Antennas
A Helical antenna is made from a coiled, small-diameter spring which is flexible and coated in plastic. The name comes from the conducting wire inside which is coiled in the form of a helix. It responds to electromagentic fields with circular polarization. A pair of these antennas is commonly attached directly to RF Code readers for indoor applications. A ΒΌ wave Whip antenna is sometimes recommended for greater efficiency