QFH Antenna | Quadrifilar Helix Antenna Basics

This page covers QFH Antenna basics and QFH antenna calculator. QFH stands for Quadrifilar Helix or Quadrifilar helicoidal. It provides link to Quadrifilar Helix Antenna Calculator which is useful to design QFH antenna.

QFH antenna is one among various antennas used to capture images from low level non geosynchronous satellites. It is very simple, effective and efficient antenna. It does not have null spots directly overhead or at other in-opportune locations like other antennas. It is popular antenna used for GPS applications.

QFH Antenna, Quadrifilar Helix Antenna

The QFH antenna consists of two types of loops in the design. This helps in noise reduction and elimination of null spots. The figure-1 depicts typical QFH antenna designed with larger loop and smaller loop.

PVC pipe, copper wires or thin tubing, coaxial cable and BNC connectors are used in its construction.

QFH Antenna Calculator

Refer QFH Antenna Calculator page which mentions QFH Antenna calculator with larger loop and smaller loop. This calculator is useful to design Quadrifilar Helix or Quadrifilar helicoidal Antenna.

Antenna Calculators

Useful converters and calculators

Following is the list of useful converters and calculators.
dBm to Watt converter
Stripline Impedance calculator
Microstrip line impedance
Noise temp. to NF

Antenna links

RF and Wireless tutorials