Quadrafilar Helicoidal Antenna

Introduction

There are references and design information for a QuadraFilar Helicoidal (QFH) antenna.

There is a live calcuator based on the highly cited work of (Coppens 2025. Accessed 2026-01-18).

Originally interested in the idea because of this Cornell project that recommended one for a TinyGS ground site.

Links to specific designs

VHF

• http://www.rocob.plus.com/main.html

VHF and UHF

• https://uuki.kapsi.fi/qha.html (Niskanen 2026)

Designs for UHF 433 MHz

• https://www.thingiverse.com/thing:5878204/
• https://www.printables.com/model/787650-fullwave-compact-qfh-antenna-for-433mhz-band
• https://www.printables.com/model/1293002-qfh-antenna-for-435-mhz-satellites
• https://www.printables.com/model/759022-qfa-qfh-antenna-70cm-band/comments

868 MHz

• https://github.com/cernohorsky/QFH-Antenna-868MHz

GPS design L1 band

• https://forum.allaboutcircuits.com/threads/diy-gps-module-qfh-antenna.110474/
• https://lea.hamradio.si/~s53mv/navsats/analog.html [MatjazVidmar2026]
• http://schripsema.org/pa3hdf/projects/gpsantenna/gpsantenna.html
• https://www.scribd.com/doc/61729826/A-Home-Made-Helical-Antenna-for-a-GPS
  • apparently a screenshot from another link that is dead.
  • I got my own screenshot

2450 MHz

• https://www.thingiverse.com/thing:634205

References

Coppens, John. 2025. Accessed 2026-01-18. “Quadrifilar Helicoidal.” Online. https://web.archive.org/web/20250915134142/https://jcoppens.com/ant/qfh/calc.en.php.

Niskanen, Antti J. 2026. “OH2GVB Quadrifilar Helical Antennas.” Online. Accessed 2026-01-18. https://uuki.kapsi.fi/qha.html.