A Ka- and S-band radio frequency module for airborne satellite communication antennas

Abstract

The present invention belongs to the field of high-frequency satellite communications technology, and in particular relates to a Ka- and S-band radio frequency module for airborne satellite communication antennas. The module comprises a multilayer structure, including multiple signal layers, multiple ground layers, at least one power layer, and at least one control layer. The signal layer is formed by laminating low-loss materials, Rogers RT / duroid 5880 and Taconic TLY-5, with interlayer signal interconnection achieved through blind and buried vias. The ground layer utilizes a double-layer copper foil structure, with a honeycomb copper pattern applied to its surface, the holes of which are staggered with the blind and buried vias of the signal layer. The power layer utilizes a PTFE substrate, on which a π-type filter network is mounted via surface mounting. The control layer utilizes an FR4 substrate, on which an impedance-matching microstrip line is provided. The module's dimensions do not exceed 50 mm × 50 mm × 5 mm, and its weight does not exceed 50 grams. This module overcomes the performance bottlenecks of traditional radio frequency modules, achieving a combination of miniaturization, high performance, and strong environmental adaptability.

Description

Technical Field

[0001] This invention belongs to the field of high-frequency satellite communications technology, and more particularly relates to a Ka- and S-band radio frequency module for airborne satellite communication antennas. Specifically, it relates to a radio frequency module designed specifically for airborne platforms (such as commercial aircraft, military drones, and high-altitude balloon communication platforms). Background Art

[0002] With advancements in airborne satellite communications technology, Ka-band and S-band have become mainstream frequency bands due to their high bandwidth and high data rates (Ka-band can reach hundreds of Mbps, S-band tens of Mbps). However, existing RF modules commonly encounter the following technical bottlenecks in high-frequency applications, as exemplified by traditional designs such as the Honeywell HTS-9000 series:

[0003] 1. Traditional designs mostly use FR4 substrates (dielectric constant ≈ 4.5, loss factor tanδ ≈ 0.02@10GHz), which have an insertion loss of up to 2.5-3.0 dB in the Ka-band (30GHz), resulting in low signal transmission efficiency and energy loss of approximately 40%-50%.

[0004] Second, the ground layer copper foil thickness is insufficient (≤20µm), resulting in a shielding effectiveness of only about 20 dB and an isolation as low as -20dB. This makes it susceptible to electromagnetic noise in airborne environments (such as coexistence of multiple devices and radar interference), increasing the bit error rate by about 5%-10%.

[0005] 3. The module size is usually ≥100mm×100mm×10mm and the weight is ≥100g, which exceeds the lightweight design requirements of the airborne platform (ideal weight <60g), limiting its application on platforms such as small drones.

[0006] 4. Under high temperature (>85°C) or vibration (>10G) conditions, the FR4 substrate's coefficient of thermal expansion (CTE≈50 ppm / °C) is too high, resulting in impedance mismatch, phase shift ≥10°, and performance degradation ≥10%, failing to meet aviation standards (such as MIL-STD-810G).

[0007] Existing technologies lack customized and optimized designs tailored to the characteristics of the Ka- and S-bands, making it difficult to achieve a balance between miniaturization, low loss, high anti-interference capabilities, and environmental adaptability. Therefore, an innovative RF module design is urgently needed to overcome these limitations and promote the further development of airborne satellite communication technology. Summary of the Invention

[0008] The present invention aims to overcome the defects in the prior art and provides a Ka and S band radio frequency module for an airborne satellite communication antenna.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a Ka- and S-band radio frequency module for an airborne satellite communication antenna, comprising: a multi-layer structure including multiple signal layers, multiple ground layers, at least one power layer, and at least one control layer; wherein the signal layer is formed by laminating low-loss materials Rogers RT / duroid 5880 and Taconic TLY-5, and inter-layer signal interconnection is achieved through blind and buried vias.

[0010] The ground layer adopts a double-layer copper foil structure, and a honeycomb copper pattern is laid on its surface. The holes of the honeycomb copper pattern are staggered with the blind holes and buried holes of the signal layer to enhance the electromagnetic shielding effectiveness.

[0011] The power layer adopts a PTFE substrate, and a π-type filter network is installed on the surface of the PTFE substrate through surface mounting. The π-type filter network is electrically connected to the signal layer through buried holes.

[0012] The control layer adopts an FR4 substrate, and an impedance-matching microstrip line is arranged on the surface of the FR4 substrate. The microstrip line forms a continuous impedance transition structure with the signal layer through a blind hole.

[0013] Among them, the size of the RF module does not exceed 50mm×50mm×5mm, and the weight does not exceed 50 grams.

[0014] Furthermore, the layout of the blind and buried vias is determined by genetic algorithm optimization, which specifically includes the following steps:

[0015] S1. Build a three-dimensional grid model of the RF module, abstracting the signal layer, ground layer, power layer, and control layer into a three-dimensional space grid. Each grid node represents a potential blind or buried via location.

[0016] S2. Set constraints, including:

[0017] Constraint 1: The center distance between any two blind or buried vias must be ≥0.2mm.

[0018] Constraint 2: The center of the blind and / or buried vias must be at least 0.5 mm away from the physical edge of the module.

[0019] Constraint three: The blind and buried vias on the signal layer must be staggered with the honeycomb copper pattern on the ground layer.

[0020] S3. Based on the three-dimensional grid model, generate multiple initial layout plans of blind and buried vias that meet the constraints of S2.

[0021] S4. Calculate the node importance of blind and buried vias; that is, evaluate the importance of each via position to signal transmission and screen key nodes.

[0022] S5. Perform performance calculations to supplement the correlation of key vias. Specifically, for each initial layout solution, calculate the path length L and impedance matching error E of the signal from the starting point to the end point. Prioritize ensuring the path connectivity of key vias. For the path length L, all key vias must be passed from the starting point to the end point before calculating the total length. For the impedance error E, focus on accumulating the impedance mismatch component of the key vias.

[0023] S6. Iteratively optimize the blind and buried via layout based on the genetic algorithm and select the optimal solution. After completing the previous steps to obtain multiple initial layout solutions that meet the physical constraints, use the genetic algorithm to perform global search optimization on the layout solutions, and use the objective function F=αL+βE as the fitness function to select the optimal blind and buried via layout solution. Among them, α represents the weight of the path length, and β represents the weight of the impedance error. The value range is [0, 1], and α+β=1.

[0024] Furthermore, step S4 specifically includes:

[0025] S4.1. Initialize the grid nodes corresponding to potential blind and buried vias, and set the initial importance of all blind and buried via nodes: S(0) = 1; ensure that all hole positions have equal importance in the initial optimization stage.

[0026] S4.2. Iteratively calculate the importance of key nodes.

[0027] The iterative calculation formula for node importance is: S(n+1)=ΣS(t)*w.

[0028] Where w is the weight coefficient between adjacent nodes, which is determined by the path length and impedance matching error; n represents the current iteration number, and t represents the number of adjacent nodes directly connected to the current node. When all nodes satisfy max|S(n+1)−S(n)|<0.01, the importance is considered to have converged and the iteration is terminated.

[0029] S4.3. Record the importance S of each node, and sort the importance S of each node in ascending order, calculate the ranking ratio value r / N, where the ranking number of a node is recorded as r and the total number of nodes is recorded as N; and select the nodes with large ratio values ​​as the key blind and buried via locations.

[0030] After the node importance converges, the importance values ​​S of all grid nodes are sorted in ascending order to generate the corresponding sorting number r; where r=1 represents the node with the lowest importance, r=N represents the node with the highest importance, and N is the total number of nodes.

[0031] Then calculate the sorting ratio value r / N of each node, and select the node with the largest sorting ratio value as the key blind via and buried via position, that is, the key hole position.

[0032] Furthermore, the microstrip line includes a gradient section, the line width of the gradient section gradually changes along the signal path, and the gradient section is connected to the signal layer through a blind hole to achieve continuous impedance transition.

[0033] Furthermore, the manufacturing process of the RF module includes: laser pre-drilling of blind and buried vias before lamination to ensure high-precision positioning; and lamination after filling the holes with conductive material to form a stable interlayer connection; wherein the lamination temperature is 200°C and the lamination pressure is 10Mpa; and chemical nickel-gold plating is performed after the microstrip line is formed to improve welding reliability and corrosion resistance.

[0034] Furthermore, the insertion loss of the RF module in the Ka band does not exceed 0.38dB, the insertion loss in the S band does not exceed 0.12dB, the isolation is not less than -35dB, and the shielding effectiveness is not less than 40dB.

[0035] Compared with the prior art, the present invention has beneficial effects.

[0036] The present invention breaks through the performance bottleneck of traditional RF modules through the systematic integration of material selection, interlayer structure optimization and anti-interference design, achieves the unity of miniaturization, high performance and strong environmental adaptability, and meets the stringent requirements of airborne satellite communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention is further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.

[0038] Figure 1 Schematic diagram of a 6-layer radio frequency module in Example 2.

[0039] Figure 2 It is a schematic diagram of the honeycomb ground plane design.

[0040] Figure 3 It is a schematic diagram of the stepped impedance transition structure. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and beneficial effects of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0042] like Figure 2-3 As shown, a Ka- and S-band radio frequency module for an airborne satellite communication antenna includes:

[0043] The multi-layer structure includes multiple signal layers, multiple ground layers, at least one power layer, and at least one control layer. The signal layer is formed by laminating low-loss materials Rogers RT / duroid 5880 and Taconic TLY-5, and inter-layer signal interconnection is achieved through blind and buried vias.

[0044] The ground layer adopts a double-layer copper foil structure, and a honeycomb copper pattern is laid on its surface. The holes of the honeycomb copper pattern are staggered with the blind holes and buried holes of the signal layer to enhance the electromagnetic shielding effectiveness.

[0045] The power layer adopts a PTFE substrate, and a π-type filter network is installed on the surface of the PTFE substrate through surface mounting (SMT). The π-type filter network is electrically connected to the signal layer through buried holes.

[0046] The control layer adopts an FR4 substrate, and an impedance-matching microstrip line is arranged on the surface of the FR4 substrate. The microstrip line forms a continuous impedance transition structure with the signal layer through a blind hole.

[0047] Among them, the size of the RF module does not exceed 50mm×50mm×5mm, and the weight does not exceed 50 grams.

[0048] Preferably, the layout of the blind vias and buried vias is determined by genetic algorithm optimization, which specifically includes the following steps:

[0049] S1. Build a three-dimensional grid model of the RF module, abstracting the signal layer, ground layer, power layer, and control layer into a three-dimensional space grid. Each grid node represents a potential blind or buried via location.

[0050] S2. Set constraints, including:

[0051] Constraint 1: The center distance between any two blind or buried vias must be ≥0.2mm to avoid short circuits or signal interference caused by processing errors.

[0052] Constraint 2: The center of the blind and / or buried vias must be at least 0.5 mm away from the physical edge of the module to prevent material cracking or hole damage during lamination.

[0053] Constraint three: Blind and buried vias on the signal layer must be staggered with the honeycomb copper pattern on the ground layer; avoid direct overlap to reduce electromagnetic leakage or impedance discontinuity.

[0054] S3. Based on the three-dimensional grid model, generate multiple initial layout plans of blind vias and buried vias that meet the constraints of S2.

[0055] S4. Calculate the node importance of blind and buried vias; that is, evaluate the importance of each via position to signal transmission and screen key nodes.

[0056] S5. Perform performance calculations to supplement the correlation of key vias. Specifically, for each initial layout solution, calculate the path length L and impedance matching error E of the signal from the starting point to the end point. Priority should be given to ensuring the path connectivity of key vias (nodes screened in S4). For the path length L, the path from the starting point to the end point must pass through all key vias before calculating the total length. For the impedance error E, focus on accumulating the impedance mismatch component near the key vias.

[0057] S6. Iteratively optimize the blind and buried via layout based on the genetic algorithm and select the optimal solution. After completing the previous steps to obtain multiple initial layout solutions that meet the physical constraints, use the genetic algorithm to perform global search optimization on the layout solutions, and use the objective function F=αL+βE as the fitness function to select the optimal blind and buried via layout solution. Among them, α represents the weight of the path length, and β represents the weight of the impedance error. The value range is [0, 1], and α+β=1.

[0058] Preferably, step S4 specifically includes:

[0059] S4.1. Initialize the grid nodes corresponding to potential blind and buried vias, and set the initial importance of all blind and buried via nodes: S(0) = 1; ensure that all hole positions have equal importance in the initial optimization stage.

[0060] S4.2. Iteratively calculate the importance of key nodes.

[0061] The iterative calculation formula for node importance is: S(n+1)=ΣS(t)*w.

[0062] Where w is the weight coefficient between adjacent nodes, which is determined by the path length and impedance matching error; n represents the current iteration number, and t represents the adjacent nodes directly connected to the current node; it is determined based on the electrical connection relationship of the three-dimensional mesh model.

[0063] When all nodes satisfy max|S(n+1)−S(n)|<0.01, the importance is determined to have converged and the iteration is terminated.

[0064] S4.3. Record the importance S of each node, and sort the importance S of each node in ascending order, calculate the ranking ratio value r / N, where the ranking number of a node is recorded as r and the total number of nodes is recorded as N; and select the nodes with large ratio values ​​as the key blind and buried via locations.

[0065] After the node importance converges, the importance values ​​S of all grid nodes are sorted in ascending order to generate the corresponding sorting number r; where r=1 represents the node with the lowest importance, r=N represents the node with the highest importance, and N is the total number of nodes.

[0066] Then calculate the ranking ratio value r / N of each node, and select the nodes with large ranking ratio values ​​as the key blind and buried via locations, that is, the key hole positions; the nodes with r / N close to 1 represent that they are ranked high in importance and have a more critical impact on signal transmission and impedance matching.

[0067] Preferably, the microstrip line includes a gradient segment, the line width of the gradient segment changes gradually along the signal path, and the gradient segment is connected to the signal layer through a blind hole to achieve continuous impedance transition.

[0068] Preferably, the manufacturing process of the RF module includes: laser pre-drilling of blind holes and buried holes before lamination to ensure high-precision positioning; and lamination after filling the holes with conductive material to form a stable interlayer connection; wherein the lamination temperature is 200°C and the lamination pressure is 10 MPa; and chemical nickel-gold plating is performed after the microstrip line is formed to improve welding reliability and corrosion resistance.

[0069] Preferably, the insertion loss of the RF module in the Ka band does not exceed 0.38dB, the insertion loss in the S band does not exceed 0.12dB, the isolation is not less than -35dB, and the shielding effectiveness is not less than 40dB.

[0070] In embodiment 1, step S6 specifically includes:

[0071] S6.1. Define the fitness function. Construct the objective function based on the signal path length L and the impedance error E near key vias: F = αL + βE. α and β are weighting coefficients for path length and impedance error, respectively, ranging from 0 to 1, and α + β = 1. The weighting coefficients can be calibrated based on expert experience or experimental data, prioritizing connectivity and low impedance mismatch at key vias. L is the total path length from the starting point to the end point through all key vias. E is the sum of the impedance mismatch components near each key via.

[0072] S6.2. Initialize the population and perform genetic operations: Use the multiple initial layout schemes generated in S3 as the initial population; each individual code represents a complete blind and buried via layout (binary or real number coding can be used to indicate whether each grid node is perforated); perform genetic operations on the population, including selection, crossover, and mutation, to generate a new generation of individuals.

[0073] S6.3. Evaluate and select the best individuals: Calculate the objective function value F of each generation of individuals and retain the best individual of the current generation; if the change in the F value for several consecutive generations is less than the preset threshold ε (such as 0.001), the algorithm is considered to have converged and the optimization is terminated; otherwise, continue to iterate until the maximum number of iterations is reached.

[0074] S6.4. Output the optimal layout plan: Output the blind and buried via layout plan with the best fitness in the final convergence state.

[0075] Example 2, as Figure 1 As shown, the UAV-mounted RF module.

[0076] 1. Prototype parameters:

[0077] Number of layers: 6 layers (2 signal layers + 2 ground layers + 1 power layer + 1 control layer).

[0078] Dimensions: 50mm×50mm×5mm.

[0079] Weight: 48 g.

[0080] Operating frequency bands: Ka-band (28 GHz), S-band (3.5 GHz).

[0081] 2. Layer structure design:

[0082] Signal layer: Material: Rogers RT / duroid 5880 and Taconic TLY-5 alternately laminated.

[0083] Insertion loss: 0.35dB@28 GHz, 0.10 dB@3.5 GHz.

[0084] Ground layer: double-layer copper foil (total thickness 70 µm), honeycomb copper.

[0085] Shielding effectiveness: ≥40 dB@28 GHz.

[0086] Power layer: PTFE substrate, embedded with π-type filter network.

[0087] Noise level: ≤-60dBm.

[0088] Control layer: FR4 substrate, 50Ω microstrip line design.

[0089] Crosstalk: ≤-55dB.

[0090] Signal path: optimized by genetic algorithm, length 9.7 mm (35% reduction).

[0091] 3. Manufacturing process:

[0092] Lamination process: Use a high temperature and high pressure laminator (temperature 200°C, pressure 10MPa), and the interlayer bonding strength is ≥1.5 N / mm.

[0093] Imaging and drilling:

[0094] Laser direct imaging (LDI) with linewidth accuracy of ±5 µm.

[0095] UV laser drilling (wavelength 355 nm), blind and buried vias with an accuracy of ±2 µm, filled with nano-silver paste.

[0096] Surface treatment: Chemical nickel-gold plating (nickel thickness 3 µm, gold thickness 0.05 µm) to improve welding reliability.

[0097] 4. Performance verification: Simulation tool: ANSYS HFSS v19.2.

[0098] Test equipment: Vector network analyzer (Keysight N5247B, frequency range 10 MHz-67 GHz).

[0099] Environmental test chamber (temperature -55°C to 125°C, humidity 0-95% RH).

[0100] Comparison results: Ka-band (28 GHz):

[0101] Traditional FR4 module: insertion loss 2.8 dB, return loss -10 dB, isolation -20 dB.

[0102] The present invention has an insertion loss of 0.35 dB, a return loss of -18 dB, and an isolation of -35 dB.

[0103] S-band (3.5 GHz): Traditional FR4 module: insertion loss 0.5 dB, return loss -12 dB, isolation -25 dB.

[0104] The present invention has an insertion loss of 0.12 dB, a return loss of -22 dB, and an isolation of -40 dB.

[0105] Environmental testing: High temperature and high humidity (85°C / 85% RH, 1000 hours): Performance degradation of 0.8%.

[0106] Vibration (20G, 10-2000 Hz): impedance change 0.3%.

[0107] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "preferred embodiments," "specific implementations," or "preferred implementations" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0108] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. Therefore, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of the present invention.

Claims

1. A Ka and S band radio frequency module for an airborne satellite communication antenna, characterized in that: include: A multi-layer structure comprising a plurality of signal layers, a plurality of ground layers, at least one power layer and at least one control layer; wherein, The signal layer is formed by laminating low-loss materials Rogers RT / duroid 5880 and Taconic TLY-5, and inter-layer signal interconnection is achieved through blind and buried vias; The ground layer adopts a double-layer copper foil structure, and a honeycomb copper pattern is laid on its surface. The holes of the honeycomb copper pattern are staggered with the blind and buried vias of the signal layer to enhance the electromagnetic shielding effectiveness. The power layer adopts a PTFE substrate, on which a π-type filter network is installed by surface mounting. The π-type filter network is electrically connected to the signal layer through buried vias. The control layer uses an FR4 substrate, and an impedance-matched microstrip line is set on the surface of the FR4 substrate. The microstrip line forms a continuous impedance transition structure with the signal layer through a blind hole; Among them, the size of the RF module does not exceed 50mm×50mm×5mm, and the weight does not exceed 50 grams.

2. The Ka- and S-band radio frequency module for an airborne satellite communication antenna according to claim 1, characterized in that: The layout of blind and buried vias is determined by genetic algorithm optimization, which includes the following steps: S1. Build a three-dimensional grid model of the RF module, abstracting the signal layer, ground layer, power layer, and control layer into a three-dimensional space grid, where each grid node represents a potential blind or buried via location; S2. Set constraints, including: Constraint 1: The center distance between any two blind or buried vias must be ≥0.2mm; Constraint 2: The center of the blind and / or buried vias must be at least 0.5 mm away from the physical edge of the module. Constraint 3: The blind and buried vias on the signal layer must be staggered with the honeycomb copper pattern on the ground layer; S3. Based on the 3D mesh model, generate multiple initial layout plans of blind and buried vias that meet the constraints of S2; S4. Calculate the node importance of blind and buried vias; that is, evaluate the importance of each via position to signal transmission and select key nodes; S5. Perform performance calculations to supplement the correlation of key vias. Specifically, for each initial layout solution, calculate the path length L and impedance matching error E of the signal from the starting point to the end point. Prioritize ensuring the path connectivity of key vias. For the path length L, the path from the starting point to the end point must pass through all key vias before calculating the total length. For the impedance error E, focus on accumulating the impedance mismatch component of the key vias. S6. Iteratively optimize the blind and buried via layout based on the genetic algorithm and select the optimal solution. After completing the previous steps to obtain multiple initial layout solutions that meet the physical constraints, use the genetic algorithm to perform global search optimization on the layout solutions, and use the objective function F = αL + βE as the fitness function to select the optimal blind and buried via layout solution. Among them, α represents the weight of the path length, and β represents the weight of the impedance error. The value range is [0, 1], and α + β = 1.

3. The Ka- and S-band radio frequency module for an airborne satellite communication antenna according to claim 2, characterized in that: Step S4 specifically includes: S4.

1. Initialize the grid nodes corresponding to potential blind and buried vias, and set the initial importance of all blind and buried via nodes: S(0) = 1; ensure that all via positions have equal importance in the initial optimization stage; S4.2, iteratively calculate the importance of key nodes; The iterative calculation formula of node importance is: S(n+1)=ΣS(t)*w; Where w is the weight coefficient between adjacent nodes, which is determined by the path length and impedance matching error; n represents the current iteration number, and t represents the adjacent nodes directly connected to the current node; When all nodes satisfy max|S(n+1)−S(n)|<0.01, the importance is determined to have converged and the iteration is terminated; S4.

3. Record the importance S of each node and sort the importance S of each node in ascending order. Calculate the ranking ratio r / N, where the ranking number of a node is r and the total number of nodes is N. Select the nodes with the largest ratio as the key blind and buried via locations. After the node importance converges, the importance values ​​S of all grid nodes are sorted in ascending order to generate the corresponding sorting number r; where r=1 represents the node with the lowest importance, r=N represents the node with the highest importance, and N is the total number of nodes; Then calculate the sorting ratio value r / N of each node, and select the node with the largest sorting ratio value as the key blind via and buried via position, that is, the key hole position.

4. The Ka- and S-band radio frequency module for an airborne satellite communication antenna according to claim 1, characterized in that: The microstrip line includes a gradient section, the line width of which gradually changes along the signal path. The gradient section is connected to the signal layer through a blind hole to achieve continuous impedance transition.

5. The Ka and S band radio frequency module for an airborne satellite communication antenna according to claim 1, characterized in that: The manufacturing process of the RF module includes: Before lamination, blind and buried vias are laser pre-drilled to ensure high-precision positioning. The holes are filled with conductive material before lamination to form stable interlayer connections. The lamination temperature is 200°C and the lamination pressure is 10 MPa. After the microstrip line is formed, chemical nickel-gold plating is performed to improve welding reliability and corrosion resistance.

6. The Ka- and S-band radio frequency module for an airborne satellite communication antenna according to claim 1, characterized in that: The insertion loss of the RF module in the Ka band does not exceed 0.38dB, the insertion loss in the S band does not exceed 0.12dB, the isolation is not less than -35dB, and the shielding effectiveness is not less than 40dB.

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