Euro Asia International Conference on Applied Sciences, Ankara, Türkiye, 30 Kasım - 02 Aralık 2018
The Low Earth Orbit (LEO) levels are used by different satellite types such as communication
satellites, earth monitoring satellites, scientific satellites and observation satellites. The orbiting time
of satellites is restricted due to their limited energy. For this reason, the loads that is located on
satellite should be designed to have low mass and they should consume the limited energy efficiently.
The antennas are basic loads on LEO satellites. Various antenna types are used in space applications
such as parabolic, helical and array antennas. However, antennas with specialized specifications are
needed within the increase in technology. The main specifications are the small size for the
development of mini satellites and the agility of beam forming. The microstrip patch antennas can be
used for the small size feature. The microstrip patch antennas are simple to design, easy to construct
and fabricate, cheap and have low mass and height.
Agility in beam forming is achieved by antennas that operate with different patterns, such as the
directional beam, the multi-directional beams and the wide-angle beams commonly known as isoflux.
Isoflux is sometimes named as saddle-shaped, M-shaped or bowl-shaped. The goal of the isoflux
pattern of the antenna is to compansate the distance variation from the satellite to the ground along the
surface curvature of the earth to provide constant power density over the ground covered by the
antenna radiation pattern. In addition, the numbers of satellites needed for covering all the points in the
coverage area on the Earth are minimized by exploiting these antennas.
In this work, a microstrip patch antenna array with isoflux radiation pattern is presented for LEO
satellites. When high transmission rate is required to transmit high volume of image data stored
onboard the satellite, X-Band high gain antenna plays an important role in mission of earth
observation from space. The proposed antenna is designed to be used in X-Band uplink. The antenna
array is simulated by the CST microwave Studio 2018.