Abstract:
The work presented in this thesis concentrates on understanding of the effect of symmetrical slots in elliptical microstrip patch antennas. Firstly a simple antenna is designed without any slots and with normal substrate material. The simulated results of that antenna is observed. After that symmetrical arc shaped slots are loaded in the same antenna and it is found that due to the symmetrical slot loading TM030 mode is modified to act like TM010 mode and thus the antenna acts like a dual band antenna with satisfactory radiation performance. Then metamaterial is loaded in the substrate of the antenna eccentrically. In this case, due to the effect of interface resonance of DPS and metamaterial layer in substrate, an additional mode is produced. Hence, previously designed dual band antenna acts like a triple band antenna. Thus using symmetrical slots and perfect combination of artificial material can be used to design multi band antennas. It is also shown that a simple elliptical patch antenna can also be used as a triple antenna if the parameters are chosen carefully. In this case, a mode splitting is suggested as the possible solution. A single mode might have split into two different modes under certain conditions. The concept of symmetrical slots is then again used in that antenna and it is found that we get a simple tetra band antenna with satisfactory radiation performance. Thus the slot loading again causes a mode modification and introduces an additional mode.
