PCB band-pass filters

Coupled-line and hairpin band-pass filters on FR-4 or RO4003C

Coupled lines, shield removed, SMA
Coupled lines, shield removed, SMA

Overview

Chebyshev or Butterworth; coupled-line or hairpin; FR-4 or RO4003C; shield, via fence, SMA.

From the simplest to the most complex: coupled lines on FR-4, up to a hairpin topology on RO4003C with a shield, via fence and SMA connectors.

Typical performance

  • VSWR < 1.5 over the passbandtypical
  • Fractional bandwidth ≈ 5–25 %typical
  • Passband loss ≈ 1–3 dB on FR-4, ≈ 0.5–1.5 dB on RO4003Ctypical

Typical values describe the antenna class, not a guarantee for a unit; “computed” marks our own simulated example.

View A
Hairpin topology
Hairpin topology

What we optimise

Pos.Parameter
P1Centre frequency
P2Bandwidth
P3Ripple

What you receive

Pos.Deliverable
D1Board and shield manufacturing files
D2A 3D model
D3S-parameters
D4A measurement protocol

Designs

Hairpin topology
Hairpin topology
Layers: copper, FR-4, ground
Layers: copper, FR-4, ground
Copper, top: coupled lines
Copper, top: coupled lines
Copper, top: hairpin
Copper, top: hairpin

Discuss your RF requirements