4x1 Patch Antenna Array Using Taper-Based Coupling for 24 GHz Radar Applications

Nowadays, microstrip patch antenna arrays are an important part of radar applications. In fact, due to their advantages such as small size, simple and economical fabrication, these structures are used as transmitters and receivers in radars operating at 24 GHz. At these frequencies, there are several considerations that designers must take into account, one of which is the appropriate antenna coupling feed. In this work, a 4x1 patch antenna array using conventional stepped impedance transitions is designed and compared to the proposed array using taper-based impedance transitions. Full-wave simulation data show how the proposal allows for a better coupling between the patch antennas and the feeding microstrip line. In fact, a reflection coefficient value of -43.60 dB was observed, compared to -18.55 dB and -22.23 dB for the single patch and stepped array designs, respectively. The above points highlight the simplicity and convenience of taper-based transitions at microwave operating frequencies.