Design of a Compact Hemispiral GPS Antenna With Direction Finding Capabilities

A nearly hemispherical spiral or “hemispiral,” an antenna for global positioning system reception, is presented with design methodology and measurements. Its set of distinct radiation patterns allows receivers to estimate the angular direction of incoming signals in the presence of noise without the need for an array. It requires no dielectric or absorbing materials and may operate from a single RF path, making it ideal for cost-constrained platforms. The antenna’s compact size also compares favorably with known reconfigurable antenna designs.