LC distributed matching for equalizing crossbar rf performance

Abstract

This disclosure relates to LC distributed matching for balancing the RF performance of cross switches. For example, a method of manufacturing an RF switch is provided, comprising: adding a first mutual inductance portion of a first transmission line to a first self-inductance portion; and adding a second mutual inductance portion of a second transmission line to a second self-inductance portion, wherein the values ​​of the first and second mutual inductance portions and the values ​​of the first and second self-inductance portions balance the impedance difference between the first and second transmission lines.

Description

Technical Field

[0001] This invention generally relates to systems and methods for LC distributed matching for balancing the RF performance of cross-switch switches. Background Technology

[0002] The increasing complexity of RF front-ends in mobile devices (e.g., the ever-increasing number of antennas for transmit (TX) and receive (RX) paths in MIMO systems driven by new communication standards such as Advanced LTE and 5G) further drives the need for more complex RF switching devices. Simpler single-pole double-throw (SPDT) switches can be replaced by more complex switches, such as four-pole four-throw (4P4T) switches, which allow for multiple paths from the transceiver to different antennas. The higher number of poles and throws in such switches leads to greater inter-path variations in related RF performance, particularly insertion loss, return loss, and linearity. These inter-path variations can result in unbalanced device-level RF performance, where the worst-performing switching path becomes the RF front-end and thus a constraint on the entire RF system. Summary of the Invention

[0003] A method of manufacturing an RF switch includes: adding a first mutual inductance portion of a first transmission line to a first self-inductance portion; and adding a second mutual inductance portion of a second transmission line to a second self-inductance portion, wherein the values ​​of the first and second mutual inductance portions and the values ​​of the first and second self-inductance portions are configured to equalize the impedance difference between the first and second transmission lines. Attached Figure Description

[0004] To gain a more complete understanding of the invention and its advantages, reference is now made to the following description in conjunction with the accompanying drawings, wherein:

[0005] Figure 1A This is a schematic diagram of an exemplary RF cross switch;

[0006] Figure 1B It is used for Figure 1A A schematic diagram of the switching unit of an RF cross switch;

[0007] Figure 1C It is used for Figure 1A A schematic diagram of the alternative switching unit for the RF cross switch;

[0008] Figure 1D It is used for Figure 1A A schematic diagram of another alternative switching unit for the RF cross switch;

[0009] Figure 1E yes Figure 1A Schematic diagram and layout of RF cross switches;

[0010] Figure 1F yes Figure 1A A further illustration of the row section of the RF cross switch;

[0011] Figure 2A yes Figure 1D A schematic diagram of the row section of an RF cross switch;

[0012] Figure 2B This is a schematic diagram of a portion of an RF cross switch according to one embodiment;

[0013] Figure 2C yes Figure 1D A schematic diagram and layout of a portion of an RF cross switch;

[0014] Figure 2D This is a schematic diagram and layout of a portion of an RF cross switch according to one embodiment;

[0015] Figure 2E This is a schematic diagram and layout of a portion of an RF cross switch according to one embodiment;

[0016] Figure 3 This is a graph showing the insertion loss performance of an RF cross switch as a function of frequency, compared to the performance of an exemplary RF cross switch.

[0017] Figure 4 This is a schematic diagram and layout of a portion of an RF cross switch according to an embodiment including a single common tuning inductor;

[0018] Figure 5 This is a schematic diagram and layout of a combination of parts of an RF cross switch according to an embodiment including a single-path-specific tuned inductor;

[0019] Figure 6 This is a schematic and layout diagram of a combination of RF cross switches based on an embodiment including a single common tuning inductor and a path-specific tuning inductor; and

[0020] Figure 7 A flowchart illustrating an embodiment of a method for balancing the path impedance of an RF cross switch is shown. Detailed Implementation

[0021] The manufacture and use of the presently preferred embodiments are discussed in detail below. However, it should be understood that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of particular ways of manufacturing and using the invention and do not limit the scope of the invention.

[0022] This invention will be described with reference to preferred embodiments in a specific context (i.e., multi-pole multi-throw cross switches (or "cross-point switches"), such as RF 4P4T switches). Embodiments of the invention can also be applied to many other switches operating in other frequency ranges and having other switch configurations. In some embodiments, the cross switch includes transmission lines with a branched structure connected to the cross switch input / output and a single switching unit. The branched transmission lines are configured to have mutual inductance and self-inductance portions for balancing impedance differences between the transmission lines. In some embodiments, the mutual inductance portions are configured to have a compensating effect, whereby the impedance of the branched transmission lines is set primarily through the self-inductance portions.

[0023] The embodiments of the invention described below advantageously narrow the gap between best-case and worst-case RF path performance, thereby allowing for a more balanced system design.

[0024] To date, simple off-chip (integrated in the package or externally) matching elements have been used to optimize the performance of a single path or a set of paths in a cross switch. One advantage of some embodiments is that the branching structure of the cross switch's transmission lines can be used to match the impedance of all multiple switching paths. Therefore, the impedance difference between the best and worst switching paths in the cross switch is minimized, achieving optimal switching performance.

[0025] Figure 1A A schematic diagram of an exemplary multi-pole multi-throw cross switch 100 with "n" inputs and "m" outputs is shown. Figure 1A In the 4P4T example, "n" equals 4, and "m" also equals 4. Due to the increased number of RF switch branches used to connect each input to each output, the chip layout of the RF section becomes larger, which in turn leads to longer connection lines for some selected paths. The switch branches are arranged in a matrix and connected by long, horizontal and vertical metal wiring or traces, such as... Figure 1A As shown, the transmission line element TL A / B,m,n Coupled to a single switching unit SW m,n Each transmission line element includes a series inductor and resistor, as well as a parallel capacitor coupled to ground. Each transmission line element TL A / B,m,n It can be composed of series inductors and resistors, as well as parallel capacitors (in Figure 1AThe lumped model representation (not shown separately) is used herein. Therefore, the transmission line element notation used herein refers to a transmission line element transmitting a metal trace with associated resistive, inductive, and / or capacitive elements, rather than a portion of a shielded coaxial cable coupled to ground. The switching unit comprises multiple individual switches, which will be described in further detail below. Switch 100 also includes input / output nodes RF,Am coupled to column transmission lines and input / output (I / O) nodes RF,Bn coupled to row transmission lines.

[0026] For example, the first column transmission line 108 associated with the RF, A1 node includes a series transmission line element TL. A1,1 TL A2,1 TL A3,1 and TL A4,1 For example, the first row transmission line 110 associated with the RF,B1 node includes a series transmission line element TL. B1,1 TL B1,2 TL B1,3 and TL B1,4 The remaining row and column transmission lines consist of similar transmission line elements.

[0027] Each RF I / O node has an associated tuned inductor (for the L of each corresponding column transmission line). A1 L A2 L A3 or L A4 And L for each line transmission line B1 L B2 L B3 or L B4 Its dimensions are designed to minimize the insertion loss of all switching paths.

[0028] The implementation of a tuning inductor for each transmission line of switch 100 is not optimal, as becomes apparent when comparing the inductance of the connection path (RF,A1→RF,B1) between input / output RF,A1 and input / output RF,B1 with the inductance of the connection path (RF,A1→RF,B4) between input / output RF,A1 and input / output RF,B4.

[0029] Connection path RF,A1→RF,B1: The total inductance along this connection path is L. A1 +L TLA1 +L TLB1 +L B1 L XY It is the inductance of a corresponding segment of the RF routing transmission line; and

[0030] Connection path RF,A1→RF,B4: The long RF line connection path from I / O node or port RF,A1 to RF,B4 results in significantly higher inductance: L A1 +4*L TLA1 +L TLB4,1 +L B4 (If all line inductance L) TLA1 (have the same value).

[0031] In the case of large switches (such as 4P4T cross switches), the total inductance of the RF routing transmission line can be in the range of ~0.8nH to 1.0nH, and is typically comparable to the inductance of a tuned inductor. In this case, the difference in total inductance can easily exceed 600 pH.

[0032] This difference in the different RF paths in the matching cross switch 100 leads to variations in insertion loss, isolation and return loss, as well as reduced harmonic and breakdown performance of the different switching paths.

[0033] exist Figure 1B The diagram shows a representative switching unit SW for switch 100. 1,1 It includes a first node or "A" bus (or transmission line) node 102 and a second node or "B" bus (or transmission line) node 106. A first individual switch SW A Coupled between the first node 102 and the internal switch node 104. First individual switch SW A Control signal CTRL A Control, control signal CTRL A For example, by Figure 1B A microprocessor or system controller, not shown, is provided. Second separate switch SW B Coupled between internal switch node 104 and second node 106. Second separate switch SW B Control signal CTRL B Control, control signal CTRL B For example, also by Figure 1B A microprocessor or system controller, not shown, is provided. Third separate switch SW C Coupled between internal switch node 104 and ground. Third separate switch SW C Control signal CTRL C Control, control signal CTRL C For example, also by Figure 1B A microprocessor or system controller, not shown, is provided. Representative switch unit SW. 1,1 Other embodiments can also be used for switch 100. For example, in Figure 1C The image shows an "L-shaped" switch, in which the individual switch SW... AIt was removed and replaced with a short-circuit connection. Figure 1D In the embodiment, a simple single switch SW A It is coupled between switch nodes 102 and 106.

[0034] Figure 1E yes Figure 1A The layout diagram of the RF cross switch, in which the tuning inductor L A1 L A2 L A3 L A4 and L B1 L B2 L B3 L B4 Each of these is shown as a physical inductor; the column transmission lines are shown as metal traces A1, A2, A3, and A4, and the row transmission lines are shown as metal traces B1, B2, B3, and B4. The input / output nodes and switching units are as described above. Figure 1A The same as shown.

[0035] Figure 1F yes Figure 1A The schematic diagram further includes a highlighted cross switch portion 200, which comprises a row of individual switch units. The cross switch portion 200 is used to better explain the exemplary cross switch 100 and embodiments of cross-point switches or cross switches with improved switch path impedance equalization. Reference is made below. Figures 2A to 2E The cross switch portion 200 and the replacement branch structure for portion 200 are described in further detail according to some embodiments.

[0036] in short, Figure 2A yes Figure 1A A schematic diagram of part 200 of the RF cross switch 100; Figure 2B This is a schematic diagram of part 202 of an RF cross switch according to one embodiment, which corresponds to part 200 but uses branched transmission lines instead of straight transmission lines; Figure 2C yes Figure 1A Layout diagram of part 200 of RF cross switch 100; Figure 2D This is a layout diagram of portion 202 of an RF cross switch according to one embodiment, which corresponds to portion 200 but uses branched transmission lines instead of straight transmission lines; and Figure 2E This is a schematic and layout diagram of a combination of portions 218A and 218B of an RF cross switch according to one embodiment, which generally corresponds to portion 200 but shows further details of the branch structure transmission line.

[0037] replace Figure 1A and Figure 1C The straight transmission line RF connection shown uses an unbalanced branch structure (see [reference needed]). Figure 2B, Figure 2D and Figure 2E (and described in further detail below) to replace at least some straight transmission line RF connections. In an embodiment, a particular transmission line may remain straight when a particular switch branch does not require specific equalization. In other embodiments, all transmission lines except one may remain straight. In some embodiments, each transmission line of the cross switch may be replaced by an unbalanced branch structure.

[0038] Figure 2A yes Figure 1A A schematic diagram of portion 200 of an exemplary RF cross switch shows the first row of transmission lines associated with I / O node RF,B1, including tuning inductor L. B1 Transmission line element TL B1,1 TL B1,2 TL B1,3 and TL B1,4 and the switching unit SW 1,1 SW 1,2 SW 1,3 and SW 1,4 . Figure 2A The I / O nodes RF,A1, RF,A2, RF,A3, and RF,A4, and their corresponding tuned inductors L are also shown. A1 L A2 L A3 and L A4 .

[0039] Figure 2B This is a schematic diagram of portion 202 of an RF cross switch according to one embodiment, which replaces portion 200 shown in an embodiment of the cross switch. While the I / O nodes, tuning inductors, and switching units are similar to those in cross switch portion 200, the row transmission lines differ and a branching structure, which will be described in further detail below, is shown. The row transmission lines of portion 202 include a first connection line comprising transmission line element 208. A second connection line comprises transmission line elements 210 and 212. The first transmission line connects to the second transmission line at an internal connection point or node “A”. A third connection line includes a connection for connecting to the switching unit SW. 1,1 and SW 1,2 The transmission line elements 204 and 206, and the fourth connection line includes a connection for connecting to the switch unit SW. 1,3 and SW 1,4 Transmission line elements 214 and 216. Transmission line elements 208 and 210 include inductors in a mutually inductant configuration, as shown in reference. Figure 2D and Figure 2E Further illustrations and descriptions are provided. For example... Figure 2D and Figure 2EAs shown in further detail, transmission line elements 204, 206, 212, 214 and 216 include inductance as a self-inductance of the metal trace.

[0040] Figure 2C yes Figure 1A A layout diagram of portion 200 of an exemplary RF cross switch, showing its relationship with... Figure 2A The same components. However, these components are shown as physical layout elements. For example, a row transmission line is shown as a metal trace B1. As shown in the layout, a tuning inductor is shown as a physical inductor.

[0041] Figure 2D This is a layout diagram of part 202 of an RF cross switch according to one embodiment, showing the connection with... Figure 2B The same components. However, these components are shown as physical layout elements. For example, the first, second, third and fourth connecting lines are shown as transmission line elements 204, 206, 208, 210, 212, 214 and 216, including portions shown as metal traces.

[0042] In one embodiment, it is possible to Figure 2E Further details of the transmission line branching structure can be seen in the equivalent cross switch portions (row transmission lines) 218A and 218B. Cross switch portion 218A is a branched transmission line in the form of an inductor schematic and generally corresponds to the previously described... Figure 2B The cross switch section 202. The cross switch section 218B is the same branch transmission line in the layout diagram form, and generally corresponds to the previously described. Figure 2D The cross switch section 202. The first branch of the branch structure includes a first connection line 220 coupled to the I / O node RF, B1, including inductor L1 and inductor L... 2A The second branch of the branch structure includes a second connecting line 222, which includes an inductor L. 2B and L 2X The third branch of the branch structure includes a section for connecting to switch SW. 1,1 and SW 1,2 The third connecting line 224. The fourth branch of the branch structure includes a connection for connecting to switch SW. 1,3 and SW 1,4 The fourth connection line 226. The first and second connection lines are coupled together at an internal connection point or node "A". Inductance L1 is associated with the self-inductance of the first connection line 220, and inductance L... 2X Associated with the self-inductance of the second connection line 222. Inductance L 2A and inductor L 2B A mutual inductance configuration having a length "l" and an internal distance "d" separating the first connecting line from the second connecting line. The "point convention" indicates the inductance L. 2Aand L 2B In a reverse mutual inductance configuration, as explained in further detail below, in one embodiment, from inductor L... 2A The outflowing current flows through connection point "A" and into inductor L. 2B The aforementioned reverse mutual inductance configuration produces a compensation effect, allowing the inductance of the branch structure of the cross switch section 218A to be equal to that of other similar branch structures in the switch. Appropriate selection of the distance "d" between the RF connection lines, the length "l" of the mutual inductance configuration, and thus the appropriate selection of the location of the connection point "A" allows for the utilization of the inductor L... 2A and L 2B The compensation effect generated by the mutual inductance "M" is used to adjust the inductance of connecting lines 220 and 222.

[0043] With inductor L 2A and L 2X Compared to shorter transmission lines, due to the longer length, an inductor L is required. 2A and L 2B The compensation effect to compensate L 2A +L 2B The higher self-inductance. When switch SW 1,1 and / or SW 1,2 When the circuit is switched on and current flows into that particular branch, a compensation effect is produced.

[0044] Further details of the compensation effect are described below.

[0045] In the presence of a second inductor L2 with current i2 (e.g., Figure 2E Inductor L in 2B In the case of current i1, due to the current i1, the inductor L1 (e.g., Figure 2E Inductor L in 2A The voltage across the terminals is:

[0046] V1 = j*w*L1*i1 + j*w*M*i2.

[0047] When M = k * sqrt(L1 * L2) and the two currents i1 and i2 are equal, the impedance of L1 becomes:

[0048] Z1 = j*w*(L1 + k*sqrt(L1*L2)), which simplifies further for simple parallel lines (L1~L2):

[0049] Z1 = j * w * L1 * (1 + k)

[0050] Since the opposite current direction "k" becomes negative, the effective inductance is reduced by 1-|k| times, thus providing a compensation effect.

[0051] Therefore, instead of using only a single common tuned inductor, this matching element can be used as follows: Figure 2E The distribution is shown. Two inductors L1 and L2 are shown. 2X Individual optimizations can be performed to minimize insertion loss for each path and balance their performance. According to an embodiment, each horizontal and vertical transmission line in the cross switch can use... Figure 2E The diagram shows a similar branch structure, and each branch structure can be slightly different to accommodate the precise cross switch layout used.

[0052] As explained earlier, inductor L1 is associated with the self-inductance of the first connection line 220, and inductor L 2X This is related to the self-inductance of the second connection line 222. Therefore, inductance L1 and inductance L 2X Define the self-inductance of the entire transmission line. Inductance L 2A and inductor L 2B The inductance is configured with a length "l" and an internal distance "d" separating the first connecting line and the second connecting line. Therefore, the inductance L 2A and inductor L 2B Define the mutual inductance portion of the entire transmission line. A first transmission line may be described as having a first self-inductance portion and a first mutual inductance portion. A second transmission line may be described as having a second self-inductance portion and a second mutual inductance portion.

[0053] Using the concepts described above, all relevant RF performance parameters on the worst-performing path in a large switching matrix can be significantly improved, although not limited to these cases. Figure 3 The graph 300 shows the S-parameter versus frequency. Traces 302, 304, 306, and 308 represent the insertion loss (S21) of each trace. Figure 3 An example of the improvement in insertion loss (in dB relative to frequency) is shown: the worst-case path shows a significant improvement despite the smaller penalty imposed on the best-performing path. Figure 3 The best performance path 302 and the worst performance path 304 in an exemplary cross switch are shown. Figure 3 The best-performing path 306 and worst-performing path 308 in the embodiment cross switch are also shown. It should be noted that the difference in frequency performance, in dB, between paths 306 and 308 in the embodiment cross switch is smaller than the difference in frequency performance, in dB, between paths 302 and 304 in the exemplary cross switch. Figure 3 The specific values ​​shown are merely examples and may vary for a particular cross switch embodiment. However, all cross switch embodiments will demonstrate a balanced improvement between the best and worst performance paths relative to the exemplary cross switch.

[0054] Cross switches can be combined with branch structures using individual tuned inductors to further improve path balancing and offer greater flexibility in cross switch design. See below for reference. Figure 4 (a tuned inductor) Figure 5 (two tuned inductors) and Figure 6 (Three tuned inductors) An example of a cross switch using individual tuned inductors is shown and described.

[0055] Figure 4 This is a schematic diagram and layout of a branch structure portion of an RF cross switch according to an embodiment including a single tuned inductor. Portion 418A is schematic and corresponds to the previously described... Figure 2E The portion 218A shown in the figure, except for the addition of a tuned inductor L connected in series with inductor L1, B1 Part 418B is in layout form and corresponds to the previous section. Figure 2E Part 218B shown in the figure, except for the addition of a tuning inductor L B1 Tuning inductor L B1 It can also be used to further adjust the impedance characteristics of the branch structure section 418A.

[0056] Figure 5 This is a schematic diagram and layout of a branch structure portion of an RF cross switch according to an embodiment including two tuned inductors. Portion 518A is schematic and corresponds to the previously described... Figure 2E The portion 218A shown in the figure, in addition to adding inductors L2 and L 2X Two additional tuned inductors L connected in series B1A and L B1B Part 518B is in layout form and corresponds to the previous section. Figure 2E Part 218B shown in the figure, except for the addition of a tuning inductor L B1A and L B1B Tuning inductor L B1A and L B1B It can also be used to further adjust the impedance characteristics of the 518A branch structure.

[0057] Figure 6 This is a schematic diagram and layout of a combination of a portion of an RF cross switch according to an embodiment including three tuned inductors. Figure 4 and Figure 5 The tuned inductor shown. Part 618A is in schematic form and corresponds to the previously shown... Figure 2E The portion 218A shown in the diagram, in addition to the addition of three additional tuning inductors L B1 L B1A and L B1B Part 618B is in layout form and corresponds to the previous section. Figure 2EPart 218B shown in the figure, except for the addition of three additional tuning inductors L B1 L B1A and L B1B Tuning inductor L B1 L B1A and L B1B It can also be used to further adjust the impedance characteristics of the 518A branch structure.

[0058] Therefore, a cross switch with multiple branched transmission lines for coupling to rows and columns of switching units is described. For example, in a 4P4T cross switch, four branched transmission lines are used to couple to four columns of switching units, and four branched transmission lines are used to couple to four rows of switching units. Those skilled in the art will understand that the design of the branched transmission lines will be highly dependent on the layout of the cross switch. The placement of input / output pads, the placement and layout design of the switching units, the placement of other pads (e.g., one or more ground pads), and other layout considerations will determine the design of the branched transmission lines. In some embodiments, not all branched transmission lines must have the same layout. However, in some embodiments, some of the branched transmission lines may be identical, and some may be symmetrical to each other. In other embodiments, some of the branched transmission lines may include tuning inductors, while others may not. The branched transmission line includes several design factor options to ensure that the total impedance of each transmission line is substantially balanced, including: the use of zero to three or more tuned inductors; the length of the self-inductance portion of the first and second connections; the length of the mutual inductance configuration; and the internal distance between the first and second connections to determine the mutual inductance and thus the compensation factor as discussed above.

[0059] Figure 7 A flowchart of an embodiment method 700 for manufacturing an RF switch is shown, the method comprising: in step 702, adding a first mutual inductance portion to a first self-inductance portion of a first transmission line; in step 704, adding a second mutual inductance portion to a second self-inductance portion of a second transmission line; and in step 706, adjusting the values ​​of the first and second mutual inductance portions and the values ​​of the first and second self-inductance portions to balance the impedance difference between the first and second transmission lines. In the embodiment manufacturing method 700, adjusting the values ​​of the first and second mutual inductance portions may include adjusting the respective lengths of the first and second mutual inductance portions, or may include adjusting the respective internal distances of the first and second mutual inductance portions. In the embodiment manufacturing method 700, adjusting the values ​​of the first and second self-inductance portions may include adjusting the respective lengths of the first and second self-inductance portions. In the embodiment manufacturing method 700, adding the first mutual inductance portion to the first self-inductance portion of the first transmission line comprises adding first and second parallel connecting wires to the first transmission line. Similarly, adding the second mutual inductance portion to the second self-inductance portion of the second transmission line may include adding first and second parallel connecting wires to the second transmission line.

[0060] The cross switch can be implemented using different package types that provide the necessary number of wiring layers. The cross switch can also be implemented using an on-chip (integrated circuit) implementation, which utilizes different semiconductor processes employing multiple wiring layers.

[0061] The advantage of the cross switch embodiments described herein is that the transition from single-element matching to distributed LC matching allows for individual matching of each switch path, resulting in switch products with more balanced RF performance.

[0062] Example 1. According to one embodiment, a method of manufacturing an RF switch includes: adding a first mutual inductance portion of a first transmission line to a first self-inductance portion; and adding a second mutual inductance portion of a second transmission line to a second self-inductance portion, wherein the values ​​of the first and second mutual inductance portions and the values ​​of the first and second self-inductance portions are configured to equalize the impedance difference between the first and second transmission lines.

[0063] Example 2. According to the method of Example 1, configuring the values ​​of the first and second mutual inductance portions includes configuring the corresponding lengths of the first and second mutual inductance portions.

[0064] Example 3. According to the method of any of the above examples, wherein configuring the values ​​of the first and second mutual inductance portions includes configuring the corresponding internal distance between the first and second mutual inductance portions.

[0065] Example 4. According to the method of any of the above examples, configuring the values ​​of the first and second self-inductance portions includes: configuring the corresponding lengths of the first and second self-inductance portions.

[0066] Example 5. The method according to any of the above examples, wherein adding a first mutual inductance portion of a first transmission line to a first self-inductance portion comprises: adding first and second parallel connection lines to the first transmission line.

[0067] Example 6. The method according to any of the above examples, wherein adding the second mutual inductance portion of the second transmission line to the second self-inductance portion comprises: adding the first and second parallel connection lines to the second transmission line.

[0068] Example 7. A transmission line for an RF switch, the transmission line comprising: a first connecting line including first and second inductor portions, wherein the first connecting line is connected between a first node and an internal node; and a second connecting line including third and fourth inductor portions, wherein the third inductor portion is connected between the internal node and a second node, and the fourth inductor portion is connected between the internal node and the third node, wherein the second inductor portion of the first connecting line and the third inductor portion of the second connecting line are in a mutual inductance configuration.

[0069] Example 8. The transmission line according to Example 7, wherein the mutual inductance configuration is configured to compensate at least a portion of the total inductance of the first connection line and at least a portion of the total inductance of the second connection line.

[0070] Example 9. A transmission line according to any of the examples above, wherein the first connecting line is connected in parallel with the second connecting line.

[0071] Example 10. The transmission line according to any of the above examples also includes a tuned inductor coupled to at least one of the first, second, or third nodes.

[0072] Example 11. The transmission line according to any of the above examples also includes at least one switching unit coupled to a second node.

[0073] Example 12. The transmission line according to any of the above examples also includes at least one switching unit coupled to a third node.

[0074] Example 13. An RF switch comprising: a plurality of switching units arranged in multiple rows and columns, wherein each switching unit includes a first node and a second node; a first plurality of transmission lines coupled to the first nodes in the multiple columns of switching units; and a second plurality of transmission lines coupled to the second nodes in the multiple rows of switching units, wherein each of the first plurality of transmission lines includes self-inductance and mutual inductance portions, wherein each of the second plurality of transmission lines includes self-inductance and mutual inductance portions, and wherein the values ​​of the self-inductance and mutual inductance portions are configured to equalize the impedance of each of the first and second plurality of transmission lines.

[0075] Example 14. An RF switch according to Example 13, wherein each mutual inductance portion includes first and second parallel connecting lines.

[0076] Example 15. An RF switch according to any of the examples above, wherein the value of each mutual inductance section is determined by the length of each mutual inductance section.

[0077] Example 16. An RF switch according to any of the examples above, wherein the values ​​of the respective mutual inductance portions are determined by the distance between the first and second parallel connecting lines.

[0078] Example 17. An RF switch according to any of the above examples, wherein the first connection line also includes a tuning inductor.

[0079] Example 18. An RF switch according to any of the above examples, wherein the second connection line further includes at least one tuning inductor.

[0080] Example 19. RF switches according to any of the examples above, including four-pole four-throw RF switches.

[0081] Example 20. An RF switch according to any of the examples above, wherein each switching unit comprises multiple individual switches.

[0082] While the invention has been described with reference to exemplary embodiments, this specification is not intended to be limiting. Those skilled in the art will understand, upon referring to this specification, various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention. Therefore, the appended claims encompass any such modifications or embodiments.

Claims

1. A method for manufacturing an RF switch, the method comprising: Add the first mutual inductance portion of the first transmission line to the first self-inductance portion; as well as Add the second mutual inductance portion of the second transmission line to the second self-inductance portion. The values ​​of the first mutual inductance portion and the second mutual inductance portion, as well as the values ​​of the first self-inductance portion and the second self-inductance portion, are configured to balance the impedance difference between the first transmission line and the second transmission line.

2. The method according to claim 1, wherein configuring the values ​​of the first mutual inductance portion and the second mutual inductance portion comprises: Configure the corresponding lengths of the first mutual inductance portion and the second mutual inductance portion.

3. The method according to claim 1, wherein configuring the values ​​of the first mutual inductance portion and the second mutual inductance portion comprises: Configure the corresponding internal distances between the first mutual inductance portion and the second mutual inductance portion.

4. The method according to claim 1, wherein configuring the values ​​of the first self-inductance portion and the second self-inductance portion comprises: Configure the corresponding lengths of the first self-inductance portion and the second self-inductance portion.

5. The method of claim 1, wherein adding the first mutual inductance portion of the first transmission line to the first self-inductance portion comprises: Add a first parallel connection line and a second parallel connection line to the first transmission line.

6. The method of claim 1, wherein adding the second mutual inductance portion of the second transmission line to the second self-inductance portion comprises: Add the first parallel connection line and the second parallel connection line to the second transmission line.

7. A transmission line for an RF switch, the transmission line comprising: The first connecting line includes a first inductor portion and a second inductor portion, wherein the first connecting line is connected between a first node and an internal node; as well as The second connection line includes a third inductor portion and a fourth inductor portion, wherein the third inductor portion is connected between the internal node and the second node, and wherein the fourth inductor portion is connected between the internal node and the third node. The second inductor portion of the first connecting line and the third inductor portion of the second connecting line are in a mutual inductance configuration, wherein the mutual inductance configuration is configured to compensate at least a portion of the total inductance of the first connecting line and at least a portion of the total inductance of the second connecting line.

8. The transmission line according to claim 7, wherein the first connecting line is connected in parallel with the second connecting line.

9. The transmission line of claim 7 further includes a tuning inductor coupled to at least one of the first node, the second node, or the third node.

10. The transmission line of claim 7 further includes at least one switching unit coupled to the second node.

11. The transmission line according to claim 7, further comprising at least one switching unit coupled to the third node.

12. An RF switch, comprising: Multiple switching units are arranged in multiple rows and columns, wherein each switching unit includes a first node and a second node; The first plurality of transmission lines are respectively coupled to the first node in the plurality of switching units located in the plurality of columns; and The second plurality of transmission lines are respectively coupled to the second node in the multiple rows of switching units. Each of the first plurality of transmission lines includes a self-inductance portion and a mutual inductance portion, and each of the second plurality of transmission lines includes a self-inductance portion and a mutual inductance portion, wherein the values ​​of the self-inductance portion and the mutual inductance portion are configured to balance the impedance of each of the first plurality of transmission lines and the second plurality of transmission lines.

13. The RF switch according to claim 12, wherein each mutual inductance portion includes a first parallel connecting line and a second parallel connecting line.

14. The RF switch of claim 13, wherein the value of each mutual inductance portion is determined by the length of each mutual inductance portion.

15. The RF switch of claim 13, wherein the value of each mutual inductance portion is determined by the distance between the first parallel connecting line and the second parallel connecting line.

16. The RF switch of claim 13, wherein the first parallel connection line further includes a tuning inductor.

17. The RF switch of claim 13, wherein the second parallel connection line further comprises at least one tuning inductor.

18. The RF switch according to claim 12, comprising a four-pole four-throw RF switch.

19. The RF switch of claim 12, wherein each switching unit comprises a plurality of individual switches.

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