Compact Broadband Dual-Polarized Antenna for Indoor MIMO Wireless Communication Systems

A compact
$({100}\;\text{mm} \times {100}\;\text{mm} \times {40}\;\text{mm})$
dual-polarized antenna with wide impedance bandwidth and high isolation is proposed for an indoor MIMO wireless communication system. The proposed antenna consists of cavity-backed bowtie antennas with parasitic elements. It can cover the DCS/PCS/UMTS/LTE 1, 2, 3, 4, 7, 9, 10, 15, 16, 23, 25 bands (1710–2690 MHz). The wide impedance bandwidth
$(\text{VSWR} < {2})$
, of about 44.5%, is achieved by using parasitic elements with optimal location and length and the cavity of an electrical wall. High-isolation
$({>}{31}\;\text{dB})$
and low-envelop correlation coefficient
$(\text{ECC} < {0}.{00425})$
between MIMO elements are achieved by orthogonal dual-polarization while suppressing the cross-polarization of each MIMO antenna element. The peak gain is higher than 7 dBi in the entire operating frequency band.