Design of dual-polarization and dual-band antenna

A new type of dual-polarization and dual-band sleeve monopole antenna is presented. The proposed antenna is composed of a circular patch and disc-conical sleeve, both of which are shorted to the ground plane through four shorting probes. Five probes are used to feed for the linear-polarization and circular-polarization. Of this antenna, the linearly-polarized can achieve an impedance bandwidth of 90% for VSWR≤2 ranging from 1.1 to 2.9 GHz, the circularly-polarized impedance bandwidth of 50% for VSWR≤2 ranging from 2.1 to 3.5GHz with a 3dB axial ratio beamwidth about 56° is also achieved.