RF & Microwave Simulators

How to Use

1. Select transmission line topology (microstrip, coplanar waveguide, or stripline) from the category filter
2. Enter propagation frequency (1–40 GHz), substrate permittivity (εr typical 3.8–10.2), and characteristic impedance (Z0 = 50 Ω standard)
3. Input physical dimensions: trace width, gap spacing, and dielectric thickness; simulator calculates attenuation, phase velocity, and dispersion
4. Review S-parameter results and group delay across the specified frequency band

Worked Example

A 50 Ω microstrip line on FR-4 substrate (εr = 4.6, h = 1.6 mm) with trace width w = 3.1 mm and length L = 50 mm at 10 GHz yields: insertion loss IL ≈ 0.42 dB, effective permittivity εeff ≈ 3.2, and phase velocity vp ≈ 1.92 × 10⁸ m/s. Measured return loss S11 = −28 dB confirms impedance matching within 5% tolerance.

Practical Notes

1. Account for copper surface roughness (RMS 0.5–2 μm); rougher surfaces increase conductor loss by 10–30% above smooth-surface models
2. Substrate loss tangent (tan δ) varies with frequency and temperature; FR-4 ranges 0.015–0.025 at 10 GHz—verify datasheet values
3. Via stitching for shielding must be spaced ≤λ/20 to suppress higher-order modes in multilayer PCB designs
4. Crosstalk between parallel traces exceeds −20 dB when edge-to-edge separation < 3× dielectric thickness