A multiple‐input–multiple‐output (MIMO) microstrip patch antenna array of four elements is proposed to cover the 5.8 GHz WLAN band. The characteristic mode analysis is carried out to design a defected ground structure that improves the MIMO performance without impacting negatively the radiation characteristics of the four‐element array. Simulations and measurements demonstrate that the implemented prototype reaches a maximum mutual coupling of −32 dB and a gain‐per‐element of 5.3 dB with good MIMO attributes, surpassing many other proposals in the antenna literature: maximum envelope correlation coefficient of 0.0001, diversity gain very close to 10 dB, capacity loss false(Clossfalse) near to 0.0023 bps/Hz at the resonant frequency, multiplexing efficiency )(ηmunormalxij of 0.935, and a total active reflection coefficient weakly dependent on the excitation phases. The presented design is proposed for operation on the IEEE 802.11a/n standard.

In this paper, an easy-to-program mathematical expression to compute the Envelope Correlation Coefficient (ECC) between two antennas by using their radiated electric fields at the far-field region is derived. The main advantage of the resulting algorithm is its higher speed to obtain results compared to those used in commercial software. This novel approach presents a discrete equation that can be employed after obtaining the electric field in spherical coordinates by computer simulations. Thus, another alternative arises to report this metric for low or high radiation efficiency antennas, instead of the less accurate S-parameter-based equation, which does not ensure high accuracy when low radiation efficiency antennas are under study. A comparison between the presented algorithm and the results given by commercial software is shown and discussed, in which is clearly observed that the results are greatly convergent, but with the advantage of achieving a lesser time computing period by the proposed method.

No abstract