Signal transmission circuit and electronic equipment based on multi-layer strip lines

Abstract

The present invention discloses a signal transmission circuit and electronic device based on multi-layer stripline. The signal transmission circuit includes: a multi-channel limiting amplifier circuit, a signal routing structure, and multiple combining switches. The signal routing structure includes multiple layers of stripline, each layer of stripline including multiple stripline transmission lines. The output end of the multi-channel limiting amplifier circuit is connected to the stripline transmission line, and signals transmitted simultaneously are transmitted through stripline transmission lines on different layers, while signals transmitted at different times are transmitted through stripline transmission lines on the same layer. Stripline transmission lines on the same layer are connected to one combining switch, while stripline transmission lines on different layers are connected to different combining switches. The present invention utilizes a multi-channel limiting amplifier circuit and multi-layer, multi-channel stripline transmission to achieve arbitrary routing between radio frequency channels. The invention also has high isolation and high integration, achieving planarization, dielectricization, and miniaturization of the radio frequency transmission network.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency signal transmission, and in particular to a signal transmission circuit and electronic equipment based on multi-layer strip lines. Background Art

[0002] Limiting amplifier switch matrix networks are widely used in wireless communications and electronic reconnaissance system receiving front ends. They are mainly used to control the transmission path of RF signals. The port switching technology of the switch matrix is ​​used to enable RF channels to share receivers and frequency synthesizer systems, reducing the size and redundancy of RF system circuits and lowering the cost of radar communication systems.

[0003] Traditional microwave switch matrices often use discrete switch modules and coaxial cables for cross-connection, resulting in bulky design. The use of insulator-through-the-wall technology is suitable for cross-transmission of two-layer RF signals, but cannot address cross-transmission of multiple layers. Switch matrix networks implemented with multi-layer hybrid boards and movable partitions offer high circuit integration but poor isolation. Therefore, achieving high isolation and miniaturization across the board has become a pressing challenge for switch matrix networks. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a signal transmission circuit and electronic equipment based on multi-layer strip lines in response to the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides a signal transmission circuit based on a multi-layer stripline, comprising: a plurality of limiting amplifier circuits with the same structure but different frequencies, a first switch array, a signal routing structure, a second switch array, a plurality of combining switches, and a power supply and control circuit;

[0006] The signal routing structure includes multiple layers of stacked strip lines, each layer of strip lines including multiple strip transmission lines;

[0007] The output end of the multi-channel limiting amplifier circuit is connected to the input end of the signal routing structure through a first switch array, and signals transmitted simultaneously are transmitted through strip transmission lines on different layers, while signals transmitted at different times are transmitted through strip transmission lines on the same layer. The output end of the signal routing structure is connected to a combining switch through a second switch array, and strip transmission lines on the same layer are connected to one combining switch, while strip transmission lines on different layers are connected to different combining switches.

[0008] The power supply and control circuit is used to provide power supply and control to the multi-channel limiting amplifier circuit, the first switch array, the second switch array and a plurality of combining switches.

[0009] The beneficial effects of the present invention are as follows: using a multi-channel limiting amplifier circuit and multi-layer multi-channel stripline transmission, arbitrary routing between RF channels is achieved; wherein, the signal routing structure organizes RF signals, distributing simultaneously transmitted signals on different layers of striplines, and distributing non-simultaneously transmitted signals on the same layer of striplines; the multi-layer striplines enable cross-transmission of microwave RF signals; the more channels, the more stripline layers, but the passive network of the multi-layer stripline transmission is transmitted in three dimensions, only increasing the thickness without increasing the length and width. This not only improves isolation, but also enhances integration through vertical transmission of the multi-layer striplines, achieving a planar, dielectric, and miniaturized design of the RF transmission network.

[0010] On the basis of the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, the signal routing structure is a rectangular structure formed by stacking multiple layers of strip lines. A plurality of metal blind slots are provided at equal intervals on the two long sides of the rectangular structure. The metal blind slots extend vertically to the bottom strip line. A microstrip line is arranged on the upper surface of the bottom strip line corresponding to the metal blind slot. All the microstrip lines on one side of the rectangular structure serve as the input end of the signal routing structure, and all the microstrip lines on the other side serve as the output end of the signal routing structure. In addition to multiple strip transmission lines, the bottom strip line also includes multiple strip adapter lines. The microstrip lines are connected to the strip transmission lines or strip adapter lines of the bottom strip line through a vertical through-hole coaxial structure. The strip adapter lines are connected to the strip transmission lines other than the bottom strip line through a vertical through-hole coaxial structure.

[0012] The beneficial effects of adopting the above-mentioned further scheme are as follows: the side metallized blind groove treatment is conducive to reducing the ground loop path when the signal routing structure is cascaded with the first and second switch arrays, thereby improving the discontinuity caused by the cascade; all microstrip lines are arranged on the upper surface of the bottom stripline, and the input and output ends are kept at the same horizontal height, which is conducive to reducing the impedance mismatch during cascading. The microstrip line is connected to the strip transmission line or strip adapter line in the bottom stripline through a vertical through-hole coaxial structure, and the strip adapter line is connected to the strip transmission line of the non-bottom stripline through a vertical through-hole coaxial structure, thereby realizing the interconnection between the input and output ends of the signal routing structure and the strip transmission channels of different layers of striplines; the vertical through-hole coaxial structure realizes three-dimensional transmission of microwave radio frequency signals.

[0013] Furthermore, the vertical through-hole coaxial structure includes: a central signal transmission via hole and a plurality of shielding via holes arranged around the central signal transmission via hole.

[0014] The beneficial effects of adopting the above further scheme are: opening a signal hole on the common ground plane of the microstrip line and the bottom strip line, using metallized through-holes to realize the interconnection of the surface microstrip and the interlayer strip line, and setting an annular grounding hole around the central signal transmission via, which can not only play a shielding role and suppress the radiation loss caused by the parasitic parallel plate mode, but also simulate the coaxial transmission line structure with the metallized through-hole to ensure the effective transmission of the signal.

[0015] Furthermore, the two long sides of the rectangular parallelepiped structure are sawtooth structures, and the metal blind groove is provided on each sawtooth of the sawtooth structure.

[0016] The beneficial effect of adopting the above further solution is: setting the input and output ports to be serrated can effectively prevent the isolation from being reduced due to partial space leakage of the same-layer strip patch cord when the signal is converted from the microstrip line to the strip line of a different layer. The metal edging of the inner side wall of the serrated groove achieves good isolation of the same-layer strip patch cord in the confined space formed by the serrated side wall metallization wall and the upper and lower layers of the strip line.

[0017] Furthermore, all sides of the signal routing structure are provided with metal edging.

[0018] The beneficial effect of adopting the above further solution is that the side metallized edging is simultaneously connected to the signal ground of each layer in the multi-layer hybrid board, effectively ensuring the isolation between the strip lines of different layers.

[0019] Furthermore, the first switch array includes multiple first single-pole single-throw switches, and the second switch array includes multiple second single-pole single-throw switches; a first single-pole single-throw switch is connected between each output end of the limiting amplifier circuit and the input end corresponding to the signal routing structure, and a second single-pole single-throw switch is connected between the output end of the signal routing structure and the corresponding combining switch.

[0020] The beneficial effects of adopting the above-mentioned further solution are as follows: switches are used for isolation at both the input and output ends of the signal routing structure, sharing the isolation requirements of the striplines on the same layer, effectively improving the isolation of the entire signal routing structure. The measured isolation between any channels of the signal transmission circuit is greater than 70dBc when 1, 2, or 3 DC-18GHz signals are working simultaneously. The excellent test performance proves the rationality and feasibility of the design. In addition, adding switches can reduce the channel spacing between striplines on the same layer, further reducing the size of the circuit and realizing a miniaturized design.

[0021] Furthermore, when a strip transmission line on the same layer is selected to transmit a signal, the first single-pole single-throw switch at the input end of the other strip transmission lines on the same layer is disconnected, and the second single-pole single-throw switch at the output end of the other strip transmission lines on the same layer is disconnected.

[0022] The beneficial effect of adopting the above further solution is as follows: when a certain channel of the stripline on the same layer is selected to transmit a signal, the switches at the input ends of other channels of the stripline on the same layer are disconnected, effectively isolating the interference of other signals on the matrix network; the switches at the output ends of other channels of the stripline on the same layer are disconnected, ensuring that the signal leaked from the stripline channel on the same layer of the matrix network cannot crosstalk with other channels.

[0023] Furthermore, the limiting amplifier circuit includes a limiter, a coupler, a first low noise amplifier, a digitally controlled attenuator, a filter, an equalizer, a second low noise amplifier and a power divider connected in sequence.

[0024] The beneficial effects of adopting the above further scheme are as follows: the input microwave signal is limited by a limiter to a large signal, thereby protecting the subsequent amplifier circuit from being burned; a self-test signal is introduced through a coupler to detect faults in the signal routing structure; the microwave signal is amplified by a first low-noise amplifier; the microwave signal is amplitude-adjusted by a digitally controlled attenuator to prevent the subsequent amplifier circuit from entering a saturation state when the input microwave signal is large; the microwave signal is filtered by a filter to suppress out-of-band interference; the microwave signal amplitude fluctuation is adjusted by an equalizer to improve gain flatness; the microwave signal is amplified for a second time by a second low-noise amplifier; and the microwave signal power is distributed by a power divider to be divided into two signal outputs.

[0025] Furthermore, the power divider is connected to a plurality of first single-pole single-throw switches.

[0026] In order to solve the above technical problems, the present invention further provides an electronic device, comprising the multi-layer stripline-based signal transmission circuit provided by the above technical solution.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A structural diagram of a signal transmission circuit based on a multi-layer stripline according to an embodiment of the present invention;

[0029] Figure 2 A cross-sectional view of a signal routing structure provided by an embodiment of the present invention;

[0030] Figure 3 A top view of the signal routing structure provided by an embodiment of the present invention;

[0031] Figure 4 A three-dimensional diagram of a vertical through-hole coaxial structure provided by an embodiment of the present invention;

[0032] Figure 5This is a structural diagram of a signal transmission circuit based on multi-layer striplines provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present disclosure through specific concrete examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0034] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0035] like Figure 1 As shown, a multi-layer stripline-based signal transmission circuit provided by an embodiment of the present invention includes: multiple limiting amplifier circuits with the same structure but different frequencies, a first switch array, a signal routing structure, a second switch array, multiple combining switches, and a power supply and control circuit. M is the number of limiting amplifier circuits, and N is the number of combining switches.

[0036] like Figure 2As shown, the signal routing structure includes multiple layers of stacked striplines, each layer of striplines includes an upper ground layer, an upper dielectric layer, a stripline transmission line layer, a lower dielectric layer, and a lower ground layer. This embodiment includes three layers of striplines. Taking the first layer of striplines as an example, it includes the first layer of circuits (i.e., the upper ground layer), the first layer of dielectrics, the second layer of dielectrics, the second layer of circuits (the first stripline transmission line layer), the third layer of dielectrics, and the third layer of circuits (i.e., the lower ground layer). The number of dielectric layers included in the upper dielectric layer and the lower dielectric layer of each stripline layer is determined according to actual needs. In this embodiment, a fourth layer of dielectrics is provided between the lower ground layer of the first stripline layer and the upper ground layer of the second stripline layer. The second and third stripline layers share the sixth layer of circuits as a common ground layer.

[0037] like Figure 3 As shown, each stripline layer includes multiple stripline transmission lines. Figure 3 In the figure, the solid lines represent the 4 strip transmission lines of the first layer, the dashed lines represent the 4 strip transmission lines of the second layer, and the dotted lines represent the 2 strip transmission lines of the third layer. The third layer of strip line is used as the bottom layer transmission line, and the internal strip line is connected to the Figure 3 Not shown in the figure.

[0038] The output end of the multi-channel limiting amplifier circuit is connected to the input end of the signal routing structure through the first switch array, and signals transmitted simultaneously are transmitted through strip transmission lines on different layers, and signals transmitted at different times are transmitted through strip transmission lines on the same layer. The output end of the signal routing structure is connected to the combining switch through the second switch array, and strip transmission lines on the same layer are connected to one combining switch, and strip transmission lines on different layers are connected to different combining switches.

[0039] The power supply and control circuit is used to provide power supply and control to the multiple limiting amplifier circuits, the first switch array, the second switch array and the multiple combining switches.

[0040] The embodiments of the present invention utilize a multi-channel limiting amplifier circuit and multi-layer, multi-channel stripline transmission to achieve arbitrary routing between RF channels. The signal routing structure organizes RF signals, distributing simultaneously transmitted signals across different stripline layers and distributing non-simultaneously transmitted signals across the same stripline layer. The multi-layer stripline layer enables cross-transmission of microwave RF signals. The more channels, the more stripline layers. However, the passive network of the multi-layer stripline transmission is transmitted in three dimensions, increasing only the thickness without increasing the length or width. This not only improves isolation but also enhances integration through vertical transmission of the multi-layer stripline layer, achieving a planar, dielectric, and miniaturized design for the RF transmission network.

[0041] Optionally, the signal routing structure is a rectangular structure formed by stacking multiple layers of strip lines, and the two long sides of the rectangular structure are respectively provided with multiple metal blind grooves at equal intervals, and the metal blind grooves extend vertically to the bottom strip line. A microstrip line is arranged on the upper surface of the bottom strip line corresponding to the metal blind groove, and all the microstrip lines on one side of the rectangular structure serve as the input end of the signal routing structure, and all the microstrip lines on the other side serve as the output end of the signal routing structure; in addition to including multiple strip transmission lines, the bottom strip line also includes multiple strip adapter lines, and the microstrip lines are connected to the strip transmission lines or strip adapter lines of the bottom strip line through a vertical through-hole coaxial structure, and the strip adapter line is connected to the strip transmission lines other than the bottom strip line through a vertical through-hole coaxial structure.

[0042] In an embodiment of the present invention, a metalized blind groove is applied to the side of the signal routing structure, which is beneficial to reducing the ground loop path when the signal routing structure is cascaded with the first and second switch arrays, thereby improving the discontinuity caused by the cascade; all microstrip lines are arranged on the upper surface of the bottom stripline, and the input and output ends are maintained at the same horizontal height, which is beneficial to reducing the impedance mismatch during cascade. The microstrip line is connected to the strip transmission line or strip adapter line in the bottom stripline through a vertical through-hole coaxial structure. The strip adapter line is connected to the strip transmission line of the non-bottom stripline through the vertical through-hole coaxial structure, thereby realizing the interconnection between the input and output ends of the signal routing structure and the strip transmission channels of different layers of striplines; the vertical through-hole coaxial structure realizes three-dimensional transmission of microwave radio frequency signals.

[0043] like Figure 4 As shown in the figure, assuming that the third layer of stripline is the bottom layer of stripline, the metal blind slot extends to the upper surface of the bottom layer of stripline (i.e., the third layer of stripline), and a microstrip line is set on the upper surface of the metal blind slot. The microstrip line is connected to the third layer of stripline transmission line through a vertical through-hole coaxial structure (the shielding via of the vertical through-hole coaxial structure is not shown in the figure), and the third layer of microstrip transmission line is connected to the first layer of stripline transmission line through a vertical through-hole coaxial structure. The vertical through-hole coaxial structure includes: a central signal transmission via and multiple shielding vias surrounding the central signal transmission via. The central signal transmission via can be a through hole, a blind via, or a semi-blind via, depending on which layers of signals are connected. The number of shielding vias can be 10 during design, and this number is not fixed. In principle, the more the better, as long as the process and reliability allow. The shielding vias can all be through holes, but if they cross the signal line, blind vias or semi-blind vias are used.

[0044] In this embodiment of the present invention, a signal via is opened on the common ground plane of the microstrip line and the bottom stripline. Metallized through-holes are used to interconnect the surface microstrip and interlayer striplines. Ring-shaped ground holes are arranged around the central signal transmission via. This not only provides shielding, suppressing radiation loss caused by parasitic parallel plate modes, but also simulates a coaxial transmission line structure with the metallized through-holes to ensure efficient signal transmission. The stripline patch cord within the bottom stripline layer is connected to the stripline transmission lines of other striplines in the same manner as described above.

[0045] Optionally, the two long sides of the signal routing structure are serrated structures, and the metal blind groove is provided on each serration of the serrated structure. In this embodiment of the present invention, the input and output ports of the signal routing structure are serrated, which can effectively prevent the isolation degradation caused by partial spatial leakage of the same-layer stripline patch cord when the signal is converted from the microstrip line to the stripline of a different layer. The metal edging of the inner sidewalls of the serrated groove achieves good isolation of the same-layer stripline patch cord within the confined space formed by the metallized walls of the serrated sidewalls and the upper and lower stripline layers.

[0046] Optionally, all sides of the signal routing structure are provided with metal edging, which is connected to the signal ground of each layer in the multi-layer hybrid board, effectively ensuring the isolation between the strip lines of different layers.

[0047] Optionally, the first switch array includes multiple first single-pole single-throw switches, and the second switch array includes multiple second single-pole single-throw switches; a first single-pole single-throw switch is connected between each output end of the limiting amplifier circuit and the input end corresponding to the signal routing structure, and a second single-pole single-throw switch is connected between the output end of the signal routing structure and the corresponding combining switch.

[0048] In this embodiment of the present invention, switches are used for isolation at both the input and output ends of the signal routing structure, thereby sharing the isolation requirements of the striplines on the same layer and effectively improving the isolation of the entire signal routing structure. In actual measurements, the isolation between any channels of the signal transmission circuit when one, two, or three DC-18 GHz signals are operating simultaneously is greater than 70 dBc. This excellent test performance demonstrates the rationality and feasibility of the design. Furthermore, adding switches can reduce the channel spacing between striplines on the same layer, further reducing the size of the circuit and achieving a miniaturized design.

[0049] Optionally, when a stripline transmission line on the same layer is enabled for signal transmission, the first single-pole single-throw switches at the input ends of other stripline transmission lines on the same layer are disconnected, and the second single-pole single-throw switches at the output ends of other stripline transmission lines on the same layer are disconnected. In this embodiment of the present invention, when a channel on a stripline on the same layer is enabled for signal transmission, the switches at the input ends of other channels on the same layer are disconnected, effectively isolating the matrix network from interference from other signals. Disconnecting the switches at the output ends of other channels on the same layer ensures that signals leaking from the stripline channels on the same layer of the matrix network cannot crosstalk with other channels.

[0050] Optionally, the limiting amplifier circuit includes a limiter, a coupler, a first low noise amplifier, a digitally controlled attenuator, a filter, an equalizer, a second low noise amplifier, and a power divider connected in sequence. The power divider is connected to a plurality of first single-pole single-throw switches.

[0051] In an embodiment of the present invention, an input microwave signal is subjected to large-signal limiting by a limiter to protect a subsequent amplifier circuit from being burned; a self-test signal is introduced through a coupler to perform fault detection on a signal routing structure; the microwave signal is amplified by a first low-noise amplifier; the microwave signal is amplitude-adjusted by a digitally controlled attenuator to prevent the subsequent amplifier circuit from entering a saturation state when the input microwave signal is large; the microwave signal is filtered by a filter to suppress out-of-band interference; the microwave signal amplitude fluctuation is adjusted by an equalizer to improve gain flatness; the microwave signal is amplified a second time by a second low-noise amplifier; and the microwave signal power is distributed by a power divider to be divided into two signal outputs.

[0052] The technical solution of the present invention is described in detail below with a specific example.

[0053] like Figure 5 As shown, the signal transmission circuit based on the multilayer stripline includes:

[0054] The embodiment of the present invention adopts a four-channel limiting amplifier circuit and a signal routing structure to process the four input microwave signals, including limiting, amplification, filtering, digitally controlled attenuation, equalization, and power division, before outputting them. The signals are routed through the multi-layer strip lines of the signal routing structure, and then synthesized into one microwave signal output through a multi-way switch, thus realizing arbitrary routing between RF channels.

[0055] The signal transmission circuit 100 based on the multi-layer stripline includes: a four-channel limiting amplifier circuit 1001, a routing component 1002, a combining switch array 1003 and a power supply and control circuit.

[0056] The four-channel limiting amplifier circuit 1001 includes, in sequence: a first limiting amplifier circuit A1 , a second limiting amplifier circuit B2 , a third limiting amplifier circuit C3 , and a fourth limiting amplifier circuit D4 .

[0057] Routing assembly 1002 includes a first switch array, a signal routing structure, and a second switch array. The signal routing structure includes three layers of stripline. The first stripline layer, represented by solid lines, includes four stripline transmission lines; the second stripline layer, represented by dashed lines, includes four stripline transmission lines; and the third stripline layer, represented by dotted lines, includes two stripline transmission lines.

[0058] The input and output ends of the signal routing structure are isolated by single-pole single-throw switches, which effectively shares the system's isolation requirements for the signal routing structure channels and realizes the high integration requirements of the signal transmission circuit.

[0059] The combining switch array 1003 includes a single-pole four-throw switch U25, a single-pole four-throw switch V26, and a single-pole four-throw switch W27.

[0060] Specifically, the first output terminal a1 of the first limiting amplifier circuit A1 is connected to the input terminal of the single-pole single-throw switch A5, the output terminal of the single-pole single-throw switch A5 is connected to the input terminal of the single-pole single-throw switch K15 through the first strip transmission line of the first layer of strip lines, and the output terminal b1 of the single-pole single-throw switch K15 is connected to the first input terminal of the single-pole four-throw switch U25; the first output terminal a3 of the second limiting amplifier circuit B2 is connected to the input terminal of the single-pole single-throw switch C7, the output terminal of the single-pole single-throw switch C7 is connected to the input terminal of the single-pole single-throw switch L16 through the second strip transmission line of the first layer of strip lines, and the output terminal b2 of the single-pole single-throw switch L16 is connected to the second input terminal of the single-pole four-throw switch U25; the first output terminal a6 of the first limiting amplifier circuit C3 is connected to the single-pole The input end of the single-throw switch F10 is connected, the output end of the single-pole single-throw switch F10 is connected to the input end of the single-pole single-throw switch M17 through the third strip transmission line of the first layer of strip line, and the output end b3 of the single-pole single-throw switch M17 is connected to the third input end of the single-pole four-throw switch U25; the first output end a9 of the first limiting amplifier circuit D4 is connected to the input end of the single-pole single-throw switch I13, the output end of the single-pole single-throw switch I13 is connected to the input end of the single-pole single-throw switch N18 through the fourth strip transmission line of the first layer of strip line, and the output end b4 of the single-pole single-throw switch N18 is connected to the fourth input end of the single-pole four-throw switch U25; the output end of the single-pole four-throw switch U25 is the combined signal output end 1 of the signal transmission circuit 100 based on the multi-layer strip line.

[0061] The second output terminal a2 of the first limiting amplifier circuit A1 is connected to the input terminal of the single-pole single-throw switch B6, the output terminal of the single-pole single-throw switch B6 is connected to the input terminal of the single-pole single-throw switch O19 through the first strip transmission line of the second layer of strip lines, and the output terminal b5 of the single-pole single-throw switch O19 is connected to the first input terminal of the single-pole four-throw switch V26; the second output terminal a4 of the second limiting amplifier circuit B2 is connected to the input terminal of the single-pole single-throw switch D8, the output terminal of the single-pole single-throw switch D8 is connected to the input terminal of the single-pole single-throw switch P20 through the second strip transmission line of the second layer of strip lines, and the output terminal b6 of the single-pole single-throw switch P20 is connected to the second input terminal of the single-pole four-throw switch V26; the second output terminal a7 of the first limiting amplifier circuit C3 is connected to the input terminal of the single-pole single-throw switch The first circuit 100 is connected to the input end of the single-pole single-throw switch G11, the output end of the single-pole single-throw switch G11 is connected to the input end of the single-pole single-throw switch Q21 through the third stripline transmission line of the second layer of stripline, and the output end b7 of the single-pole single-throw switch Q21 is connected to the third input end of the single-pole four-throw switch V26; the second output end a10 of the first limiting amplifier circuit D4 is connected to the input end of the single-pole single-throw switch J14, the output end of the single-pole single-throw switch J14 is connected to the input end of the single-pole single-throw switch R22 through the fourth stripline transmission line of the second layer of stripline, and the output end b8 of the single-pole single-throw switch R22 is connected to the fourth input end of the single-pole four-throw switch V26; the output end of the single-pole four-throw switch V26 is the combined signal output end two of the signal transmission circuit 100 based on the multi-layer stripline.

[0062] The third output terminal a5 of the second limiting amplifier circuit B2 is connected to the input terminal of the single-pole single-throw switch E9, the output terminal of the single-pole single-throw switch E9 is connected to the input terminal of the single-pole single-throw switch S23 through the first strip transmission line of the third layer of stripline, and the output terminal b9 of the single-pole single-throw switch S23 is connected to the first input terminal of the single-pole double-throw switch W27; the third output terminal a8 of the third limiting amplifier circuit C3 is connected to the input terminal of the single-pole single-throw switch H12, the output terminal of the single-pole single-throw switch H12 is connected to the input terminal of the single-pole single-throw switch T24 through the second strip transmission line of the third layer of stripline, and the output terminal of the single-pole single-throw switch T24 is connected to the second input terminal of the single-pole double-throw switch W27; the output terminal of the single-pole double-throw switch W27 is the combined signal output terminal three of the signal transmission circuit 100 based on the multi-layer stripline.

[0063] When the multi-layer stripline-based signal transmission circuit 100 is in operation, a first microwave signal inputted from the outside first enters the first limiting amplifier circuit A1, which performs limiting, amplification, filtering, digitally controlled attenuation, equalization, and power division on the first microwave signal inputted, and outputs the power division. A second microwave signal inputted from the outside first enters the second limiting amplifier circuit B2, which performs limiting, amplification, filtering, digitally controlled attenuation, equalization, and power division on the second microwave signal inputted, and outputs the power division. A third microwave signal inputted from the outside first enters the third limiting amplifier circuit C3, which performs limiting, amplification, filtering, digitally controlled attenuation, equalization, and power division on the third microwave signal inputted, and outputs the power division. A fourth microwave signal inputted from the outside first enters the fourth limiting amplifier circuit D4, which performs limiting, amplification, filtering, digitally controlled attenuation, equalization, and power division on the fourth microwave signal inputted, and outputs the power division.

[0064] The first microwave signal processed by the first limiting amplifier circuit A1 passes through the single-pole single-throw switch A5 and the single-pole single-throw switch K15. The second microwave signal processed by the second limiting amplifier circuit B2 passes through the single-pole single-throw switch C7 and the single-pole single-throw switch L16. The third microwave signal processed by the third limiting amplifier circuit C3 passes through the single-pole single-throw switch F10 and the single-pole single-throw switch M17. The fourth microwave signal processed by the fourth limiting amplifier circuit D4 passes through the single-pole single-throw switch I13 and the single-pole single-throw switch N18. The single-pole single-throw switches improve the isolation between the channels. Finally, the microwave signals are combined into one output through the single-pole four-throw switch U25. The output end of the single-pole four-throw switch U25 is the combined signal output end 1 of the signal transmission circuit 100 based on the multi-layer stripline.

[0065] The second microwave signal processed by the first limiting amplifier circuit A1 passes through the single-pole single-throw switch B6 and the single-pole single-throw switch O19. The second microwave signal processed by the second limiting amplifier circuit B2 passes through the single-pole single-throw switch D8 and the single-pole single-throw switch P20. The second microwave signal processed by the third limiting amplifier circuit C3 passes through the single-pole single-throw switch G11 and the single-pole single-throw switch Q21. The second microwave signal processed by the fourth limiting amplifier circuit D4 passes through the single-pole single-throw switch J14 and the single-pole single-throw switch R22. The single-pole single-throw switches improve the isolation between the channels. Finally, the microwave signal is combined into one output through the single-pole four-throw switch V26. The output end of the single-pole four-throw switch V26 is the combined signal output end two of the multi-layer stripline-based signal transmission circuit 100.

[0066] The third microwave signal processed by the second limiting amplifier circuit B2 passes through the single-pole single-throw switch E9 and the single-pole single-throw switch S23. The third microwave signal processed by the third limiting amplifier circuit C3 passes through the single-pole single-throw switch H12 and the single-pole single-throw switch T24. The single-pole single-throw switches improve the isolation between the channels. Finally, the third microwave signal is combined into one output through the single-pole double-throw switch W27. The output end of the single-pole double-throw switch W27 is the combined signal output end three of the signal transmission circuit 100 based on the multi-layer stripline.

[0067] The following is an analysis of the channel isolation when three signals are working simultaneously.

[0068] Within the DC-18 GHz bandwidth, assuming that the isolation between adjacent striplines on the same layer is 30 dB, the isolation between adjacent striplines on different layers is 70 dB, and the isolation between switches A5 and W27 is 40 dB. Assuming that channels a2-b5, a3-b2, and a8-b10 are selected, the first microwave input signal is routed to combined signal output terminal 2, the second microwave input signal is routed to combined signal output terminal 1, and the third microwave input signal is routed to combined signal output terminal 3.

[0069] When inputting a signal, the signal leakage paths mainly include transmission path leakage and space radiation leakage. The following lists four main isolated leakage paths, and the remaining leakage paths are not listed here one by one.

[0070] 1) When a2 input signal:

[0071] Isolation leakage path 1: The a2 signal passes through the signal routing structure (stripline isolation on different layers) and is output to b2 via switch L16 (closed).

[0072] Isolation: 70 (strip lines on different layers) + 0 (switch L16) = 70dB;

[0073] Isolation leakage path 2: a1 and a2 have the same signal size. The a1 signal passes through switch A5 (open), the signal routing structure (same-layer stripline isolation), and outputs b2 through switch L16 (closed).

[0074] Isolation: 40 (switch A5) + 30 (stripline on the same layer) + 0 (switch L16) = 70dB.

[0075] Isolation leakage path 3: a1 and a2 have the same signal size. The a1 signal passes through switch A5 (disconnected), the signal routing structure (stripline transmission on the same layer), and is output to b1 through switch K15 (disconnected).

[0076] Isolation: 40 (switch A5) + 40 (switch K15) = 80dB.

[0077] Isolation leakage path 4: The a2 signal passes through the signal routing structure (stripline isolation on different layers) and is output to b10 via switch T24 (closed).

[0078] Isolation: 70(strip lines on different layers)+0(T24)=70dB;

[0079] 2) When a3 input signal:

[0080] Isolation leakage path 1: The a3 signal passes through the signal routing structure (stripline isolation on different layers) and is output to b5 via switch O19 (closed).

[0081] Isolation: 70 (strip lines on different layers) + 0 (switch O19) = 70dB;

[0082] Isolation leakage path 2: a4 and a3 have the same signal size. The a4 signal passes through switch D8 (open), the switch matrix (same-layer stripline isolation), and is output to b5 through switch O19 (closed).

[0083] Isolation: 40 (switch D8) + 30 (stripline on the same layer) + 0 (switch O19) = 70dB.

[0084] Isolation leakage path 3: a4 and a3 have the same signal size. The a4 signal passes through switch D8 (disconnected), the signal routing structure (same-layer stripline transmission), and is output to b6 through switch P20 (disconnected).

[0085] Isolation: 40 (switch D8) + 40 (switch P20) = 80dB.

[0086] Isolation leakage path 4: The a3 signal passes through the switch matrix (stripline isolation on different layers) and is output to b10 via switch T24 (closed).

[0087] Isolation: 70 (strip lines on different layers) + 0 (switch T24) = 70dB;

[0088] Isolation leakage path 5: a5 and a3 have the same signal size. The a5 signal passes through switch E9 (open), the signal routing structure (stripline transmission on the same layer), and is output to b9 through switch S23 (open).

[0089] Isolation: 40 (switch D8) + 40 (switch S23) = 80dB.

[0090] 3) When a8 inputs the signal,

[0091] Isolation leakage path 1: The a8 signal passes through the signal routing structure (stripline isolation on different layers) and is output to b2 via switch L16 (closed).

[0092] Isolation: 70 (strip lines on different layers) + 0 (switch L16) = 70dB;

[0093] Isolation leakage path 2: a8 and a6 have the same signal size. The a6 signal passes through switch F10 (open), the signal routing structure (same-layer stripline isolation), and outputs b2 through switch L16 (closed).

[0094] Isolation: 40 (switch F10) + 30 (stripline on the same layer) + 0 (switch L16) = 70 dB.

[0095] Isolation leakage path 3: a8 and a6 have the same signal size. The a6 signal passes through switch F10 (disconnected), the signal routing structure (stripline transmission on the same layer), and is output to b1 through switch M17 (disconnected).

[0096] Isolation: 40 (switch F10) + 40 (switch M17) = 80dB.

[0097] Isolation leakage path 4: The a8 signal passes through the signal routing structure (stripline isolation on different layers) and is output to b5 via switch O19 (closed).

[0098] Isolation: 70 (strip lines on different layers) + 0 (switch O19) = 70dB;

[0099] Isolation leakage path 5: a8 and a7 have the same signal size. The a7 signal passes through switch G11 (open), and the signal routing structure is isolated by the same-layer stripline, and is output to b5 through switch O19 (closed).

[0100] Isolation: 40 (switch D8) + 30 (stripline on the same layer) + 0 (switch O19) = 70dB.

[0101] Isolation leakage path 6: a8 and a7 have the same signal size. The a7 signal passes through switch G11 (disconnected), and is output to b6 through switch Q21 (disconnected).

[0102] Isolation: 40 (switch G11) + 40 (switch Q21) = 80dB.

[0103] The above analysis and calculations demonstrate that when simultaneously transmitting channels are arranged on different stripline layers, the isolation of the transmission circuit primarily depends on the isolation of the stripline layers. The isolation of stripline layers on the same layer can be improved by adding switches. The electric field distribution of stripline layers on different layers is confined within the confined space between the upper and lower ground layers and the metal cladding on both sides, allowing for very high isolation. Furthermore, stripline layers on the same layer can be cascaded with multiple switches to mitigate crosstalk between channels, depending on the isolation requirements.

[0104] The multilayer stripline-based signal transmission circuit 100 of the present invention employs a four-channel limiting amplifier circuit and a signal routing structure to power-divider the four microwave signals input. Simultaneously transmitted signals are distributed across fully shielded, highly isolated striplines on different layers, while non-simultaneously transmitted signals are distributed across the same stripline layer, achieving arbitrary routing between RF channels. Single-pole, single-throw switches are used at both the input and output ends of the signal routing structure for isolation, effectively balancing the system's isolation requirements for matrix network circuit channels. Tested isolation between any two or three DC-18 GHz signals was greater than 70 dBc, demonstrating excellent test performance. The multilayer stripline structure enables three-dimensional transmission of RF signals. Adding switches reduces the channel spacing between striplines on the same layer, reducing the size to one-third that of conventional components. This achieves both high isolation and a planar, dielectric, and compact design.

[0105] An embodiment of the present invention further provides an electronic device, comprising the multi-layer stripline-based signal transmission circuit provided by the above technical solution.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A signal transmission circuit based on a multi-layer stripline, characterized in that: include: Multiple limiting amplifier circuits with the same structure but different frequencies, a first switch array, a signal routing structure, a second switch array, a plurality of combining switches, and a power supply and control circuit; The signal routing structure includes multiple layers of stacked strip lines, each layer of strip lines including multiple strip transmission lines; The output ends of the multiple limiting amplifier circuits are connected to the input ends of the signal routing structure through the first switch array, and the signals transmitted simultaneously are transmitted through the strip transmission lines of different layers, and the signals transmitted at different times are transmitted through the strip transmission lines of the same layer; the output ends of the signal routing structure are connected to the combining switches through the second switch array, and the strip transmission lines of the same layer are connected to one combining switch, and the strip transmission lines of different layers are connected to different combining switches; The power supply and control circuit is used to provide power and control to the multiple limiting amplifier circuits, the first switch array, the second switch array and the multiple combining switches; The signal routing structure is a rectangular parallelepiped structure formed by stacking multiple layers of strip lines. A plurality of metal blind slots are provided at equal intervals on each of the two long sides of the rectangular parallelepiped structure. The metal blind slots extend vertically to the bottom strip line. A microstrip line is provided on the upper surface of the bottom strip line corresponding to the metal blind slot. All the microstrip lines on one side of the rectangular parallelepiped structure serve as input ends of the signal routing structure, and all the microstrip lines on the other side serve as output ends of the signal routing structure. In addition to multiple strip transmission lines, the bottom strip line also includes multiple strip adapter lines. The microstrip line is connected to the strip transmission line or strip adapter line of the bottom strip line through a vertical through-hole coaxial structure. The strip adapter line is connected to the strip transmission line other than the bottom strip line through a vertical through-hole coaxial structure.

2. The multi-layer stripline-based signal transmission circuit according to claim 1, characterized in that: The vertical through-hole coaxial structure includes a central signal transmission via hole and a plurality of shielding via holes surrounding the central signal transmission via hole.

3. The multi-layer stripline-based signal transmission circuit according to claim 1, wherein: The two long sides of the rectangular parallelepiped structure are sawtooth structures, and the metal blind groove is arranged on each sawtooth of the sawtooth structure.

4. The multi-layer stripline-based signal transmission circuit according to claim 1, wherein: All sides of the signal routing structure are provided with metal edging.

5. The multi-layer stripline-based signal transmission circuit according to any one of claims 1 to 4, characterized in that: The first switch array includes a plurality of first single-pole single-throw switches, and the second switch array includes a plurality of second single-pole single-throw switches; a first single-pole single-throw switch is connected between each output end of the limiting amplifier circuit and the corresponding input end of the signal routing structure, and a second single-pole single-throw switch is connected between the output end of the signal routing structure and the corresponding combining switch.

6. The multi-layer stripline-based signal transmission circuit according to claim 5, characterized in that: When a strip transmission line on the same layer is selected to transmit a signal, the first single-pole single-throw switch at the input end of the other strip transmission lines on the same layer is disconnected, and the second single-pole single-throw switch at the output end of the other strip transmission lines on the same layer is disconnected.

7. The multi-layer stripline-based signal transmission circuit according to claim 5, characterized in that: The limiting amplifier circuit comprises a limiter, a coupler, a first low-noise amplifier, a digitally controlled attenuator, a filter, an equalizer, a second low-noise amplifier and a power divider which are connected in sequence.

8. The multi-layer stripline-based signal transmission circuit according to claim 7, characterized in that: The power divider is connected to a plurality of the first single-pole single-throw switches.

9. An electronic device, characterized in that: A signal transmission circuit based on a multi-layer stripline comprising the method according to any one of claims 1 to 8.

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