Micro strip antennas are low-profile antennas. A metal patch mounted at a ground level with a di-electric material in-between constitutes a Micro strip or Patch Antenna. These are very low size antennas having low radiation.


FREQUENCY RANGE:
The patch antennas are popular for low profile applications at frequencies above 100MHz.

CONSTRUCTION AND WORKING OF MICRO STRIP ANTENNA:
Micro strip antenna consists of a really thin metallic strip placed on a ground plane with a di-electric material in-between. The radiating element and feed lines are placed by the method of photo-etching on the di-electric material. Usually, the patch or micro-strip is chosen to be square, circular or rectangular in shape for the benefit of research and fabrication. The subsequent image shows a micro-strip or patch antenna.

MICRO STRIP ANTENNA

The length of the metal patch is λ/2. When the antenna is happy, the waves generated within the di-electric undergo reflections and also the energy is radiated from the perimeters of the metal patch, which is incredibly low.

RADIATION PATTERN:
The graph of microstrip or patch antenna is broad. It’s low radiation power and narrow frequency bandwidth.

RADIATION PATTERN

The Radiation Pattern of a microstrip or patch antenna is shown above. It has less directivity. To possess a greater directivity, an array may be formed by using these patch antennas.

ADVANTAGES:
The following are the benefits of Micro strip antenna:
i) Lightweight.
ii) Low cost.
iii) Ease of installation.

DISADVANTAGES:
The following are the disadvantages of Micro strip antenna:
i) Inefficient radiation.
ii) Narrow frequency bandwidth.

APPLICATIONS:
The following are the applications of Micro strip antenna:
i) Used in Spacecraft applications.
ii) Used in Aircraft applications.
iii) Used in Low profile antenna applications.