Wide tunable balanced antenna for mobile terminals and its potential for MIMO applications

This paper presents a wideband reconfigurable balanced antenna for use in current and future mobile wireless communication systems and its potential for reconfigurable MIMO applications. The balanced antenna is a simple thin dipole. Using a single external matching circuit and a balun, the antenna can provide three tunable resonant frequencies simultaneously to cover the low band (705 MHz to 951 MHz), mid-band (1692 MHz to 2457 MHz) and high-band (2862 to over 3000 MHz). When combined with a two-port chassis-antenna, which has a wide tuning range, it becomes a reconfigurable MIMO antenna for small terminals. Measurements show that the prototype antenna can tune the operating frequency from 646 MHz to 848 MHz and 1648 MHz to 2074 MHz with instantaneous bandwidths of 14 MHz to 93 MHz. This MIMO antenna provides low-correlation and high efficiency within these operating bands.