Most of published shared-antennas focus mainly on the characteristics of multi-band and multipolarization,that is,a high profile and a complex structure.A dual-band circularly polarized shared-antenna is presented with a simple structure and wide beam coverage.Firstly,to reduce the size and weight,the shared-aperture antenna is applied for the quad-operating frequencies(UHF1/UHF2/S1/S2)with a stacked microstrip patch antenna and high dielectric constant substrates.All the quad-operating bands can be freely ...