Simulation of a rectangular spiral shaped microstrip patch antenna

For some applications it is required to design antennas operating at lower frequencies, have relatively low lateral size and a narrow beam broadside radiation pattern. To that end a new rectangular spiral shaped microstrip antenna is designed and simulated by using of commercial software CST Microwave Studio. The parameters are optimized to have an operation frequency around 1-3.5 GHz, maximum lateral size of 3.5 cm, a minimum directivity of 6 dBi and a HPBW less than 90°. The achieved results are promising and are tunable to specific parameters.