Interference within an antenna system can be enhanced by improving the impedance matching profile, where the forward wave from the source to the antenna will be dominated over the reflected wave. The VSWR should be near to one where as S11 will be less than -10 dB.
The antenna as a load to the source should be resistive.
The mode generated within the system should be the dominant mode. If the design is based on hybrid mode then appropriate adjustments should be made to optimize the antenna parameter.
The type of dielectric material as substrate or antenna can significantly alter the performance.
The fabrication mechanism plays an important role to decide the noise performance.
The effect of the ground plane
The position of the antenna and environment (Physical as well as Electrical) plays a crucial role to improve the signal quality.