric substrate combined with six circular annular slot structures to form an energy circulation system, improving the transmission efficiency and B1 of the LWA. + The uniformity of field distribution is improved by using a flexible design to reduce the gap between the LWA and the human body, thereby increasing the signal strength. The flexible layer uses segmented high-dielectric flexible material to shorten the resonant wavelength of the LWA, increase the transmission rate, and thus improve the imaging quality.

[0010] To achieve the above objectives, the first aspect of the present invention proposes a flexible leaky wave antenna for uniform and efficient radio frequency transmission in ultra-high field MRI, comprising a double-layer dielectric substrate, a transmission line, an isolation pad, and an LWA structural layer. The double-layer dielectric substrate includes a first dielectric substrate and a second dielectric substrate. The transmission line includes a first copper layer, which is laid on the upper surface of the first dielectric substrate. An isolation pad is disposed between the first dielectric substrate and the second dielectric substrate to form a spaced arrangement of the double-layer dielectric substrate. The LWA structural layer includes a second copper layer. Six equally spaced annular grooves of the same size are formed on the LWA structural layer. A disk is embedded in each of the six annular grooves. The LWA structural layer is disposed below the isolation pad and is attached to the second dielectric substrate. A flexible layer made of segmented high-dielectric flexible material is disposed below the second dielectric substrate.

[0011] Furthermore, the flexible layer comprises four parts with different dielectric constants. The flexible layer includes a first part, a second part, a third part, and a fourth part. The first part, the second part, the third part, and the fourth part have the same width but different lengths. The flexible layer is made of a flexible composite material synthesized from different chemical materials.

[0012] The four portions with different dielectric constants can shorten the resonant wavelength of LWA and increase the transmission rate. Simultaneously, the energy circulation system formed by the combination of a double-layer dielectric substrate and a six-ring gap structure optimizes B1. + Field distribution uniformity. This can improve signal transmission efficiency, affect image quality, and reduce imaging instability.

[0013] Furthermore, both the first copper layer and the second copper layer are made of flexible circuit boards; The first dielectric substrate and the second dielectric substrate are made of a composite material or a low-conductivity rubber pad.

[0014] The use of a flexible circuit board allows the LWA to conform to different body curves, significantly reducing the gap between the LWA and the body. This improves signal strength, reduces noise and artifacts, enhances image quality, and optimizes scan time while increasing patient comfort. It also boasts high signal reception efficiency, thereby increasing the SNR in imaging.

[0015] Furthermore, the copper layer thickness of the transmission line and the LWA structure layer is adapted to the operating frequency requirements of 7T ultra-high field MRI.

[0016] A second aspect of this invention proposes a design method for a flexible leaky antenna for uniform and efficient radio frequency transmission in ultra-high field MRI, comprising the following steps: Step 1: Select materials for bilayer dielectric substrates based on relative permittivity, loss tangent, and cost. Step 2: Based on the operating frequency of 7T and the approximate size of the actual human body imaging calculation model, perform preliminary simulation on the initial model; Step 3: After obtaining the desired result in Step 2, based on the design requirements of flexible fit to the human body, determine the material, dielectric constant and size of each segment of the flexible layer; Step 4: Based on the design of flexible LWA with high transmission efficiency and B1 + The uniform field distribution characteristic determines the use of a ring structure to form an energy circulation system, improving transmission efficiency and B1. + Field uniformity; Step 5: By observing the simulation results, find ways to change B1. + Key parameters for field uniformity and transmission efficiency to achieve B1 in flexible LWA + Uniform field distribution and high transmission efficiency; Step 6: Establish a full simulation model, perform small-scale optimizations to enhance the performance of the flexible LWA, obtain the results, and complete the design.

[0017] Furthermore, in step 2, the size of the human body imaging calculation model is constructed based on common clinical human body shape data to ensure the compatibility of the antenna with the human body curve.

[0018] Furthermore, the key parameters mentioned in step 5 include the diameter of the annular groove, the material of the flexible layer, the dielectric constant and size of each segment, and the width of the transmission line.

[0019] Furthermore, the initial model described in step 2 involves first fabricating a leaky antenna on a rigid PCB board. The LWA structure layer and transmission line of the leaky antenna on the rigid PCB board are simulated using the parameters of the rigid PCB board. The first and second dielectric substrates are made of R04003C material, and the flexible layer is made of HPP material.

[0020] The beneficial effects of the present invention through the above technical solution are as follows: (1) The LWA structure of this invention is simple, and the combined design method makes it easy to manufacture and has a low cost. It can be used to meet the needs of various medical imaging, magnetic resonance imaging and other medical imaging applications.

[0021] (2) The double-layer dielectric substrate structure and the six-ring gap structure of this invention together constitute an energy circulation system. This improves the transmission efficiency of LWA and B1. + Uniformity of field distribution.

[0022] This design establishes a channel for the transmission, reflection, and radiation of radio frequency (RF) energy. After injection through the transmission line, RF energy is transferred to the lower LWA (Light Wave Wafer) structural layer via dielectric coupling between the two substrates. The spacing of the isolation pads precisely matches the operating wavelength of ultra-high field MRI, preventing standing wave loss between the two substrates and providing physical space for energy circulation. Traditional leaky antennas tend to attenuate energy radiation in a single direction, resulting in low transmission efficiency and uneven field distribution. However, six sets of equidistant circular slots form an array of radiation nodes, allowing RF energy to be evenly distributed within the LWA structural layer. Through the combined leakage and reflection of each circular groove, energy is radiated uniformly along the antenna's length, avoiding localized energy concentration or excessive attenuation. The size matching between the embedded disk and the circular groove further optimizes the impedance characteristics of each radiation node, reducing energy reflection loss and converting more RF energy into effective radiation. Simultaneously, the equidistant arrangement of the six nodes ensures B1... + The field forms a uniform coverage within the imaging area.

[0023] (3) This invention has high plasticity. The LWA uses flexible materials (flexible circuit board and segmented high dielectric flexible material), which can perfectly fit different human body curves, greatly reducing the gap between the LWA and the human body. It improves signal strength, reduces noise and artifacts, improves image quality, and optimizes scanning time and enhances patient comfort. It has high signal reception efficiency, thereby increasing the SNR in imaging.

[0024] (4) The flexible layer of this invention uses segmented high-dielectric flexible material to shorten the resonant wavelength of LWA and improve the transmission rate. At the same time, it is combined with an energy circulation system to optimize B1. + Field distribution uniformity. This can improve signal transmission efficiency, affect image quality, and reduce imaging instability. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a flexible leaky antenna for uniform and efficient radio frequency transmission in ultra-high field MRI. Figure 2 A flowchart illustrating the steps of a flexible leaky antenna design method for uniform and efficient radio frequency transmission in ultra-high field MRI. Figure 3 This is a schematic diagram of the energy circulation system of a flexible leaky antenna for uniform and efficient radio frequency transmission in ultra-high field MRI. Figure 4 B1 for rigid PCB board LWA + Field distribution map; Figure 5 B1 for rigid PCB board LWA + Field value line chart; Figure 6 SAR for rigid PCB LWA10g picture; Figure 7 The transmission efficiency curve of LWA on a rigid PCB board; Figure 8 B1 for flexible LWA + Field distribution map; Figure 9 SAR for flexible LWA 10g picture; Figure 10 The transmission efficiency curve for flexible LWA; Figure 11 The simulation diagram is for a flexible LWA. Figure 12 This is a simulation diagram of a rigid PCB board LWA.

[0026] Reference numerals: 1 is the transmission line, 2 is the isolation pad, 3 is the LWA structural layer, 4 is the first dielectric substrate, 5 is the second dielectric substrate, 6 is the annular groove, 7 is the disk, and 8 is the flexible layer. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: Example 1 like Figures 1-12 As shown, a flexible leaky wave antenna for uniform and efficient radio frequency transmission in ultra-high field MRI includes a double-layer dielectric substrate, a transmission line 1, an isolation pad 2, and an LWA structure layer 3. The double-layer dielectric substrate includes a first dielectric substrate 4 and a second dielectric substrate 5. The transmission line 1 includes a first copper layer, which is laid on the upper surface of the first dielectric substrate 4. An isolation pad 2 is disposed between the first dielectric substrate 4 and the second dielectric substrate 5 to form a spaced arrangement of the double-layer dielectric substrate. The LWA structure layer 3 includes a second copper layer. Six equally spaced annular grooves 6 of the same size are formed on the LWA structure layer 3. A disk 7 is embedded in each of the six annular grooves 6. The LWA structure layer 3 is disposed below the isolation pad 2 and is attached to the second dielectric substrate 5. A flexible layer 8 made of segmented high-dielectric flexible material is disposed below the second dielectric substrate 5.

[0028] The flexible layer 8 comprises four parts with different dielectric constants. The flexible layer 8 includes a first part, a second part, a third part, and a fourth part. The first part, the second part, the third part, and the fourth part have the same width but different lengths. The flexible layer 8 is made of a flexible composite material synthesized from different chemical materials, specifically acrylamide, N,N'-methylenebisacrylamide, formamide, ammonium persulfate, and barium titanate.

[0029] By using materials with different dielectric constants, B1 can be made... +The field distribution is more uniform. Furthermore, materials with high dielectric constants can reduce the antenna wavelength, as shown in formula (1): (1); in, Where is the dielectric constant. The wavelength. By increasing the dielectric constant of the material. , The wavelength will decrease.

[0030] In order to adjust B1 + To improve the uniformity of the field distribution and enhance the transmission efficiency of LWA, in this embodiment: the width of the first part, the second part, the third part, and the fourth part is 85mm, the length of the first part is 154mm, the dielectric constant is 210, the length of the second part is 106mm, the dielectric constant is 80, the length of the third part is 70mm, the dielectric constant is 170, and the length of the fourth part is 120mm, the dielectric constant is 60.

[0031] Both the first copper layer and the second copper layer are made of flexible printed circuit boards (FPCs), which are circuit boards made of flexible substrates (such as polyimide or polyester film) and have the characteristics of being bendable and foldable.

[0032] The first dielectric substrate 4 and the second dielectric substrate 5 are made of a composite material or a low-conductivity rubber pad. The composite material is specifically made of acrylamide, N,N'-methylenebisacrylamide, formamide, ammonium persulfate and barium titanate.

[0033] The copper layer thickness of the transmission line 1 and the LWA structure layer 3 is adapted to the operating frequency requirements of 7T ultra-high field MRI.

[0034] A schematic diagram of an energy cycle system is shown below. Figure 3 As shown.

[0035] A design method for a flexible leaky-wave antenna for uniform and efficient radio frequency transmission in ultra-high field MRI includes the following steps: Step 1: Select materials for bilayer dielectric substrates based on relative permittivity, loss tangent, and cost. Step 2: Based on the operating frequency of 7T and the approximate size of the actual human body imaging calculation model, perform preliminary simulation on the initial model; Step 3: After obtaining the desired result in Step 2, based on the design requirements of flexible fit to the human body, determine the material, dielectric constant and size of each segment of the flexible layer 8; Step 4: Based on the design of flexible LWA with high transmission efficiency and B1 +The uniform field distribution characteristic determines the use of a ring structure to form an energy circulation system, improving transmission efficiency and B1. + Field uniformity; Step 5: By observing the simulation results, find ways to change B1. + Key parameters for field uniformity and transmission efficiency to achieve B1 in flexible LWA + Uniform field distribution and high transmission efficiency; Step 6: Establish a full simulation model, perform small-scale optimizations to enhance the performance of the flexible LWA, obtain the results, and complete the design.

[0036] In step 2, the size of the human body imaging calculation model is constructed based on common clinical human body shape data to ensure the compatibility of the antenna with the human body curve.

[0037] The key parameters mentioned in step 5 include the diameter of the annular groove 6, the material of the flexible layer 8, the dielectric constant and size of each segment, and the width of the transmission line 1.

[0038] The initial model described in step 2 is to first fabricate a leaky antenna on a rigid PCB board. The LWA structure layer 3 and transmission line 1 of the leaky antenna on the rigid PCB board are simulated using the parameters of the rigid PCB board. The first dielectric substrate 4 and the second dielectric substrate 5 are made of R04003C material, and the flexible layer 8 is made of HPP material.

[0039] The simulation software used in steps 1-6 is Sim4Life.

[0040] To facilitate understanding, the following simulation experiments were conducted in conjunction with the accompanying drawings. First, the LWA of the rigid PCB board designed after step 2 was simulated, and then the flexible LWA was also simulated.

[0041] Figure 4 B1 for rigid PCB board LWA + Field distribution diagram. As can be seen from the field distribution pattern, B1 + The field strength along the antenna's longitudinal direction (the direction of the human body's long axis) varies significantly, exhibiting a non-uniform characteristic of high field strength near the coil and low field strength further away from the coil. There are abrupt changes in field strength in some areas (such as strong tomography at the edges). (B1 of the rigid PCB LWA...) + The field is not uniform, resulting in differences in MR signal intensity at different locations within the imaging area.

[0042] Figure 5 B1 for rigid PCB board LWA + Line graph of electric field strength. The electric field strength values ​​fluctuate dramatically, with the vertical axis showing a range of approximately 0.1 × 10⁻⁻⁻⁶. 6 T~1.2×10⁻ 6 T, the difference in field intensity at different spatial locations can reach an order of magnitude, quantitatively verifying B1. +Field inhomogeneity. In the edge region beyond ±400 mm of the horizontal axis, the field strength rapidly decreases to 0.3 × 10⁻⁻⁻⁶. 6 Below T indicates that the effective imaging range of traditional rigid antennas is limited, and the signal strength in the edge region is insufficient.

[0043] Figure 6 SAR for rigid PCB LWA 10g Figure. Represents specific absorptivity (average absorbed power of 10g continuous tissue), peak SAR. 10g The peak power is 1.16048 W / kg, with peak position coordinates (-0.0005, -0.0155, 0.1705). Rigid antennas cannot be fitted to the human body; the air gap between the antenna and the skin causes radio frequency energy to focus in a localized area, increasing the risk of localized thermal effects and indirectly affecting imaging stability.

[0044] Figure 7 This is a graph showing the transmission efficiency of a rigid PCB LWA. The horizontal axis represents frequency, and the vertical axis represents efficiency. The rigid PCB LWA operates at a frequency of 300MHz in a 7TMRI. Based on the trend of the curve, it can be inferred that the transmission efficiency of a traditional rigid antenna is less than 90% near 300MHz.

[0045] Figure 8 B1 for flexible LWA + Field distribution map, and Figure 4 In comparison, the field distribution uniformity is improved. The radio frequency field exhibits a continuous and stable distribution along the longitudinal direction (the long axis of the human body), with no obvious abrupt changes in field strength, and the difference in field strength between the edge and center regions is reduced. The segmented high-dielectric flexible material conforms to the human body, optimizing the penetration depth of the field strength in different tissues. Uniform B1 + The field ensures that the MR signal intensity is consistent across all parts of the imaging area, improving image contrast and resolution and reducing artifacts.

[0046] Figure 9 SAR for flexible LWA 10g Figure. SAR with flexible antenna. 10g Peak test results table, and Figure 6 This creates a contrast. Peak SAR 10g The energy density is 1.55181 W / kg, and the peak position coordinates are (-0.312645, 0.197807, 1.21391) m; the new antenna has a more uniform energy distribution and a more dispersed peak area.

[0047] Uniform energy radiation disperses SAR values ​​over a wider area, reducing the risk of local tissue damage.

[0048] Figure 10 The transmission efficiency curve of flexible LWA is shown in the figure. Figure 7In contrast, the 7TMRI operating frequency has a transmission efficiency ≥90% (judging from the vertical axis of the curve in the range of 0.8~1.0, it is close to 1.0), and the efficiency curve is stable with no obvious fluctuations.

[0049] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention should be included within the scope of the present invention.

Claims

1. A flexible leaky-wave antenna for uniform and efficient radio frequency transmission in ultra-high field MRI, characterized in that, The application relates to a flexible leaky-wave antenna (LWA) structure, which comprises a double-layer dielectric substrate, a transmission line (1), an isolation pad (2) and an LWA structure layer (3), the double-layer dielectric substrate comprises a first dielectric substrate (4) and a second dielectric substrate (5), the transmission line (1) comprises a first copper layer, the first copper layer is laid on the upper surface of the first dielectric substrate (4), the isolation pad (2) is arranged between the first dielectric substrate (4) and the second dielectric substrate (5) to form a double-layer dielectric substrate, the LWA structure layer (3) comprises a second copper layer, six circular ring grooves (6) of the same size are equidistantly arranged on the LWA structure layer (3), and a disc (7) is embedded in each of the six circular ring grooves (6), the LWA structure layer (3) is arranged below the isolation pad (2) and is attached to the second dielectric substrate (5), and a flexible layer (8) made of a segmented high-dielectric flexible material is arranged below the second dielectric substrate (5).

2. A flexible leaky-wave antenna for uniform and efficient radio frequency transmission in ultra-high field MRI according to claim 1, characterized in that, The flexible layer (8) comprises four parts with different dielectric constants, the flexible layer (8) comprises a first part, a second part, a third part and a fourth part, the first part, the second part, the third part and the fourth part have the same width and different lengths, and the flexible layer (8) is made of a soft synthetic material synthesized by different chemical materials.

3. A flexible leaky-wave antenna for uniform and efficient radio frequency transmission in ultra-high field MRI according to claim 1, characterized in that, The first copper layer and the second copper layer are both composed of a flexible circuit board. The first dielectric substrate (4) and the second dielectric substrate (5) are made of a synthetic material or a low-conductivity rubber pad.

4. A flexible leaky-wave antenna for uniform and efficient radio frequency transmission in ultra-high field MRI according to claim 1, characterized in that, The thickness of the copper layers of the transmission line (1) and the LWA structure layer (3) is adapted to the working frequency requirement of the 7T ultra-high field MRI.

5. A method of flexible leaky-wave antenna design for uniform and efficient radio frequency transmission in ultra-high field MRI, characterized in that, The application comprises the following steps: Step 1: screening the material of the double-layer dielectric substrate based on the relative dielectric constant, the loss tangent and the cost index; Step 2: performing preliminary simulation on the initial model according to the working frequency of the 7T and the approximate size of the actual human body imaging calculation model; Step 3: determining the material, the dielectric constant and the size of each segment of the flexible layer (8) based on the design requirement of the flexible attachment to the human body after obtaining the ideal result in step 2; Step 4: Design flexible LWA high transmission efficiency and B1 + The characteristic of uniform field distribution determines the circular ring structure to form an energy circulation system to improve transmission efficiency and B1 + Field uniformity; Step 5: Find the key parameters to change B1 + field uniformity and transmission efficiency to achieve B1 + field distribution uniform and high transmission efficiency; Step 6: establishing a full simulation model, performing small-range optimization, enhancing the performance of the flexible LWA, obtaining the result and completing the design.

6. A flexible leaky-wave antenna design method for uniform and efficient radio frequency transmission in ultra-high field MRI according to claim 5, characterized in that, The size of the human body imaging calculation model in step 2 is constructed based on the clinical common human body type data, so as to ensure the adaptability of the antenna to the human body curve.

7. A flexible leaky-wave antenna design method for uniform and efficient radio frequency transmission in ultra-high field MRI as claimed in claim 5, wherein, The key parameters in step 5 include the diameter of the circular ring groove (6), the material, the dielectric constant and the size of each segment of the flexible layer (8) and the width of the transmission line (1).

8. A flexible leaky-wave antenna design method for uniform and efficient radio frequency transmission in ultra-high field MRI as claimed in claim 5, wherein, The initial model in step 2 is a leaky-wave antenna made of a hard PCB board, the LWA structure layer (3) and the transmission line (1) of the leaky-wave antenna made of the hard PCB board are simulated by using the hard PCB board parameters, the first dielectric substrate (4) and the second dielectric substrate (5) are made of R04003C material, and the flexible layer (8) is made of HPP material.

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