A Dual-Band Circularly Polarized Microstrip Antenna for BDS Application

摘要

A dual-band circularly polarized (CP) microstrip antenna for BeiDou Navigation Satellite System (BDS) is presented. A circular patch with notches and a ring slot with notches are used for upper and lower band radiators respectively. Meanwhile, the circular patch acts as a coupling patch to feed the ring slot radiator. A quarter wavelength transformer and branch impedance adapter are introduced for impedance matching. The measured and simulated results show good CP radiation at 1618 MHz and 2452 MHz. The gains of the proposed antenna are 7.91 dBi and 5.24 dBi at the upper band and the lower band respectively.