Monopole antenna array arrangement for card-type mobile terminal

This work investigates the fundamental monopole antenna array arrangement for actual mobile terminals that satisfies the requirements for beam-steering, diversity and multiple-input-multiple-output (MIMO) transmission. We take particular note of the range below 0.5 λ for the element spacing. Using an element spacing of greater than 0.2 λ, mounted on the mobile terminals, simulated by card-type and laptop PC type terminals, resulted in approximately 2.5 dB and 5.0 dB more power in two- and four-element configurations, respectively, compared to the single-antenna configuration. Furthermore, the two- and four-element configurations yield a correlation coefficient of less than 0.7, and achieve 1.6 and 3.2 fold higher MIMO capacity, respectively, compared to the single-antenna configuration. From a comprehensive perspective, multiple monopole antennas mounted on an actual mobile terminal with an element spacing of greater than 0.2 λ can operate at high gain according to the array size with the desired diversity gains and acceptable MIMO channel capacity.