Design of a dual-band indoor antenna with orthogonal bi-directional radiation pattern

Abstract

In recent years, MIMO (Multi-Input Multi-Output) transmission technique has attracted increasing attention, as it can satisfy the need for exponential increase in data traffic for mobile communications, especially when used for indoor areas. In this paper, an antenna design is proposed that can operate in the 2.6 GHz and 3.5 GHz bands and produce an orthogonal bi-directional radiation pattern. Some characteristics of the proposed antenna, such as reflection coefficient (S₁₁), transmission coefficient (S₂₁) and far-field radiation pattern are simulated and evaluated by means of FDTD (finite-difference time-domain) methods. The results show that S₁₁ and S₂₁ are below -10 dB and -15 dB, and moreover, the MIMO performance can probably be improved because the difference between the two directional gain levels is achieved by approximately 15 dB when four slits are etched into the ground plane.