Mutual Coupling Effect on Ultrawideband Linear Antenna Array Performance

This paper studies the mutual coupling effect between array elements of two- and four-element UltraWideBand (UWB) linear arrays on their performances. For simplicity, it is assumed that both antenna arrays are fed by independent microstrip lines with the same power amplitudes and equal phases. From authors' study, array bandwidth improvement is achieved for both array types when the mutual coupling is strong enough or interelement spacing is small. The mutual coupling also enhances the array realized gain especially in the midfrequency band (5-8.5 GHz) while it deteriorates the gain outside that frequency range.