**2. Theories**

#### **2.1 Microstrip antenna**

Microstrip antennas are electrically thin, lightweight, comfortable, low cost, easily fabricated and can be connected to Microwave Integrated Circuits (MICs) at various frequencies [11]. There are various types of microstrip antenna designs on the taper section. There is a rectangular, circular, triangle shape according to the empirical analysis of antenna design. The design of the antennas varies with the single side and the double side. This study designed bi-ellipse microstripline antenna with 8x2 and 8x4 array, to produce greater gain so that it could be more optimally applied to radar communication systems.
