Novel Reliable and Practical Decoupling Mechanism for Strongly Coupled Antenna Arrays

In this paper, a novel antenna decoupling approach is investigated. The introduced concept is based on expelling the currents flowing between the closely spaced antennas through a tapered slot etched on the array ground plane. The method is free from extra-reactive components and transmission lines. Although they are closely spaced and strongly coupled, the technique allows a high improvement in port isolation. A practical implementation of this mechanism is applied to a monopole-array of two elements working at 2.45GHz and closely packed (0.069λ0). The obtained results are very attractive and a decoupling of about 40 dB is achieved with good impedance matching. Moreover, radiation diversity is obtained with a gain of 1.9 dBi. Furthermore, the decoupled array is integrated in a real receiving system and the proposed decoupling technique is checked through array signal processing. Hence, obtained results confirm the effectiveness of the proposed decoupling mechanism. In addition to its efficient port isolation, the most attractive features of the proposed decoupling technique are simplicity and ease of implementation in compact multi-antenna devices.