A double-layer ring-shaped four-port network radio frequency microwave switch

Abstract

The present application relates to the field of radio frequency microwave, and particularly relates to a double-layer annular four-port network radio frequency microwave switch, comprising: a substrate, the substrate is a rectangular plate with double surfaces; a co-planar waveguide structure, the co-planar waveguide structure adopts a three-in-one design, comprising a signal line and ground lines on both sides of the signal line; the co-planar waveguide structure is symmetrically arranged at the center of each side of the substrate; the signal line branch is further provided with a Pad window, a Pad lead and an air bridge structure; an upper electrode, the upper electrode is fixed on the co-planar waveguide through an anchor point, and the upper electrode is a cantilever type straight plate structure containing an array of release holes; a Y-type power divider structure, the Y-type power divider structure is narrow-band cascaded with the co-planar waveguide structure, and is used for accurately distributing an input signal to multiple output channels; a power division port of the Y-type power divider structure is connected with the upper electrode through a double-contact structure; a cascaded through-hole, used for realizing cascaded operation of a double-layer double-pole double-throw switch, ensuring signal integrity and realizing efficient transmission.

Description

Technical Field

[0001] This invention relates to the field of radio frequency microwave, and in particular to a dual-layer ring four-port network radio frequency microwave switch. Background Technology

[0002] Radio frequency (RF) MEMS switches are indispensable core components in modern communication technologies, attracting significant attention due to their low insertion loss, high isolation, and miniaturization characteristics in the microwave band. These superior properties make RF MEMS switches promising for wide application in high-performance communication systems, radar systems, and other RF and microwave fields. Compared to traditional RF switches, RF MEMS switches, with their advantages of low insertion loss, high isolation, and miniaturization, have become a major driving force for the development of modern communication technologies. In the future, through further optimization of their performance and expansion of their application areas, RF MEMS switches are expected to play an even more important role in next-generation communication systems.

[0003] Chinese patent application CN202211131029.4 discloses a DC-60GHz radio frequency MEMS switch. The proposed coplanar waveguide transmission line groove structure enables impedance matching of the transmission line, thereby increasing return loss and improving signal transmission efficiency. By designing a groove structure on the transmission line, the impedance matching problem caused by directly integrating the switch in the coplanar waveguide structure is solved. Furthermore, the coplanar waveguide transmission line is narrowed and a defective structure is designed to achieve high isolation of the switch. Anchor points are used to fix the switch's metal beam, thereby reducing the switch's elastic coefficient and lowering the driving voltage. This results in an RF MEMS switch with advantages such as large bandwidth, high isolation, low driving voltage, low insertion loss, good return loss, direct integration on the coplanar waveguide, and miniaturization.

[0004] One of the main problems with traditional RF MEMS switches is their ability to transmit signals only in a single channel, failing to meet the demands of multi-channel signal processing. While existing technologies have partially overcome this limitation by adding output ports, the fixed design of the input and output ports restricts the switch's application in complex communication systems, limiting its unidirectional signal transmission capabilities. With the increasing demands for high-frequency signal processing and multi-channel switching in modern communication and electronic systems, developing an RF MEMS switch capable of simultaneously handling multiple signal channels is crucial. This new type of switch needs to be smaller, more integrated, and possess stronger multi-channel coordination capabilities. Furthermore, its design must support array-based configurations to meet the flexibility and scalability requirements of future high-density, large-scale communication devices. Therefore, developing a miniaturized, highly integrated, multi-channel RF MEMS switch not only addresses the bottlenecks of traditional technologies but also provides important technical support and innovative pathways for high-performance communication systems, radar systems, and other high-frequency applications. Summary of the Invention

[0005] This invention provides a dual-layer ring four-port network radio frequency microwave switch, which can improve the multi-channel isolation and insertion loss performance of the switch.

[0006] To address the aforementioned technical problems, this application provides the following technical solution: a double-layer ring four-port network radio frequency microwave switch, comprising:

[0007] Substrate: The substrate is a rectangular plate integrally formed on both sides;

[0008] Coplanar waveguide structure: The coplanar waveguide structure adopts a three-in-one design, including a signal line and ground lines on both sides of the signal line; the coplanar waveguide structure is symmetrically arranged at the center of each side of the substrate; the side branches of the signal line are also connected to Pad windows, Pad leads and air bridge structures in sequence; Upper electrode: The upper electrode is fixed to the coplanar waveguide structure by anchor points, and the upper electrode is a cantilevered straight plate structure with arrayed release holes;

[0009] Y-type power divider structure: The Y-type power divider structure is cascaded with a coplanar waveguide structure in a narrowband configuration to accurately distribute the input signal to multiple output channels; the power divider port of the Y-type power divider structure is connected to the upper electrode through a double-contact structure.

[0010] Cascaded vias: The cascaded vias are located at the corners of the transmission structure in the Pad region and the coplanar waveguide structure, and are used to realize the cascading of double-layer double-pole double-throw switches.

[0011] The basic principles and beneficial effects of this solution: This solution integrates a coplanar waveguide structure, a Y-type power divider, a cantilevered straight-plate top electrode, an air bridge, and a pad onto a single dielectric substrate, achieving miniaturization and weight reduction of the switch, facilitating installation and deployment. This solution employs a symmetrical layout: the coplanar waveguide structure and Y-type power divider in the switch design are symmetrically arranged along the axis of symmetry X (the centerline of the substrate), which facilitates the port and channel layout of the symmetrical switch, improving the miniaturization of the switch. The overall structure is symmetrical about the origin, and the switch within a single channel uses an independently configured drive electrode, switching between different operating modes by applying a drive voltage. Both branches of the power divider are connected to the contact portion of the RF MEMS switch, and the RF MEMS switches of the two branches are relatively distributed to shorten the length of the two arms of the power divider, avoiding significant radiation loss caused by open-circuit capacitance when only one end is conducting. Similarly, as at the corner of the power divider, an air bridge structure and a 45° bevel are incorporated at the channel corner of the ring-shaped four-port RF MEMS switch. This bevel transition structure facilitates a smooth signal transmission transition, reduces signal reflection and loss, and improves the switch's matching performance. Through optimized design, the switch achieves high isolation and low insertion loss, which improves communication quality and reduces interference.

[0012] Furthermore, the power divider port of the Y-type power divider structure is driven by electrostatic force with respect to the upper electrode.

[0013] Furthermore, the through-hole structure of the cascaded through holes includes one of the following: cylindrical, hourglass-shaped, and frustum-shaped.

[0014] Furthermore, the through-hole structure of the cascaded through holes is filled with a metallic material, including but not limited to Au, Cu, W, and Al.

[0015] Beneficial effects: The design of the cascaded through holes not only improves the conductivity of the through holes, but also enhances their mechanical strength, ensuring a reliable connection between multi-layer structures.

[0016] Furthermore, the substrate is a rectangular plate made of materials such as glass and silicon, using an integrated double-sided process.

[0017] Furthermore, the operating frequency range of the dual-layer ring four-port network radio frequency microwave switch is from the L to the Ka band.

[0018] Beneficial effects: It can meet the communication needs of multiple scenarios from low frequency to high frequency, and it still has excellent insertion loss and isolation performance under high frequency conditions.

[0019] Furthermore, the substrate is a rectangular plate integrally formed on both sides, and its material includes, but is not limited to, glass and silicon.

[0020] Furthermore, the input and output ports of the dual-layer ring four-port network radio frequency microwave switch can be replaced.

[0021] Beneficial effects: The interchangeable port settings enable bidirectional signal transmission, improving communication efficiency. Attached Figure Description

[0022] Figure 1 This is a structural diagram of the dual-layer ring four-port network radio frequency microwave switch according to an embodiment of the present invention;

[0023] Figure 2 This is a top view of the overall structure of the double-layer ring four-port network radio frequency microwave switch according to an embodiment of the present invention;

[0024] Figure 3 This is a structural diagram of the Y-type power divider according to an embodiment of the present invention;

[0025] Figure 4 This is a structural diagram of the cantilevered straight plate upper electrode according to an embodiment of the present invention;

[0026] Figure 5 This is a diagram of the coplanar waveguide structure described in an embodiment of the present invention;

[0027] Figure 6This is a simulation diagram of the isolation of port 1 of the dual-layer ring four-port network radio frequency microwave switch according to an embodiment of the present invention;

[0028] Figure 7 This is a simulation diagram of the isolation of port 7 of the dual-layer ring four-port network radio frequency microwave switch as described in an embodiment of the present invention;

[0029] Figure 8 This is a simulation diagram of the insertion loss of the dual-layer ring four-port network radio frequency microwave switch according to an embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram of the substrate and heat sink structure in Example 2;

[0031] Figure 10 A diagram showing the connections of each port;

[0032] Figure 11 This is a schematic diagram showing the state of the cantilevered straight plate upper electrode receiving electrostatic force under different conditions in Example 2;

[0033] Figure 12 This is a schematic diagram of the heat sink connection in the testing circuit. Detailed Implementation

[0034] The following detailed description illustrates the specific implementation method:

[0035] The markings in the accompanying drawings include: substrate 1, coplanar waveguide structure 2, Y-type power divider structure 3, air bridge structure 4, cantilevered straight plate top electrode 5, concave anchor point 6, Pad window 7, Pad lead 8, cascaded via 9, drive electrode 10, dual contact structure 11, air bridge support 12, ring four-port network 13, heat sink 14, detection electrode 15, port 101, port 2 102, port 3 103, port 4 104, port 5 105, port 6 106, port 7 107, and port 8 108.

[0036] Example 1 is attached. Figure 1-8 As shown,

[0037] A dual-layer ring four-port network radio frequency microwave switch, comprising:

[0038] Substrate 1: The substrate is a rectangular plate with a single, double-sided design, and is made of glass with a thickness of 525um to achieve a single, double-sided process layout with a side length of 4090um.

[0039] Coplanar waveguide structure 2: The coplanar waveguide structure 2 is a three-in-one structure with the ground line on both sides of the signal line. The signal line is provided with a Pad window 7, a Pad lead 8 and an air bridge structure 4. The coplanar waveguide structure 2 and the air bridge structure 4 are made of Au material.

[0040] Cantilevered straight plate upper electrode 5: The cantilevered straight plate upper electrode 5 contains a 4×7 array of release holes, which are cascaded with the concave anchor point 6 to realize a signal path. The cantilevered straight plate upper electrode 5 is a rectangular plate integrally formed with a thickness of 2.2um, and the metal layer is an Au cover layer.

[0041] Y-type power divider structure 3: The Y-type power divider structure 3 is cascaded with the coplanar waveguide structure 2 in a narrow band. The power divider port of the Y-type power divider structure 3 is connected to the cantilevered straight plate upper electrode 5 through a double contact structure 11 via electrostatic drive.

[0042] Cascading via 9: The cascading via 9 is set on the Pad window 7 and at the corner of the coplanar waveguide transmission structure to cascade the double-layer double-pole double-throw switch. The cascading via uses the cascading structure material as the corresponding process material to reduce path loss.

[0043] Contacts: The double-layer ring four-port network RF microwave switch is cascaded with a double contact structure 11 at the output end of the Y-type power divider structure 3. The contacts are equilateral rectangular structures and are made of Au as the process material.

[0044] Pad window 7 and Pad lead 8: The Pad window 7 and Pad lead 8 are arranged in a corresponding layout. The signal line side branch Pad window 7 and Pad lead 8 are made of Au as the process material. The cascaded Pad window 7 and Pad lead 8 of the drive electrode 10 are made of Al as the process material.

[0045] Ring-shaped four-port network 13: The ring-shaped four-port network 13 is cascaded with the coplanar waveguide structure 2, the cantilevered straight plate top electrode 5, the Y-type power divider structure 3, the cascaded through hole 9 and the air bridge structure 4. Au is used as the relevant process material, and the ring-shaped four-port network 13 is set with a side length of 2588um.

[0046] like Figure 6 The diagram shown is a simulation of the isolation of the RF microwave switch in the dual-layer ring four-port network. Taking the influence of port 2 (102), port 4 (104), port 6 (106), and port 8 (108) on port 1 (101) as an example, port 2 (102) and port 4 (104) are output terminals on the same layer, while port 6 (106) and port 8 (108) are output terminals on different layers. Figure 6 The S-parameter performance curves show that the isolation between ports is better than -70dB.

[0047] like Figure 7The diagram shown is a simulation of the isolation of the RF microwave switch in the dual-layer ring four-port network. Taking the influence of port 2 (102), port 4 (104), port 6 (106), and port 8 (108) on port 7 as an example, port 6 (106) and port 8 (108) are output terminals on the same layer, while port 2 (102) and port 4 (104) are output terminals on different layers. Figure 6 The S-parameter performance curve shows that the port isolation parameter is better than -70dB, and... Figure 6 The comparison revealed that the isolation parameters of the heterogeneous input ports were nearly identical.

[0048] like Figure 8 The figure shown is a simulation diagram of the insertion loss of the dual-layer ring four-port network 13 RF microwave switch. Taking the influence of the input at port 101 and the output at port 102 as an example, all the cantilevered straight plate upper electrodes 5 on the conductive path are shown. It can be seen that the insertion loss performance between the input at port 101 and the output at port 102 is less than -0.8dB.

[0049] The grounding optimization function of air bridges: In coplanar waveguide (CPW) structures, the ground lines on both sides of the signal line need to remain continuous. When the signal path has branches or bends (such as the corner of the ring four-port network 13), the ground lines may generate parasitic inductance and capacitance due to structural discontinuities, leading to impedance abrupt changes. Air bridges ensure the stability of ground potential and reduce signal reflection and loss by bridging the ground lines in different areas. For example, near the PadPad window 7 and PadPad lead 8 of the signal line side branch, air bridges can connect the segmented ground line areas, avoiding high-frequency radiation loss caused by ground line breaks, thereby indirectly improving signal integrity.

[0050] This scheme employs direct signal optimization using a 45° bevel cut: right-angle turns cause impedance abrupt changes in the signal path, leading to standing waves and reflections. The 45° bevel cut, by transforming a right angle into a slope, makes the electromagnetic field D distribution more uniform, reducing reflections caused by discontinuities (e.g., the reflection coefficient of a right-angle turn in a microstrip line can be optimized from approximately -10dB to -30dB). In the ring four-port network 13, the bevel cut directly affects the geometry of the signal transmission path, ensuring a smooth transition of the signal wavefront and reducing insertion loss. Synergistic effect: when air bridges and bevel cuts are used simultaneously at corners, the air bridge solves the ground discontinuity problem, while the bevel cut optimizes the physical shape of the signal path 0. For example, a 45° beveled coplanar waveguide turn structure, combined with an air bridge connecting the ground wires on both sides, can reduce the overall insertion loss to below 0.2dB (unlikely exceeding 0.5dB without optimization). This combination reduces loop interference (air bridge effect) and path abrupt loss (skew effect) during signal transmission, thereby significantly improving isolation (up to -70dB) and bandwidth characteristics at high frequencies (such as Ka band).

[0051] The air bridge indirectly stabilizes the signal transmission environment by optimizing ground continuity, while the 45° bevel directly optimizes the signal path geometry. Together, these two features enable a low-reflection, low-loss microwave switch design. This integrated design allows the patented RF switch to achieve high isolation (<-70dB) and low insertion loss (<0.8dB) in the L to Ka bands, meeting the requirements of complex multi-channel systems.

[0052] The dual-layer ring four-port network RF microwave switch described in this invention has advantages such as high isolation, low insertion loss, and ease of integration. The symmetrical layout improves the miniaturization of the switch, and the air bridge structure and 45° bevel at the channel corners of the ring four-port RF MEMS switch help achieve a smooth transition in signal transmission, reduce signal reflection and loss, and improve the switch's matching performance. The invented dual-layer ring four-port network RF microwave switch has strong practicality within its operating frequency range.

[0053] While existing technology allows multiple ports to be integrated into a single switch, this significantly reduces the switch's lifespan. If the upper electrode of a switch collapses, the switch is rendered unusable. Most existing switches are single-pole single-throw or single-pole double-throw switches. While multi-pole multi-throw switches are functionally feasible, their performance is difficult to guarantee, especially in high-frequency applications, where electrode reliability, channel insertion loss, and multi-channel isolation performance are significantly reduced.

[0054] Compared with traditional RF microwave switches, the dual-layer ring four-port network RF microwave switch has significant advantages. It has better isolation and insertion loss performance, and the implementation of multi-port input and output helps to improve signal transmission efficiency, making it highly practical.

[0055] The overall control process of the embodiment is described in detail here, as shown in the appendix. Figure 10The diagram illustrates the connections of ports 101, 102, 103, 104, 105, 106, 107, and 108. For example, with port 101 as input and ports 102 and 104 as outputs, when an RF signal is input to port 101, it enters the ring-shaped four-port network 13 through the coplanar waveguide structure 2. Further, a Y-shaped power divider cascaded with narrowband transmission lines precisely divides the RF signal to ports 102 and 104. Taking the division to port 102 as an example, the divided RF signal is transmitted to the cantilevered straight-plate upper electrode 5 via a dual-contact structure 11. Electrostatic force drives the connection between the dual-contact structure 11 and the cantilevered straight-plate upper electrode 5. The signal extends to the output end through the anchor point with the cantilevered straight-plate upper electrode 5. The anchor point, cantilevered straight plate upper electrode 5, dual contacts, Y-shaped power divider, and coplanar waveguide structure 2, etc., form a symmetrical and equally divided structure with the input end. The signal is transmitted to the second port 102 for signal output through the coplanar waveguide structure 2, and the fourth port 104 is similarly transmitted. The biggest innovation of the dual-layer ring four-port network RF microwave switch 13 described in this embodiment is that the input signal of the first port 101 can be transmitted to the back layer through the cascaded through-hole 9 and then transmitted to the sixth port 106, the seventh port 107, and the eighth port 108 through the symmetrical structure, realizing controllable multi-channel output that is not possible in the prior art. At the same time, the dual-layer ring four-port network RF microwave switch 13 described in this embodiment overcomes the shortcomings of single-function ports and single channels. Through the ingenious combination of interchangeable port input and output, cascaded through-hole 9, and symmetrical structure, it realizes efficient signal transmission and multi-channel switching, significantly improving system flexibility and spectrum utilization, and meeting the needs of complex communication scenarios.

[0056] Example 2

[0057] The difference between Example 2 and Example 1 is as follows: (See attached) Figure 9 As shown, a plurality of heat sinks 14 are also provided around the substrate 1, as illustrated in the attached figure. Figure 11 As shown, each driving electrode is also provided with a detection electrode 15. The structure of the detection electrode 15 is the same as that of the cantilevered straight plate upper electrode 5. The distance between the detection electrode 15 and the driving electrode is greater than the distance between the upper electrode and the driving electrode.

[0058] Each detection electrode 15 is connected to a separate heat sink 14 to form a circuit; the 16 circuits are connected in parallel to form a detection circuit. Data attenuation testing or current change testing is performed on the detection circuit to detect the adhesion of the electrostatic force generated by the driving electrode to the upper electrode and the detection electrode. This scheme uses current to test the detection circuit, as shown in the attached diagram. Figure 12As shown, each heat sink 14 is considered as a resistor. In this scheme, the resistance value of each heat sink 14 is different. Each heat sink 14 and a single detection electrode 15 are connected in series to form a branch. Then, the branches of each detection electrode 15 are connected in parallel to form a parallel detection circuit. A rated voltage is input to the parallel detection circuit, and the current in the parallel detection circuit is monitored. Since the resistance values ​​on each branch are different, the reading of the current detection module changes with the resistance values ​​in the parallel detection circuit. For example, when one resistor is closed (i.e., when the detection electrodes 15 of one or more resistors are closed), they will enter the circuit in parallel. In the detection circuit, the total resistance is obtained by connecting these resistors in parallel. Since the individual resistors have different values, the combined resistance will also vary. The resistance values ​​in this design are adaptively adjusted based on actual usage. By arranging and combining the resistance values, the current value when all resistors are connected (all heat sinks 14 are connected in parallel to the detection electrode 15) and the current value when one or more resistors are missing can be determined. Based on the final current value, the connection status of the resistors in the detection circuit can be determined; that is, all or some of the resistors are connected to the detection circuit, and thus, which resistors are not connected. In this design, the heat sinks not only accelerate antenna heat dissipation but also act as resistors in the detection circuit. In this design, the constant voltage and current detection module supplied to the detection circuit can be externalized; that is, corresponding interfaces are set on the detection circuit to connect the power supply (constant voltage) and the ammeter to test the current.

[0059] This solution applies a detection voltage to the driving electrode before each use of the antenna. This detection voltage is greater than the driving voltage (i.e., when the antenna is working, the driving voltage generated by the driving electrode produces an electrostatic force, causing the upper electrode to contact the contact point). In other words, the generated electrostatic force is greater than that generated by the driving voltage. At this point, both the detection electrode 15 and the upper electrode can be attracted, allowing them to connect to the contact point. This then enables all detection lines and information transmission lines to conduct. The information transmission line diagram is attached. Figure 10 As shown, information exchange between ports can be achieved by connecting the corresponding upper electrodes to form a path. Since the detection voltage is greater than the driving voltage, the driving electrode will only connect the detection circuit during detection; during normal antenna use, the driving electrode will not be connected.

[0060] This solution allows for the detection of the status of each driving electrode in the information transmission path of a port without connecting the port itself. It completes the signal transmission path detection, thus verifying the connection status of each port. This solves the problem of needing to input a signal at one port and output signals at several other ports, then detecting the presence or absence of signals at each port to determine if the connection between the ports is smooth. This solution eliminates the need for port-based input / output signal detection, thus avoiding the step of inserting probes or sensors into the ports for signal transmission detection, making it more convenient for everyday use.

[0061] The above are merely embodiments of the present invention. The invention is not limited to the fields covered by these embodiments. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A double-layer ring four-port network radio frequency microwave switch, characterized in that, include: Substrate: The substrate is a rectangular plate integrally formed on both sides; Coplanar waveguide structure: includes signal lines and ground lines on both sides of the signal lines; the coplanar waveguide structure is symmetrically arranged at the center of each side of the substrate; the side branches of the signal lines are also connected in sequence to Pad windows, Pad leads and air bridge structures; Upper electrode: The upper electrode is fixed to the coplanar waveguide structure by anchor points. The upper electrode is a cantilevered straight plate structure with arrayed release holes. Y-type power divider structure: The Y-type power divider structure is cascaded with a coplanar waveguide structure in a narrowband configuration to accurately distribute the input signal to multiple output channels; the power divider port of the Y-type power divider structure is connected to the upper electrode through a double-contact structure. Cascaded vias: The cascaded vias are located at the corners of the transmission structure in the Pad region and the coplanar waveguide structure, and are used to realize the cascaded double-pole double-throw switches; The substrate is surrounded by several heat sinks, each with a different resistance. The switch in a single channel uses an independently configured drive electrode, and each drive electrode is also equipped with a detection electrode. The distance between the detection electrode and the drive electrode is greater than the distance between the upper electrode and the drive electrode. Each detection electrode and a single heat sink are connected to form a circuit. Sixteen lines are connected in parallel to form a detection line. Data attenuation test or current change test is performed on the detection line to detect the adsorption of the electrostatic force generated by the driving electrode on the upper electrode and the detection electrode.

2. The dual-layer ring four-port network radio frequency microwave switch according to claim 1, characterized in that: The power divider port of the Y-type power divider structure is driven by electrostatic force to the upper electrode.

3. A double-layer ring four-port network radio frequency microwave switch according to claim 2, characterized in that: The through-hole structure of the cascaded through-hole is one of the following: cylindrical, hourglass-shaped, or frustum-shaped.

4. A double-layer ring four-port network radio frequency microwave switch according to claim 1, characterized in that: The cascaded through-hole structure is filled with metallic material.

5. A double-layer ring four-port network radio frequency microwave switch according to claim 1, characterized in that: The substrate is a rectangular plate made of glass and silicon using a single double-sided process.

6. A double-layer ring four-port network radio frequency microwave switch according to claim 1, characterized in that: The operating frequency range of the dual-layer ring four-port network radio frequency microwave switch is from the L to the Ka band.

Images