Miniaturisation technique for quadrifilar helix antenna

We address a new miniaturization technique for quadrifilar helix antennas (QHAs). An innovative combination of sinusoidal and modified fractal curves is proposed in order to design compact QHAs compatible with space application size constraints. Relative size reductions in the range of 30%–80% can be obtained without a major degradation of most antenna performances. A comparative study is performed in order to highlight the capabilities of the proposed miniaturization technique.