DESIGN OF TRIPLE BAND U-SLOT MIMO ANTENNA FOR SIMULTANEOUS UPLINK AND DOWNLINK COMMUNICATIONS

In this paper, two microstrip antennas with a U-slot on the patch are presented for base station applications to provide simultaneous communications for uplink and downlink, respectively. The intended antennas are expected to operate in triple bands, i.e., to cover GSM and LTE bands. The three designated bands for uplink antenna are from 823 MHz to 830 MHz for lower band, 1.738 GHz to 1.761 GHz for middle band, and 2.321 GHz to 2.355 GHz for upper band. Similarly, the antenna which is designed for downlink operates in three bands from 872 MHz to 880 MHz for lower band, 1.81 GHz to 1.85 GHz for middle band, and 2.338 GHz to 2.375 GHz for upper band. These frequency band(s) satisfy the requirements of GSM850, GSM1800, and LTE2300 bands. Comparisons among designed, simulated, and measured results are presented. Isolation parameters and the Envelope Correlation Coefficient (ECC) values of Multiple Input Multiple Output (MIMO) antenna in all specified bands are also presented.