Gain Enhancement of a mmWave Patch Antenna Array Having Limited Number of Input Ports

mmWave sensors are rapidly being used in various fields due to their low power consumption, compact size, and cost-effectiveness, particularly for applications like target detection and tracking. This study investigates the gain enhancement of a patch antenna array operating in the mmWave frequency band of 76 GHz – 81 GHz, where commercial single-chip integrated circuits are available. We analyze the S-parameters and radiation patterns of a reference antenna in detail, comparing simulation results with experimental measurements to ensure accuracy. Acknowledging the challenges posed by mmWave patch antennas, we propose a straightforward method to enhance peak gain while preserving the capabilities of the commercial patch structure. Specifically, by twinning one of the input port signals using a power divider, we increase the number of elements in the array without altering the number of input ports. Our findings suggest that this technique can increase the peak gain by 1.3 dB and narrow the beam by 4°, resulting in practical benefits such as enhanced target detection range and accuracy in radar applications while mostly preserving the functioning of the system.