Antenna design considerations for MIMO TV white-space handsets

The trend in wireless communication is to provide high-speed services utilizing MIMO antenna systems. Moreover, cognitive radio (CR) technology targets to exploit the so-called TV white space (TVWS) utilizing tunable antennas operating over vacant TV bands. The joint requirements for cognition and spatial multiplexing expressed by sufficient antenna matching and decoupling bandwidth, frequency agility over the TVWS as well as minimum occupying space and complexity impose significant challenges to antenna engineers. The paper discusses the major design considerations for compact TVWS terminals and presents a promising approach that empowers the TVWS device with CR-MIMO capabilities under modern smartphone size constraints. The idea is to aggregate a pair of antennas per communication port for a) providing attractive bandwidth properties across the desired TV bands and b) isolating the communication ports within a local interference cancellation setup.