The study of microstrip patch antennas has made great progress in recent years. Compared with conventional antennas, microstrip patch antennas have more advantages and better prospects in terms of low cost, low profile, ease of fabrication etc. Moreover, the microstrip patch antennas can provide dual and circular polarizations, dual-frequency operation, frequency agility, broad band-width, feedline flexibility, beam scanning and omnidirectional patterning. In this project different configurations of microstrip antennas are designed in software and their advantages and disadvantages over conventional microwave antennas are discussed, based upon the results obtained.
Antennas are designed using HFSS software. The proposed system is operating at 2.45GHz frequency band known as ISM band and 1.8 GHz frequency band known as cellular band.
Multiple antenna configurations for the patch antenna are studied and simulated. These include rectangular patch and array, circular patch and array and hexagonal patch and array. The antennas are compared with reference to some of their properties including return loss, bandwidth, gain and directivity. The experimental results show that the rectangular patch antenna is better than the circular and hexagonal patch antenna in terms of gain. The best antenna has achieved a gain of 8.15dB as compared to gains of circular and hexagonal antennas i.e. 7.76dB and 8.10dB respectively. Other experiment results obtained w.r.t. VSWR, return loss and radiation pattern also show that the rectangular antenna is achieving best performance characteristic over circular and hexagonal antennas. Further results for arrays and ISM band are given in upcoming chapters.