Microstrip & Transmission Line Calculator
Z₀ · εeff · W synthesis · loss · electrical length · microstrip / stripline / CPW
Structure & substrate
Structure
Microstrip
Stripline (symmetric)
CPW (no bottom ground)
Grounded CPW
Substrate preset
— custom —
FR-4 (εr 4.4, tanδ 0.02)
Rogers RO4350B (3.66, 0.0037)
Rogers RO4003C (3.55, 0.0027)
RT/duroid 5880 (2.20, 0.0009)
Alumina 99.6% (9.8, 0.0001)
Air (1, 0)
εr
tan δ
Units
mm
mil
Height h
(sub)
Cu thickness t
Frequency
MHz
GHz
Conductor
Copper (5.8e7 S/m)
Gold (4.1e7)
Silver (6.3e7)
Aluminium (3.5e7)
Geometry / target
Mode
Analysis — geometry → Z₀
Synthesis — Z₀ → width
Trace width W
Gap S
Target Z₀ (Ω)
Gap S (fixed during synthesis)
Line length L (for electrical length)
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Models: microstrip — Hammerstad–Jensen (quasi-static, ±≈0.2 % for 0.01≤W/h≤100), Wheeler thickness correction; stripline — Pozar closed forms (εeff = εr exactly); CPW/GCPW — Gupta elliptic-integral formulas via the Hilberg K/K′ approximation. Synthesis uses bisection against the same analysis equations. Dielectric loss: Pozar αd; conductor loss: first-order αc ≈ Rs/(Z₀W) with skin effect (no surface-roughness factor). Dispersion is not modelled — quasi-static values.
Cross-section