Abstract
AbstractIn mobile communication using a satellite, it is required to use a mobile antenna which has a circular polarization with a good axial ratio over wide angles. If a conventional microstrip antenna is used as an element antenna, it is difficult to improve the axial ratio over a broad angle even if a good axial ratio is obtained in the boresight direction. This paper investigates a circularly polarized microstrip antenna with a good axial ratio over wide angles. A method is proposed in which a combination of λ/4 short‐circuit microstrip antennas and the principle of operation is confrimed experimentally. First, it is shown that a good axial ratio cannot in principle be obtained over wide angles, since the directivity is restricted by the permittivity in a conventional microstrip antenna.Next, configurations and characteristics are presented for combinations of rectangular λ/4 short‐circuit microstrip antennas and circular λ/4 short‐circuit microstrip antennas suitable for obtaining a good circular polarization over wide angles. Conditions for a good axial ratio over wide angles are presented for both rectangular and circular structures. Further, experiments have been carried out for combinations of circular λ/4 short‐circuit microstrip antennas. Performance observed is the axial ratio less than 2 dB over wide angles of $60 degrees.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
