Simplified lossless decoupling and matching network for two symmetric antennas

Abstract

A simplified lossless decoupling and matching network (DMN) is proposed for two symmetric antennas. Even–odd mode analysis proves that a conventional 4-port lossless DMN has two redundant freedoms for two symmetric antennas. Therefore, the number of reactive components can be reduced for easier realization, which results in 15 ((6 × 5)/(2 × 1)) possible simplified topologies. The constraint conditions on input even–odd mode equivalent impedances of every simplified DMN are discussed in detail. Though the constraint on impedance is different for every topology, in all, they cover the whole impedance range for two symmetric antennas. The design concept, formulation, and experimental results will be introduced.

Keywords:

• decoupling and matching network (DMN)
• multiple-input multiple-output (MIMO)
• two symmetric antennas
• even–odd mode analysis