Microstrip line-fed L-strip patch antenna

A wideband electromagnetic-coupled single-layer microstrip patch antenna is studied experimentally. With dielectric and foam substrates of total thickness ~ 0.13 λ0, a rectangular patch antenna with impedance bandwidth (SWR ≤ 2) of 49% and 3 dB gain bandwidth of 54% are obtained. It has an average gain of 6.5 dBi and stable radiation patterns across the passband. Furthermore, with the employment of a stacked parasitic patch, a 58% impedance and gain bandwidth is achieved with similar radiation patterns and a higher average gain. A notable structure in the feeding design is that an inverted L-shaped strip is connected to the end of the microstrip line and no matching network is required.