Gain of microstrip antenna

[kamranraja]

Hi everyone, How is surface current of the microstrip antenna related to gain of the microstrip antenna? Thanks

 

[vfone]

Less surface current, higher the gain. Also to get better microstrip antenna radiation (higher gain) is to have less currents that propagates into the substrate. The radiation performance (and gain) of microstrip antennas is degraded by the diffraction of surface waves at the edge of the substrate.