Two-dimensional Standing-Wave Microstrip Array Antenna

The concept of standing‐wave array antennas is presented. In this new array structure, a high‐order standing wave is excited to produce a focused beam. To verify the concept in a simple manner, a five‐patch microstrip array is considered. A cavity model is used to illustrate the principle of antenna operation. Measured radiation patterns and input impedances agree relatively well with the theoretical values to confirm the concept of a standing wave in the antenna cavity. The bandwidths of the array antenna are about the same as those of a comparable single‐patch antenna. The impedance bandwidth of the array structure is 0.9% while the 3‐dB gain bandwidth is 2.7%. The aperture efficiency is about 79% assuming the aperture area includes the ground plane. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:927–930, 2017