Wideband Low Profile Multiport Antenna With Omnidirectional Pattern and High Isolation

A wideband high-isolation two-port antenna of low profile and omnidirectional pattern is presented. This two-port system consists of a collocated antenna pair with a cone antenna in the middle and a ring radiator around the cone, both placed over a rectangular ground plane. The overall dimensions are 0.64λ × 0.64λ × 0.11λ at the lowest frequency of operation. The isolation between the two ports is more than 37 dB and achieved by employing polarization orthogonality. The operational band is from 800 to 2700 MHz and the achieved isolation is verified with measurements of a fabricated prototype. Overall, the proposed antenna pair can be employed for simultaneous transmit and receive applications or MIMO and diversity systems in commercial wireless communication bands.