A LOW COMPLEXITY DIRECTION FINDING SYSTEM BASED ON A SIX-PORT INTEGRATED MIMO ANTENNA SYSTEM

In this paper, a low complexity microwave based direction finding (df) system is presented. the proposed system consists of a single six-port (sp) circuit integrated with a reconfigurable multiple-input-multiple-output (mimo) antenna system. the sp circuit covers a wide frequency band (1.68-2.25 ghz). the sp circuit is also characterized for phase error compensation caused by the slight asymmetry of sp and power detectors. the reconfigurable mimo antenna system used is a compact design and covers several well-known wireless standards in the frequency bands from 0.7 ghz to 3 ghz. the sp circuit is integrated with the reconfigurable mimo antenna system to form a complete beam forming mode for second generation cognitive radio (cr) platforms. the proposed design is a complete integrated solution with df capabilities for cr platforms. the design is suitable to be used in compact wireless handheld and mobile communication devices. the fabricated integrated system achieves ±16o accuracy in its direction of arrival estimates.