You can make your own spread sheet using formulas provided by Wedell's book "Transmission Line Design Handbook" page 196, 197, 198 (attached)Differential Impedance Ω. Coplanar Waveguide With Ground Characteristic Impedance Calculator. The Layer Stack Manager's impedance calculator uses the Wideband Debye model, with a default frequency value of 1 GHz. Insert multiple Differential Pair definitions per layer. The impedance of the structure is the ratio of the voltage between, and the current in, the conductors. Impedance—if not treated correctly—has a remarkably negative impact on circuit performance. When examining coupled transmission lines for common-mode or differential driving, you either have to source two separate TDR/TDT signals on the two lines simultaneously, or you have to measure the even/odd mode impedances. The Si8000m adds enhanced modelling to predict the finished impedance of multiple dielectric PCB builds and also takes into account the local variations in dielectric constant on close spaced differential structures. While you can theoretically connect up to 32 devices (or even more by using an RS-485 repeater), the actual number of nodes will depend on the chosen communication speed or baud rate. 3. To explore the differential pair transmission line results, nominate the calculated variable - either the Trace Width or Trace Gap - by clicking the appropriate . Calculate differential pairs impedance to each other over a cross hatched ground. 81 Updates & Additions: Corrected S/H and W/H formula for the Edge Coupled Embedded differential pair calculator. 1. 4. One of the features of this type of microstrip is the coupling between lines. $egingroup$ So basically your answer shows that the JLCPCB impedance calculator results are generally in the same ballpark as the proven field simulators. D+ and D-) _P/_N (e. Converts C to F, F to C. 6mm spacing with a trace width of 0. 7563 mm (~30 mils). Track Width. The differential pair is unbalanced, the interference is not common-mode, and the differential pair fails to reject its interference. Characteristic impedance is purely a function of the capacitance and. e. Overview. To use this tool, enter the values for. For better impedance control, use PCB design software you can trust. Single-Ended Impedance The trace impedance (single-ended) in an individual trace is normally calculated by ignoring any neighboring traces, so no coupling to other conductors in the design will be included. Coplanar_Waveguide_Calculator. 10. JLCPCB Impedance Calculator. 10. RF Attenuators. A coplanar differential raises the diff impedance while lowering Zo with adjacent grounds so it needs a thinner height of dielectric. Given the constrain of comparing the same differential impedance and the same line width, loosely coupled differential pairs have less cross talk. Modeling approximation can be used to understand the impedance of. 6 Ω. txem = design (txem,3e9,LineLength=0. The design approach of controlled impedance routing is a key ingredient of high speed PCB design, in which effective methods and tools must be adopted to ensure the intended high speed. Either the desired impedance at a specific frequency is used to determine the waveguide width, or the width is entered and the impedance is calculated. nm um mm cm m mil inch. 5. Differential Coplanar Waveguide Calculator. calculate the impedance and capacitance of PCB traces. Anyone have suggestion of one? Thanks Alan . Activity points. Figure 1. The reflection coefficient (Γ) relates to impedance (Z) through the formula Z = Z₀ * (1 + Γ) / (1 – Γ), where Z₀ is the characteristic impedance of the medium or transmission line. A plot of the simulated coplanar impedance vs coplanar gap is shown below. Characteristic. 3 as fr4 material with 1. Click here to see the user guide of our impedance. The tool automatically chooses the type of board construction based on material selected and is linked to our 2D field solver-based impedance calculator which allows you to design any controlled impedance traces. 7. With PCBWay impedance calculator, you can calculate the approximate impedance of your PCB / high frequency circuit board. INPUT DATA. For example: Yellow Violet Red Gold: 4 7 x100 ±5% = 4700 Ohm, 5% tolerance. Electrical Spacing. But a coplanar ground design will do no harm there either. 9. As an example, LVDS specifies that the differential impedance of a differential pair should be 85 Ohms. Figure 6-2 shows the basicHemming a pair of pants is a common clothing alteration that can vary in cost depending on several factors, including the type of pants, hem style, length adjustments, tailor’s expertise, and location. This calculator is designed to calculate the characteristic impedance of a broadside couple stripline (see diagram below). One should note that some routing and computer architecture standards (i. This is a lot of terms to calculate in a simulation!1. Create a coplanar waveguide transmission line using a gold substrate as the dielectric. Thus any equation used to calculate the impedance is approximate and demonstrated in Table 1. 如何利用Q2D計算共面差分帶對的差分阻抗視頻顯示了使用Q2D計算共面差分帶對的流程The video shows the flow to calculate coplanar. Another example of using large distances to separate out unwanted components might be to calculate the impedance of a differential pair that exists in the absence of a reference plane. This can be set to zero, but the calculated loss will not include conductor losses. All your PCB design, data management and collaboration needs can now. In both cases, you’ll need to enter your stackup information into the calculator to get accurate results. Enter the relative permitivity, width of the trace, the ground plane spacing, and the substrate thickness to calculate the characteristic impedance. 7. Hence calculating impedance can be pretty tedious. Track and gap widths are of concern in controlled impedance, but unless your speaker and mic connections (I assume audio frequencies) are going a long way you should not have any particular requirement for controlled impedance. Phase differences between theSome differential impedance requirement for differential pairs, where the signals must be routed together Just as an example, consider a 2-layer board on standard thickness 62 mil core (Dk = 4. 92445. Antipads on vias are precisely sized to hit a target impedance at high frequencies. It is the same structure as regular stripline, but the model is more complex with the addition of the trace spacing for the differential pair. Impedance (Z o ): 76. So, to calculate the differential impedance of Figure 1, simply calculate the impedance of Figure 3, and double it. If you control impedance, you place a tolerance in the fabrication notes. Embedded Microstrip. The Simbeor impedance calculator calculates the width(s) required to achieve the specified impedance. This adds to the total signal t pd. Enter the values of trace width (w), trace thickness. Calculate Coplanar impedance for given PCB parameters. The Si8000m adds enhanced modelling to predict the finished impedance of multiple dielectric PCB builds and also takes into account the local variations in dielectric constant on close spaced differential structures. The vias on these differential pairs have their own impedance, which can create signal integrity problems on long interconnects. The equations quoted below are from Reference 1, and are offered here as a starting point for a design, subject to further analysis, testing and design verification. Characteristic Impedance [ohms] Electrical Length Understanding Coplanar Waveguide with Ground. 1 (a). 35,851. With this combination of powerful impedance modeling you can quickly determine the manufacturing variations for each of your designs and model resin-rich areas between differential traces to achieve the highest yields from yourThe formula for calculating the flow rate (Q) of a pipe is: Flow Rate (Q) = Cross-Sectional Area (A) * Velocity (V) This formula relates flow rate to the cross-sectional area and velocity of the fluid in the pipe. dear friends I want to route 100 ohm differential pairs of LAN on two layer pcb ( 1. There are single end trace impedance and distance between traces in the pair. , power and/or GND) constitutes a stripline layout. With a gap between trace and upper ground plane = 60 mils, the trace width is 100 mils which is close to Altium's calculator. Conclusion. Creating and Configuring an Impedance Profile. If trace width is increased for the metal losses reduction, the single end impedance will be reduces. Optimization results for example 2. button. Yet I got a ZDiff CPW with ground capable calculator: Differential surface coplanar waveguide with ground calculations: *0. The other metrics used to describe transmission line impedance depend on the relative arrangement of two transmission lines. e. Impedance Calculation. Radio Frequency Engineering Calculator. But a coplanar ground design will do no harm there either. The impedance is determined by the ratio of trace width to clearance, so size reduction is possible without limit, the only penalty being higher losses. CPW consists of a central strip flanked by two metal half-planes that carry the return current. Edge coupled differential pair Edge coupled internal symmetric differential pair Edge coupled internal asymmetric differential pair Edge coupled embedded differential pair Broadside coupled shielded differential pair Broadside coupled non. so i have had a look at a App-Note of the PHY chip: it contains a lot of good information - and for me its clear i have to do a differential pair for the TX+/TX- and RX+/RX- traces. (FDTIM). PCB Coplanar Waveguide Calculator RF PCBs can be complex boards that need careful interconnect design and layout. Zo (diff) is calculated to be 244 ohms, so dividing by two yields a value of 122 ohms for the semi-coplanar structure. Actual board thickness 59. Transmission-Line Calculator. Stripline Impedance. Figure 4. First, we integrate the resistive loss to determine the power dissipation per unit length. Single ended. Stripline construction usually does not require ground stitching, sometimes it's better no having vias around. These transmission line arrangements are standard trace geometries implemented in PCB design software. Controlled impedance is typically required in single-ended microstrip, embedded microstrip, stripline differential pair, and planar PCB transmission lines. ϵ r is the substrate dielectric. Impedance Calculation 5. Create a new impedance profile, then select Single-Coplanar or Differential-Coplanar from the Impedance Profile Type drop-down list. In addition, the outputs impedances can be odd, even, common and differential. If, in addition to a differential impedance (Z Diff), you also need a defined Z 0, proceed as follows:. In the image below, I am comparing differential vias with merged. To avoid microstrip modes, have h >> (w+2g) and extend component side ground away from the trace by > (w+2g). Simultaneous Switching Noise Guidelines. and thats the first time iam doing ethernet things. Going to a coplanar arrangement can provide more losses when the coplanar ground is close, which forces a thinner microstrip (more loss from skin effect). Technical Consultant Zach Peterson explores a viewer question surrounding Coplanar Routing, specifically how to route on a single-layer board. We can then use the familiar P = I_0^2R/2 to calculate the resistance. Excessive Zs can pose safety risks, while too low Zs may cause tripping issues. 5. Enter the relative permitivity, width of the trace, the ground plane spacing, and the substrate thickness to calculate the characteristic impedance. This I the answer. 5. , in x-y plane) is scaled by an amount M(u,v) in the mapped domain (i. 5 mm, trace width W = 0. Impedance Calculation 5. The grounded differential coplanar wave guide is the differential version of the grounded coplanar wave guide and is used in high-speed digital systems that require maximum noise immunity. The signal propagation is dependent on the via gap. • Ground planes must not be broken in the GND reference layer immediately beneath he transmission line. Figure 2. This calculator is designed to find the characteristic impedance of an asymmetric stripline - a flat conductor between two ground planes. Staff member. PCB samples, finding that predicted accuracy varies according to target impedance. Planar transmission line. The main takeaway for me: To get to around 80 ohms, I should not pull ground on the signal. 75 mm track on a 0. In the PCB panel’s Differential Pairs Editor mode, its three main regions change to reflect the differential pair hierarchy of the current PCB design (in order from the top):. Maximum near end channel to channel cross talk for 100 Ohm, 5 mil wide differential pairs, as the channel to channel edge spacing increases. We get a lot of questions about trace impedance and how to calculate the right trace size to hit a specific impedance in a manufacturable PCB. You can use an online coplanar waveguide calculator to play around with your design. g. Trace Thickness. 3. Printed circuit planar transmission lines used to create filters in a 20 GHz spectrum analyser. 1. For example, high-speed designs rely on controlled impedance with differential pair routing guidelines, while high-current DC designs need to have wide traces that do not necessarily have specific impedance. Dimensions are in meters. 1. Joined Jan 22, 2008 Messages 51,800 Helped 14,703 Reputation 29,682 Reaction score 13,944 Trophy points 1,393 LocationKiCAD doesn't have a calculator for differential coplanar waveguide. 3. 1. Using an online differential impedance calculator, the height of the dielectric layer, h, is needed. There are four different types of impedance used in characterizing differential trace impedances. A mistake was made when designing a set of mother and daughter PCBs, resulting the daughter board to have its LVDS pairs at ~100Ω differential impedance, while the motherboard ~90Ω. 8. – Avoid serpentining one side of the differential pair to match skew. Plane cross-overs and broadside coupling review PDN analysis - minimizes AC impedance. • Coplanar Waveguide: a strip conductor with two ground. The idea here is to determine the spacing required for a given width with the goal of hitting a specific differential impedance value. T T = trace thickness. Use the Edit / Copy to. The edge couple differential symmetric stripline transmission line is a common technique for routing differential traces. 5. 3mm, as shown below: This increases the impedance slightly to 91. This is more than the to times trace width which is recommended (also read as close as possibly). 8. The stripline impedance calculator provided below is useful for gaining an initial estimate of trace impedance for striplines. 1 has six signal layers, but only has one pair of. However, due to the importance of this particular transmission line type, it is explained in detail on the Waveguide Port Overview. 1<W/H<3. The structure on the right is a stub filter and is a low-pass filter. Z 0, air is the characteristic impedance of air. 15 mm spacing. Stackup impedance analysis, single-ended, differential pairs and CPW. differential etching on the track resulting in a track cross-section which is trapezoidal[1]. 4. Modern digital systems and low-level analog boards need methods for achieving precise characteristic impedance calculations and impedance control. These transmission line arrangements are standard trace geometries implemented in PCB design software. A two part calculator which gives ideal and preferred value resistors, showing most formulas used and a link to the others. php 12064 Bytes 26-05-2021 05:38:25 Coplanar Waveguide Impedance Calculator ( Bottom layer as well as adjacent copper is ground )Ideally the traces in the differential pair only interact with each other, as another answer said. 254mm. Typical impedance tolerances are 10% and 7%, and can go as low as 5% or 2% in the extreme cases. A differential stripline pair refers to two traces located between two reference plane layers, which are routed as a differential pair. The microstrip impedance represents the characteristic impedance of the microstrip line, which is the uniform impedance provided by the uniform cross-sectional dimensions along the microstrip (flat copper conductor) length; to prevent signal reflection. For an embedded (internal) microstrip, the formulas provided in paragraph 4. Conductor = metal ( "Gold" ); Design the coplanar waveguide at a frequency of 3 GHz, line length of 0. If JLCPCB's 4-layer PCB is. 36 mm substrate, has an impedance to ground, unbalanced, of about 49 ohms. A PCB impedance table will provide the trace width required to have a target impedance value on a standard stackup. High-speed designs carry a requirement for controlled impedance, crosstalk control, and the need for interplane capacitance. The differential impedance will be a bit less than 2x the single-ended impedance. 1. Differential Impedance Ω. Those pairs connect via a dedicated FFC cable. To find the impedance of a capacitor (Zc) and an inductor (Zl) in an AC circuit, you use the following formulas: For the capacitor: Zc = 1 / (2πfC) For the inductor: Zl = 2πfL Where f is the frequency, C is the capacitance, and L is the inductance. There are four different types of impedance used in characterizing differential trace impedances. Ohm. 2. Differential microstrip and stripline pairs have common-mode noise immunity if they are routed symmetrically, but they also need to have controlled differential impedance to. Generally, the procedure is to look at how nearby conductors modify the impedance of the trace by comparing the impedance of a trace without ground to a. Understanding Coplanar Waveguide with Ground. Reference: R. For example, a single 0. Note: The Impedance table is broken down into two different views. 2 High-Speed Signal Trace Lengths. TransLine. What is the effect of a split in a solid plane on the impedance of a coplanar differential pair? The differential pair passes over a solid plane (logic return) and then crosses a 50-mil void into an I/O area that has a solid plane of. One disadvantage is potentially lousy heat. Stripline Impedance. •The differential pair must be routed symmetrically. The STLC online tool enables the user to precisely calculate the wave. Stripline symmetrical. The ground plane helps keep the EMI localized and the trace impedance continuous. 1mm). To answer, Zac. Z0,air Z 0, a i r = characteristic impedance of air. 9. Differential Pair Termination. If a coplanar arrangement is selected, you can approximate this trace. The single-ended impedance of a trace in a differential pair will depend on the distance to the other trace, and applying a length-tuning structure is equivalent to changing the distance between the traces while meandering. September 27, 2023 by GEGCalculators. 5. Differential pair on a reference plane for differential mode (left picture) and common mode (right picture) line impedance In addition to the four line impedance types the Impedance Calculator is also able to calculate the Coupling Factor between two traces on either the same signal layer (horizontal coupling) or between two traces on different. 0 and (t/h) less than 0. I have no luck finding an asymmetric differential stripline impedance calculator online. Output ⊕. php 12064 Bytes 26-05-2021 05:38:25 Coplanar Waveguide Impedance Calculator ( Bottom layer as well as adjacent copper is ground ) Ideally the traces in the differential pair only interact with each other, as another answer said. Your idea of crisscrossing traces to create a "twisted" pair is intriguing, but I suspect it will cause you more headaches: 1) signal reflections at each via 2) every buried via is a potential defect point for board manufacturing. Conductor is assumed to have zero thickness and to be uniformly spaced between the ground planes. The single-ended channel has 58. 2. 25, but gives me nice trace from the module to the stub then to microcontroller. Ls =. The receiver, which is on the motherboard, is a standard LVDS receiver, with 100Ω termination resistors. Thus, the author. The Si8000m assumes negligible insertion loss in the transmission line; should you wish to model insertion loss the Si9000e adds. CPW feed and antenna are on the same plane. The distance between one differential pair and an adjacent differential pair for high-speed signals. Re: Routing High Speed differential pairs across connectors / and or flex pcb. 5. The concept of driving the conductors as a differential pair implies the presence of a zero voltage ground. Cm = mutual capacitance = |C 12 |=|C 21. Right-click in the Differential Pair Classes region to create a new class. 6. In the case where you are routing differential pairs, then the potential between the two pairs will always be opposing (i. The calculation looks correct, but the tracks are too wide. Zeven: This is the even-mode impedance of the differential pair. Calculate the Differential Microstrip Impedance of a transmission line based on the the distance between the strips, height of the substrate, trace thickness and dielectric constant of the substrate. pH nH uH mH H kH. The calculator below uses Wadell’s equations to determine the differential impedance of symmetric. Note: Units do not matter for this. 3. The board house achieves these tolerances by observing how their process affects impedance. Only one trace width or pair geometry can meet a particular target impedance per layer. Coplanar Waveguide Analysis/Synthesis Calculator. Calculates the differential pair impedance of a balanced line. Differential Pair Impedance Calculator Calculates the differential pair impedance of a balanced line. There are 3 types of single-ended models: single-ended non-coplanar, coplanar single-ended, and coplanar single-ended without ground. The impedance is configured on the Impedance tab of the Layer Stack Manager. Propagation delay mismatches in different nets are notorious for producing signal synchronization problems. Step 8: Select View Impedance Tables. The characteristic impedance (Z 0) of a transmission line is the resistance it would exhibit if it were infinite in length. For my results, I find that the minimum inductance is 292 nH per meter when ( w/h) = 1. 1. Inputs Trace Thickness Substrate Height Trace Width Trace Spacing Dielectric Constant Outputs. 2. So, to calculate the differential impedance of Figure 1, simply calculate the impedance of Figure 3, and double it. Hence, without loss of generality, one. 1kOhm, 1% tolerance: Brown Black Black Brown Brown. The trace width required to deliver a specific impedance is calculated as part of the impedance profile, configured in the Impedance tab of the Layer Stack Manager. . Note: The results are only for approximation and rough. Fabricators give trace impedance tables as guides to designers that need to implement controlled impedance in their PCBs. Use the following equation to calculate the impedance of a stripline trace layout. 1. Calculate the Differential Microstrip Impedance of a transmission line based on the the distance between the strips, height of the substrate, trace thickness and dielectric constant of the substrate. 8 substrates of various thicknesses. The reason for creating this tool is I failed to find any other (free and open source) alternative. differential traces you need to take into account local variations in the material Er in order to obtain the most accurate prediction of impedance. It incorporates many features that PCB designers and engineers are in regular need. 331 1 2 5. Although the geometry of a PCB layout may be complex, the routing features in ECAD. Our impedance calculator features two main types of impedance models, single-ended and differential, within each trace structure. 6 mm is used) can anybody help me how to calculate 100 ohm impedance. Fourteen new coplanar differential models have grown the library to 39 structures at introduction, with more to come. The advantages of coplanar waveguide are that active devices can be mounted on top of the circuit, like on microstrip. Differential impedance is the double of odd mode. Coplanar Waveguide Analysis/Synthesis Calculator. For differential pairs of microstrips, the formulas involved are much more complicated because coupling between the traces in the differential pair must be included in the impedance calculation. 29mm, space between trace and top ground is also 0. Hi folks I’ve just emerged from a rabbit hole & thought I’d share what I learned regarding available impedance calculators for coplanar waveguide (CPW) and coplanar waveguide w/GND (GCPW). 0. Critical Signals (continued) Signal Name Description HDMI_DATA1x High-Definition Multimedia Interface (HDMI) differential data pair, positive or negativeIn fact, striplines often make components such as band-pass filter's more accurately, with more symmetric roll-off and no lower cutoff frequency. A solution to the problems of microstrip is coplanar waveguide (CPW) shown in Figure [Math Processing Error] 3. The Basics of Differential Signaling. In this example, the impedance a coplanar conductor-backed waveguide is calculated using the FDE solver’s Power and Impedance Integration tool, and the result is compared with the approximate analytic result from an online impedance calculator [1]. Impedance Calculation 5. Hello Community, iam currently designing a board that contains an 100MBit Ethernet connection. Quadrature coupler design uses quarter-wavelength tuning and two I/O pairs to split, combine, and produce outputs with a 90° offset. The Polar Si8000m and Si9000e field solvers include a range of controlled impedance structures for modelling differentials without grounds (no reference planes. Verified with Agilent LineCalc and Agilent Momentum simulations. Differential Pair Impedance (Z_diff) = (2 × Z_single) / sqrt (1 + (2d / s)) Where: Differential Pair Impedance (Z_diff) represents the characteristic impedance of the differential. This parameter is used for the loss calculations. NOTE: The formulas used in the program are valid for 0. Learn. The impedance of the surface microstrip shown is 50 ohms, so the impedance of the broadside coupled differential pair will be twice 50. Sierra Circuits’ Trace Width, Current Capacity and Temperature Rise Calculator is an advanced PCB tool that works based on the latest IPC-2152 standard. The differential via design shown in Figure 2 was built and tested. The lower ground can be used for heat sinking purposes while providing mechanical support and preventing the fields from coupling to interconnects on lower circuit layers [3], [4]. For differential vias, stitching vias can affect the impedance, but the impedance is much more sensitive to antipad sizes and layer arrangement/Dk value on each layer. The affordable Differential microstrip line with solder resist, definition window of Sequid's impedance calculator Microstrip; Embedded Microstrip; Coated Microstrip; Stripline; Coplanar Waveguide; Grounded Coplanar Waveguide; Coated Grounded Coplanar Waveguide 12 Feb 2016 Active calculator for coplanar waveguide with. In both cases, you’ll need to enter your stackup information into the calculator to get accurate results. I am using microstrips on external layers only. On a reference plane, there is an edge coupled differential microstrip line with two traces. 6mm thick board always calls for crazy thick traces, instead focus on keeping the distance you need to route your USB lines short, this way you dont need to worry about impedance anywhere near as much, you can reduce how much trace width you need a bit by routing a picketed ground along side the differential pair. Use via-s (absolutely not recommended for impedance-critical routes) hack the connector and remove some of its SMD pins, and wire one pair under those pins. Because the traces are together on the same layer (plane) I'm not sure how "coplanar" differs. Target Impedance Decoupling Method 1. Select the dimension unit of the stripline: mm mils. One disadvantage is potentially lousy heat. the PCB power-ground plane pair can simply be modeled as a series connected resistor, inductor,. This calculator can calculate the impedance and propagation delay of the embedded microstrip. 1,235. The differential micro strip calculator requires some parameters. The coplanar stripline (CPS) consists of a dielectric substrate with two parallel strip conductors separated by a narrow gap. There's a free calculator for edge-coupled. Microstrip Impedance Calculator. If a coplanar arrangement is selected, you can approximate this trace routing. I created coplanar waveguide on the same layer as the differential pair to serve as a coupling for the diff pair. The engineer must specify controlled impedance signals in the schematic and classify specific nets to be either differential pairs (100Ω, 90Ω or 85Ω) or single-ended nets (40Ω, 50Ω, 55Ω, 60 Ω or 75Ω). 2. The minimum width for a stripline that is encased by metal on the edges is 5 times the line width, in order for the impedance to calculate with the "normal" closed form equations. This calculator requires symmetry in the trace widths and location between plane layers. Single and differential coplanar structures; Multiple adjacent dielectric layers, with different dielectric properties. Wavelength calculator Calculates the wavelength of a signal using Ereff. 1524mm (I've used this for the differential spacing after the caps as well). A Grounded Differential Coplanar Waveguide (GDCPW) is a transmission line structure used in RF and microwave circuits. The controlled impedance method applies to any trace that handles high-speed or high-frequency signals. It also ensures low impedance and the capability to tune the impedance by adjusting the spacing between the ground layer and the signal conductor. Let’s look closely at these two situations and how the structure of a via/pad + antipad can lead to signal integrity problems. We’ll go over how differential pairs can hel. •Maintains 50 Ω ± 15 % single-ended and 100 Ω ± 20 % differential impedance. –Intra-pair skew matching (50 ps of t RX HBR3) –Inter-pair skew matching • Minimize crosstalk 14 . This calculator is designed to calculate the characteristic impedance of an edge coupled stripline.