A Compact Dual-Band Microstrip Ring Antenna Using Multiring Ground for GPS L1/L2-Band

A compact dual-band circularly polarized microstrip ring antenna for GPS
L
1 and
L
2 bands is proposed. The antenna comprises a two-ring radiator and a multiring-etched ground, forming two Yagi–Uda double-ring antennas, respectively. It operates in dual bands with a small ground size and unidirectional radiation. The proposed antenna yields right-hand circular polarization and fully covers GPS
L
1 and
L
2 bands.