Compact square quadrifilar helix antenna for SDARS application in portable terminals
Presented is a new method for designing a compact square quadrifilar helix antenna with circular polarisation, operated at satellite digital audio radio service (SDARS) band (2320–2345 MHz) and intended for applications in portable terminals. This new antenna comprises four helix antennas, which are wound around a square pillar orthogonally and excited with a phase difference of 90°