911EDA PCB Design Services Logo

Broadside-Coupled Stripline Impedance Calculator

Welcome to our Broadside-Coupled Stripline Impedance Calculator, your go-to resource for calculating the impedance of broadside-coupled striplines on PCBs based on precise operational parameters. This specialized calculator enables you to determine the impedance for different broadside-coupled stripline configurations accurately.

Click to learn more about the different types of traces.

Broadside-coupled striplines consist of two parallel traces aligned vertically within the substrate, effectively carrying differential signals and improving signal integrity in high-speed applications.

Inputs Required:

  • Trace Thickness (oz/ft², mils, cm, mm, µm, in)
  • Height to Plane (mils, cm, mm, µm, in)
  • Height Between Traces (mils, cm, mm, µm, in)
  • Trace Width (mils, cm, mm, µm, in)
  • Dielectric Constant

Outputs Provided:

  • 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 broadside-coupled stripline impedance calculator.
Trace Thickness (t)
Height to Plane (hp)
Height Between Traces (ht)
Trace Width (w)
Dielectric constant (εr)

*  This calculator assesses the impedance of broadside-coupled striplines by carefully considering critical geometric ratios essential for electrical integrity. For accurate and reliable results, the width to height plane ratio (w/hp) should be maintained between 0.1 and 2.0 to ensure proper confinement of the electromagnetic fields, which is crucial for stable impedance and signal integrity. Additionally, the thickness to height plane ratio (t/hp) must not exceed 0.25 to avoid disrupting the stripline’s electromagnetic field distribution. Deviating from these ratios can lead to impedance calculations that do not reflect actual performance, potentially causing design issues in line with PCB standards.

Broadside-coupled striplines consist of two conductive traces that are aligned vertically on different layers within a dielectric substrate, with ground planes on the outer sides. The impedance of a broadside-coupled stripline depends on the width of the traces (w), the thickness of the traces (t), the height to the ground plane (hp), the height between the traces (hb), and the dielectric constant of the substrate (εr).

The calculator uses a specific formula to accurately estimate the impedance of your broadside-coupled stripline:

  1. Impedance Calculation Formula:

    • Z0 = (80 / √(εr)) × log((1.9 × (2 × hp + t)) / (0.8 × w + t)) × (1 - (hp / (4 × (hb + hp + t))))
    • This function calculates the impedance by considering the vertical alignment of the traces and their proximity within the dielectric substrate, taking into account the trace width, thickness, and the heights involved. The logarithmic part of the formula adjusts for the path of electromagnetic waves, and the multiplicative factor refines the calculation by considering the separation between the traces and their relation to the surrounding dielectric and ground planes.

While using our Broadside  Coupled-Stripline 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.

911EDA PCB Design Services Logo
  • 2131 Palomar Airport Rd., Ste. 239
    Carlsbad, CA 92011
  • (800) 320-2480
  • sales@911eda.com
Home » PCB Design Calculators » Broadside-Coupled Stripline Impedance Calculator

© 2024 911EDA. All rights reserved.