For typical PCB parameters (ε r = 4, H 1 = 61. This limits the use of ƛ/4 microstrip stepped-impedance resonators in low-frequency filter applications. **Note: Like our stripline impedance calculator, all of our RF calculators allow SI prefix input. Development Kits. I have been fiddling around with GPS antenna trace impedance matching. 2-side PCB, one side with signals, the other with GND. Loop Inductance Calculator. 08. These calculators will return an impedance value for pairs of trace width, substrate thickness, and copper weight values. Nowadays, devices are more complex and delicate, so more appropriate calculations can increase the functionality of PCBs and devices. coplaner waveguide spacing. microstrip target impedance: 50 Ω. For example, if you wish to input "25000000", just type "25M" instead. What is a trace impedance calculator and why should you avoid them? Get a better view of the trace impedance controversy in this article. Unequal-split Power Divider Calculator. For small-signal RF circuits, the power delivered to the load is maximized by conjugate-matching it to the source with a. 3 is a plot of impedance versus trace width for the three most common types of transmission lines in PCBs-- surface microstrip (SMS), buried microstrip (BMS) and centered stripline (CSL). In radio technology, crosstalk is a phenomenon wherein a signal in a conductor jumps to an adjacent conductor. Provide values for H, T, W and the relative permittivity of the dielectric and click the button corresponding to unknown parameter Z o to calculate its value. To use the calculator, place values in either the velocity of propagation field or the dielectric constant field. So, the dielectric at my 5-6GHz frequency range is 3. 1 er. Polar or rectangular grids only allow direct reading of S11. Useful converters and calculators. Basic Calculator. The trace resistance of a microstrip is important in determining how much power it dissipates. Circuit designers classify power loss in microstrip lines into conductor loss, dielectric loss, and radiation loss. In this example, the characteristic impedance of the microstrip transmission line is controlled through the trace’s width. Ensuring impedance-controlled routing also requires knowledge of the substrate’s dielectric constant and your required trace width. Pasternack's Microstrip Calculator computes a microstrip's height/width ratio, impedance and relative dielectric constant for a microstrip transmission line. coupledmicrostrip = coupledMicrostripLine (Name=Value) sets Properties using one or more name-value arguments. Calculate characteristic impedance of transmission line: layout: Plot all metal layers and board. Microstrip Patch Antenna Calculator Formula. The twisted pair helps create a more uniform inductance and capacitance per unit length of wire to ensure a constant impedance, by keeping the return path as close to the signal as possible. Some free characteristic impedance calculators are surveyed in this section in terms of available geometries, accuracy, formulas, and references. The IPC Formulas and Wadell’s Method. If the ratio (L/W) is close to unity, the radiation pattern will be symmetric but may not provide a resonable input impedance. A better estimate of the frequency where the higher-order microstrip mode becomes a problem is given by Equation (4. 2 (t / h) 2 for W/h > 1. Asymmetric Stripline. Provide values for three of the four parameters h, t, w, Z 0 and the relative permittivity of the dielectric. We recommend the software from Polar Instruments if you want to get exact impedance calculation. VSWR Calculator. 50Ω. The stepped-impedance lowpass microstrip filters, which use a cascaded structure of alternating high- and lowimpedance transmission lines. (2) When the line width (w) of the characteristic impedance (Zo) is calculated. One of the features of this type of microstrip is the coupling between lines. A great example is the surface microstrip which forms on the outer layers of the PCB. In order to obtain the maximum energy transmission, the microstrip line needs to achieve impedance matching with both ends. Microstrip Length (L) in inches. 3. This example is based on Problem 5. calculate the impedance and capacitance of PCB traces. This calculator is heavilly based on . Edge-Coupled Traces. 0 Dimensional units: mm milsh is the height of the microstrip line above the ground plane. View All Tools. 11ac 802. microstrip = microstripLine (Name=Value) sets properties using one or more name value pair arguments. Once you know the characteristic impedance, the differential. The patch cutout for the feed inset should be > 2 times the microstrip width. At low frequencies near 0 GHz, the input impedance is inductive since. 3. Microstrip Impedance. The calculator utilizes the formula for calculating the impedance of a microstrip trace: Impedance (Z) = [87 / √(ε + 1. Impedance Matching pins of IC to microstrip line. 34. These tools seamlessly integrate with the rest of your design tools in a. Most claim to use some or all of these formulas these formulas, but I have discovered ones, for instance, that appear to mistakenly substitute 0. Differential Impedance Ω. The microstrip line is a printed wire separated by a dielectric on the ground layer. Matlab/Freemat file 1. An example is shown. This calculator uses JavaScript and will function in most modern browsers. Coax Impedance (Transmission Line) Calculator. Input Zo, and click on [ Synthesis ] button. To use this calculator, enter the values for the wire diameter and substrate dielectric and press the "calculate" button. Description. Typical realisation technologies are printed circuit board (PCB), alumina coated with a. The patch cutout for the feed inset should be > 2 times the microstrip width. To calculate this, you need some values. Edge Coupled Stripline Differential Impedance Calculator. Microstrip line. 9, h = 0. t is the Thickness of track (1 oz/ft2 = 0. (18) Topic 59: Input Impedance/Admittance The equation for input impedance can be defined as a function. subtracted from each measurement. Differential microstrip impedance calculator is an online electronic tool to measure the opposition to alternating current. Calculate Stripline impedance for given PCB parameters. The Differential microstrip impedance calculator is used to compute the differential (Zd) and single-ended impedance (Zo) of an edge-coupled microstrip line just by entering the width, separation and thickness of the trace along with the dielectric thickness and constant of the coupled line. Phone: +44 (0)1425 489 111 / +49 (0) 8104 628 0. Include both the pcb dielectric thickness as well as the wire insulation in the height calculation. Include both the pcb dielectric thickness as well as the wire insulation in the height calculation. Asymmetric Stripline Impedance Overview. EEWeb offers a free online broadside coupled stripline impedance calculator. 32 and 5. AppCad from Agilent) microstrip impedance calculators on the web. Reset. These losses are dependent on: The loss tangent or dissipation factor of the dielectric material. Impedance in Ohms. dual or asymmetric stripline microstrip calculator to find the impedance of printed circuit boards of a known dielectric constant of material, using javascript language. Modeling approximation can be used to understand the impedance of. Example (PageIndex{1}): Microstrip Design. 2. Understanding coax can be helpful when working with it. To use these to design for a target impedance, simply cycle through various geometric values for the trace width until the calculator returns the target impedance. A solution to the problems of microstrip is coplanar waveguide (CPW) shown in Figure [Math Processing Error] 3. This technique doesn’t work for wide band requirements, but is a simple way to achieve this at a specific. This calculator is designed to calculate the characteristic impedance of an edge coupled microstrip. Use an online differential microstrip impedance calculator; Use an online differential stripline impedance calculator The lateral dimensions, however, are well controlled being photolithographically defined and then etched. Simons, "Coplanar Waveguide Circuits, Components, and Systems", Wiley. with electrodes very close to the microstrip. Height: Height of the substrate. The thickness and width of the printed wire, the distance between the printed wire and the ground, and the dielectric constant of the dielectric determine the characteristic. When in doubt, use 1 for copper, . Go to our microwave calculator page, our microstrip calculator does this calculation for you! It's time for a Microwaves101 Rule of Thumb! For pure alumina (ε R =9. CPW consists of a central strip flanked by two metal half-planes that carry the return current. Where: Z 0 is the characteristic impedance of the microstrip; ε r is the relative permittivity (dielectric constant) of the substrate material; h is the height of the microstrip above the ground plane; W is the width of the microstrip trace; By knowing the values of the dielectric constant, height, and width, you can use this formula to calculate the characteristic. The microstrip patch antenna calculator determines the length (L) and width (W) of a rectangular microstrip patch antenna for a given resonant frequency or vice versa. Based on the assessment in the Polar Instruments article, Wheeler’s method appears to be the most accurate method for calculating microstrip. might have been the test equipment calibration, impedance mismatch amongst the measurement system’s cables and adapters, or trace impedance errors resulting from structural defects in the etched microstrip lines. 37 mil, H = 30 mil and T = 1. The Smith Chart graphically maps S11=reflection coefficient= (ZL-Z0)/ (ZL+Z0) to Load Impedance (ZL), normalized to Z0 (source impedance = center of chart). Modified 1 year, 4 months ago. Characteristic impedance is purely a function of the capacitance and. Microstrip lines are used to convey microwave -frequency signals. The formula includes dispersion, so a frequency vector has to be defined. Such a stripline is constructed with two traces referenced to the same reference planes above and below the traces with a dielectric material between them. The width of the conducting layer is important to calculate the radiation intensity since it directly affects. 3G-Aerial admin. Electronics and Electrical Engineering Tools. example. 0300) creates a microstrip line of length 0. This is the only way to calculate the total impedance of a circuit in parallel that includes both resistance and reactance. 0; 1 < εr < 15 ) Select the units for all dimensions: mm mils. W/H. Patch antenna with a quarter-wavelength matching section. In some cases, users require a custom impedance value. Polar or rectangular grids only allow direct reading of S11. Our free impedance calculator for coplanar strips can help you with your design features to ensure your PCB is a working as you intend. Once you have the reflection coefficient, you can use it to calculate the S-parameters by comparing with your feedline impedance. *Accurate for arbitrary values of Er and w/h ratios. They consist of a conductor fabricated on the dielectric substrate of permittivity ‘𝜀r’ with a grounded plane. (2) When the line width (w) of the characteristic impedance (Zo) is calculated. In Figure 3. H = distance to nearest reference plane. The websites associated with hits 2-5 all calculate the microstrip impedance for this stackup to be 50. This allows you to double check the calculator and make sure that it selected appropriate values, by making sure the impedance correctly matches the input impedance. 6 as magnitude of S11 instead of 0. PCB Coplanar Strips Calculator. Microstrip Mitred Bend Formula or Equation. For this reason, trace width is important in the design of striplines. The microstrip calculator determines the width and length of a microstrip line for a given characteristic impedance (Zo) and electrical length or vice versa. Be aware that there are many microstrip impedance calculators on the Internet that give sometimes widely varying results. October 18, 2023 Maurizio Di Paolo Emilio. For this calculation, the units of d and h can be ignored as long as they have the same unit. 2. PCB Trace Impedance Calculator. Additional benefits of patch antennas is that they are easily fabricated making them cost effective. Since the antennas showed low return losses compared to. This calculator requires symmetry in the trace widths and location between plane layers. I've tested now several, because the first two did show a huge difference in the calculated impedance for a CPW waveguide on silicon, with exactly the same parameters (dieletric constant, geometry etc). 39 for the effective dielectric constant. Values for L and C will be calculated for the four. Microstrip Transmission Line Calculator Using IPC-2141 Equation. Scientific Calculator. of typical printed circuit board trace geometries. The characteristic impedance (Z o) of coplanar waveguide with ground or microstrip lines with signal side ground plane can be calculated using the active calculator or the equations at the bottom of the page. Overview. 475): Equation 5. 0. A coplanar waveguide calculator will operate in one of two ways. Calculate Microstrip impedance for given PCB parameters. Embedded Microstrip Trace. LC Impedance matching network designer Enter the input and output impedances to be matched and the centre frequency. dBm to Watt converter Stripline Impedance calculator Microstrip line impedance Antenna G/T Noise temp. W is the width of the microstrip trace. 5 GHz. 4. For example, if u = 1 and ε r = 10, then from the figure, Z 0 ε e = 126 Ω and ε e / ε r = 0. Microstrip trace geometry, Waddell’s equations for microstrip impedance, and effective dielectric constant of microstrip traces. Each of the transmission lines consists of a signal trace and a reference plane(s). In fact, striplines often make components such as band-pass filter's more accurately, with more symmetric roll-off and no lower cutoff frequency. The microstrip calculator determines the width and length of a microstrip line for a given characteristic impedance (Zo) and electrical length or vice versa. 4, loss tangent =. Γn is the reflection coefficient. This calculator is designed to calculate the characteristic impedance of a broadside couple stripline (see diagram below). The plots show the magnitude and phase of the input impedance. 3 predicts Zo to be about 46 Ω, generally consistent withHere lies the challenge: impedance calculators must balance speed and accuracy. Visit to learn more about our other electrical engineering tools and resources. This calculator is designed to determine the magnitude of the crosstalk on a stripline if its dimensions and source voltage is provided. since a number of factors can affect impedance. 5. This calculator computes the trace width of a stripline if the maximum current, trace thickness, temperature rise, ambient temperature and length are given. Microstrip impedance shall be calculated according to above Eq. Microstrip is a type of electrical transmission line which can be fabricated with any technology where a conductor is separated from a ground plane by a dielectric layer known as "substrate". 4. SAVE & ACCEPT. Z = R + jX, where j is the imaginary component:. 6. **Note: Like our stripline impedance calculator, all of our RF calculators allow SI prefix input. More. Microstrip patch antenna is used in mobile handset due to simple look, lower cost, small size and light in weight. This tool helps you create a matching circuit so that optimal power transfer occurs between unmatched loads. microstrip line are assumed to be quasi-TEM, and dispersion along the microstrip line is taken into account using the empirical formulas given in Appendix C. Impedance (Z o ): 76. First, let’s use the “analyze” approach. Calculation tip for defined Z 0 as well as Z Diff. The Smith Chart graphically maps S11=reflection coefficient= (ZL-Z0)/ (ZL+Z0) to Load Impedance (ZL), normalized to Z0 (source impedance = center of chart). 6 Ω and ε e = 6. I can't quite get it when microstrip starts to behave more like a coplanar waveguide. An example of a wire microstrip might most often be found in prototypes or reworked boards where a wire is used over the top of pcb or copper clad material. 4. A circuit trace routed on an outside layer of the PCB with a reference plane (i. An asymmetric stripline is constructed between two plane layers, where the distance above the trace is not equal to the distance below. Line Width (W) in mils. 8) as a substrate. (1) When the characteristic impedance (Zo) of the line width (w) is calculated. This tool will help you create a matching circuit so that optimal power transfer occurs between unmatched loads. Microstrip Impedance Calculator. 5 mil and the impedance value is only affected typically by 2 ohms. Broadside-Coupled Traces. There is a dielectric material between them. The shape of the fields, and thus the. The CST Cable Studio Impedance Calculator can be started from Cables > Impedance Calculator. Width (W) Height (H) Calculate. 04 in the ε eff. impedance variation with frequency. Before, working with a trace impedance calculator, one should be aware of which equations the calculation uses. Differential Impedance Calculator. Single-stub matching is a very common method for impedance matching using microstrip lines at frequences in the UHF band (300-3000 MHz) and above. The calculator below uses Wadell’s. 5mm. The characteristic impedance is given by: Eq. THESE FORMULAS ARE APPROXIMATIONS! They should not be used when a high degree of accuracy is required. Figure 5. Can anyone explain this discrepancy? 1. To avoid microstrip modes, have h >> (w+2g) and extend component side ground away from the trace by > (w+2g). Characteristic impedance calculator for a 4-layer board. could someone point me towards reliable and proven method to calculate impedances for edge coupled differential microstrip?From here, we can see that there are specific stack-ups where a CPW and a microstrip/stripline will have 50 Ohm impedance and the same trace width, even though the ground clearance is quite close clearance to the trace in the CPW. (1) When the characteristic impedance (Zo) of the line width (w) is calculated. The JLCPCB Impedance Calculator computes track width values and recommended stack-ups from user-input values of board layer, thickness, copper weight, target impedance, trace spacing (for edge-coupled pairs), and impedance trace to copper gap (coplanar waveguides). 3. 96s/h )If you wanna confirm how good is the tool any of the two ways can be followed: 1. So two estimates have been calculated for the frequency at which the first higher-order. dBm to Watt converter. Within. Hits: 6158. T-Match Topology. 1. Microstrip Impedance Calculator Note: valid for (w/h) from 0. The new version includes: This software is intended to assist with microwave circuit design in predicting the impedance of a circuit made with Rogers High Frequency circuit materials. Rectangle Loop Inductance Calculator. Usually Microstrip separated from the ground by using dielectric substrate. Assume microstrip line for which propagation occurs with. dBm to Watt converter Stripline Impedance calculator Microstrip line impedance Antenna G/T Noise temp. Following equation or formula is used for Microstrip Mitred Bend Calculator. A coil inductance formula is based on the basic loop inductance. Stripline Calculator. These two adjustments lead to: Equation DGB2: This equation is the same as, and reduces to, IPC’s Equation 5. Coil Inductance Calculator. . Output Power Ratio (PA/ PB) Calculate. The characteristic impedance of the microstrip line changes with an increase in frequency. With Altium Designer, you won’t have to rely on an external calculator to size a printed antenna or design an impedance matching network. Type: Options are microstrip (single-ended), coplanar (single-ended), edge-coupled (differential), and dual coplanar (differential). Here lies the challenge: impedance calculators must balance speed and accuracy. The result of a Schwarz-Christoffel mapping is used to find the radial gap capacitor. Note that if the wire is insulated, then the results of this calculator will just be an estimate. H (Dielectric thickness) : Embedded microstrips are commonly crafted using printed circuit boards, although other materials can be used. Characteristic impedance of a microstrip line. Differential Impedance of Microstrip. 2. The microstrip line is mainly based on transverse electromagnetic waves. You may enter custom values or choose from a list of commonly. To use this calculator, simply input your microstrip geometry and Dk value, and the tool will return the differential impedance value for a pair of microstrip traces. This calculator is designed to compute the maximum allowable current that can flow through a stripline. Choose a calculator to tune your PCB design. 4. Most RF Coaxial Cables have an impedance of 50 ohms or 75 ohms. A closed form impedance transformation is generated for the parallel plate radial microstrip line. This technique doesn’t work for wide band requirements, but is a simple way to achieve this at a specific. 02 m Slotline Equation. Just as a sanity check, we can quickly calculate the total inductance of a trace determined with this method and compare it with typical values. The calculator below uses Wadell’s. There are 3 types of microstrip models to choose from- uncoated, coated, and embedded. 035 mm) h is the Thickness of dielectric. For example, a 2 inch microstrip line over an Er = 4. Electromagnetic Compatibility Laboratory Microstrip Impedance Calculator Provide values for H, T, W and the relative permittivity of the dielectric and click the button. The microstrip calculator determines the width and length of a microstrip line for a given characteristic impedance (Zo) and electrical length or vice versa. A calculator for solving the maximum current a microstrip can handle. Finally, there is a bandwidth that can be defined in the frequency domain (units of Hz). Following is the list of useful converters and calculators. VSWR, Return Loss and Reflection Coefficient. 23. The KiCad PCB Calculator is a set of utilities to help you find the values of components or other parameters of a layout. The characteristic impedance is an important parameter determining the power handling capacity of a waveguide, both average and peak powers. Microstrip impedance calculator Mixer spur calculator mmWave Link Budget calculator Noise Figure/Temp converter Optimal Mitre calculator Path loss calculator. To help you run through the above integral, you can download a microstrip trace taper calculator worksheet for use in Excel. For simple cases it's just applying the formula found all over the internet or use one of the online calculators. Viewed 205 times 1 $egingroup$ I am attempting to determine the trace width needed for routing a differential signal of 100 Ω on a PCB I am designing. 5. Microstrip Calculator computes a microstrip's height/width ratio, impedance and relative dielectric constant for a microstrip transmission line. Don’t forget to check out our other. The original source of formula is IPC-2141: Controlled Impedance Circuit Boards and High-Speed Logic Design, April 1996. A two part calculator which gives ideal and preferred value resistors, showing most formulas used and a link to the others. •Its results are accurate enough for the intended purpose. Geometric Parameter Definitions: Saturn PCB - Toolkit for Impedance Calculation. Impedance (Ω): The desired impedance. The substrate parameters. The line impedance and the phase velocity (in terms of an effective permittivity) is calculated with the formula of Kirschning/Jansen from 1980. 2. ELECTROMAGNETIC COMPATIBILITY (EMC) CALCULATORS – Electromagnetic Compatibility Laboratory, Missouri University of Science & Technology VERY VERY VERY…EXTENSIVE. Need Help to calculate input and output impedance of this amplifier: Homework Help: 11: May 26, 2023: How to calculate the input current through my buck converter? General Electronics Chat: 5: Dec 20, 2018: Can You Calculate The Input Impedance? General Science, Physics & Math: 27: Dec 3, 2018: A: How to calculate. INPUT DATA. You may also check it on amazon. Microstrip lines have three parameters that we can change to achieve 50 ohm impedance: Due to design constraints, there is only one parameter (track width,) left to achieve 50 ohm. Impedance calculation. Equation 11. Using the Microwaves101 microstrip calculator, we see that 50 ohms on 10 mil alumina corresponds to 9. to NF RF and Wireless tutorials WLAN 802. The Sierra Circuits Impedance Calculator uses the 2D numerical solution of Maxwell’s equations for PCB transmission lines. This calculator is designed to calculate the characteristic impedance of a symmetric stripline - a flat conductor between two ground planes whose distance between the conductor and the planes is the same for both reference planes. Introducing the newest version of the Microwave Impedance Calculator from Rogers’ Advanced Connectivity Solutions. A differential stripline pair refers to two traces located between two reference plane layers, which are routed as a differential pair. Multiply the result by the square root of the ratio of (1 + (2 * h / w)) to (1 – (2 * h / w)). This means that on each side of the feed line there should be a distance of 1/2 the microstrip width on each side of the microstrip between the microstrip feed line and the patch antenna. [1] This paper constructs a simple formula of distribute conductance of a microstrip line and then of the dielectric attenuation with only one arbitrary constant, p = 1. As can be seen from the table, the calculators cover a variety of geometries such as microstrip, embedded microstrip,This calculator is designed to calculate the characteristic impedance of an edge coupled stripline. 1 W/H 3. The characteristic impedance (Z o) of a microstrip transmission line can be calculated using the active calculator or the equations at the bottom of the page. 0; 1 < ε r < 15 ) Select the units for all dimensions: mm mils. Following is the list of useful converters and calculators. The phase is mostly + 90 ∘ or − 90 ∘, indicating that Zin is mostly reactive. Radar Calculators. Visit to learn about our other electrical engineering tools & resources. Wire Microstrip Impedance Calculator. Rectangle Inductance Description. Compared to waveguides, microstrip is generally has a lower power handling capacity, and higher losses due to the fact that it is not enclosed. 0300 meters. 0 dielectric would have a delay of about 270 ps. 4. The quarterwave impedance transformation calculator is used to match an input and an output impedance at a given frequency for maximum power transfer. (4)The impedance depends on the net width, the net height, the board type and so one. Tuesday, October 31, 2023. Since the line length is given as a fraction of wavelength, λ=1 (screen 18). 39 for the effective dielectric constant. The inductance of a ~1 in. 352278 [-] coupling =-9. In fact, striplines often make components such as band-pass filter's more accurately, with more symmetric roll-off and no lower cutoff frequency. This can be achieved by regulating the inner and outer diameter of the coaxial cable, along with the. L-Match Topology. Most RF Coaxial Cables have an impedance of 50 ohms or 75 ohms. JLCPCB Impedance Calculator. Modeling approximation can be used to design the microstrip trace. Dipole Antenna Calculator. 8. T-Match Topology. *Solder resist PCB coating will have the effect of lowering the impedance (due to the 30um or so of Er 3. The substrate parameters (ε r and h) are required. To use this tool, enter the trace width, thickness, ambient temperature, temperature rise, and the microstrip length and click the "calculate" button. Yes, any dielectric above will have an effect, although not a large one since most of the field is below the microstrip. In microstrip, the width of the conductor and thickness of. It actually depends upon the D/H ratio. Microstrip Impedance Calculator Enter the Height, Width and Permittivity to get the Impedance of the Microstrip Note : The unit of the height and width entered must be the same. For a case of dielectric constant of 4. b) The characteristic impedance of the line. 1: 300-to- 50 Ω match using an quarter-wave section of line. The quality of an impedance match can be expressed mathematically by the reflection coefficient (Γ). WILKINSON POWER DIVIDER CALCULATOR. New Online Microwave Impedance Calculator. Relative Dielectric. Description. 243 [ohm] coupling = 0. The parasitic capacitance and inductance created by nearby conductors. Following equation or formula is used for Differential Microstrip Impedance Calculator. This calculator is designed to calculate the characteristic impedance of an edge coupled stripline. Calculators. ThePCB Impedance Calculator. As seen here:Figure 3. With our handy calculator, you can choose from 50 Ohm, 75 Ohm, 93 Ohm and 95 Ohm coaxial cables. dBm to Watt converter Stripline Impedance calculator Microstrip line impedance Noise temp. 5. Result: Microstrip Patch Antennas (or simply patch antenna) are increasingly useful because the antenna is printed directly onto a circuit board. The outputs of this tool give you the component values as well as a graph of the impedance looking into the L circuit from the source. Microstrip Patch Antenna Calculator Calculate dimensions and edge impedance for desired resonant frequency. Where a Microstrip Line Calculator Fails. Dielectric Thickness (h) Dielectric Constant (εr) Calculate. The amplitude increases as the coupling length increases up to a point. e. Altium Designer’s differential line impedance calculator will set up your impedance-controlled differential pair routing widths for you. This calculator will help you calculate the guided wavelength, provided the dimensions of the microstrip are given as well as the velocity of propagation, the microstrip material's dielectric constant, and the input frequency. example. The high-impedance lines act as series inductors and the low-impedance lines act as shunt.