  A Radio interferometer comprises several antennas, spared over a large area.
Say ALMA(Atacama Large Millimeter/submillimeter Array), VLA(very large array),
VLBA(Very Long Baseline Array), GMRT(Giant Metrewave Radio Telescope), MWA(
Murchison Widefield Array), EHT(Event Horizon Telescope), and the SKA(Square
Kilometer Array), the name itself speaks about square-kilometres of area. Most
radio observatories are constructed or constitute giant dish antennas, and few
constitute an extensive array of antennas. However, what if a simple antenna
like Dipole, Loop or Yagi-UDA is considered an element of an interferometer?
Then how does it affect the visibility of the instrument? Yes, it will be less,
but how weak? Furthermore, what is the math to reach it? These questions pushed
for this work. Here, one can find the detailed derivation starting from a
simple Young's double slit experiment to a radio interferometer intensity
distribution in terms of the Gain of the antenna element. This literature aided
in understanding the interferometer of yagi antennas of Gain 11dBi, resulting
in a visibility of 0.0714. This clarity was insignificant in the current work.
Hence using this work, one can design and construct a suited interferometer for
their requirement.
