A　compact　dual-band　circularly　polarized　microstrip　ring　antenna　for　GPS　L1　and　L2　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　L1　and　L2　bands.