Abstract This paper presents the design of a dual-band and dual-polarized microstrip antenna for global navigation satellite systems reflectometry (GNSS-R) for the L1/E1/B1 and L5/E5a/B2a bands. In order to allow advanced GNSS-R signal processing and sensing techniques, the design has been carried out for dual-band and dual-polarization operation with isolated ports to receive both left and right-hand circular polarizations. The design procedure to allow receiving both bands independently and with high isolation is described in detail. Numerical and experimental results show that the antenna presents good performance in terms of impedance matching, circular polarization purity and isolation between the ports. The measured levels of axial ratio are 0.86 dB and 1.89 dB for the L1/E1/B1 and L5/E5a/B2a bands, respectively. The measured isolation levels are larger than 30 dB and 40 dB in the L1/E1/B1 and L5/E5a/B2a bands, hence proving that the proposed antenna concept can be properly used in dual-band dual-polarized GNSS-R applications. dualband dual band dualpolarized polarized GNSSR GNSS R (GNSS-R L1E1B1 LEB L1 E1 B1 L E B L1/E1/B L5E5aB2a LEaBa L5 E5a B2a techniques dualpolarization righthand right hand polarizations detail matching 086 0 86 0.8 189 1 89 1.8 respectively 3 4 applications L1E1B aB Ea Ba 08 8 0. 18 1.