1. Distance between pairs should be (traces on top layer = microstrip) 4 times the layer. T represents trace thickness. A differential stripline pair refers to two traces located between two reference plane layers, which are routed as a differential pair. The characteristic impedance (Z 0) of a transmission line is the resistance it would exhibit if it were infinite in length. This tool helps calculate the impedance of an edge-coupled microstrip. While you can get away with small impedance mismatches, some signal drivers will have an impedance that does not match the standard 50 Ohm value typically used with signal traces. 1. and thats the first time iam doing ethernet things. then select Single-Coplanar or Differential-Coplanar from the Impedance Profile Type drop-down list. Dielectric Thickness: mm. To find the equation of a line with two ordered pairs, you can use the point-slope formula: y – y₁ = m (x – x₁) Where: (x₁, y₁) is one of the ordered pairs on the line. Select the dimension unit of the stripline: mm mils. Always consider delays caused by vias. 8 ohms for residential and below 0. The Si8000 Quick Solver is convenient to use for this purpose, as shown in Figure 4. Since my layer thickness is 0. When in doubt, use 1 for copper, . An embedded microstrip is a microstrip transmission line or flat conductor separated from the ground place via a dielectric material. Converts C to F, F to C. model impedance by combining Polar's proven boundary element field-solving engine with easy graphing of process windows. These transmission line arrangements are standard trace geometries implemented in PCB design software. If you’re designing an RF PCB for microwave or higher frequencies, controlled impedance routing should be top of mind to ensure signal. Figure 4. Impedance (Z o ): 76. The structure on the left is called a hairpin filter and is an example of a band-pass filter. Ohm’s Law provides the framework for solving network analysis problems; when the curtain gets pulled back, Ohm’s Law updates to become the relationship between voltage, current, and impedance, not resistance. Aspencore network. g. Click here to see the user guide of our impedance. One should note that some routing and computer architecture standards (i. This adds to the total signal t pd. Unfortunately, stating “should match the input impedance of the differential vias/pads” in Point #3 is easier said than done. There are some advantages to using a microstrip transmission line over other alternatives. However, you can get a very accurate calculation without the use of advanced field solver software. Adjust the distance "s". The perforated regions above and below are not transmission. To calculate the resistance, we use a slightly different technique. Anyone know of any free software that can do that? The only one I was able to find was Si9000 and Si8000m by Polar instruments, but they aren't free. Embedded Microstrip. 10. 150" pitch. when i use Saturn PCB design to match the differential impedance to 100ohms i get 0. The impedance of the structure is the ratio of the voltage between, and the current in, the conductors. 5. The trace width (0. With t = 35 um (typical for copper with plating on a pcb), Z odd drops to 44 ohms, according to LineCalc. Just as important as determining an appropriate trace width for a single-ended trace is determination of an appropriate spacing between two traces in a differential pair. T T = trace thickness. Technical Consultant Zach Peterson explores a viewer question surrounding Coplanar Routing, specifically how to route on a single-layer board. Inputs Trace Thickness Substrate Height Trace Width Trace Spacing Dielectric Constant Outputs. A Grounded CPW transmission line calculator. It incorporates many features that PCB designers and engineers are in regular need. GEGCalculators. 2. For two layer boards, a coplanar waveguide geometry usually gives more useful dimensions than a microstrip geometry. The odd-mode impedance is the impedance of one trace, of a differential pair, when driven differentially. To do this: 1) Set all port impedances to a variable. e. 1 Ohms characteristic impedance in the gap region, while the differential channel has 106. If you have a dense 16-layer board, and your note reads: “All signal layers: 0. Note: Units do not matter for this calculation as long as they are consistent. But a coplanar ground design will do no harm there either. Most of the dedicated TL tools doesn't have this option, only if you use a full EM simulator. It can be calculated by the following equation: Where: Zodd = odd mode impedance. CPW consists of a central strip flanked by two metal half-planes that carry the return current. Asymmetric Stripline Impedance Formula. 1. Hello Community, iam currently designing a board that contains an 100MBit Ethernet connection. beammy. e. For differential pairs, there is also a spacing value given. Characteristic impedance Z 0 of microstrip is also a function of the ratio of the height to the width W/H (and ratio of width to height H/W) of the transmission line, and also has separate solutions depending on the value of W/H. Coplanar microstrip routing: In coplanar microstrip routing, the signal trace is routed in parallel to two ground planes. The Si8000 Quick Solver is convenient to use for this purpose,. This means that the channel dimensions of both FETs must be the same and that R 1 must equal R 2. 05" -- 0. Microstrip. Flexibility Using 9-hole differentials offers flexibility for golfers with limited time, allowing them to maintain their handicap index without always completing. The differential impedance will be a bit less than 2x the single-ended impedance. Impedance signals are very rich and treasure valuable information about both the measurement system and the particles under study. Stripline symmetrical. Coplanar Waveguide Calculator. 1. – Keep differential skew to ±30 ps by ensuring trace lengths are matched within 5mm of each other. Z0,air Z 0, a i r = characteristic impedance of air. 3) The characteristic impedance is the impedance set for the ports when S11 is minimized. Since stripline traces are typicallyEnter values for W and L for a microstrip line to determine its Zo and Electrical Length. Reaction score. 10. 2. Input Your Specs to Get Started. Differential pairs with vias and right-angle bends are acceptable. Simultaneous Switching Noise Guidelines. The guides says spacing under 0. An impedance table should also be included in the fab drawing. Applies to Altium NEXUS Client version: 3. If. 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. 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. txem = design (txem,3e9,LineLength=0. The types of traces where impedance control is applied are: Single-ended and differential pairs of microstrip lines. Jan 31, 2016 #2 FvM Super Moderator. Gain in dB, Voltage gain. 1) Make sure you have half the differential impedance between the individual traces and the reference plane below. Be sure to check our download area for stuff we couldn't fit into a simple HTML calculator. Signal layer. Differential Pairs: Displays differential pair analysis results for differential pair nets and single-ended results for single-ended nets. Stripline construction usually does not require ground stitching, sometimes it's better no having vias around. Spacing and width value pairs that will give a differential. 2 of the Microstrip Calculator, h=H1 and b=H2-H1. Coplanar waveguide is a type of electrical planar transmission line which can be fabricated using printed circuit board technology, and is used to convey microwave-frequency signals. Stripline is another type of transmission line that can be easily built on a pcb. Dimensions are in meters. Local regulations. Excessive Zs can pose safety risks, while too low Zs may cause tripping issues. conductor backed coplanar waveguide (CB-CPW) [2]. It is useful to get the approximate value of the. The answer lies in the spacing between the traces in the pair. 5. The same situation occurs in a coplanar differential pair on the same layer. The odd mode impedance is measured by calculating impedance across one line while a complementary signal drives the other line. 1. 3 as fr4 material with 1. This is often resin filled (as. 6 mil "measured copper top to bottom" er of FR4 = 4. How the composite structure of FR4 effects the prediction of impedance. mm mils. First, calculate the slope (m) using the two ordered pairs. Impedance (Ω): The desired impedance. By understanding the microstrip transmission line, designers can. For example, ECL logic has a 50 Ω characteristic impedance, and TTL has a source impedance range of 70 Ω to 100 Ω. Three Techniques for Creating a 3D Model of a Coplanar Waveguide. Typical impedance tolerances are 10% and 7%, and can go as low as 5% or 2% in the extreme cases. When you need to do trace length matching in PCB design, your goal is to minimize timing differences between traces in a length-matching differential pair in a serial protocol, multiple traces. The IPC-2141 trace Impedance calculator will help make initial design easier by allowing the user to input basic parameters and get a calculated impedance according to the IPC-2141 standard. We recommend the software from Polar Instruments if you want to get exact impedance calculation. The Field Solvers in the Si6000b allow you to accurately graph impedance against various PCB parameters. Spacing and width value pairs that will give a differential impedance of 100 Ohms on Dk = 4. Remember, the lower the impedance the greater the current drain, the higher. 3. These parameters include:For impedance controlled systems, the proper way to provide isolation is to use ground pour in a coplanar arrangement in addition to placing a reference layer in the PCB stackup. Impedance captures the real. A quick solving calculator lets you. The capacitance calculated using this tool is the capacitance between a flat conductor and two equidistant ground planes. The Saturn PCB Toolkit is the best freeware resource for PCB related calculations you can find. This I the answer. Version 6. 29mm, space between trace and top ground is also 0. They offer different approaches to laying out the circuit and, also, the choice of PCB material for a circuit design can have an impact on the final performance possible with each circuit technology. Remember, the trace width on a standard thickness PCB with two layers was about 110. If it’s not. Color Code. The stripline impedance calculator provided below is useful for gaining an initial estimate of trace impedance for striplines. 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. USB traces must be 90 Ohms differential. 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). Single Ended Impedance Ω. I tried using different line width (10mils,15mils,20mils,25mils,30mils) of the differential pair but it doesn’t help me. W. 5. The default units for all given values, except the subtrate. And that they have the same separation from each other along the entire length of the line. Impedance captures the real and complex. The design of a board starts with the design of the circuit schematics by the design engineer. A solution to the problems of microstrip is coplanar waveguide (CPW) shown in Figure [Math Processing Error] 3. 946 for silver, or 1. 2 High-Speed Signal Trace Lengths. **Note: Like our stripline impedance calculator, all of our RF calculators allow SI prefix input. Incidentally, the trace thickness parameter does have a significant effect. Their hardware design guideline said the traces between the USB and the termination resistors should have a differential impedance of 90 ohms. Differential pairs can be viewed and managed in the Differential Pair Editor. With t = 35 um (typical for copper with plating on a pcb), Z odd drops to 44 ohms, according to LineCalc. Ultimately you could consider adjusting the spacing "S" to the. ) (The difference between W1 and W2 is based on etch factor. Cross-section geometry of a stripline trace. The Calculator Calculates the values of the Characteristic Impedance, Capacitance per unit length and propogation speed. Reference: R. Impedance Calculation 5. For example, a single 0. Type: Options are microstrip (single-ended), coplanar (single-ended), edge-coupled (differential), and dual coplanar (differential). COPLANAR WAVEGUIDE WITH GND IMPEDANCE CALCULATOR - Create the ideal trace for your antenna. 3. e. Reference plane assignment validation Critical placement and routing. 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. GCPW achieves an extra level of grounding and isolation by fabricating a. 6mm (4L-01) When using our free Defined layer buildup 4L-01, you will reach the desired impedances e. When the differential pair or coplanar waveguide is designed with very close spacings, almost all the electric field occurs in the horizontal gap between the traces. Differential. The odd mode impedance is the impedance of one transmission line when the pair is driven differentially. Coplanar Wave Guides 5. 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). In addition, the outputs impedances can be odd, even, common and differential. For most high-speed signals, you are actually working with differential pairs, so you are designing to an odd-mode/differential impedance. 004” trace, 0. Where1,481. Planar transmission lines can be classified as striplines, microstrip lines, slotlines, coplanar striplines, or parallel-plate waveguides. Hence, without loss of generality, one. The receiver, which is on the motherboard, is a standard LVDS receiver, with 100Ω termination resistors. Development Kits. If a coplanar arrangement is selected, you can approximate this trace routing. The concept of driving the conductors as a differential pair implies the. 2. Differential pairs are very simple: they are composed of two traces, routed side-by-side, and that carry equal magnitude and opposite polarity signals on each trace. The differential micro strip calculator requires some parameters. The distance between one differential pair and an adjacent differential pair for high-speed signals shouldn't be less than five times the trace's width (5W). Differential. September 27, 2023 by GEGCalculators. Track Thickness: mm. –Intra-pair skew matching (50 ps of t RX HBR3) –Inter-pair skew matching • Minimize crosstalk 14 . Only one trace width or pair geometry can meet a particular target impedance per layer. The differential impedance target, as well as the single-ended impedance of each trace, is maintained by keeping the spacing between the two traces constant. This allows you to incorporate differential 50/100 ohm Digital, 40/80. When you want to determine the width and length of a microstrip line for any given characteristic impedance and electrical length, or vice versa, a microstrip calculator is the right tool to do so. 3. PCB samples, finding that predicted accuracy varies according to target impedance. and a whole lot more! To participate you need to register. 81. Z 0 now meets your requirements. Take note that this assumes that the distance between the conductor and the planes is not the same for both reference planes; hence the asymmetric term. 1. These transmission line arrangements are standard trace geometries implemented in PCB design software. The reference plane is not far enough to accommodate 100-ohm differential impedance. Characteristic. Coplanar waveguides are open quasi-TEM waveguide geometries that use copper pour and a ground plane to provide shielding along the length of a PCB trace. GEG Calculators is a comprehensive online platform that offers a wide range of calculators to cater to various. Plane pour definitions and return current paths. 25, but gives me nice trace from the module to the stub then to microcontroller. Intrinsic Impedance, Z0: Ohm < Prev; Even mode impedance for commonly-driven transmission lines . Under high-speed differential signaling standards, you'll often need to set the differential impedance to a specific value while also setting the single-ended impedance of each trace in the pair to its own value. 0 and still meet the impedance spec. To add the impedance models, click on ⊕ under the impedance calculator section and provide the following. With PCBWay impedance calculator, you can calculate the approximate impedance of your PCB / high frequency circuit board. The ground plane helps keep the EMI localized and the trace impedance continuous. If you need to use differential pairs, you simply define traces in each layer as differential pairs and the impedance calculator will determine the correct spacing between traces. (Inverted) Differential PairCoplanar Stripline Differential Pair Coplanar. Based on: The factors that influence differential pair via impedance will affect the input impedance seen at the vias. com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals. 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. If a different frequency is required, pick. pairs for aciving 85 Ohm diff. Differential Impedance is the impedance between two differential pair signal traces. So, to calculate the differential impedance of Figure 1, simply calculate the impedance of Figure 3, and double it. The board house achieves these tolerances by observing how their process affects impedance. 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. coplanar stripline, the width of the coplanar strips can be varied to control resonance. Zo (diff) is calculated to be 244 ohms, so dividing by two yields a value of 122 ohms for the semi-coplanar structure. 6), the impedance will be approximately 50 Ohms. Using an online differential impedance calculator, the height of the dielectric layer, h, is needed. 1. Si Crosstalk option – Multi line and differential pair (lossless) crosstalk. Note: The Impedance table is broken down into two different views. TransLine. It is this. Differential pairs can be added manually or through the Differential Pair Rule Wizard or created from nets. What is the effective dielectric constant of a coplanar waveguide? The effective dielectric constant of a CPW depends on the geometry and materials used but is typically in the range of 2 to 5. A Trace Length Calculator for Differential Pairs and Nets. The bottom line is, study carefully, and take PCB trace impedance equations with a proper dose of. As always, use this information at your own risk. 92445. Simultaneous Switching Noise Guidelines. But a coplanar ground design will do no harm there either. Single-Ended Impedance The trace impedance (single-ended) in an individual trace is normally calculated by ignoring. (dielectric constant Dk=4. Distance units: Substrate Height, H Trace Width, W Thickness, TA coplanar waveguide calculator will operate in one of two ways. Figure 1. The Si8000 Quick Solver is convenient to use for this purpose, as shown in Figure 4. #2 depends on the quality of your board house. There are 3 types of single-ended models: single-ended non-coplanar, coplanar single-ended, and coplanar single-ended without ground. 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. Simulation Setup. 5. Overview. Relative Dielectric Constant ( εr ): Track Width (S): mm. The height to the next layer ground plane is 0. Where: Z0 Z 0 = characteristic impedance of the asymmetric stripline in ohms (Ω). 5. g. It can vary widely depending on these factors but is typically in the range of a few picohenries per millimeter. The iCD Design Integrity software incorporates the iCD Stackup Planner, iCD PDN Planner, iCD CPW Planner and SmartSolver software plus a myriad of functionality specifically developed for high-speed PCB design. The odd mode impedance is the impedance of one transmission line when the pair is driven differentially. In microstrip lines, coplanar striplines, and slotlines, electric and magnetic fields are distributed in the dielectric substrate and air. 4. On-Chip Termination. Antipads on vias are precisely sized to hit a target impedance at high frequencies. The classic coplanar waveguide (CPW) is formed by a microstrip conductor strip separated from a pair of ground plane pours, all on the same layer, affixed to a dielectric medium. High-speed designs carry a requirement for controlled impedance, crosstalk control, and the need for interplane capacitance. Calculators. Just enter the given values for trace thickness, substrate heights, trace width, and substrate dielectric. The idea here is to determine the spacing required for a given width with the goal of hitting a specific differential impedance value. Calculation tip for defined Z 0 as well as Z Diff. 3 shall be used. Details: In the list below, [1] is the reference design stackup information; [2] and [3] are the processes to get the result. I am using microstrips on external layers only. 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]. PCB Coplanar Waveguide Calculator RF PCBs can be complex boards that need careful interconnect design and. Mutual inductance and capacitance exist between the two traces in a differential pair. The differential pairs should be loosely coupled. 1. We offer an affordable online solution to calculate the line impedance on printed circuit boards (PCB). , equal in magnitude but opposite in polarity). Trace Thickness. For future reference, coupled microstrip implies around 5-10 trace widths of copper-free space along the entire length of each trace - i. 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. Differential Impedance of Microstrip. Coplanar Waveguide With Ground Characteristic Impedance Calculator. Plane cross-overs and broadside coupling review PDN analysis - minimizes AC impedance. Ls =. e. 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. Co = self-capacitance = C 11 = C 22 . 1. CPW. This calculator determines the impedance of a symmetric differential stripline pair. g. The coplanar stripline (CPS) consists of a dielectric substrate with two parallel strip conductors separated by a narrow gap. Below is an example of an impedance. Press Analyze to see the results. According to this guidelines, the differential pair (DP and DM signals of the USB) must have 90 ohm impedance to each other. The advantages of coplanar waveguide are that active devices can be mounted on top of the circuit, like on microstrip. PCB Coplanar Waveguide Calculator RF PCBs can be complex boards that need careful interconnect design and layout. The same situation occurs in a coplanar differential pair on the same layer. Here is a problem, I am simulating a grounded coplanar waveguide with width of 0. •Maintains 50 Ω ± 15 % single-ended and 100 Ω ± 20 % differential impedance. Track Width. 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. Thus a. Types of Planar Transmission Lines. 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. – Construct high-speed vias with controlled impedance. Parasitics affect signals in two ways: Skew in differential pairs: Parasitics (mostly capacitance) on one line will decrease the signal velocity relative to the other line, causing excess skew. 36 mm substrate, has an impedance to ground, unbalanced, of about 49 ohms. A Grounded Differential Coplanar Waveguide (GDCPW) is a transmission line structure used in RF and microwave circuits. W = Width of a trace in a differential pair; S = Distance between the trace in a differential pair; and H = Dielectric height above the group plane. calculate the surface impedance instead of using scaled surface impedance. W W = trace width. . 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. The KiCad PCB Calculator is a set of utilities to help you find the values of components or other parameters of a layout. Addedreference impedance (100 Ω for differential, 50 Ω for single-end). The trace width (0. D_P and D_N) KiCad looks for these suffix pairs when using the differential pair routing tool during PCB layout. It is widely accepted that the most accurate impedance calculations are produced with a 3D field solver due to the complex geometry in any PCB layout. Since R and L vary with frequency, let’s take a look at the calculated values and the analytical solutions in the. A differential pair consists of two well matched, source-coupled transistors as shown in Figure 6-1. , power and/or GND) constitutes a stripline layout. The differential pair is all about balance. 36 Differential coplanar structures; Reduce time to market. The differences between the two structures can be seen in the illustration below. 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. We usually use stitch pattern of 0. 6193. The differential pair is unbalanced, the interference is not common-mode, and the differential pair fails to reject its interference. The STLC online tool enables the user to precisely calculate the wave. Differential Pair Impedance Calculator. •Do not route high speed signals over any plane split; avoid any discontinuities in the reference plane. Summary. There are four different types of impedance used in characterizing differential trace impedances. Coupled Coplanar TracksStripline Capacitance. Dual stripline. Figure 1. High speed PCBs and signaling standards almost entirely use differential pairs with precise impedance. Use an online differential stripline impedance calculator Calculating Differential vs. Planar transmission line. 1. Coplanar_Waveguide_Calculator. ENIG plating always provides greater total losses. The impedance of the surface microstrip shown is 50 ohms, so the impedance of the broadside coupled differential pair will be twice 50. To answer, Zac. , typically 100 Ω). There's a free calculator for edge-coupled. $egingroup$ So basically your answer shows that the JLCPCB impedance calculator results are generally in the same ballpark as the proven field simulators. GDCPW is known for its balanced configuration, which helps reduce common-mode noise and interference in high-frequency signal. The vias on these differential pairs have their own impedance, which can create signal integrity problems on long interconnects. Coplanar Waveguide Calculator. 1. 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 etch length of the differential pair groups do not need to match. The main takeaway for me: To get to around 80 ohms, I should not pull ground on the signal. The range of accepted values is 20 to 90 Ω for single-ended and 50 to 150 Ω for differential signals. 4 Edge Coupled Differential Stripline Edge coupled differential striplines are differential pairs which are routed on 1 layers. i know that i can use. It consists of a pair of center conductors separated by ground planes on the same substrate. Users need only specify the material properties for. Note: The results are only for approximation and rough. Coplanar waveguides are open quasi-TEM waveguide geometries that use copper pour and a ground plane to provide shielding along the length of a PCB trace. **Note: Like our stripline impedance calculator, all of our RF calculators allow SI prefix input. Zeven: This is the even-mode impedance of the differential pair. Differential Pair Termination. While this calculator will provide a baseline, any final design considerations should be made towards loss, dispersion, copper roughness, phase shift, etc. Create a new impedance profile, then select Single-Coplanar or Differential-Coplanar from the Impedance Profile Type drop-down list. I got the following question regarding the impedance of a grounded coplanar waveguide(gcw) and microstrip as shown in the image attached: If I increase the spacing w in the gcw to large values I am expecting getting a similar impedance results for the microstrip if the other parameters remain the same since both geometries equalise. Coplanar Wave Guides 5. This form of microstrip is composed of two traces. 3. A coplanar waveguide with groundplane distance H = 1. 36 Differential coplanar structures Reduce time to market. 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.