CN217114817U - Feed network system - Google Patents

Abstract

The utility model discloses a feed network system belongs to antenna feed technical field. The power synthesis system comprises four constant-amplitude 90-degree network sub-arrays of 2x2 rectangular arrays and a power synthesis network which is positioned at the bottom of the sub-arrays and consists of four-in-one Wilkinson power synthesizers; the constant-amplitude 90-degree network sub-arrays of the four arrays realize signal synthesis output through a four-in-one Wilkinson power synthesizer in cascade connection; the constant-amplitude 90-degree network subarray comprises a first metal grounding plate, a first microwave substrate, a first metal signal line, a first semi-solidified sheet, a second microwave substrate, a second metal grounding plate, a second semi-solidified sheet, a second metal signal line, a third microwave substrate and a third metal grounding plate which are sequentially stacked from top to bottom; microwave substrates are bonded through prepregs; the feed network capable of butting the right-handed constant-amplitude 90-degree antenna signals of the four feed points is realized. The utility model discloses reduce the horizontal transverse dimension of feed network, realize the miniaturization and the high integration of antenna array.

Description

Feed network system

Technical Field

The utility model relates to antenna feed technical field, in particular to feed network system suitable for perpendicular interconnection technique PCB of high density.

Background

At present, a feed network mostly adopts a form of a power synthesizer and a phase shifting line, the dispersion effect of the phase shifting line is obvious, the influence of the phase shifting line on the phase is only aimed at a certain frequency point or a very narrow bandwidth, the structure is not symmetrical and uniform enough, and the reconfigurability is poor.

The current LTCC and HTCC technologies are complex in processing technology, one layer of LTCC and HTCC technologies are manufactured, and a plurality of design reliability difficulties exist, and the shrinkage and the thermal expansion coefficient of the substrate and the wiring during cofiring are one of important challenges, which are mainly reflected in three aspects: the sintering densification finishing temperatures are different; the sintering shrinkage rates of the substrate and the slurry are inconsistent; the sintering densification speed is not matched, the mismatching is easy to cause the surface of the substrate after sintering to be uneven, warped and layered, and the adhesion of metal wiring is reduced as another result of the mismatching. LTCC substrates are fragile, have low thermal conductivity, are still a critical issue for heat dissipation, and have long processing cycles, are expensive, and are not convenient for large-scale production in short cycles.

Among the stripline antenna feed network of present multilayer microwave printed board processing preparation, processing simple manufacture, material microstructure is even, can realize low dielectric constant and lower loss, and thermal behavior and mechanical properties are all guaranteed, but two-sided blind hole technical application is less, leads to electromagnetic shield effect poor, influences the transmission of signal between the multiply wood, and is mostly one deck planar structure, and the size is great, is unfavorable for miniaturized development.

The southeast university of 2021 discloses a phased-array antenna feed network, which is realized by adopting a high-density multilayer hybrid board, but only has a single-side blind hole processing technology, and does not realize double-sided blind holes and buried hole processes.

In the PCB processing technology, the distance between a grounding hole and a buried resistance edge is at least 500um safety distance, so that the situation that punching is deviated to the buried resistance can be guaranteed, and the design of the multilayer microwave printed board is limited by the processing precision.

SUMMERY OF THE UTILITY MODEL

To the problem that exists among the above-mentioned background art, the utility model provides a feed network system. The system adopts a longitudinal three-dimensional stacking form, reduces the horizontal and transverse sizes of the feed network, and realizes the miniaturization and high integration of the antenna array.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a feed network system comprises four equal-amplitude 90-degree network sub-arrays arranged in a rectangular array and a power synthesis network positioned at the bottom of the network sub-arrays; the constant-amplitude 90-degree network sub-arrays of the four arrays realize signal synthesis output by cascading a four-in-one Wilkinson power synthesizer; the constant-amplitude 90-degree network subarray comprises a first metal grounding plate, a first microwave substrate, a first metal signal line, a first semi-solidified sheet, a second microwave substrate, a second metal grounding plate, a second semi-solidified sheet, a second metal signal line, a third microwave substrate and a third metal grounding plate which are sequentially stacked from top to bottom; microwave substrates are bonded through prepregs;

the first electric bridge and the second electric bridge in the constant-amplitude 90-degree network are both 90-degree electric bridges, and the ports of the first electric bridge and the second electric bridge are both positioned on one side of the corresponding edge of the constant-amplitude 90-degree network; wherein the third bridge is a 180 ° bridge; 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 with four feeding end points corresponding to the antenna; the first combined port of the first bridge is connected with the fifth difference port of the third bridge, and the second combined port of the second bridge is connected with the sixth difference port of the third bridge; the third combined port of the third bridge is used for outputting an antenna signal;

the first metal grounding plate is connected with the second metal grounding plate through the first metalized shielding hole; the first metal grounding plate is connected with the third metal grounding plate through the second metalized shielding hole, and the second metalized shielding hole penetrates through the second metal grounding plate.

Further, the constant-amplitude 90-degree network is of a symmetrical structure.

Further, the antenna is a microstrip antenna; the feed network system is connected with four feed endpoints of the microstrip antenna through the SSMP connector; the constant-amplitude 90-degree network subarray is connected with the Wilkinson power synthesizer through an SSMP connector.

Further, 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; and the second combined port of the second electric bridge and the sixth difference port of the third electric bridge are connected through corresponding second metalized radio frequency holes.

Furthermore, 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 respectively connected with four corresponding feed terminals of the antenna through corresponding third metallized radio frequency holes above the respective ports; and the third combined port of the third bridge outputs an antenna signal through a fourth metallized radio frequency hole positioned below the third combined port.

Further, the axes of the third metallized rf hole and the fourth metallized rf hole of the first differential port of the first bridge and the third combined port of the third bridge are offset and share the second metallized shielding hole; and the axes of the upper-layer metallized radio frequency hole and the lower-layer metallized radio frequency hole are superposed and share the corresponding second metallized shielding hole.

Further, the isolation ports of the first bridge, the second bridge and the third bridge are all equivalently grounded by adopting sector metal; the radius of the fan-shaped metal is a quarter wavelength.

Further, a third metallized radio frequency hole is punched before one-time mixed pressing, and the width of a welding disk ring is 3 mils;

the fourth metallized radio frequency hole is punched before secondary mixed pressing, and the width of a welding disc ring is 3 mils;

and the second metallized radio frequency hole is drilled by back drilling after secondary mixed pressing, and the width of the bonding pad ring is 5 mils.

The utility model adopts the beneficial effect that above-mentioned technical scheme produced lies in:

1. the utility model discloses a feed network all adopts the stripline structure, owing to walk the adjacent upper and lower two-layer metal floor that all has of line, so energy leakage is less and can not disturbed by external circuit basically. And moreover, the strip line structure is adopted to be presented in a longitudinal three-dimensional stacking form, so that the horizontal and transverse sizes of the feed network can be reduced, and the miniaturization and high integration of the antenna array are realized.

2. The utility model discloses a multilayer microwave printed board form, isolation resistor adopt to bury and hinder the form and simplified circuit design, because the earthing hole distance buries among the PCB processing technology and hinders marginal distance 500um safety interval at least, just can guarantee to punch and can not beat inclined to one side to bury and hinder, in order to avoid the restriction of the machining precision of microwave printed board, electric bridge isolation port department adopts the fan-shaped metal equivalent of 1/4 lambda to replace the earthing hole to realize equivalent ground connection, improved the isolation of electric bridge simultaneously. The diameters of the signal via holes and the shielding holes and the corresponding sizes of the pad rings are reasonably arranged according to the proportion, so that the processing and manufacturing of double-sided blind holes and middle layer buried holes in the multilayer microwave printed board are realized. The signal transmission shares the second metallized shielding hole, so that a good electromagnetic shielding effect is achieved. Compared with the LTCC process and the HTCC process, the low-dielectric-constant high-loss low-loss high-temperature co-fired ceramic material is simple to manufacture, uniform in microstructure, capable of achieving low dielectric constant and low loss, guaranteed in thermal performance and mechanical performance, low in processing cost, short in processing period, convenient to produce in batches, and wide in application value and applicability.

3. Most of the existing feed networks adopt a mode of connecting a phase shifting line and a power synthesizer, the dispersion effect of the phase shifting line is obvious, and the influence of the phase shifting line on the phase is only aimed at a certain frequency point or within a very narrow bandwidth. The utility model discloses only adopt 90 electric bridges and 180 electric bridges and Wilkinson power combiner can realize phase control, and the phase shift line can be avoided using to the structural symmetry, and the isolation is high in corresponding the frequency band, and the phase unbalance degree is low, and the design structure symmetry is unified, and reconfigurability is strong.

4. The feed network can be butted with antenna units with four feed points, and compared with single-point and double-point feed networks, the 3dB axial ratio bandwidth of the antenna can be remarkably improved on the basis of keeping the high gain of the microstrip antenna.

Drawings

Fig. 1 is a schematic diagram of a feeding network system of a central antenna according to the present invention;

fig. 2 is a schematic diagram of a constant-amplitude 90 ° network layered structure in an embodiment of the present invention;

fig. 3 is a specific structure diagram of a constant-amplitude 90 ° network in an embodiment of the present invention;

fig. 4 is a design diagram of a feed network after 1/4 λ sector equivalent grounding in the embodiment of the present invention;

fig. 5 is a schematic diagram of a laminated structure of a constant-amplitude 90-degree network PCB in an embodiment of the present invention;

fig. 6 is a schematic front view of the mesh via holes and the semi-conductive vias of 90 ° with equal amplitude in the embodiment of the present invention;

fig. 7 is a schematic top view of a port-shared ground hole in an embodiment of the present invention;

fig. 8 is a schematic diagram of a back drilling process residual end in an embodiment of the present invention;

fig. 9 is a return loss diagram of a constant-amplitude 90 ° network port according to the present embodiment;

fig. 10 is a constant-amplitude 90 ° network port insertion loss diagram according to the present embodiment;

fig. 11 is a diagram of isolation between ports of the equal-amplitude 90 ° network according to the present embodiment;

FIG. 12 is a phase diagram of a 90 ° network port with equal amplitude according to the present embodiment;

fig. 13 is a return loss diagram of the port of the wilkinson power combiner according to the embodiment;

fig. 14 is a diagram of the insertion loss of the port of the wilkinson power combiner in the present embodiment.

Detailed Description

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

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

The embodiment of the invention relates to an antenna feed network system based on a multilayer mixed-voltage buried resistance technology and a high-density vertical interconnection technology PCB technology, which comprises the following steps: the power transmission network comprises a first bridge, a second bridge and a third bridge which are connected with each other to form an upper layer and a lower layer of transmission network which have the same amplitude and phase difference of 90 degrees in sequence and a four-in-one Wilkinson power synthesis network. The feed network unit comprises four feed points which are in butt joint with the upper layer antenna.

The whole feed network adopts multilayer stripline structure to appear in vertical three-dimensional stacking form, and the upper and lower two adjacent layers of wiring all have metal floors, can reduce the horizontal and transverse size of feed network, realize the miniaturization and the high integration of antenna array.

Wherein the first bridge, the second bridge are 90 ° bridges, the third bridge is 180 ° bridge, and both the 90 ° bridge and the 180 ° bridge have four ports.

The first electric bridge and the second electric bridge in the constant-amplitude 90-degree network are both 90-degree electric bridges, and the ports of the first electric bridge and the second electric bridge are both positioned on one side of the corresponding edge of the constant-amplitude 90-degree network; wherein the third bridge is a 180 ° bridge; 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 with four feeding end points corresponding to the antenna; the first combined port of the first bridge is connected with the fifth difference port of the third bridge, and the second combined port of the second bridge is connected with the sixth difference port of the third bridge; a third combined port of the third bridge is used for outputting an antenna signal;

in this embodiment, the 2-port and the 3-port of the first bridge are differential ports, which are respectively the first differential port and the second differential port of the first bridge; the port 6 is a combined port, which is a first combined port of the first bridge, the port 10 is an isolated port, and the port 4 and the port 5 of the second bridge are differential ports, which are respectively a third differential port and a fourth differential port of the second bridge; the 7 port is a closed port which is a second closed port of the second bridge; the 11 ports are isolated ports. The 8 port and the 9 port of the third bridge are differential ports, namely a fifth differential port and a sixth differential port of the third bridge; the port 1 is a combined port and is a third combined port of the third electric bridge; the 12 ports are isolated ports. The 2 port and the 3 port of the first electric bridge and the 4 port and the 5 port of the second electric bridge are connected with four feeding end points corresponding to the antenna, and the feeding relations of equal amplitude and 90 degrees are respectively formed.

The 6 ports of the first bridge are connected with the 8 ports of the third bridge, the 7 ports of the second bridge are connected with the 9 ports of the third bridge, and finally received antenna signals are output from the 1 port of the third bridge.

The isolation resistors of the Wilkinson power combiner are all in the form of 100 omega buried resistors. The four constant-amplitude 90-degree feed receiving subarrays realize the synthesis and output of radio frequency receiving signals through a cascade four-in-one Wilkinson power synthesizer.

The system is applied to a receiving phased array antenna system; the working frequency of the system is 19.6-21.2 GHz.

The utility model discloses well 90 electric bridges and 180 electric bridges's isolation port should be connected 50 omega matching resistance ground treatment, and resistance adopts and buries the technology of hindering, because the earthing hole distance is buried and is hindered closely, and the restriction of processing technology precision can't be realized, consequently adopts 1/4 lambda fan-shaped metal equivalent to replace the earthing hole to realize equivalent ground, broken through the restriction of processing technology, realized the high isolation of electric bridge.

The utility model discloses in receive multiply wood via hole processing technology restriction, 1 port and 2 ports, also between the interconnection port (6 ports and 8 ports, 7 ports and 9 ports) need the peripheral ground hole of sharing, when the through-hole corresponds the position lower floor and has the circuit figure, remain upper metallization hole according to the stromatolite structure needs, change the through-hole into half and switch on the blind hole. Simulation results show that the method can not only ensure the original performance, but also improve the isolation and reduce the return loss, and meet the actual processing requirements.

The utility model discloses well break through inherent technical bottleneck, blind hole and buried via hole adopt multiple mode and the pad ring size of difference of punching, adopt the buried via hole in the multilayer microwave printing board to mix earlier and press the back drill process method who punches from top to bottom after, when adopting the back drill form to punch, the back drill remains the end degree of depth and is 0.15mm, combine the reasonable width that sets up the pad ring of actual technology process level after the emulation with HFSS, it is possible to make the miniaturized two-sided buried via hole of radio frequency signal realize in 5 layers microwave mixing boards, thereby present the feed network with multilayer three-dimensional framework form, equal-amplitude 90 network element size is 12mm x 12mm, reach phased array antenna feed network and integrate, miniaturized target.

The feed network and the upper microstrip antenna system can be interconnected by using a connector, and can also be directly integrated with mixed voltage. Due to the maturity of the multilayer mixed-voltage buried resistance technology and the high-density vertical interconnection technology PCB technology, the mass production of large-scale antenna arrays with high integration level becomes possible. Miniaturization and high integration of the feed network can be realized.

This embodiment adopts four antenna element's array structure, and it adopts the utility model discloses a feed network refers to fig. 1 and fig. 2, and whole constant amplitude, 90 networks are mixed by 5 layers of microwave board and are pressed and form, and the stromatolite order is in proper order: the microwave integrated circuit comprises a metal, a microwave substrate, a metal, a prepreg, a metal, a microwave substrate and a metal, wherein the microwave substrates are bonded through the prepreg, a first bridge circuit and a second bridge circuit are positioned on a metal L2 layer, and a third bridge circuit is positioned on a metal L4 layer; the metal L1 layer, the metal L3 layer, and the metal L5 layer are all metal ground plates, and are respectively a first metal ground plate, a second ground plate, and a third metal ground plate. The whole feed network structure is divided into three layers: the first layer is formed by a first electric bridge and a second electric bridge, the first layer and the third electric bridge of the second layer are mutually connected to form an upper layer right-handed constant-amplitude 90-degree network and are cascaded with a superior microstrip antenna through four ports of 2, 3, 4 and 5. The third layer is a four-in-one Wilkinson power combiner.

Wherein the first bridge, the second bridge are 90 ° bridges, the third bridge is 180 ° bridge, and both the 90 ° bridge and the 180 ° bridge have four ports.

The 2 port and the 3 port of the first electric bridge are differential ports, the 6 port is a closed port, the 10 port is an isolated port, the 4 port and the 5 port of the second electric bridge are differential ports, the 7 port is a closed port, and the 11 port is an isolated port. The 8 port and the 9 port of the third bridge are differential ports, the 1 port is a closed port, and the 12 port is an isolated port. All the isolated ports are grounded through the via holes after being connected with 50 omega buried resistors.

The 2 port and the 3 port of the first electric bridge and the 4 port and the 5 port of the second electric bridge are connected with four feed points of the antenna unit at the previous stage, and the four feed points form a constant-amplitude 90-degree feed relation respectively.

The 6 ports of the first electric bridge are connected with the 8 ports of the third point bridge, the 7 ports of the second electric bridge are connected with the 9 ports of the third point bridge, and finally received right-hand equal-amplitude 90-degree antenna signals are output from the 1 port of the third electric bridge.

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

all ports are matched, and the power input from the combined port is equally distributed to two differential ports, with a 90 ° phase shift between the two output ports, and no power is coupled to the isolated port. A 90 hybrid network has a high degree of symmetry, with any port being an input port, the output port always being on the opposite side of the input port of the network, and the isolated port being the remaining port on the same side of the input port. The symmetry response in the scattering matrix is that each row can be transposed from the first row.

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

in a 180 hybrid network, referring to fig. 3, when used as a combiner, the input signals are applied at ports 8 and 9, the sum of the input signals will be formed at port 1, and the difference of the input signals will be formed at ports 1 and 2.

The four-way Wilkinson power combiner is provided with four input ports and one output combining port. A wilkinson power combiner is one such network: when the output ports are all matched, it still has the useful property of being lossless, and it simply dissipates the reflected power. The isolation resistor has a resistance of 100 omega.

When the antenna receives signals with right-hand equal amplitude and 90 degrees, the ports 2, 3, 4 and 5 receive the signals with equal amplitude, the phases are respectively-90 degrees, -180 degrees, -270 degrees and-360 degrees, the signals of the port 2 and the port 3 of the first electric bridge are combined into a signal phase of 0 degree at the port 6 and transmitted to the port 8 of the third electric bridge through the coaxial structure, and the signals of the port 4 and the port 5 of the second electric bridge are combined into a signal phase of-180 degrees at the port 7 and transmitted to the port 9 of the third electric bridge through the coaxial structure. The phase difference between the port 8 and the port 9 of the third bridge is 180 degrees, and finally the two paths of signals are synthesized and output at the port 1.

And each four equal-amplitude 90-degree network receiving sub-arrays realize signal synthesis output by cascading a four-in-one Wilkinson power synthesizer.

The system is applied to a phased array antenna system;

the working frequency band of the system is 19.6-21.2 GHz.

Fig. 4 shows a design structure after an equivalent grounding is realized by adopting 1/4 lambda sector metal to equivalently replace a grounding hole.

Fig. 5 shows a specific lamination diagram of a constant-amplitude 90 ° network, and specific in-layer positions of via holes and semi-conductive through holes are determined according to an actual lamination sequence, see fig. 6.

Fig. 7 shows that 1 port and 2 port, and a second metalized shielding hole is needed to be shared between interconnection ports (6 port and 8 port, 7 port and 9 port), when a circuit pattern is arranged below a through hole, an upper layer metalized hole is reserved according to the requirement of a laminated structure, and the upper layer metalized hole is changed into a semi-conductive through blind hole.

It is further noted here that the size of the pad ring required for different kinds of vias varies from process to process.

The blind holes (L1-L2) are from L1 to L2, are metallized, filled with metal and perforated before the first mixing and pressing. The pad ring width was 3 mils. (l1 to l2)

The buried holes (L2-L4) are buried holes from the L2 layer to the L4 layer, metallized holes are filled with metal, and back drilling and punching are carried out after the second mixed pressing. The pad ring width was 5 mils.

The blind holes (L4-L5) are from the L4 layer to the L5 blind hole, the metallized hole is filled with metal, and the hole is punched before the second mixing and pressing. The pad ring width was 3 mils.

The blind holes (L1-L3) are from L1 layers to L3 layers, are metallized, filled with metal, punched after the first mixed pressing, and then mixed pressing is carried out.

In the back drilling residual shown in fig. 8, when the back drilling mode is used for drilling, and the depth of the back drilling residual end is 0.15mm, the simulation result shows that the design requirement is met, and meanwhile, the condition meets the processing requirement.

Fig. 9, fig. 10, fig. 11, fig. 12, fig. 13, and fig. 14 show simulation results after adding the SSMP model of the connector in the embodiment, in the operating frequency band of 19.6 to 21.2GHz, return loss of five input/output ports is lower than-15 dB, insertion loss is between-6.1 to-6.6 dB, isolation between 2, 3, 4, and 5 ports is smaller than-18 dB, phase difference between two adjacent ports is 90 °, phase imbalance is smaller than 0.5 °, return loss of wilkinson power combiner port is smaller than-18.8 dB, and insertion loss is about-6.4 dB, which all satisfy requirements.

Therefore, in the embodiment of the present invention, a plurality of bridges and power combiners are stacked in a three-dimensional manner to form a feeding network system, thereby avoiding the dispersion effect caused by the phase-shifting line. The embodiment of the utility model provides an in use symmetrical structural design, according to the reasonable size that sets up through-hole and semi-conductive through-hole aperture and correspond the pad ring of actual processing technology, can realize the miniaturization and the high integration of feed network. The design brings great flexibility and expandability, the scale can be adjusted according to actual needs, the requirements of system size, weight and universality are met, and the method has very wide application value and applicability technical effect.

Claims (8)

1. A feed network system comprises four equal-amplitude 90-degree network sub-arrays arranged in a rectangular array and a power synthesis network positioned at the bottom of the network sub-arrays; the constant-amplitude 90-degree network sub-arrays of the four arrays realize signal synthesis output by cascading a four-in-one Wilkinson power synthesizer; the constant-amplitude 90-degree network subarray is characterized by comprising a first metal grounding plate, a first microwave substrate, a first metal signal line, a first semi-solidified sheet, a second microwave substrate, a second metal grounding plate, a second semi-solidified sheet, a second metal signal line, a third microwave substrate and a third metal grounding plate which are sequentially stacked from top to bottom; microwave substrates are bonded through prepregs;

the first bridge and the second bridge in the constant-amplitude 90-degree network are both 90-degree bridges, and the ports of the first bridge and the second bridge are both positioned on one side of the corresponding edge of the constant-amplitude 90-degree network; wherein the third bridge is a 180 ° bridge; 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 with four feeding end points corresponding to the antenna; the first combined port of the first bridge is connected with the fifth difference port of the third bridge, and the second combined port of the second bridge is connected with the sixth difference port of the third bridge; the third combined port of the third bridge is used for outputting an antenna signal;

the first metal grounding plate is connected with the second metal grounding plate through the first metalized shielding hole; the first metal grounding plate is connected with the third metal grounding plate through the second metalized shielding hole, and the second metalized shielding hole penetrates through the second metal grounding plate.

2. The feed network system of claim 1, wherein said constant amplitude, 90 ° network is a symmetrical structure.

3. The feed network system of claim 1, wherein said antenna is a microstrip antenna; the feed network system is connected with four feed endpoints of the microstrip antenna through the SSMP connector; the constant-amplitude 90-degree network subarray is connected with the Wilkinson power synthesizer through an SSMP connector.

4. The feed network system of claim 1, wherein the first combined port of the first bridge and the fifth difference port of the third bridge are connected by corresponding second metallized rf holes; and the second combined port of the second electric bridge and the sixth difference port of the third electric bridge are connected through corresponding second metalized radio frequency holes.

5. The feed network system of claim 4, wherein the first and second differential ports of the first bridge and the third and fourth differential ports of the second bridge are connected to four corresponding feed terminals of the antenna through corresponding third metallized RF holes located above the respective ports; and the third combined port of the third bridge outputs an antenna signal through a fourth metallized radio frequency hole positioned below the third combined port.

6. The feed network system of claim 5, wherein the first differential port of the first bridge and the third combined port of the third bridge share a common second metallized shielding hole, and the third metallized rf hole and the fourth metallized rf hole are off-axis; and the axes of the upper-layer metallized radio frequency hole and the lower-layer metallized radio frequency hole are superposed and share the corresponding second metallized shielding hole.

7. The feed network system of claim 1, wherein the isolated ports of the first bridge, the second bridge and the third bridge are all implemented with sector-shaped metal to achieve equivalent grounding; the radius of the fan-shaped metal is a quarter wavelength.

8. The feed network system of claim 6, wherein the third metallized rf aperture is perforated prior to the first mixing and pressing, and the pad ring has a width of 3 mils;

the fourth metallized radio frequency hole is punched before the second mixed pressing, and the width of the welding disk ring is 3 mils;

and the second metallized radio frequency hole is drilled by back drilling after the second mixed pressing, and the width of the pad ring is 5 mils.

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