A feeding network system

Abstract

The present invention discloses a feed network system, belonging to the field of antenna feeding technology. It comprises four 2x2 rectangular arrays of equal-amplitude, 90° network sub-arrays and a power combining network composed of a four-in-one Wilkinson power combiner located at the bottom of the sub-arrays. The four arrays of equal-amplitude, 90° network sub-arrays achieve signal synthesis output through a cascaded four-in-one Wilkinson power combiner. The equal-amplitude, 90° network sub-arrays comprise a first metal ground plate, a first microwave substrate, a first metal signal line, a first prepreg, a second microwave substrate, a second metal ground plate, a second prepreg, a second metal signal line, a third microwave substrate, and a third metal ground plate, stacked sequentially from top to bottom. The microwave substrates are bonded together by prepregs, thereby achieving a feed network capable of connecting four feed points with right-handed equal-amplitude, 90° antenna signals. The present invention reduces the horizontal and lateral dimensions of the feed network, achieving miniaturization and high integration of the antenna array.

Description

Technical Field

[0001] The present invention relates to the field of antenna feeding technology, and in particular to a feeding network system suitable for a high-density vertical interconnection technology PCB. Background Art

[0002] Currently, most feed networks use a power combiner plus a phase-shifting line. The dispersion effect of the phase-shifting line is obvious, and the influence of the phase-shifting line on the phase is only targeted at a certain frequency point or within a very narrow bandwidth. The structure is not symmetrical and unified, and the reconfigurability is poor.

[0003] The current LTCC and HTCC processes are complex, requiring layer-by-layer fabrication and presenting numerous design reliability challenges. The shrinkage and thermal expansion coefficient of the substrate and wiring during co-firing present a significant challenge, primarily manifesting in three key areas: inconsistent densification temperatures; inconsistent shrinkage between the substrate and the slurry; and mismatched densification rates. These mismatches can easily lead to surface unevenness, warping, and delamination of the substrate after firing. Another consequence of this mismatch is decreased adhesion of the metal wiring. LTCC substrates are fragile and have low thermal conductivity, making heat dissipation a key issue. Furthermore, the long processing cycle and high cost make them unsuitable for large-scale production within a short period of time.

[0004] At present, the stripline antenna feed network made by multi-layer microwave printed circuit boards is simple to process and manufacture, and the material microstructure is uniform, which can achieve low dielectric constant and low loss, and both thermal performance and mechanical properties are guaranteed. However, double-sided blind hole technology is rarely used, resulting in poor electromagnetic shielding effect, affecting the transmission of signals between multi-layer boards. In addition, most of them are single-layer planar structures with large sizes, which is not conducive to the development of miniaturization.

[0005] In 2021, Southeast University disclosed a phased array antenna feeding network, which was implemented using a high-density multi-layer mixed-pressure board, but only had single-sided blind hole processing technology, and did not realize double-sided blind hole and buried hole technology.

[0006] In the PCB processing technology, the ground hole must be at least 500um away from the edge of the buried resistor to ensure that the punching will not deviate to the buried resistor, which limits the design of the multi-layer microwave printed circuit board to the processing accuracy. Summary of the Invention

[0007] To address the problems in the above-mentioned background technology, the present invention proposes a feed network system that adopts a vertical three-dimensional stacking structure to reduce the horizontal dimensions of the feed network and achieve miniaturization and high integration of the antenna array.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A feed network system includes four equal-amplitude, 90-degree network sub-arrays arranged in a rectangular array and a power combining network located at the bottom of the network sub-arrays; the four equal-amplitude, 90-degree network sub-arrays are cascaded through a four-in-one Wilkinson power combiner to achieve signal synthesis output; the equal-amplitude, 90-degree network sub-arrays include a first metal ground plate, a first microwave substrate, a first metal signal line, a first prepreg, a second microwave substrate, a second metal ground plate, a second prepreg, a second metal signal line, a third microwave substrate, and a third metal ground plate, which are stacked in sequence from top to bottom; the microwave substrates are bonded together by prepregs;

[0010] The first and second bridges in the equal-amplitude, 90° network are both 90° bridges, and the ports of the first and second bridges are both located on the corresponding edge of the equal-amplitude, 90° network; the third bridge is a 180° bridge; the first and second differential ports of the first bridge and the third and fourth differential ports of the second bridge are respectively connected to the four feeding terminals corresponding to the antenna; the first combined port of the first bridge is connected to the fifth differential port of the third bridge, and the second combined port of the second bridge is connected to the sixth differential port of the third bridge; the third combined port of the third bridge is used to output antenna signals;

[0011] The first metal ground plate is connected to the second metal ground plate through a first metal shielding hole; the first metal ground plate is connected to the third metal ground plate through a second metal shielding hole, and the second metal shielding hole passes through the second metal ground plate.

[0012] Furthermore, the equal-amplitude, 90° network is a symmetrical structure.

[0013] Furthermore, the antenna is a microstrip antenna; the feeding network system is connected to the four feeding terminals of the microstrip antenna through an SSMP connector; and the constant amplitude, 90° network subarray is connected to the Wilkinson power combiner through the SSMP connector.

[0014] Furthermore, the first combined port of the first bridge and the fifth differential port of the third bridge are connected through corresponding second metallized RF holes; the second combined port of the second bridge and the sixth differential port of the third bridge are connected through corresponding second metallized RF holes.

[0015] Furthermore, the first difference port and the second difference port of the first bridge and the third difference port and the fourth difference port of the second bridge are respectively connected to the four feeding terminals corresponding to the antenna through the corresponding third metallized RF holes located above their respective ports; the third combined port of the third bridge outputs the antenna signal through the fourth metallized RF hole located below it.

[0016] Furthermore, the first differential port of the first bridge and the third combined port of the third bridge have their third metallized RF holes and fourth metallized RF holes offset from each other in axis, and share the second metallized shielding hole; the second combined port of the second bridge and the sixth differential port of the third bridge, as well as the first combined port of the first bridge and the fifth differential port of the third bridge, have their upper-layer metallized RF holes and lower-layer metallized RF holes with their axis coincident, and share the corresponding second metallized shielding hole.

[0017] Furthermore, the isolation ports of the first bridge, the second bridge and the third bridge are all grounded using sector-shaped metal; the radius of the sector-shaped metal is a quarter of a wavelength.

[0018] Furthermore, the third metallized RF hole is punched before the mixing and pressing, and the width of the pad ring is 3 mils;

[0019] The fourth metallized RF hole is punched before the secondary mixing process, and the width of the pad ring is 3 mils;

[0020] The second metallized RF hole is back-drilled after secondary mixing, and the width of the pad ring is 5 mils.

[0021] The beneficial effects of the above technical solution of the present invention are:

[0022] The feed network of this invention utilizes an entirely stripline structure. Because adjacent traces have metal floors on both upper and lower layers, energy leakage is minimal and virtually immune to interference from external circuits. Furthermore, the stripline structure's vertical, three-dimensional stacking reduces the horizontal dimensions of the feed network, enabling miniaturization and high integration of the antenna array.

[0023] 2. The present invention utilizes a multilayer microwave printed circuit board (PCB) with embedded isolation resistors, simplifying circuit design. Because PCB processing requires a safety clearance of at least 500 μm between the grounding via and the edge of the embedded resistor to ensure that the hole does not deviate from the embedded resistor, to avoid the limitations of microwave PCB processing precision, a 1 / 4λ sector-shaped metal equivalent grounding hole is used at the isolation port of the bridge to achieve equivalent grounding while simultaneously improving the isolation of the bridge. By rationally proportionally setting the apertures of the signal vias and shielding vias and the corresponding pad ring dimensions, the fabrication of double-sided blind vias and intermediate buried vias in a multilayer microwave PCB is achieved. Signal transmission shares a second metallized shielding via, providing excellent electromagnetic shielding. Compared to LTCC and HTCC processes, the fabrication is simpler, the material microstructure is uniform, and low dielectric constant and loss are achieved. Both thermal and mechanical properties are guaranteed, reducing processing costs and cycle times, facilitating mass production, and possessing broad application value and technical applicability.

[0024] 3. Existing feed networks mostly use phase-shifting lines and power combiners. These lines have significant dispersion effects, and their influence on phase is limited to a specific frequency or within a very narrow bandwidth. The present invention achieves phase control using only 90° and 180° bridges and a Wilkinson power combiner. Its symmetrical structure eliminates the need for phase-shifting lines, resulting in high isolation within the corresponding frequency band, low phase imbalance, and a symmetrical, unified design structure with strong reconfigurability.

[0025] 4. This feeding network can connect to the antenna unit with four feed points. Compared with the single-point and dual-point feeding networks, it can significantly improve the 3dB axial ratio bandwidth of the antenna while retaining the high gain of the microstrip antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the antenna feeding network system in the present invention;

[0027] Figure 2 Schematic diagram of a network layered structure with equal amplitude and 90° in an embodiment of the present invention;

[0028] Figure 3 This is a specific structural diagram of a constant-amplitude, 90° network in an embodiment of the present invention;

[0029] Figure 4 This is a design diagram of the feeding network after 1 / 4λ sector equivalent grounding in an embodiment of the present invention;

[0030] Figure 5 Schematic diagram of a PCB stacked structure with a constant amplitude and a 90° network in an embodiment of the present invention;

[0031] Figure 6 Schematic diagram of the front view structure of the constant amplitude, 90° network vias and semi-vias in an embodiment of the present invention;

[0032] Figure 7 Schematic diagram of a top view of a common grounding hole for ports in an embodiment of the present invention;

[0033] Figure 8 Schematic diagram of the residual end of the backdrilling process in an embodiment of the present invention;

[0034] Figure 9 This is the return loss diagram of the constant amplitude 90° network port in this embodiment;

[0035] Figure 10 This is the insertion loss diagram of the constant amplitude 90° network port in this embodiment;

[0036] Figure 11 This is the isolation diagram between the ports of the equal-amplitude 90° network in this embodiment;

[0037] Figure 12This is the phase diagram of the network port with constant amplitude and 90° in this embodiment;

[0038] Figure 13 This is a diagram of the return loss of the Wilkinson power combiner port in this embodiment;

[0039] Figure 14 This is a diagram of the port insertion loss of the Wilkinson power combiner of this embodiment. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] This embodiment describes an antenna feed network system based on a multi-layer mixed-voltage buried resistor and high-density vertical interconnect PCB process. The system includes a first bridge, a second bridge, and a third bridge interconnected to form a two-layer transmission network with equal amplitude and 90° phase shift, and a four-in-one Wilkinson power combining network. The feed network unit includes four feed points for connecting to the upper antenna.

[0043] The overall feed network adopts a multi-layer stripline structure, which is presented in a vertical three-dimensional stacking form. There are metal floors on the upper and lower layers of adjacent wiring, which can reduce the horizontal lateral dimensions of the feed network and realize the miniaturization and high integration of the antenna array.

[0044] The first bridge and the second bridge are 90° bridges, and the third bridge is a 180° bridge. Both the 90° bridge and the 180° bridge have four ports.

[0045] The first and second bridges in the equal-amplitude, 90° network are both 90° bridges, and the ports of the first and second bridges are both located on the corresponding edge of the equal-amplitude, 90° network; the third bridge is a 180° bridge; the first and second differential ports of the first bridge and the third and fourth differential ports of the second bridge are respectively connected to the four feeding terminals corresponding to the antenna; the first combined port of the first bridge is connected to the fifth differential port of the third bridge, and the second combined port of the second bridge is connected to the sixth differential port of the third bridge; the third combined port of the third bridge is used to output antenna signals;

[0046] In this embodiment, ports 2 and 3 of the first bridge are differential ports, representing the first and second differential ports of the first bridge, respectively; port 6 is a combined port, representing the first combined port of the first bridge; port 10 is an isolated port; ports 4 and 5 of the second bridge are differential ports, representing the third and fourth differential ports of the second bridge, respectively; port 7 is a combined port, representing the second combined port of the second bridge; and port 11 is an isolated port. Ports 8 and 9 of the third bridge are differential ports, representing the fifth and sixth differential ports of the third bridge, respectively; port 1 is a combined port, representing the third combined port of the third bridge; and port 12 is an isolated port. Ports 2 and 3 of the first bridge, and ports 4 and 5 of the second bridge, are connected to the four corresponding feeding terminals of the antenna, forming a constant amplitude, 90° feeding relationship.

[0047] Port 6 of the first bridge is connected to port 8 of the third bridge, port 7 of the second bridge is connected to port 9 of the third bridge, and the final received antenna signal is output from port 1 of the third bridge.

[0048] The isolation resistors of the Wilkinson power combiners are all 100Ω buried resistors. Four equal-amplitude, 90°-angled feed receiving subarrays combine the RF receive signals for output via a cascaded four-in-one Wilkinson power combiner.

[0049] The system is applied to a receiving phased array antenna system; the operating frequency of the system is 19.6 to 21.2 GHz.

[0050] In the present invention, the isolated ports of the 90° bridge and the 180° bridge need to be connected to a 50Ω matching resistor for grounding. The resistor adopts a buried resistor process. Since the grounding hole is close to the buried resistor, it cannot be achieved due to the limitation of the processing accuracy. Therefore, a 1 / 4λ fan-shaped metal is used to replace the grounding hole to achieve equivalent grounding, breaking through the limitation of the processing technology and realizing high isolation of the bridge.

[0051] Due to the limitations of multilayer board via processing, this method requires that ports 1 and 2, as well as interconnected ports (ports 6 and 8, and ports 7 and 9), share a peripheral grounding via. When a circuit pattern exists below the corresponding via, the upper metallized via is retained based on the stacking structure and converted to a semi-conducting blind via. Simulation results show that this approach not only maintains the original performance but also improves isolation and reduces return loss, meeting practical processing requirements.

[0052] The present invention overcomes inherent technical bottlenecks by adopting multiple drilling methods and different pad ring sizes for blind and buried vias. A process method of first mixing and then back-drilling the upper and lower layers is adopted for the buried vias in a multi-layer microwave printed circuit board. When back-drilling is adopted, the depth of the back-drilled residual end is 0.15 mm. After HFSS simulation and combined with the actual process level, the width of the pad ring is reasonably set, making it possible to implement miniaturized double-sided buried vias for RF signals in a 5-layer microwave mixed-pressure board. The feed network is thus presented in the form of a multi-layer three-dimensional architecture, and the size of the uniform-amplitude 90° network unit is 12 mm × 12 mm, achieving the goal of integrating and miniaturizing the phased array antenna feed network.

[0053] The feed network and the upper microstrip antenna system can be interconnected using connectors or directly integrated with hybrid circuits. The maturity of multi-layer hybrid circuit buried resistor technology and high-density vertical interconnect PCB processes has enabled the mass production of highly integrated, large-scale antenna arrays. This allows for miniaturization and high integration of the feed network.

[0054] This embodiment adopts an array structure of four antenna units, which adopts the feeding network of the present invention. Figure 1 and Figure 2 The entire constant-amplitude, 90° network is constructed from a composite laminate of five microwave boards. The stacking order is: metal, microwave substrate, metal, prepreg, microwave substrate, metal, prepreg, metal, microwave substrate, metal. The microwave substrates are bonded together using prepreg. The first and second bridge circuits are located on metal layer L2, and the third bridge circuit is located on metal layer L4. Metal layers L1, L3, and L5 are all metal ground planes, serving as the first, second, and third metal ground planes, respectively. The overall feed network structure consists of three layers: the first and second bridges form the first layer, and the third bridge on the second layer is interconnected to form a two-layer, right-handed, constant-amplitude, 90° network. This network is cascaded to the upstream microstrip antenna via ports 2, 3, 4, and 5. The third layer is a four-in-one Wilkinson power combiner.

[0055] The first bridge and the second bridge are 90° bridges, and the third bridge is a 180° bridge. Both the 90° bridge and the 180° bridge have four ports.

[0056] Ports 2 and 3 of the first bridge are differential ports, port 6 is a combined port, and port 10 is an isolated port. Ports 4 and 5 of the second bridge are differential ports, port 7 is a combined port, and port 11 is an isolated port. Ports 8 and 9 of the third bridge are differential ports, port 1 is a combined port, and port 12 is an isolated port. All isolated ports are connected to 50Ω buried resistors and then grounded vias.

[0057] Ports 2 and 3 of the first bridge and ports 4 and 5 of the second bridge are connected to the four feeding points of the upper-level antenna unit, forming equal-amplitude and 90-degree feeding relationships.

[0058] Port 6 of the first bridge is connected to port 8 of the third bridge, port 7 of the second bridge is connected to port 9 of the third bridge, and the final received right-handed, equal-amplitude, 90° antenna signal is output from port 1 of the third bridge.

[0059] The scattering matrix S describing the 90° bridge is as follows:

[0060]

[0061] All ports are matched. Power input from the sum port is distributed equally to the difference ports. There is a 90° phase shift between the two output ports, and no power is coupled to the isolation port. A 90° hybrid network is highly symmetrical: any port can serve as an input port. The output port is always on the side opposite the input port of the network, while the isolation port is the remaining port on the same side as the input port. This symmetry is reflected in the scattering matrix by swapping the positions of each row with the first row.

[0062] The scattering matrix S describing the 180° bridge is as follows:

[0063]

[0064] In a 180° hybrid network, see Figure 3 When used as a synthesizer, the input signal is applied to port 8 and port 9, and the sum of the input signals will be formed at port 1, while the difference of the input signals will be formed at ports 1 and 2.

[0065] The four-way Wilkinson power combiner has four input ports and one output combining port. A Wilkinson power combiner is a network that, when all output ports are matched, still has the useful characteristic of being lossless; it only dissipates reflected power. The isolation resistor has a value of 100Ω.

[0066] When the antenna receives a right-handed, constant-amplitude, 90° signal, ports 2, 3, 4, and 5 receive equal-amplitude signals with phases of -90°, -180°, -270°, and -360°, respectively. The signals from ports 2 and 3 of the first bridge are combined at port 6 to achieve a phase of 0°, which is then transmitted via the coaxial structure to port 8 of the third bridge. The signals from ports 4 and 5 of the second bridge are combined at port 7 to achieve a phase of -180°, which is then transmitted via the coaxial structure to port 9 of the third bridge. The phase difference between ports 8 and 9 of the third bridge is 180°, and the two signals are ultimately combined and output at port 1.

[0067] Each of the four equal-amplitude 90° network receiving sub-arrays achieves signal synthesis output by cascading a four-in-one Wilkinson power combiner.

[0068] The system is applied to a phased array antenna system;

[0069] The system operates in a frequency band of 19.6 to 21.2 GHz.

[0070] Figure 4 The design structure of using 1 / 4λ sector metal to replace the grounding hole to achieve equivalent grounding is given.

[0071] Figure 5 The specific stacking diagram of the equal-amplitude 90° network is given. According to the actual stacking sequence, the specific positions of the vias and semi-vias in the layers are determined. Figure 6 .

[0072] Figure 7 It is shown that the second metallized shielding hole needs to be shared between port 1 and port 2, and between interconnected ports (port 6 and port 8, port 7 and port 9). When there is a circuit pattern under the through hole, the upper metallized hole needs to be retained according to the stacking structure and changed into a semi-conducting blind hole.

[0073] It should be further explained here that different types of holes require different pad ring sizes in the process.

[0074] Blind vias (L1-L2) are blind vias from L1 to L2, plated, filled with metal, and drilled before the first press. The pad ring width is 3 mils. (L1 to L2)

[0075] Buried vias (L2-L4) are plated-through vias from L2 to L4, filled with metal, and drilled using a second mixed-press backdrill. The pad ring width is 5 mils.

[0076] Blind vias (L4-L5) are plated-through vias from L4 to L5, filled with metal, and drilled before the second lamination. The pad ring width is 3 mils.

[0077] Blind vias (L1-L3) are blind vias from L1 layer to L3 layer, which are metallized holes and filled with metal. They are punched after the first mixing and then mixed again.

[0078] Figure 8 The back drill residue shown in the figure shows that when the back drill is used for drilling, the depth of the back drill residue end is 0.15 mm. The simulation results show that it meets the design requirements and this condition also meets the processing requirements.

[0079] Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 and Figure 14 The simulation results after adding the connector SSMP model in a specific embodiment are given. In the operating frequency band of 19.6~21.2GHz, the return losses of the five input and output ports are all lower than -15dB, the insertion loss is between -6.1 and -6.6dB, the isolation between ports 2, 3, 4, and 5 is all less than -18dB, the phase difference between adjacent ports is 90°, the phase imbalance is less than 0.5°, the return loss of the Wilkinson power combiner port is less than -18.8dB, and the insertion loss is around -6.4dB, all meeting the requirements.

[0080] It can be seen that the technical solution in the embodiment of the present invention forms a feed network system by stacking multiple bridges and power combiners in a three-dimensional form, thereby avoiding the dispersion effect caused by the use of phase shift lines. In the embodiment of the present invention, a symmetrical structural design is applied, and the apertures of the through holes and semi-conducting holes and the size of the corresponding pad rings are reasonably set according to the actual processing technology, so as to achieve miniaturization and high integration of the feed network. The design brings great flexibility and scalability, and can be adjusted in scale according to actual needs to meet the system size, weight and versatility requirements, and has very wide application value and applicable technical effects.

Claims

1. A feed network system comprising four equal-amplitude, 90° network sub-arrays arranged in a rectangular array and a power combining network located at the bottom of the network sub-array; the four equal-amplitude, 90° network sub-arrays are cascaded through a four-in-one Wilkinson power combiner to achieve signal synthesis output; characterized in that: The constant amplitude, 90° network sub-array comprises a first metal ground plate, a first microwave substrate, a first metal signal line, a first prepreg, a second microwave substrate, a second metal ground plate, a second prepreg, a second metal signal line, a third microwave substrate, and a third metal ground plate, which are stacked in sequence from top to bottom; the microwave substrates are bonded together by prepregs; The first and second bridges in the equal-amplitude, 90° network are both 90° bridges, and the ports of the first and second bridges are both located on the corresponding edge of the equal-amplitude, 90° network; the third bridge is a 180° bridge; the first and second differential ports of the first bridge and the third and fourth differential ports of the second bridge are respectively connected to the four feeding terminals corresponding to the antenna; the first combined port of the first bridge is connected to the fifth differential port of the third bridge, and the second combined port of the second bridge is connected to the sixth differential port of the third bridge; the third combined port of the third bridge is used to output antenna signals; Both the 90° and 180° bridges have four ports. The first, second, and third bridges are interconnected to form a transmission network with equal amplitudes and phases that differ by 90°. The first and second bridge circuits are located in the first metal signal line layer, and the third bridge circuit is located in the second metal signal line layer. The first metal ground plate is connected to the second metal ground plate through a first metal shielding hole; the first metal ground plate is connected to the third metal ground plate through a second metal shielding hole, and the second metal shielding hole passes through the second metal ground plate; The first combined port of the first bridge and the fifth differential port of the third bridge are connected through corresponding second metallized radio frequency holes; the second combined port of the second bridge and the sixth differential port of the third bridge are connected through corresponding second metallized radio frequency holes; The first differential port and the second differential port of the first bridge and the third differential port and the fourth differential port of the second bridge are connected to the four feeding terminals corresponding to the antenna through corresponding third metallized radio frequency holes located above their respective ports; the third combined port of the third bridge outputs the antenna signal through the fourth metallized radio frequency hole located below it; The first differential port of the first bridge and the third combined port of the third bridge have their third metallized radio frequency holes and fourth metallized radio frequency holes offset from each other in axis and share the second metallized shielding hole; The second combined port of the second bridge and the sixth differential port of the third bridge, as well as the first combined port of the first bridge and the fifth differential port of the third bridge, have their upper metallized RF holes and lower metallized RF holes axially aligned, and share corresponding second metallized shielding holes; The isolation ports of the first bridge, the second bridge and the third bridge are all equivalently grounded by sector-shaped metal; the radius of the sector-shaped metal is one quarter of a wavelength.

2. A feed network system according to claim 1, characterized in that: The equal-amplitude, 90° network is a symmetrical structure.

3. A feed network system according to claim 1, characterized in that: The antenna is a microstrip antenna; the feeding network system is connected to the four feeding terminals of the microstrip antenna through an SSMP connector; and the constant amplitude and 90° network subarrays are connected to the Wilkinson power combiner through the SSMP connector.

4. A feed network system according to claim 1, characterized in that: The third metallized RF hole is punched before the first mixing and pressing, and the width of the pad ring is 3 mils; The fourth metallized RF hole is punched before the second mixing and pressing, and the width of the pad ring is 3 mils; The second metallized RF hole is back-drilled after the second mixing and the width of the pad ring is 5 mils.

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