Multi-mode ground reconfigurable MIMO antenna system

In this work, a novel 4-element, meandered-line inverted F-shaped antenna is presented. The proposed design is multi-band, frequency agile with multiple-input-multiple-output (MIMO) operation capability. The additional mode of reconfigurability was obtained by controlling the surface currents on the ground plane. Reconfigurability in the proposed design is achieved using a unique combination of PIN and varactor diodes. PIN diodes are used for mode selection while varactor diodes are used for smooth variation of resonant frequencies over tuned bands. The proposed design covers several wireless standards including LTE 900 MHz, GSM 1800, WLAN 2450 MHz with several other bands in the frequency range between 0.7 to 3 GHz. The proposed antenna design is planar and realized on a single printed circuit board. The proposed design is a suitable candidate for mobile terminals and small wireless handheld devices for cognitive radio applications.