Antenna system combining sensing and communication tasks for cognitive radio front-ends

Abstract

This paper presents an antenna system combining sensing and communication tasks, to be implemented into the RF front-end for cognitive radio systems. The sensing task was performed by the means of an ultra-wideband quasi-omnidirectional antenna. Whilst, the communication task was ensured by a narrowband antenna. Both antennas were designed on the same layer of a FR4 substrate. Therefore, the isolation between them must take into consideration. The mutual coupling was less than -15dB over the whole frequency bandwidth. The proposed sensing antenna covers a wide range frequency bands from ranging 2 to 5GHz. Whilst, the communication antenna operates at 2.8GHz. The whole antenna system was designed, fabricated, and measured. Measurement and simulation results are in good agreement, which prove the proposed structure.