Multi-Band Circularly Polarized Ferrite Antenna Operating with Negative Effective Permeability

This paper presents the development of an antenna device operating with a right-hand circular polarization (RHCP) for Global Navigation Satellite Systems (GNSS) applications, operating in the frequency bands L1 (1.5756 GHz), L2 (1.227 GHz) and E6 (1.278 GHz). The antenna exploits the potential of biased ferrite materials to naturally generate a circular polarization. In addition, to achieve a right-hand circular polarization over a wide frequency band, the antenna uses a carefully selected and polarized ferrite material to ensure that the device operates where the effective permeability of the ferrite has a negative real part. It also allows the reduction of antenna dimensions due to the high permittivity of ferrites. All performances in terms of impedance matching and radiation pattern are reported and the concept is validated by the prototype measurements.