A low profile compact reconfigurable MIMO antenna for cognitive radio applications

A novel meandered line, multi-band, planar inverted F shape frequency agile multiple-input multiple-output (MIMO) antenna is presented. The proposed dual-element MIMO antenna is compact with frequency tuning capability over a wide-band. The frequency reconfigurability was achieved using a unique combination of PIN and varactor diodes. PIN diodes are used for mode selection while the varactor diode is used to sweep the frequency over a wide band especially below 1 GHz. The proposed single substrate design is compact with small form factor and suitable for small wireless handheld devices for cognitive radio applications. Good MIMO performance metrics were achieved with reasonable isolation. The antenna system is developed on a single substrate area of dimensions 65×120×1.56 mm
³
.