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Embedded Microstrip Impedance Calculator

Welcome to our Embedded Microstrip Impedance Calculator, your essential resource for calculating the impedance of embedded microstrip lines in PCBs using precise operational parameters. This dedicated calculator enables you to assess the impedance for specific embedded microstrip configurations accurately.

Click to learn more about the different types of traces.

Embedded Microstrip traces are frequently used in environments requiring increased electromagnetic interference shielding. They provide improved electrical isolation and reduce signal loss compared to standard microstrip designs.

Inputs Required:

  • Trace Thickness (oz/ft², mils, cm, mm, µm, in)
  • Substrate Height (mils, cm, mm, µm, in)
  • Trace Height Above Plane (mils, cm, mm, µm, in)
  • Trace Width (mils, cm, mm, µm, in)
  • Dielectric Constant

Outputs Provided:

  • Target Impedance (Ohms)
  • Warnings for Values Exceeding Acceptable Ranges

PCB Design Calculators

Disclaimer: Please note that the results provided by this calculator are for estimation purposes only and should be used as a guide during the design process. We make every effort to ensure the accuracy of this tool, but it is important to verify all calculations through standard design verification processes. We are not liable for any errors in calculations or their consequences in your projects.

Diagram of a microstrip line to reference while using Microstrip Impedance Calculator.
Trace Thickness (t)
Substrate Height (h)
Height Above Plane (hp)
Trace Width (w)
Dielectric constant (εr)

* This calculator determines the impedance based on the ratio of the total height above the ground plane ('h') to the height of the substrate above the ground plane ('h_p'). The (h/h_p) ratio should be greater than 1.2 for accurate and reliable results. This range ensures the electromagnetic field's behavior is consistent with the assumptions used in the embedded microstrip model, maintaining stable impedance calculations. Ratios below this threshold may not conform to typical embedded microstrip behaviors, potentially leading to inaccuracies in impedance estimation and signal integrity issues.

Embedded microstrip transmission lines consist of a conductive trace embedded within a dielectric substrate with a continuous ground plane on the opposite side. The impedance of an embedded microstrip line depends on its width (w), the thickness of the trace (t), the total height (h) above the ground plane, and the height of the substrate above the ground plane (hp), along with the dielectric constant of the substrate (εr).

The calculator uses a specific formula to estimate the impedance of your embedded microstrip line accurately:

  1. Logarithmic Function:

    • Z0 = (60 / √(εrp)) × log((5.98 × hp) / (0.8 × w + t))
    • This function calculates the effective width of the microstrip, taking into account the increase in trace width due to the fringing fields where the electric field lines spread out around the edges of the trace, effectively increasing its width.
  2. Effective Dielectric Constant:

    • εrp = εr × (1 - exp(-1.55 × (h / hp)))
    • This part of the formula helps calculate the effective dielectric constant for an embedded microstrip, accounting for the non-ideal behaviors due to the trace being embedded within the substrate rather than being on the surface.

While using our Embedded Microstrip Impedance Calculator, remember that complex PCB designs often require expert guidance. If you need additional support, our team at 911EDA is ready to assist with comprehensive PCB design services and engineering solutionsLeverage our expertise in PCB design and electronic engineering to enhance your project's success. Learn more about our services and how we can help bring your ideas to life by visiting our PCB Design Services and Engineering Services pages.

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