2P · rfsynth Microwave synthesis

← All topologies

Microstrip synthesis

Branch-line coupler

Quadrature hybrid: an equal split with 90° between the outputs. Four quarter-wave arms in a ring.

validated  Well-behaved closed form A quarter-wave network of uniform lines. The closed-form response is exact for the ideal transmission-line model; what it does not include is junction discontinuity and the isolation resistor's parasitics.

Specification

0.1 – 40 GHz.
Permittivities are datasheet design values, transcribed by hand. Check them against the current datasheet before you commit copper.

What reaches the engine

Type over any of these and the laminate becomes custom. tan δ does not reach the response, which is lossless; it decides whether this page warns you about a lossy laminate. εr, h and copper thickness all reach the microstrip solution. 1 oz copper is 0.035 mm.

What you get

Enter a specification and press Synthesise. 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 six real process envelopes: Lintek in Australia, PCBWay and JLCPCB
  • The models used and the range over which they are valid
  • A KiCad footprint and a DXF you can take straight to CAD
  • A parametric CST macro, on the three bandpass filters

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