Analysis of impedance matching techniques in tapered microstrip patch antenna

This paper presents an analysis of four impedance matching techniques to apply in tapered microstrip patch antenna fed by microstrip-line. The techniques used are inset-feed, quarter-wave transformer, displaced-line, and hybrid-line, which is a combination of the other three techniques. The antennas were designed to an operation frequency of 5 GHz. Antenna analysis and measurement were done using commercial software Ansys Designer™ and Agilent vector network analyzer, respectively. From obtained results we observe antenna bandwidth improvement considering each microstrip-line feeding technique used for antenna impedance matching. Tapered antenna using the hybrid-line feeding technique achieved a 430 MHz (8.28%) measured bandwidth, corresponding to an increase of 391% in relation to the inset-fed tapered antenna 110 MHz (2.20%) bandwidth. Simulated and measured results are presented, being observed a good agreement between them.