A compact dual-band air core helix antenna may include two sets of quadrifilar helix antenna elements with each of the antenna elements having different arm lengths. The helix antenna may be configured such that the antenna elements are printed on a foldable printed circuit board. Radiating elements of the antenna elements may be fed with four inputs and each of the four inputs may have a same amplitude and quadrature phase difference (e.g., 0, 90, 180, 270 degree phase shifts).
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