Hybridization band gap based smart antennas: Deep subwavelength yet directional and strongly decoupled MIMO antennas

In this paper, we show how the concept of hybridization band gaps can be utilized to create antennas for MIMO applications. Those strongly decoupled antennas present at the same time a very small form factor and a very low correlation. To that aim, we first explain briefly the concept of hybridization between a resonator and the free space waves continuum. Then we expose the methodology we use to design multi-ports antennas based on that concept. We present numerical and experimental results of 2 ports MIMO antennas at 2.45 GHz, printed on a PCB, whose areas are smaller than 2.6*2.6 cm2. The two ports display experimentally peak gains of a about 4 dB, efficiencies of 80%, a coupling lower than -30 dB and a correlation lower than 0.1.