Microstrip synthesis

Edge-coupled bandpass filter

Parallel-coupled half-wave resonators — the classic microstrip bandpass. Widest bandwidth of the three, and the easiest to etch.

validated Response validated against published data The edge-coupled bandpass synthesis is checked against Pozar, *Microwave Engineering*, Example 8.7 — the anchor case for the whole engine, and part of its regression suite.

Specification

Centre frequency (GHz)

0.1 – 40 GHz.

Fractional bandwidth

0.10 means a 10 % passband. Above about 0.2 the coupled-line gaps get very tight — the fab check will tell you.

Order (sections)

Number of resonators. Higher is steeper and lossier.

Response

Passband ripple (dB)

Chebyshev only. 0.1 dB is a common choice for a clean passband; 0.5 dB buys steeper skirts.

System impedance (Ω)

Substrate

Permittivities are datasheet design values.

What you get

Enter a specification and press Synthesize. Every result includes:

Physical dimensions — widths, gaps and lengths in millimetres
A drawn layout, to scale
The predicted response, with the honesty label above attached to it
A manufacturability check against a real Australian shop's process envelope
The models used and the range over which they are valid
A KiCad footprint and a DXF you can take straight to CAD

Nothing is stored against you, and the result page has a shareable address.